Medium Enterprise Design Profile Reference Guide

Last Updated: July 8, 2010

Building Architectures to Solve Business Problems

ii

Medium Enterprise Design Profile Reference Guide

About Cisco Validated Design (CVD) Program
The CVD program consists of systems and solutions designed, tested, and documented to facilitate faster, more reliable, and more predictable customer deployments. For more information visit www.cisco.com/gohttps://www.scribd.com/designzone.
ALL DESIGNS, SPECIFICATIONS, STATEMENTS, INFORMATION, AND RECOMMENDATIONS (COLLECTIVELY, "DESIGNS") IN THIS MANUAL ARE PRESENTED "AS IS," WITH ALL FAULTS. CISCO AND ITS SUPPLIERS DISCLAIM ALL WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OR ARISING FROM A COURSE OF DEALING, USAGE, OR TRADE PRACTICE. IN NO EVENT SHALL CISCO OR ITS SUPPLIERS BE LIABLE FOR ANY INDIRECT, SPECIAL, CONSEQUENTIAL, OR INCIDENTAL DAMAGES, INCLUDING, WITHOUT LIMITATION, LOST PROFITS OR LOSS OR DAMAGE TO DATA ARISING OUT OF THE USE OR INABILITY TO USE THE DESIGNS, EVEN IF CISCO OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. THE DESIGNS ARE SUBJECT TO CHANGE WITHOUT NOTICE. USERS ARE SOLELY RESPONSIBLE FOR THEIR APPLICATION OF THE DESIGNS. THE DESIGNS DO NOT CONSTITUTE THE TECHNICAL OR OTHER PROFESSIONAL ADVICE OF CISCO, ITS SUPPLIERS OR PARTNERS. USERS SHOULD CONSULT THEIR OWN TECHNICAL ADVISORS BEFORE IMPLEMENTING THE DESIGNS. RESULTS MAY VARY DEPENDING ON FACTORS NOT TESTED BY CISCO.
CCDE, CCENT, Cisco Eos, Cisco Lumin, Cisco Nexus, Cisco StadiumVision, Cisco TelePresence, Cisco WebEx, the Cisco logo, DCE, and Welcome to the Human Network are trademarks; Changing the Way We Work, Live, Play, and Learn and Cisco Store are service marks; and Access Registrar, Aironet, AsyncOS, Bringing the Meeting To You, Catalyst, CCDA, CCDP, CCIE, CCIP, CCNA, CCNP, CCSP, CCVP, Cisco, the Cisco Certified Internetwork Expert logo, Cisco IOS, Cisco Press, Cisco Systems, Cisco Systems Capital, the Cisco Systems logo, Cisco Unity, Collaboration Without Limitation, EtherFast, EtherSwitch, Event Center, Fast Step, Follow Me Browsing, FormShare, GigaDrive, HomeLink, Internet Quotient, IOS, iPhone, iQuick Study, IronPort, the IronPort logo, LightStream, Linksys, MediaTone, MeetingPlace, MeetingPlace Chime Sound, MGX, Networkers, Networking Academy, Network Registrar, PCNow, PIX, PowerPanels, ProConnect, ScriptShare, SenderBase, SMARTnet, Spectrum Expert, StackWise, The Fastest Way to Increase Your Internet Quotient, TransPath, WebEx, and the WebEx logo are registered trademarks of Cisco Systems, Inc. and/or its affiliates in the United States and certain other countries. All other trademarks mentioned in this document or website are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (0809R) © 2010 Cisco Systems, Inc. All rights reserved

Medium Enterprise Design Profile Reference Guide

iii

About the Authors

Solution Authors

Martin Pueblas, CCIE#2133, CISSP#40844—Technical Leader, CMO Enterprise Solutions Engineering (ESE), Cisco Systems
Martin is the lead system architect of the Cisco SAFE Security Reference Architecture. He is a network security expert with over 17 years of experience in the networking industry. He obtained his CCIE certification in 1996 and CISSP in 2004. Martin joined Cisco in 1998 and has held a variety of technical positions. Started as a Customer Support Engineer in Cisco’s Technical Assistance Center (TAC) in Brussels, Belgium. In 1999 moved to the United States where soon became technical leader for the Security Team. Martin’s primary job responsibilities included acting as a primary escalation resource for the team and delivering training for the support organization. At the end of 2000, he joined the Advanced Engineering Services team as a Network Design Consultant, where he provided design and security consulting services to large corporations and Service Providers. During this period, Martin has written a variety of technical documents including design guides and white papers that define Cisco’s best practices for security and VPNs. Martin joined Cisco’s Central Marketing Organization in late 2001, where as a Technical Marketing Engineer, he focused on security and VPN technologies. In late 2004, he joined his current position acting as a security technical leader. As part of his current responsibilities, Martin is leading the development of security solutions for enterprises.

Martin Pueblas

Steve Gyurindak, CCIE#9057, CISSP#61046—Solutions Architect, Enterprise Solutions Engineering (ESE), Cisco Systems
Steve is a solutions architect with over 15 years of industry experience. He joined Cisco in 2000 and worked the first 8 and a half years as a Systems Engineer covering the Service Provider, North Florida/Alabama Commercial, Georgia Enterprise and US Channels sales markets. Steve has been recognized for his work with some of Cisco's most influential customers as well as for his work in South America and Europe. Steve joined ESE in 2009 to lead the development of customer-focused architectures and designs for the Education Market. Steve has a Bachelor of Science degree in Telecommunications from the State University of New York at Buffalo, and is currently pursuing a Master's of Science degree in Network Telecommunications at New York University. In addition to a CCIE in Routing and Switching, Steve holds the following certifications: CISSP, CCNP, CCDP, CCNA, CCDA, MCSE, and MCNE.

Steve Gyurindak

John Strika, Technical Marketing Engineer, CMO Enterprise Solutions Engineering (ESE), Cisco Systems
John is a Technical Marketing Engineer in Cisco's Public Sector ESE team, with expertise in the areas of mobility and location-based services. He has coauthored documents on enterprise mobility and Wi-Fi location-based services. As a member of Cisco's Enterprise Architecture Board, he helps maintain Cisco's vision and architectural direction and define Cisco's roadmap for context-aware and presence solutions. Previously, John was Cisco's first mobility consulting systems engineer, responsible for architecting creative wireless solutions for large enterprise customers. His 28 years of experience spans network design and implementation, applications development, facilities planning and management, consulting, and general management. His past roles have included mission-critical telecommunications design and development at AT&T and systems programming and data communications management with Wall Street brokerages and commercial banks. Prior to joining Cisco, Strika was at Telxon Corporation (parent of Cisco's Aironet wireless acquisition) for nine years, reaching the position of Southern Division Vice President of Wireless Technologies and Services. He is a member of the IEEE and has held several Federal Communications Commission licenses in the use and modification of amateur and commercial radio. His educational background is in electrical engineering and computer applications programming from Columbia University and in finance from Fordham University's College of Business Administration, and he holds a masters of communications technology certificate from the American Institute. He was a charter Novell Certified Netware Engineer in the greater New York City area. Always seeking opportuni-

John Strika

iv

Medium Enterprise Design Profile Reference Guide

About the Authors

Solution Authors

ties to use his mobility and advanced communications knowledge to improve public safety as well as the safety of our public servants, John has served in volunteer search and rescue as well as a Reserve Deputy.

Rahul Kachalia, CCIE#11740—Technical Marketing Engineer, CMO Enterprise Solutions Engineering (ESE), Cisco Systems
Rahul is a technical marketing engineer in Cisco's Enterprise Solution Engineering group, helping to create the design guidance that will help build the 21st century school network infrastructure. Rahul has more than 14 years of broad engineering experience, primarily in service provider core and edge focused products and technologies including broadband, MPLS, VPN and managed services. He has led many assurance projects to develop
Rahul Kachalia

solutions that can deliver design guidance and accelerate deployments from traditional WAN infrastructure to next-generation IP/MPLS managed core networks. In the Enterprise Solution Engineering group he has also worked on designing next-generation unified virtual campus networks for large enterprise customers. In addition to CCIE, Rahul holds CCNP, CCNA, MCSE, MCP, and CNE. He holds a bachelor's degree from Mumbai University, India.

Dan Hamilton, CCIE #4080 —Technical Leader, CMO Enterprise Solutions Engineering (ESE), Cisco Systems
Dan has over 15 years experience in the networking industry. He has been with Cisco for 9 years. He joined Cisco in 2000 as a Systems Engineer supporting a large Service Provider customer. In 2004, he became a Technical Marketing Engineer in the Security Technology Group (STG) supporting IOS security features such as infrastructure security, access control and Flexible Packet Matching (FPM) on the Integrated Security Routers (ISRs), mid-range routers and the Catalyst 6500 switches. He moved to a Product Manager role in STG in 2006, driving the development of new IOS security features before joining the ESE Team in 2008. Prior to joining Cisco, Dan was a network architect for a large Service Provider, responsible for designing and developing their network managed service offerings. Dan has a Bachelor of Science degree in Electrical Engineering from the University of Florida.

Dan Hamilton

Srinivas Tenneti, CCIE#10483—Technical Marketing Engineer, CMO Enterprise Solutions Engineering (ESE), Cisco Systems
Srinivas is a Technical Marketing Engineer for WAN and branch architectures in Cisco's ESE team. Prior to joining the ESE team, Srinivas worked two years in Commercial System Engineering team where he worked on producing design guides, and SE presentations for channel partners and SEs. Before that, he worked for 5 years with other Cisco engineering teams. Srinivas has been at Cisco for 8 years.

Srinivas Tenneti

Medium Enterprise Design Profile Reference Guide

v

C O N T E N T S

CHAPTER

1

Medium Enterprise Design Profile (MEDP)—Service Fabric Design Considerations Service Fabric Design 1-1 Main and Large Site Design 1-2 Medium Site Design 1-3 Small Site Design 1-3 Building Profiles 1-3 Large Building Design 1-3 Medium Building Design 1-3 Small Building Design 1-3 Extra Small Building Design 1-4 Access Devices 1-4 LAN/WAN Design Considerations 1-4 LAN Design Considerations 1-4 Routing Protocol Selection Criteria 1-4 High Availability Design Considerations 1-5 Access Layer Design Considerations 1-5 LAN Service Fabric Foundational Services 1-6 WAN Design Considerations 1-6 WAN Transport 1-6 WAN Service Fabric Foundational Services 1-7 Security Design Considerations Mobility
1-7 1-7

1-1

Unified Communications 1-8 Call Processing Considerations 1-8 Gateway Design Considerations 1-8 Dial Plan Considerations 1-9 Survivability Considerations 1-9
2

CHAPTER

Medium Enterprise Design Profile (MEDP)—LAN Design LAN Design
2-1 2-4 2-7

2-1

LAN Design Principles

Medium Enterprise LAN Design Models Main Site Network Design 2-9

Medium Enterprise Design Profile Reference Guide

i

Contents Remote Large Campus Site Design 2-10 Remote Medium Campus Site Design 2-11 Remote Small Campus Network Design 2-12 Multi-Tier LAN Design Models for Medium Enterprise 2-13 Campus Core Layer Network Design 2-13 Core Layer Design Option 1—Cisco Catalyst 6500-E-Based Core Network 2-14 Core Layer Design Option 2—Cisco Catalyst 4500-E-Based Campus Core Network 2-15 Core Layer Design Option 3—Cisco Catalyst 4500-E-Based Collapsed Core Campus Network 2-17 Campus Distribution Layer Network Design 2-18 Distribution Layer Design Option 1—Cisco Catalyst 6500-E Based Distribution Network 2-19 Distribution Layer Design Option 2—Cisco Catalyst 4500-E-Based Distribution Network 2-21 Distribution Layer Design Option 3—Cisco Catalyst 3750-X StackWise-Based Distribution Network 2-22 Campus Access Layer Network Design 2-23 Access Layer Design Option 1—Modular/StackWise Plus/FlexStack Access Layer Network 2-24 Access Layer Design Option 2—Fixed Configuration Access Layer Network 2-24 Deploying Medium Enterprise Network Foundation Services 2-25 Implementing LAN Network Infrastructure 2-25 Deploying Cisco Catalyst 6500-E in VSS Mode 2-26 Deploying Cisco Catalyst 4500-E 2-34 Deploying Cisco Catalyst 3750-X StackWise Plus 2-38 Deploying Cisco Catalyst 3560-X and 2960-S FlexStack 2-41 Designing EtherChannel Network 2-41 Network Addressing Hierarchy 2-49 Network Foundational Technologies for LAN Design 2-50 Designing the Core Layer Network 2-50 Designing the Campus Distribution Layer Network 2-56 Designing the Multilayer Network 2-56 Spanning-Tree in Multilayer Network 2-59 Designing the Routed Access Network 2-60 Multicast for Application Delivery 2-64 Multicast Addressing Design 2-64 Multicast Routing Design 2-65 Designing PIM Rendezvous Point 2-66 Dynamic Group Membership 2-73 Designing Multicast Security 2-74 QoS for Application Performance Optimization 2-75 Medium Enterprise LAN QoS Framework 2-76 Medium Enterprise Design Profile Reference Guide ii .

Contents Designing Medium Enterprise LAN QoS Trust Boundary and Policies Medium Enterprise LAN QoS Overview 2-80 Deploying QoS in Campus LAN Network 2-84 QoS in Catalyst Fixed Configuration Switches 2-84 QoS in Cisco Modular Switches 2-85 Deploying Access-Layer QoS 2-87 Deploying Network-Layer QoS 2-105 High-Availability in LAN Network Design 2-119 Medium Enterprise High-Availability Framework 2-119 Baselining Campus High Availability 2-120 Network Resiliency Overview 2-121 Device Resiliency Overview 2-122 Operational Resiliency Overview 2-124 Design Strategies for Network Survivability 2-126 Implementing Network Resiliency 2-127 Implementing Device Resiliency 2-130 Implementing Operational Resiliency 2-141 Summary 3 2-150 2-79 CHAPTER Medium Enterprise Design Profile (MEDP)—WAN Design 3-1 WAN Design 3-1 WAN Transport 3-3 Private WAN Service 3-3 Internet Service 3-4 Metro Service 3-4 Leased-Line Service 3-7 WAN Aggregation Platform Selection in the Medium Enterprise Design Profile Main Site WAN Aggregation Platform Selection 3-8 Large Remote Site WAN Aggregation Platform Selection 3-10 Medium Remote Site WAN Aggregation Platform Selection 3-10 Small Remote Site WAN Aggregation Platform Selection 3-11 Implementation of WAN Reference Design 3-11 WAN Infrastructure Design 3-11 Leased-Line Service 3-12 Routing Design 3-13 QoS 3-19 QoS Implementation 3-21 QoS Implementation at WAN Aggregation Router 1 3-22 Implementation Steps for QoS Policy at WAN Aggregation Router 1 3-7 3-24 Medium Enterprise Design Profile Reference Guide iii .

Contents QoS Policy Implementation for WAN Aggregation Router 2 3-26 QoS Policy Between the Main Site and Large Remote Site 3-29 QoS Policy Between the Main Site and Medium Remote Site Location 3-30 QoS Policy Between Main Site and Small Remote Site Location 3-32 QoS Policy Implementation Between the Main Site and Core 3-33 QoS Policy Between Large Remote Site and Main Site Location 3-34 QoS Policy Between Remote Medium Site and Main Site Location 3-36 QoS Policy Implementation Between Small Remote Site and Main Site Location 3-37 Redundancy 3-38 Multicast 3-43 Summary 4 3-46 CHAPTER Medium Enterprise Design Profile (MEDP)— Mobility Design Mobility Design 4-1 4-1 Accessibility 4-5 WLAN Controller Location 4-7 WLAN Controller Connectivity 4-8 Controller Connectivity to the Wired Network 4-8 Controller Connectivity to Wireless Devices 4-10 Access Points 4-19 Usability 4-26 Quality-of-Service 4-26 Guest Access 4-27 Manageability 4-32 Reliability 4-35 Controller Link Aggregation 4-35 Controller Redundancy 4-38 AP Controller Failover 4-40 Wireless LAN Controller Configuration 4-40 WLAN Controller and Wired Network Connections Remote Site 4-43 Mobility Groups 4-43 WLAN Configuration 4-45 Staff Data WLAN 4-45 Staff Voice WLAN 4-46 Guest Access WLAN 4-46 WLAN QoS 4-49 Access Point Configuration AP 1520 Configuration Medium Enterprise Design Profile Reference Guide 4-41 4-50 4-51 iv .

1X and EAP 5-31 Impacts of 802.1X in Medium Enterprise Networks 5-32 Cisco NAC Appliance 5-32 NAC Appliance Components 5-33 NAC Appliance Modes and Positioning 5-35 NAC Deployment in the Medium Enterprise Design Profile 5-39 Secure Mobility Threats Mitigated 5-44 5-46 5-29 Medium Enterprise Network Security Deployment Guidelines 5-47 Internet Border Router Edge ACL Deployment 5-47 Module 1—Implement Anti-spoofing Denies 5-47 Module 2—Implement Explicit Permits 5-48 Module 3—Implement Explicit Deny to Protect Infrastructure 5-48 Module 4—Implement Explicit Permit for Traffic to the Enterprise Public Subnet Medium Enterprise Design Profile Reference Guide 5-48 v .Contents Adding the AP1520 MAC Address to the WLAN Controller 4-52 Configuring the AP1520 as a Root Access Point (RAP) 4-52 WCS Configuration 4-54 WCS Users and User Groups WCS Virtual Domains 4-55 Reference Documents 4-57 5 4-54 CHAPTER Medium Enterprise Design Profile (MEDP)—Network Security Design Security Design 5-1 5-6 5-1 Network Foundation Protection Internet Perimeter Protection 5-8 Internet Border Router Security 5-10 Internet Firewall 5-10 Cisco ASA Botnet Traffic Filter 5-11 Intrusion Prevention 5-13 Cisco IPS Global Correlation 5-14 E-Mail Security Guidelines 5-17 Web Security Guidelines 5-22 Data Center Protection 5-26 Network Access Security and Control 5-28 Cisco Catalyst Integrated Security Features 5-29 Cisco Unified Wireless Network (CUWN) Integrated Security Features Cisco Identity-Based Network Services (IBNS) 5-30 IEEE 802.1X on the Network 5-31 802.1X Protocol 5-30 802.

Contents Internet Firewall Deployment 5-48 Firewall Hardening and Monitoring 5-50 Network Address Translation (NAT) 5-52 Firewall Access Policies 5-52 Firewall Redundancy 5-55 Routing 5-56 Botnet Traffic Filter 5-57 Intrusion Prevention Deployment 5-61 Deploying IPS with the Cisco ASA 5-61 IPS Global Correlation Deployment 5-61 Web Security Deployment 5-66 Initial System Setup Wizard 5-67 Interface and Network Configuration 5-67 WCCP Transparent Web Proxy 5-71 Web Access Policies 5-74 Catalyst Integrated Security Features Deployment NAC Appliance Deployment 5-76 NAC Deployment for Wired Clients 5-76 NAC Deployment for Wireless Clients 5-89 Additional Information A 5-98 5-75 APPENDIX Reference Documents A-1 Medium Enterprise Design Profile Reference Guide vi .

represented by sites and buildings of varying sizes (see Figure 1-2). If it fails. Figure 1-1 Service Fabric Foundation Network Network Foundation Guidance Cisco SAFE Security Architecture Guidance Enterprise Design Profiles Mobility Guidance Collaboration Services Guidance 229341 Service Fabric Design The model used for the Medium Enterprise Design Profile service fabric is based around the desire to represent as many medium enterprise environments as possible. all applications. and solutions use to interact and communicate with one another. See Figure 1-1. and technologies deployed in the Medium Enterprise Design Profile will also fail. When Medium Enterprise Design Profile Reference Guide 1-1 . mobility. buildings are also sized with the determining factor being the number of users or connections to the network in that building as well as physical size. The service fabric is the most important component of the Medium Enterprise Design Profile.CH A P T E R 1 Medium Enterprise Design Profile (MEDP)—Service Fabric Design Considerations The service fabric is the foundational network that all enterprise services. Additionally. service awareness and differentiation. the service fabric must be constructed in a fashion that supports all the applications and services that will ride on it. The service fabric is made up of four distinct components local and wide area network (LAN/WAN). as well as access flexibility. security. Each of these critical foundation components must be carefully designed and tuned to allow for a secure environment that provides business continuity. and unified communications. To do that a modular design is used. depending on the site size profile. solutions. it must be aware of what is type of traffic is transversing and treat each application or service with the right priority based on the needs and importance of that application. applications. Like the foundation of a house. The sites are made up of one or more building.

The profile of the main/large site is made up of six buildings. The buildings will connect back to the resilient core via multiple 10Gb Ethernet links. Medium Enterprise Design Profile Reference Guide 1-2 229343 IP IP IP IP IP IP Serverfarm . an average size of 35 users per work area is used. This approach allows the network architect to essentially build their own medium enterprise environment by mixing the different site and building profiles provided. and will also have all other sites within the enterprise connecting to it. Figure 1-2 Main Large Site Medium Enterprise Design Profile Overview Large Building Medium Building Small Building Extra Small Building IP IP IP IP Service Block Secure Mobility WAE Wireless LAN Controller NAC Server QFP Internet Data Center www M V SRST/Video Cisco ACS Gateway Appliance NAC Manager Video Surveillance Media Server Web Security Core QFP Cisco UCM Email Security Web Email Server Server Cisco Security Intelligence Operation Internet Edge SensorBase MetroE HDLC Service Block Core Core Service Block Small Data Center Small Data Center Service Block Large Building Medium Building Small Building Medium Building Small Building Small Building Remote Large Site Remote Medium Site Remote Small Site Main and Large Site Design The main and large site designs are meant to represent significantly sized sites containing the largest user populations. The large site will connect to the main site via a 1Gb Metro Ethernet link. The main site and large site are almost identical. Additionally. The core will also connect to a serverfarm design and service block. with the exception that the main site is connected to outside entities such as the Internet using the Internet edge components. the buildings range in size from large to extra small.Chapter 1 Service Fabric Design Medium Enterprise Design Profile (MEDP)—Service Fabric Design Considerations representing a working room. it is expected that half of all network can be accessed via wireless.

there are 2 outdoor mesh access points to cover the outdoor skirt of the building. there are 6 outdoor mesh access points to cover the outdoor skirt of the building. additionally. The ports are distributed over four different floors. The buildings will connect to the medium site core via multiple 10Gb links. The medium building is made up of designed for 80 phones. each floor having 400 access ports. and extra small. additionally. Medium Building Design The medium building was designed for 800 Ethernet access ports ranging in bandwidth from 100mb to 1Gb. The medium site is connected to the main site via a 100mb Metro Ethernet link. The ports are distributed over two different floors. The buildings also have distribution switches that connect the access switches together as well as connect the building itself to the core network. There are 10 wireless access points using the IEEE 802. The large building designed for 160 phones.11 ABGN standards. and the core will also connect to a small serverfarm and service block. There are 40 wireless access points using the IEEE 802. the core and distribution networks are collapsed into one.1 ABGN standards. there are four outdoor mesh access points to cover the outdoor skirt of the building. small. additionally. There are 80 wireless access points using the IEEE 802. in this case. there are 20 access points per floor. Small Site Design The small site profile represents a site made up of just one building. medium. The small building is designed for 30 phones. Small Building Design The small building is designed for 200 Ethernet access ports ranging in bandwidth from 100mb to 1Gb.1 ABGN standards. there are 20 access points per floor. This link interconnects the small site to the other sites as well as external networks such as the Internet. The small site is connected to the main site via a fractional DS3 with a 20mb bandwidth rating. All buildings have access switches that connect users. This link interconnects the medium site to the other sites as well as external networks such as the Internet. Large Building Design The large building is designed for 1600 Ethernet access ports ranging in bandwidth from 100mb to 1Gb. The ports are all located on one floor. Medium Enterprise Design Profile Reference Guide 1-3 . each floor having 400 access ports. Building Profiles There are four building profiles: large.Chapter 1 Medium Enterprise Design Profile (MEDP)—Service Fabric Design Considerations Service Fabric Design Medium Site Design The medium site design is targeted at enterprise sites that have approximately 3 buildings ranging in size from medium to small.

application-aware network with flexible access. Distribution layer—The distribution layer uses a combination of Layer-2 and Layer-3 switching to provide for the appropriate balance of policy and access controls. Designed for critical network edge functionality to provide intelligent application and device aware services. The service fabric routers and switches support many different routing protocols that will work medium enterprise environments. MP3. and flexibility in subnet allocation and VLAN usage. cameras. There are 3 wireless access points using the IEEE 802. The service fabric consists of four major components. Network architects must consider all the following critical design factors when selecting the right routing protocol to be implemented throughout the internal network: • • Network design—Proven protocol that can scale in full-mesh site network designs and can optimally function in hub-and-spoke WAN network topologies. desktops. additionally.11 ABGN wireless access. etc). The sections below provide a brief description of each of these components. recomputation independent of number of routes in the network. Scalability—Routing protocol function must be network and system efficient that operates with a minimal number of updates. because they allow for the routing of information between buildings and sites. there is 1 outdoor mesh access point to cover the outdoor skirt of the building. • Routing Protocol Selection Criteria Routing protocols are essential for any network. Medium Enterprise Design Profile Reference Guide 1-4 . availability. Half of all the devices are expected to connect to the network using 802. mobile phones. The extra small building designed for up of 10 phones. Access layer—Demarcation point between network infrastructure and access devices. The ports are all located on one floor. and personal devices (iPod.1 ABGN standards. displays. Selecting the right routing protocol can vary based on the end-to-end network infrastructure. Access Devices The devices that connect to the Medium Enterprise Design Profile network include phones. laptops. LAN Design Considerations Hierarchical network design model components: • • Core layer—The site backbone consisting of a Layer-3 core network interconnecting to several distributed networks and the shared services block to access local and global information. LAN/WAN Design Considerations The service fabric LAN/WAN is made up of routers and switches deployed in a three-tier hierarchical model that use Cisco IOS to provide foundational network technologies needed to provide a highly available.Chapter 1 LAN/WAN Design Considerations Medium Enterprise Design Profile (MEDP)—Service Fabric Design Considerations Extra Small Building Design The extra small building is designed for 48 100mb Ethernet access ports.

optimizes distribution performances.) Operational resiliency—Enables higher level resiliency capabilities. it comes at some cost in administration. role.e. and a multitude of other factors which are beyond the routing protocol. Operational considerations—Simplified network and routing protocol design that can ease the complexities of configuration. and network service type the appropriate resiliency option should be deployed: • • • Link resiliency—Provides redundancy during physical link failures (i. and the layer of communication used here must be considered in any design. and allows for the use of well known end-to-end troubleshooting tools. management. fiber cut.. See Figure 1-3. configuration. software crashes.. providing complete network availability even during planned network outage conditions. it is important to identify network fault domains and define rapid recovery plans to minimize the application impact during minor and major network outages. bad transceivers.Chapter 1 Medium Enterprise Design Profile (MEDP)—Service Fabric Design Considerations LAN/WAN Design Considerations • Rapid convergence—Link state versus DUAL recomputation and synchronization. Traditional Layer 2 connectivity is prevalent in most networks today. Performing the routing function in the access-layer simplifies configuration.) Device resiliency—Protects network during abnormal node failure triggered by hardware or software (i. Medium Enterprise Design Profile Reference Guide 1-5 . commonly referred to as routed-access. Implementing a Layer 3 access-layer in lieu of the traditional Layer 2 access replaces the required Layer 2 trunks with a single point-to-point Layer 3 link. Access Layer Design Considerations The access layer represents the entry into the network.e. incorrect cablings. The implementing of a Layer 3 access does not require any physical or logical link reconfiguration or changes. non-responsive supervisor etc. however. The switch that the client connects to will ultimately connect up to the network distribution. Network reconvergence also varies based on network design. Pushing Layer 3 function one tier down on Layer 3 access switches changes traditional multilayer network topology and the forwarding path. configuration. and troubleshooting. etc. • High Availability Design Considerations To ensure business continuity and prevent catastrophic network failure during unplanned network outage. and timely resiliency. The emerging method of connectivity is a Layer 3 connection. Depending on the network system tier. The service fabric design must ensure network survivability by following three major resiliency methods pertaining to most types of failures. consisting of wired and wireless access from the client to the network.

Layer 3 access switches provides an IP gateway function and becomes a Layer-2 demarcation point to locally connected endpoints that could be logically segmented in multiple VLANs. The service fabric design model covers the following WAN transport design considerations: • • • MPLS/VPN Internet Metro Ethernet Medium Enterprise Design Profile Reference Guide 1-6 . LAN Service Fabric Foundational Services The service fabric uses essential foundational services to efficiently disseminate information that are used by multiple clients. Designing the foundational services in a manner consistent with the needs of the medium enterprise is paramount. WAN transport differs greatly from LAN transport due to the variables such as the type of connection used.Chapter 1 LAN/WAN Design Considerations Medium Enterprise Design Profile (MEDP)—Service Fabric Design Considerations Figure 1-3 Control Function in Multi-Layer and Routed-Access Network Design VSL VSL Core Core Routing VSL Distribution Layer 3 Routing VSL Distribution Layer 3 STP Layer 2 Access Admin VLAN 10 Library VLAN 20 Arts VLAN 30 Routing Access Layer 2 Admin VLAN 10 Library VLAN 20 Arts VLAN 30 228467 Multi-Layer Network Routed-Access Network At the network edge. Some of the key foundational services discussed include the following: • • Multicast routing protocol design considerations Designing QoS in site network WAN Design Considerations WAN Transport In order for sites to communicate with one another and/or to communicate outside the medium enterprise network. as well as identify and prioritize different applications traffic based on their requirements. the speed of the connection. and the distance of the connection. the network traffic must traverse over a WAN.

Protecting users from harmful content. Without it. The service fabric was developed with the following security design considerations: • • Network Foundation Protection (NFP)—Ensuring the availability and integrity of the network infrastructure. medium enterprise solutions. regardless of whether they are meeting in a conference room. and other malicious software. Provide easy. laptops. Network endpoint protection—Protecting servers and enterprise-controlled systems (desktops. and external (extranets) networks and protecting internal resources and users from malware. malware. Most users will connect wirelessly to site networks. Protecting the confidentiality and privacy of users. etc. and other malicious software. botnets. Internet perimeter protection— Ensuring safe connectivity to the Internet. In designing the mobility portion of the service fabric. Ensuring systems are up-to-date and in compliance with the medium enterprises’ network security policies. contractors. viruses. Data center protection—Ensuring the availability and integrity of centralized applications and systems. the WAN must deploy essential foundational services to ensure the proper transport and prioritization of medium enterprise services. “Medium Enterprise Design Profile (MEDP)—Network Security Design.) from viruses. visiting colleagues. the WAN Service Fabric Foundation Services considered are as follows: • • • • Routing protocol design Quality-of-service (QoS) WAN resiliency Multicast Security Design Considerations Security of the Medium Enterprise Design Profile service fabric is essential. Enforcing authentication and role-based access for users residing at the main and remote sites. at lunch with colleagues in the site cafeteria. Medium Enterprise Design Profile Reference Guide 1-7 . • • • Each of these security design considerations are discussed in further detail in Chapter 5. Additionally. or simply enjoying a breath of fresh air outside a site building. or shut down. and services are open to be compromised. Enforcing E-mail and web browsing policies for enterprise users. manipulated.” Mobility Mobility is an essential part of the enterprise environment. secure guest access to guests such as temporary workers. Network access security and control—Securing the access edges. Enforcing E-mail and web browsing policies. other devices will also rely on the mobile network. protecting the control and management planes.Chapter 1 Medium Enterprise Design Profile (MEDP)—Service Fabric Design Considerations Security Design Considerations WAN Service Fabric Foundational Services Similar to the LAN. applications. vendors and other visitors. the following design criteria were used: • Accessibility—Enables enterprise users and guests to be accessible and productive.

helping to ensure that video and audio information arrives on time. Reliability—Provide adequate capability to recover from a single-layer fault of a WLAN accessibility component or controller wired link. Extend the services of the network safely to authorized parties.1x and Extensible Authentication Protocol (EAP). easy to understand WLAN management framework is desired to provide small. This gives preferential treatment to real-time traffic. latency sensitive applications (such as IP telephony and video-conferencing) are supported over the WLAN using appropriately applied QoS. medium and large sites within the enterprise with the same level of wireless LAN management scalability. applications. with all information sent and received on the WLAN being encrypted. Several considerations for gateways include the following: • • • PSTN trunk sizing Traffic patterns Interoperability with the call processing system Medium Enterprise Design Profile Reference Guide 1-8 . locations. reliability and ease of deployment that is demanded by very large enterprise business customers. operate. Manageability—Enterprise network administrators must be able to easily deploy. gateways. Some of the considerations include the following: • • • Scale—The number of users. A single. guidance on designing scalable and resilient call processing systems is essential for deploying a unified communications system.11n technology. Security—Segment authorized users and block unauthorized users. • • • Unified Communications Call Processing Considerations How calls are processed in the medium enterprise environment is an important design consideration. and so forth Performance—The call rate Resilience—The amount of redundancy Gateway Design Considerations Gateways provide a number of methods for connecting an IP telephony network to the Public Switched Telephone Network (PSTN). and manage hundreds of access points within multiple enterprise site deployments.Chapter 1 Unified Communications Medium Enterprise Design Profile (MEDP)—Service Fabric Design Considerations • Usability—In addition to extremely high WLAN transmission speeds made possible by the current generation of IEEE 802. Enforce security policy compliance on all devices seeking to access network computing resources. Enterprise users enjoy rapid and reliable authentication through IEEE 802. Ensure that wireless LAN accessibility is maintained for users and visitors in the event of common failures.

and an integral part of all call processing agents. Specifically. Medium Enterprise Design Profile Reference Guide 1-9 . the dial plan performs the following main functions: • • • • • Endpoint addressing Path selection Calling privileges Digit manipulation Call coverage Survivability Considerations Voice communications are a critical service that must be maintained in the event of a network outage for this reason the service fabric must take survivability into consideration. Generally.Chapter 1 Medium Enterprise Design Profile (MEDP)—Service Fabric Design Considerations Unified Communications Dial Plan Considerations The dial plan is one of the key elements of an unified communications system. the dial plan is responsible for instructing the call processing agent on how to route calls.

Chapter 1 Unified Communications Medium Enterprise Design Profile (MEDP)—Service Fabric Design Considerations Medium Enterprise Design Profile Reference Guide 1-10 .

CH A P T E R 2 Medium Enterprise Design Profile (MEDP)—LAN Design LAN Design The Medium Enterprise LAN design is a multi-campus design. Medium Enterprise Design Profile Reference Guide 2-1 . where a campus consists of multiple buildings and services at each location. as shown in Figure 2-1.

Chapter 2 LAN Design Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-1 Medium Enterprise LAN Design Large Building Medium Building Small Building Extra Small Building Services Block Data Center Main Site Internet Edge WAN PSTN Internet Services Block Services Block Services Block Data Center Data Center Data Center Remote Small Site Remote Large Site Remote Medium Site Figure 2-2 shows the service fabric design model used in the medium enterprise LAN design. Medium Enterprise Design Profile Reference Guide 2-2 229353 Large Building Medium Building Small Building Medium Building Small Building .

Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design LAN Design Figure 2-2 Medium Enterprise LAN Design Service Fabric Design Model Mobility Security Unified Communications This chapter focuses on the LAN component of the overall design. and infrastructure demands. and to protect the network against unmanaged devices and applications. and so on. • • Medium Enterprise Design Profile Reference Guide 228469 Local Area Network (LAN) Wide Area Network (WAN) 2-3 . such as endpoints. The LAN design interconnects several other components. Designing network foundation services for LAN designs in medium enterprise—Provides guidance on deploying various types of Cisco IOS technologies to build a simplified and highly available network design to provide continuous network operation. security. Considerations of a multi-tier LAN design model for medium enterprises—Provides guidance for the enterprise campus LAN network as a platform with a wide range of next-generation products and technologies to integrate applications and solutions seamlessly. including networking role. This section also provides guidance on designing network-differentiated services that can be used to customize the allocation of network resources to improve user experience and application performance. data center. capacity. which becomes a common framework along with critical network technologies to deliver the foundation for the service fabric design. This LAN design provides guidance on building the next-generation medium enterprise network. size. and unified communications (UC) can be integrated into the overall design. This chapter is divided into following sections: • • LAN design principles—Provides proven design choices to build various types of LANs. The LAN component consists of the LAN framework and network foundation technologies that provide baseline routing and switching guidelines. LAN design model for the medium enterprise—Leverages the design principles of the tiered network design to facilitate a geographically dispersed enterprise campus network made up of various elements. to provide a foundation on which mobility. WAN.

and UC features essential to the service fabric design model. Figure 2-3 Three-Tier and Two-Tier LAN Design Models Three-Tier LAN Design Core Two-Tier LAN Design Distribution Collapsed Core/Distribution Access Access Medium Enterprise Design Profile Reference Guide 2-4 228470 . The two proven. and management – Reduces fault domains at every tier • • • Modularity—Allows the network to grow on an on-demand basis Resiliency—Satisfies user expectations for keeping network always on Flexibility—Allows intelligent traffic load sharing by using all network resources These are not independent principles. as well as providing an interconnect point for the WAN aspect of the network.Chapter 2 LAN Design Principles Medium Enterprise Design Profile (MEDP)—LAN Design LAN Design Principles Any successful design or system is based on a foundation of solid design theory and principles. time-tested hierarchical design frameworks for LAN networks are the three-tier layer and the two-tier layer models. The successful design and implementation of a campus network requires an understanding of how each of these principles applies to the overall design. resilient. This chapter provides design guidelines that are built upon the following principles to allow a medium enterprise network architect to build enterprise campuses that are located in different geographical locations: • Hierarchical – Facilitates understanding the role of each device at every tier – Simplifies deployment. Designing the medium enterprise LAN building blocks in a hierarchical fashion creates a flexible and resilient network foundation that allows network architects to overlay the security. modular. The use of a guiding set of fundamental engineering design principles serves to ensure that the LAN design provides for the balance of availability. understanding how each principle fits in the context of the others is critical in delivering a hierarchical. In addition. and flexible network required by medium enterprises today. and manageability required to meet current and future advanced and emerging technology needs. as shown in Figure 2-3. security. mobility. flexibility. Designing the LAN component of the overall medium enterprise LAN service fabric design model is no different than designing any large networking system. operation.

and ties the campus together with the rest of the network. quality of service (QoS). such as the following: – Aggregating and terminating Layer 2 broadcast domains – Aggregating Layer 3 routing boundaries – Providing intelligent switching. as well as providing differentiated services to various classes of service applications at the edge of network • Core layer The core layer is the network backbone that connects all the layers of the LAN design. and efficient physical cable layout design. and network access policy functions to access the rest of the network – Providing high availability through redundant distribution layer switches to the end-user and equal cost paths to the core. computing and data storage services located within the data center and other areas.html. Cisco recommends building an extended-star physical network topology from a centralized building location to all other buildings on the same campus. Traditionally. distribution and core. where traffic enters or exits the campus network.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design LAN Design Principles The key layers are access. To meet network application and end-user demands. • Distribution layer The distribution layer interfaces between the access layer and the core layer to provide many key functions. but now provide intelligent services to various types of endpoints at the network edge. The core layer serves as the aggregator for all the other campus blocks.com/en/US/docs/solutions/Enterprise/Campus/campover. To build a simplified. the primary function of an access layer switch is to provide network access to the user. cost-effective. distribution. see the enterprise class network framework at the following URL: http://www. the next-generation Cisco Catalyst switching platforms no longer simply switch packets. Introducing modularity in the LAN hierarchical design further ensures that the LAN network remains resilient and flexible to provide critical network services as well as to allow for growth and changes that may occur in a medium enterprise. Access layer switches connect to the distribution layer switches to perform network foundation technologies such as routing. Figure 2-4 shows a sample three-tier LAN network design for medium enterprises where the access. Building intelligence into access layer switches allows them to operate more efficiently. and security. providing for connectivity between end devices. • Access layer The access layer represents the network edge. and services within the network. routing.cisco. and core are all separate layers. Note For more information on each of these layers. optimally. Medium Enterprise Design Profile Reference Guide 2-5 . Each layer can be seen as a well-defined structured module with specific roles and functions in the LAN network. and securely.

Chapter 2 LAN Design Principles Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-4 Three-Tier LAN Network Design Example Building B – Marketing and Sales Building C – Engineering Access Distribution Building A – Management Core Distribution Access Building D – Research and Development Building E – Information Technology Building F – Data Center The primary purpose of the core layer is to provide fault isolation and backbone connectivity. In this scenario. having separate distribution and core layers is not required. A core layer also provides for flexibility in adapting the campus design to meet physical cabling and geographical challenges. and printers) and those that affect the data center. Cisco recommends the two-tier LAN network design. In some cases. Isolating the distribution and core into separate layers creates a clean delineation for change control between activities affecting end stations (laptops. Medium Enterprise Design Profile Reference Guide 2-6 229354 . WAN. Figure 2-5 shows a two-tier LAN network design example for a medium enterprise LAN where the distribution and core layers are collapsed into a single layer. or other parts of the network. routing protocols. In smaller locations where there are less users accessing the network or in campus sites consisting of a single building. or switching hardware than the rest of the campus. a separate core layer can use a different transport technology. also known as the collapsed core network design. phones. because of either physical or network scalability. If necessary. separate core and distribution layers are not needed. providing for more flexible design options when needed.

and flexible LAN network. resilient. Cost-effectiveness—Integrated specific network components that fit budgets without compromising performance.multiple campuses can co-exist within a single medium enterprise system that offers various academic programs. the enterprise network architect must understand the network and application demands so that this design ensures a hierarchical. Resilient—Sub-second network recovery during abnormal network failures or even network upgrades. operation.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Medium Enterprise LAN Design Models Figure 2-5 Two-Tier Network Design Example Access Floor 6 – Research and Development Floor 5 – Engineering WAN Floor 4 – Serverfarm Floor 3 – Information Technology Floor 2 – Management PSTN Collapsed Distribution/ Core If using the small-scale collapsed campus core design. Medium Enterprise Design Profile Reference Guide 229274 2-7 . and management. • • • As shown in Figure 2-6. Medium Enterprise LAN Design Models Both LAN design models (three-tier and two-tier) have been developed with the following considerations: • Scalability—Based on Cisco enterprise-class high-speed 10G core switching platforms for seamless integration of next-generation applications required for medium enterprises. Simplicity—Reduced operational and troubleshooting cost via the use of network-wide configuration. modular. Platforms chosen are cost-effective and provide investment protection to upgrade network as demand increases.

Collapsing the LAN and WAN functionality into a single Cisco platform can provide all the needed requirements for a particular remote site as well as provide reduced cost to the overall design.Chapter 2 Medium Enterprise LAN Design Models Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-6 Medium Enterprise LAN Design Model HDTV IP Main Large Site Large Building Medium Building Small Building Extra Small Building Cisco 6500 VSS Cisco 4500 Cisco 4500 Cisco 3750 Stackwise CUCM/Unitity ACS/CSA-MC NAC Mgr WCS VSOM/VSMS DMM/CVP DHCP/DNS NTTP/FTP NTP Core DC Service Block WAE ACNS WLC NAC Cisco 6500 VSS DMZ ESA Web/Email Internet Edge www ASR Cisco 3800 WSA ASR GigaPOP MetroE HDLC PSTN Internet NLR HDLC Cisco 375ME VSOM/VSMS WAE/ACNS DHCP/DNS NTTP/FTP/NTP WLC/NAC Cisco 2800 VSOM/VSMS WAE/ACNS DHCP/DNS NTTP/FTP/NTP WLC/NAC Cisco 6500 VSS Cisco 2800 Cisco 3800 VSOM/VSMS DHCP/DNS WAE/ACNS NTTP/FTP/NTP WLC/NAC Cisco 4500 DC Appliance Block DC Appliance Block DC Appliance Block Cisco 6500 VSS Cisco 4500 Cisco 4500 Cisco 4500 Cisco 4500 Cisco 4500 Large Building Medium Building Small Building Medium Building Small Building Small Building Remote Large Site Remote Medium Site Remote Small Site HDTV HDTV IP IP Depending on the remote campus office facility. the number of employees and the networked devices in remote campuses may be equal to or less than the main site. as discussed in more detail in the following section. Campus network designs for the remote campus may require adjusting based on overall campus capacity. all the remote medium enterprise campuses interconnect to a centralized main site that provides shared services to all the employees independent of their physical location. Medium Enterprise Design Profile Reference Guide 2-8 229355 . The WAN design is discussed in greater detail in the next chapter. Table 2-1 shows a summary of the LAN design models as they are applied in the overall medium enterprise network design. but it is worth mentioning in the LAN section because some remote sites may integrate LAN and WAN functionality into a single platform. Using high-speed WAN technology.

servers. Medium Enterprise Design Profile Reference Guide 2-9 .Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Medium Enterprise LAN Design Models Table 2-1 Medium Enterprise Recommended LAN Design Model Medium Enterprise Location Main campus Remote large campus Remote medium campus Remote small campus Recommended LAN Design Model Three-tier Three-tier Three-tier with collapsed WAN edge Two-tier Main Site Network Design The main site in the medium enterprise design consists of a centralized hub campus location that interconnects several sizes of remote campuses to provide end-to-end shared network access and services. Multiple buildings of various sizes exist in one location. as shown in Figure 2-8. IP-enabled endpoints. Figure 2-7 Main Site Reference Design Large Building Access Medium Building Small Building Extra Small Building Distribution Core Data Center Block DMZ Service Block WAN Edge QFP PSTN Gateway QFP Internet Edge WAN PSTN GigaPOP 229356 Internet NLR The main site typically consists of various sizes of building facilities and various organization department groups. as shown in Figure 2-7. and security and network edge devices. and includes end users. The network scale factor in the main site is higher than the remote campus site.

Medium Enterprise Design Profile Reference Guide 2-10 228475 . with the same common types of applications. the remote large site is not much different from the main site.” Remote Large Campus Site Design From the location size and network scale perspective. endpoints. because it requires a separate WAN device that connects to the three-tier LAN model. “Medium Enterprise Design Profile (MEDP)—WAN Design. WAN design is discussed in more detail in Chapter 3. and keeps all network elements protected and available. and network services. Cisco recommends the three-tier LAN design model for the remote large site campus. To enforce external network access policy for each end user. given the size and number of employees at this location. the three-tier model also provides external gateway services to the employees for accessing the Internet. Similar to the main site.Chapter 2 Medium Enterprise LAN Design Models Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-8 Main Site Reference Design Large Building Access Medium Building Small Building Distribution Core Data Center Block Service Block WAN Edge QFP PSTN Gateway WAN PSTN The three-tier LAN design model for the main site meets all key technical aspects to provide a well-structured and strong network foundation. it can be distant from the main campus site and requires a high-speed WAN circuit to interconnect both campuses. users. Geographically. The remote large site can also be considered as an alternate campus to the main campus site. separate WAN devices are recommended to provide application delivery and access to the main site. as shown in Figure 2-9. Note The WAN design is a separate element in this location. The modularity and flexibility in a three-tier LAN design model allows easier expansion and integration in the main site network. Similar to the main site.

Figure 2-10 shows the remote medium campus in more detail. Because there are fewer employees and networked devices at this site as compared to the main or remote large site campus sites. the need for a separate WAN device may not be necessary.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Medium Enterprise LAN Design Models Figure 2-9 Remote Large Campus Site Reference Design Medium Building Access Small Building Distribution Core Data Center Block Service Block WAN Edge PSTN Gateway WAN PSTN Remote Medium Campus Site Design Remote medium campus locations differ from a main or remote large site campus in that there are less buildings with distributed organization departments. A remote medium campus network is designed similarly to a three-tier large campus LAN design. thereby reducing the need to build a similar campus network to that recommended for main and large campuses. thus collapsing the WAN and core LAN functionality into a single platform. the platform chosen in the core layer also serves as the WAN edge. A remote medium campus may have a fewer number of network users and endpoints. and in addition. All the LAN benefits are achieved in a three-tier design model as in the main and remote large site campus. Medium Enterprise Design Profile Reference Guide 228476 2-11 .

Chapter 2 Medium Enterprise LAN Design Models Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-10 Remote Medium Campus Site Reference Design Access Data Center Block Distribution/Core Service Block WAN Edge PSTN Gateway WAN PSTN Remote Small Campus Network Design The remote small campus is typically confined to a single building that spans across multiple floors with different academic departments. Medium Enterprise Design Profile Reference Guide 2-12 228477 . In such smaller scale campus network deployments. and improves overall network efficiency and manageability. and WAN traffic and application needs must be considered. The network scale factor in this design is reduced compared to other large campuses. Although the network scale factor is reduced compared to other larger campus locations. WAN bandwidth requirements must be assessed appropriately for this remote small campus network design. Before deploying a collapsed core and distribution layer in the remote small campus network. the distribution and core layer functions can collapse into the two-tier LAN model without compromising basic network demands. Figure 2-11 shows the remote small campus in more detail. the application and services demands are still consistent across the medium enterprise locations. sufficient WAN link capacity is needed to deliver consistent network services to employees. considering all the scale and expansion factors prevents physical network re-design. Similar to the remote medium campus location. This design model is recommended only in smaller locations. A single Cisco platform can provide collapsed core and distribution LAN layers. the WAN functionality is also collapsed into the LAN functionality. However.

Campus Core Layer Network Design As discussed in the previous section. and Internet edge. Each LAN design model for a medium enterprise location is based on the key LAN layers of core. WAN. security. distribution. Each design recommendation is optimized to keep the network simplified and cost-effective without compromising network scalability. Three core layer design models are available. choosing a core layer design also depends on the size and location within the design. and access. This section provides more detailed design guidance for each tier in the LAN design model. Similarly to choosing a LAN design model based on a location within the medium enterprise design. Figure 2-12 shows the three core layer design models. and resiliency. each of which is based on either the Cisco Catalyst 6500-E Series or the Cisco Catalyst 4500-E Series Switches. Medium Enterprise Design Profile Reference Guide 228476 2-13 . the core layer becomes a high-speed intermediate transit point between distribution blocks in different premises and other devices that interconnect to the data center.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Multi-Tier LAN Design Models for Medium Enterprise Figure 2-11 Remote Small Campus Site Reference Design Medium Building Access Small Building Distribution Core Data Center Block Service Block WAN Edge PSTN Gateway WAN PSTN Multi-Tier LAN Design Models for Medium Enterprise The previous section discussed the recommended LAN design model for each medium enterprise location.

Core Layer Design Option 1—Cisco Catalyst 6500-E-Based Core Network Core layer design option 1 is specifically intended for the main and remote large site campus locations. the core layer interconnects several other network systems that are implemented in different roles and service blocks. and network scalability. and the overall network scale capacity is common in both sites and thus. high availability. Core layer design option 1 is based on Cisco Catalyst 6500 Series switches using the Cisco Virtual Switching System (VSS). Building a VSS-based network changes network design. which is a software technology that builds a single logical core system by clustering two redundant core systems in the same tier. cost. Medium Enterprise Design Profile Reference Guide 2-14 228479 . similar core design principles are required. high-speed and low-latency applications (such as Cisco TelePresence). The single logical connection between core and the peer network devices builds a reliable. and management dramatically.Chapter 2 Multi-Tier LAN Design Models for Medium Enterprise Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-12 Core Layer Design Models for Medium Enterprises Core Design Option – 1 Switch-1 Core VSL Switch-2 Core Design Option – 2 Core Design Option – 3 Core Collapsed Core/Distribution 228478 Cisco Catalyst 6500 Cisco Catalyst 4500 Cisco Catalyst 4500 Each design model offers consistent network services. expansion flexibility. point-to-point connection that develops a simplified network topology and builds distributed forwarding tables to fully use all resources. It is assumed that the number of network users. Figure 2-13 shows the physical and operational view of VSS. The following sections provide detailed design and deployment guidance for each model as well as where they fit within the various locations of the medium enterprise design. Using VSS to virtualize the core layer into a single logical system remains transparent to each network device that interconnects to the VSS-enabled core. Figure 2-13 VSS Physical and Operational View Virtual Switch Domain VSL Switch-1 Switch-2 VSS – Single Logical Switch To provide end-to-end network access. operation. Figure 2-14 shows a reference VSS-enabled core network design for the main campus site.

VSS-based core layer design may not be necessary. Medium Enterprise Design Profile Reference Guide 2-15 .html. core layer design option 2 was developed to provide a cost-effective alternative while providing the same functionality as core layer design option 1. Core Layer Design Option 2—Cisco Catalyst 4500-E-Based Campus Core Network Core layer design option 2 is intended for a remote medium-sized campus and is built on the same principles as for the main and remote large site campus locations. Figure 2-15 shows the remote medium campus core design option in more detail. see the Campus 3.com/en/US/docs/solutions/Enterprise/Campus/VSS30dg/campusVSS_DG.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Multi-Tier LAN Design Models for Medium Enterprise Figure 2-14 VSS-Enabled Core Network Design Large Building Access Medium Building Small Building Extra Small Building Distribution Core Data Center Block Service Block Internet Edge Block VSL DMZ WAN Edge QFP PSTN Gateway QFP WAN PSTN Gigapop 229357 Internet NLR Note For more detailed VSS design guidance.0 Virtual Switching System Design Guide at the following URL: http://www. Therefore.cisco. Because this site is smaller in comparison to the main and remote large site campus locations. a fully redundant. and it is assumed that this location contains distributed building premises within the remote medium campus design. The size of this remote site may not be large.

The Cisco Catalyst 4500-E Series modular platform is a one-size platform that helps enable the high-speed core backbone to provide uninterrupted network access within a single chassis. a single Cisco Catalyst 4500-E Series Switch can be deployed in the core role and bundled with 1+1 redundant in-chassis network components. two-chassis design using VSS as described in core layer option 1 provides the greatest redundancy for large-scale locations. especially when network scale factor is not too high. This cost-effective core network design provides protection against various types of hardware and software failure and offers sub-second network recovery. Although a fully redundant. the redundant supervisors and line cards of the Cisco Catalyst 4500-E provide adequate redundancy for smaller locations within a single platform. Figure 2-16 Highly Redundant Single Core Design Using the Cisco Catalyst 4500-E Platform Core Redundant Supervisor Redundant Power Cycle Diversed Fiber Paths Redundant Line Cards Distribution 228482 Medium Enterprise Design Profile Reference Guide 2-16 228481 . Figure 2-16 shows the redundancy of the Cisco Catalyst 4500-E Series in more detail.Chapter 2 Multi-Tier LAN Design Models for Medium Enterprise Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-15 Remote Medium Campus Core Network Design Medium Building Access Small Building Distribution Shared Service Block Data Center Block Service Block WAN Edge PSTN Gateway Core WAN PSTN The cost of implementing and managing redundant systems in each tier may introduce complications in selecting the three-tier model. Instead of a redundant node in the same tier.

Single highly resilient Cisco Catalyst 4500-E switches with a Cisco Sup6L-E supervisor must be deployed in a centralized collapsed core and distribution role that interconnects to wiring closet switches. To provide consistent services and optimal network performance. The cost-effective supervisor version supports key technologies such as robust QoS. and management cost for the medium-sized campus network design. simplification. As discussed in the previous section. the remote small campus has a two-tier LAN design model. and much more at a lower scale. The future expansion from a single core to a dual VSS-based core system becomes easier to deploy. operational. Implementing redundant components increases the core network resiliency during various types of failure conditions using Non-Stop Forwarding/Stateful Switch Over (NSF/SSO) and EtherChannel technology. • • • Core Layer Design Option 3—Cisco Catalyst 4500-E-Based Collapsed Core Campus Network Core layer design option 3 is intended for the remote small campus network that has consistent network services and applications service-level requirements but at reduced network scale. The Layer 3 network ports must be bundled into a single point-to-point logical EtherChannel to simplify the network. Resiliency—Because hardware or software failure conditions may create catastrophic results in the network. the single core system must be equipped with redundant system components such as supervisor. security. and a WAN edge router. However. resiliency. making it an ideal solution for small-scale network designs. the remote medium campus core layer design must be leveraged to build this two-tier campus core. scalability. line card. such as the VSS-enabled campus design. and cost-effectiveness in the small campus network design must not be compromised. Remote small campus locations have consistent design guidance and best practices defined for main. This cost-effective single resilient core system for a medium-size enterprise network meets the following four key goals: • Scalability—The modular Cisco Catalyst 4500-E chassis enables flexibility for core network expansion with high throughput modules and port scalability without compromising network performance. Medium Enterprise Design Profile Reference Guide 2-17 . and remote medium-sized campus cores. Simplicity—The core network can be simplified with redundant network modules and diverse fiber connections between the core and other network devices. and helps retain the original network topology and the management operation. for platform selection. a shared service block. so the role of the core system is merged with the distribution layer. The remote small campus is considered to be confined within a single multi-story building that may span academic departments across different floors. An EtherChannel-based campus network offers similar benefits to an Multi-chassis EtherChannel (MEC). high availability. Cost-effectiveness—A single core system in the core layer helps reduce capital. and power supplies.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Multi-Tier LAN Design Models for Medium Enterprise This core network design builds a network topology that has similar common design principles to the VSS-based campus core in core layer design option 1.based network. remote large site. Figure 2-17 shows the remote small campus core design in more detail.

depending on network scale. the distribution layer design provides consistent network operation and configuration tools to enable various network services. The framework of the distribution layer system in the medium enterprise design is based on best practices that reduce network complexities and accelerate reliability and performance. and cost. The following the core layer design options in different campus locations. Medium Enterprise Design Profile Reference Guide 2-18 228481 .Chapter 2 Multi-Tier LAN Design Models for Medium Enterprise Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-17 Core Layer Option 3 Collapsed Core/Distribution Network Design in Remote Small Campus Location Medium Building Access Small Building Distribution Shared Service Block Data Center Block Service Block WAN Edge PSTN Gateway Core WAN PSTN Campus Distribution Layer Network Design The distribution or aggregation layer is the network demarcation boundary between wiring-closet switches and the campus core network. To build a strong campus network foundation with the three-tier model. expansion flexibility. high availability. Each design model offers consistent network services. application demands. Three simplified distribution layer design options can be deployed in main or remote campus locations. the distribution layer has a vital role in consolidating networks and enforcing network edge policies. as shown in Figure 2-18. and network scalability.

maintenance. such as spanning-tree loop. as shown in Figure 2-19. • 229358 Medium Enterprise Design Profile Reference Guide 2-19 228484 Access Access Access . Figure 2-19 VSS-Enabled Distribution Layer Network Design Conferencing Engineering Rooms Lab Lobby Access Switch-1 Distribution VSL Switch-2 The distribution block and core network operation changes significantly when redundant Cisco Catalyst 6500-E Series switches are deployed in VSS mode in both the distribution and core layers. Clustering redundant distribution switches into a single logical system with VSS introduces the following technical benefits: • • A single logical system reduces operational. A single logical IP gateway develops a unified point-to-point network topology in the distribution block. and is based on Cisco Catalyst 6500-E Series switches using the Cisco VSS. which eliminates traditional protocol limitations and enables the network to operate at full capacity. and ownership cost. and control plane overhead. Implementing the distribution layer in VSS mode eliminates or reduces several deployment barriers. Hot Standby Routing Protocol (HSRP)/Gateway Load Balancing Protocol (GLBP)/Virtual Router Redundancy Protocol (VRRP).Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Multi-Tier LAN Design Models for Medium Enterprise Figure 2-18 Distribution Layer Design Model Options Design Option – 1 Switch-1 Distribution VSL Switch-2 Design Option – 2 Design Option – 3 Distribution Distribution Distribution Layer Design Option 1—Cisco Catalyst 6500-E Based Distribution Network Distribution layer design option 1 is intended for main campus and remote large site campus locations.

The additional link provides greater redundancy in case of link failover. Designing a common core and distribution layer option using VSS provides greater redundancy and is able to handle the amount of traffic typically present in the main and remote large site campus locations. • • • Medium Enterprise Design Profile Reference Guide 2-20 . Core/distribution layer interconnection option 3—Two physical links between each core switch with the corresponding distribution switch. This design creates four equal cost multi-path (ECMP) with multiple control plane adjacency and redundant path information. Core/distribution layer interconnection option 4—Two physical links between each core switch with the corresponding distribution switch. Core/distribution layer interconnection option 5—This provides the most redundancy between the VSS-enabled core and distribution switches as well as the most simplified configuration. load balancing. Figure 2-20 Core/Distribution Layer Interconnection Design Considerations Design Option – 1 Switch-1 Distribution VSS Domain ID : 1 VSL Switch-2 Design Option – 2 Switch-1 VSL Switch-2 Design Option – 3 Switch-1 VSL Switch-2 Design Option – 4 Switch-1 VSL Switch-2 Design Option – 5 Switch-1 VSL Switch-2 Switch-1 Access VSS Domain ID : 2 VSL Switch-2 Switch-1 VSL Switch-2 Switch-1 VSL Switch-2 Switch-1 VSL Switch-2 Switch-1 VSL Switch-2 228486 The various core/distribution layer interconnects offer the following: • • Core/distribution layer interconnection option 1—A single physical link between each core switch with the corresponding distribution switch. Figure 2-20 shows five unique VSS domain interconnect options. predictable network recovery. Deploying VSS mode in both the distribution layer switch and core layer switch provides numerous technology deployment options that are not available when not using VSS. Multiple links provide greater redundancy in case of link failover. Core/distribution layer interconnection option 2—A single physical link between each core switch with the corresponding distribution switch. Cisco recommends deploying this option because it provides higher redundancy and simplicity compared to any other deployment option. There is one link direction between each switch as well as one link connecting to the other distribution switch.Chapter 2 Multi-Tier LAN Design Models for Medium Enterprise Medium Enterprise Design Profile (MEDP)—LAN Design • Cisco VSS introduces unique inter-chassis traffic engineering to develop a fully-distributed forwarding design that helps in increased bandwidth. Also these links are logically grouped to appear like option 1 but with greater redundancy. Each variation builds a unique network topology that has a direct impact on steering traffic and network recovery. but each link is logically grouped to appear as one single link between the core and distribution layers. because it appears as if there is only one logical link between the core and the distribution. and network stability.

Figure 2-21 Two Cisco Catalyst 4500-E-Based Distribution Layer Options Distribution Design 1 – Hybrid Distribution Block Conferencing Engineering Rooms Lab Lobby Access Distribution Design 2 – Multi-Layer Distribution Block Conferencing Engineering Rooms Lab Lobby Distribution 229359 Cisco Catalyst 4500-E – Sup6-E Cisco Catalyst 4500-E – Sup6E-L The hybrid distribution block must be deployed with the next-generation supervisor Sup6-E module. Both distribution layer design options use a cost-effective single and highly resilient Cisco Catalyst 4500-E as an aggregation layer system that offers consistent network operation like a VSS-enabled distribution layer switch. The Sup6L-E supervisor is a cost-effective distribution layer solution that meets all network foundation requirements and can operate at moderate capacity. Implementing redundant Sup6-Es in the distribution layer can interconnect access layer switches and core layer switches using a single point-to-point logical connection. The Cisco Catalyst 4500-E Series provides the same technical benefits of VSS for a smaller network capacity within a single Cisco platform. as shown in Figure 2-22.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Multi-Tier LAN Design Models for Medium Enterprise Distribution Layer Design Option 2—Cisco Catalyst 4500-E-Based Distribution Network Two cost-effective distribution layer models have been designed for the medium-sized and small-sized buildings within each campus location that interconnect to the centralized core layer design option and distributed wiring closet access layer switches. the multilayer distribution block option requires the Cisco Catalyst 4500-E Series Switch with next-generation supervisor Sup6L-E deployed. This cost-effective and resilient distribution design option leverages core layer design option 2 to take advantage of all the operational consistency and architectural benefits. Alternatively. This distribution layer network design provides protection against various types of hardware and software failure. The two Cisco Catalyst 4500-E-based distribution layer options are shown in Figure 2-21. Both models are based on a common physical LAN network infrastructure and can be chosen based on overall network capacity and distribution block design. A single Catalyst 4500-E with multiple redundant system components can be deployed to offer 1+1 in-chassis redundancy. which can handle a medium-sized enterprise distribution block. and can deliver consistent sub-second network recovery. Medium Enterprise Design Profile Reference Guide 2-21 .

Distribution layer design option 2 meets the following goals: • Scalability—The modular Cisco Catalyst 4500-E chassis provides the flexibility for distribution block expansion with high throughput modules and port scalability without compromising network performance. Medium Enterprise Design Profile Reference Guide 2-22 229360 Redundant Line Cards . and is based on the Cisco Catalyst 4500-E Series switches. line card. • • • Distribution Layer Design Option 3—Cisco Catalyst 3750-X StackWise-Based Distribution Network Distribution layer design option 3 is intended for a very small building with a limited number of wiring closet switches in the access layer that connects remote classrooms or and office network with a centralized core. Resiliency—The single distribution system must be equipped with redundant system components. Simplicity—This cost-effective design simplifies the distribution block similarly to a VSS-enabled distribution system. enabling the network to operate at full capacity. the remote medium campus location is smaller and may not need a VSS-based redundant design. Implementing redundant components increases network resiliency during various types of failure conditions using NSF/SSO and EtherChannel technology.Chapter 2 Multi-Tier LAN Design Models for Medium Enterprise Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-22 Highly Redundant Single Distribution Design Conferencing Engineering Rooms Lab Lobby Access Redundant Supervisor Distribution Redundant Power Cycle Distribution layer design option 2 is intended for the remote medium-sized campus locations. network upgrades and expansion become easier to deploy using distribution layer option 2. Fortunately. and ownership cost for the medium-sized campus network design. and power supplies. The single IP gateway design develops a unified point-to-point network topology in the distribution block to eliminate traditional protocol limitations. which helps retain the original network topology and the management operation. Although the remote medium and the main and remote large site campus locations share similar design principles. as shown in Figure 2-23. such as supervisor. operational. Cost-effectiveness—The single distribution system in the core layer helps reduce capital.

The wide variety of possible types of devices that can connect and the various services and dynamic configuration mechanisms that are necessary. multiple Catalyst 3750-X can be stacked into a high-speed backplane stack ring to logically build as a single large distribution system. the need for various levels of mobility. when failover occurs. Cisco StackWise Plus supports up to nine switches into single stack ring for incremental network upgrades. and include IT-managed devices such as Cisco TelePresence and non-IT-managed devices such as employee laptops. as shown in Figure 2-24. This is achieved by stacked group members acting as a single virtual Catalyst 3750-X switch. It is a 1:N form of redundancy where any member can become the master. in which member chassis replicate the control functions with each member providing distributed packet forwarding. while being able to provide the appropriate balance of security and availability expected in more traditional. and so on attach to the wired portion of the campus network. This distribution layer design option recommends using the Cisco Catalyst 3750-X StackWise Plus Series platform for the distribution layer switch. where end devices such as PCs. a number of network users and IT-managed remote endpoints can be limited in this building. Not only does the access layer switch allow users to access the network. and increases effective throughput capacity up to 64 Gbps. The chassis redundancy is achieved via stacking. such as IP phones and wireless access points (APs).Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Multi-Tier LAN Design Models for Medium Enterprise Figure 2-23 Cisco StackWise Plus-enabled Distribution Layer Network Design Utilities Department Access Storage Department S/H Department Distribution While providing consistent network services throughout the campus. The campus network infrastructure resources operate in shared service mode. With Cisco StackWise Plus technology. each designed with unique hardware and software capability to function in a specific role. It is also the place where devices that extend the network out one more level. the access layer switch must provide network protection so that unauthorized users or applications do not enter the network. The logical switch is represented as one switch by having one stack member act as the master switch. Medium Enterprise Design Profile Reference Guide 228489 2-23 . the need for a cost-effective and flexible operations environment. make the access layer one of the most feature-rich parts of the campus network. This distribution layer design option is ideal for the remote small campus location. Based on several endpoint factors such as function and network demands and capabilities. are attached. The fixed-configuration Cisco Catalyst 3750-X Series switch is a multilayer platform that supports Cisco StackWise Plus technology to simplify the network and offers flexibility to expand the network as it grows. Campus Access Layer Network Design The access layer is the first tier or edge of the campus. The challenge for the network architect is determining how to implement a design that meets this wide variety of requirements. Thus. any member of the stack can take over as a master and continue the same services. two access layer design options can be deployed with campus network edge platforms. Enterprise campuses may deploy a wide range of network endpoints. cameras. printers. Cisco TelePresence. fixed-configuration environments. The next-generation Cisco Catalyst switching portfolio includes a wide range of fixed and modular switching platforms.

and a constant network availability switching infrastructure. the Catalyst 3560-X must be deployed with an internal or external redundant power supply solution using the Cisco RPS 2300. high performance. Based on StackWise Plus architecture.Chapter 2 Multi-Tier LAN Design Models for Medium Enterprise Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-24 Access Layer Design Models Access Design Option 1 – Modular/Stackable Access Design Option 2 – Fix Configuration Access Cisco Catalyst 4500-E Sup6E-L Cisco Cisco Catalyst 3750-X Catalyst 2960-S FlexStack StackWise Plus Cisco Catalyst 3560-X Cisco Catalyst 2960 Access Layer Design Option 1—Modular/StackWise Plus/FlexStack Access Layer Network Access layer design option 1 is intended to address the network scalability and availability for the IT-managed critical voice and video communication network edge devices. The Catalyst 2960-S with FlexStack technology is Cisco's latest innovation in access-layer tier. Access Layer Design Option 2—Fixed Configuration Access Layer Network This entry-level access layer design option is widely chosen for enterprise environments. The next-generation fixed configuration Cisco Catalyst 3560-X and Catalyst 2960 Series is a commonly deployed platform for wired network access that can be in a mixed configuration with critical devices such as Cisco IP Phones and non-mission critical endpoints such as library PCs. The FlexStack module must be installed on each Catalyst 2960-S switches that are intended to be deployed in stack-group. printers. For non-stop network operation during power outages. To accelerate user experience and campus physical security protection. The Cisco Catalyst 4500-E with supervisor Sup6E-L can be deployed to protect devices against access layer network failure. these devices require low latency. the FlexStack design is currently supported on Layer-2 Catalyst 2960-S Series switches. Cisco StackWise Plus technology provides flexibility and availability by clustering multiple Cisco Catalyst 3750-X Series Switches into a single high-speed stack ring that simplifies operation and allows incremental access layer network expansion. Cisco FlexStack module is hot-swappable module providing flexibility to deploy FlexStack without impacting business network operation. and so on. The Cisco Catalyst 3750-X Series leverages EtherChannel technology for protection during member link or stack member switch failure. Increasing aggregated Medium Enterprise Design Profile Reference Guide 2-24 229361 . Cisco Catalyst 4500-E Series platforms offer consistent and predictable sub-second network recovery using NSF/SSO technology to minimize the impact of outages on enterprise business and IT operation. The fixed configuration Cisco Catalyst switching portfolio supports a wide range of access layer technologies that allow seamless service integration and enable intelligent network management at the edge. Following to the Catalyst 3750-X StackWise Plus success. The Cisco FlexStack is comprised with hardware module and software capabilities. the Catalyst 2960-S model offers high availability. Implementing a modular. Cisco StackWise Plus and latest Cisco's innovation FlexStack-capable platform provides flexibility to increase network scale in the densely populated campus network edge. increased port-density with unified single control-plane and management to reduce the cost for small enterprise network. The Cisco Catalyst 3750-X Series is the alternate Cisco switching platform in this design option. However the architecture of FlexStack on Catalyst 2960-S series platform differs from StackWise Plus.

this design reduces network congestion and latency to significantly improve application performance. and reliability requirements. The Medium Enterprise Reference network is designed with consistency to build simplified network topology for easier operation. the network must be designed to provide a consistent user experience independent of the geographical location of the application. The Cisco Catalyst 3560-X Series Switches offer limited software feature support that can function only in a traditional Layer 2 network design. intelligent. Depending on network size. To provide a consistent end-to-end enhanced user experience.E Cisco Catalyst 3750-X Stackwise and Catalyst 2960-S FlexStack Cisco Catalyst 3560-X and 2960 Medium Enterprise Design Profile Reference Guide 2-25 . the campus location. the next step for the medium enterprise design is to establish key network foundation services. scalability. and troubleshooting independent of campus location. intelligently provide differentiated services to various class-of-service traffic. Both design options offer consistent network services at the campus edge to provide differentiated. The following network foundation design principles or services must be deployed in each campus location to provide resiliency and availability for all users to obtain and use the applications the medium enterprise offers: • • • • • • Implementing LAN network infrastructure Network addressing hierarchy Network foundation technologies for LAN designs Multicast for applications delivery QoS for application performance optimization High availability to ensure user experience even with a network failure Design guidance for each of these six network foundation services are discussed in the following sections. For a campus network. the Cisco Catalyst 3560-X is an alternate switching solution for the multilayer distribution block design option discussed in the previous section. management. including where they are deployed in each tier of the LAN design model. and capacity. the Medium Enterprise Reference design applies the following common set of Cisco Catalyst platforms in different campus network layers: • • • • Cisco Catalyst 6500-E in VSS mode Cisco Catalyst 4500. the Cisco Catalyst 2960-S supports critical network control services to secure the network edge. The Cisco Catalyst must leverage the 1G dual uplink ports to interconnect the distribution system for increased bandwidth capacity and network availability.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services power capacity allows flexibility to scale with enhanced power-over-Ethernet (PoE+) on a per-port basis. Regardless of the application function and requirements that medium enterprises demand. Deploying Medium Enterprise Network Foundation Services After each tier in the model has been designed. and secured network access to trusted and untrusted endpoints. With its wire-speed 10G uplink forwarding capacity. as well as simplified management. Implementing LAN Network Infrastructure The preceding sections provided various design options for deploying the Cisco Catalyst platform in multi-tier centralized main campus and remote campus locations. The distribution options recommended in the previous section can accommodate both access layer design options.

Migrating VSS from the standalone Catalyst 6500-E system requires multiple pre and post-migration steps to deploy virtual-system that includes building virtual-system itself and migrating the existing standalone network configuration to operate in virtual-system environment.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design This subsection focuses on building the initial LAN network infrastructure setup to bring the network up to the stage to start establishing network protocol communication with the peer devices. all the distributed physical interfaces between two chassis are automatically appended with the switch ID (i. Domain ID Defining the domain identifier (ID) is the initial step in creating a VSS with two physical chassis. enterprise network administrator must adhere to Cisco recommended best practices to take complete advantage of virtualized system and minimize the network operation downtime when migration is required in a production network. it will create single large system. Prior to enabling the Cisco Catalyst 6500-E in VSS mode.shtml This subsection is divided into the following categories that provide guidance for deploying mandatory steps and procedure in implementing VSS and its components in campus distribution and core.. The switch ID value is 1 or 2. The deployment and configuration guidelines remain consistent for each recommended Catalyst platform independent of their network role. When implementing VSS in multi-tier campus network design. Medium Enterprise Design Profile Reference Guide 2-26 . each VSD supports up to two physical switches to build a logical virtual switch. • • • • • VSS Identifiers Virtual Switch Link Unified Control-Plane Multi-Chassis EtherChannel VSL Dual-Active Detection and Recovery VSS Identifiers This is the first premigration step to be implemented on two standalone Cisco Catalyst 6500-E in the same campus tier that are planned to be clustered into a single logical entity. The domain ID value ranges from 1 to 255. Virtual Switch Domain (VSD) is comprised with two physical switches and they must be configured with common domain ID. troubleshooting. Advanced network services implementation and deployment guidelines will be explained in subsequent section.cisco. Refer to the following document for step-by-step migration procedure: http://www. Within VSD. Post VSS migration when two physical chassis is clustered.e. and management. the unique domain ID between different VSS pair will prevent network protocol conflicts and allow simplified network operation. Switch ID In current software version. from the control-plane and management plane perspective. therefore. Deploying Cisco Catalyst 6500-E in VSS Mode All the VSS design principles and foundational technologies defined in this subsection remains consistent when the Cisco Catalyst 6500-E is deployed in VSS mode at campus core or distribution layer. each physical chassis must be uniquely configure switch-ID to successfully deploy VSS. Cisco VSS defines the following two types of physical node identifiers to distinguish remote node within the logical entity as well as to set logical VSS domain identity to uniquely identify beyond the single VSS domain boundary.com/en/US/products/ps9336/products_tech_note09186a0080a7c74c.

The significance of the switch ID remains within VSD and all the interfaces ID associated to the switch ID will be retained independent of control-plane ownership. the lower switch ID is a tie-breaker when both virtual-switch node are deployed with default settings. The default switch priority is 100. Virtual-switch configured with high priority takes the control-plane ownership while the low priority switch boots up in redundant mode. the Cisco VSS technology enables the capability to extend various types of single-chassis internal system components to multi-chassis level.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services <switch-id>/<slot#>/<port#> or TenGigabitEthernet 1/1/1. Each virtual-switch must be deployed with the direct physical links and extend the backplane communication boundary over the special links known as Virtual-Switch Link (VSL). Cisco recommends deploying both virtual-switch nodes with identical hardware and software to take full advantage of distributed forwarding architecture with centralized control and management plane. Figure 2-25 VSS Domain and Switch ID Domain 20 SW1 SW2 Core Domain 10 SW1 SW2 Distribution Access The following simple configuration shows how to configure VSS domain ID and switch ID: Standalone Switch 1: VSS-SW1(config)# switch virtual domain 20 VSS-SW1(config-vs-domain)# switch 1 Standalone Switch 2: VSS-SW2(config)# switch virtual domain 20 VSS-SW2(config-vs-domain)# switch 2 Switch Priority During both virtual-switch bootup processes. Virtual Switch Link To cluster two physical chassis into single a logical entity. Medium Enterprise Design Profile Reference Guide 228955 2-27 . See Figure 2-25. the switch priority is negotiated between both virtual switches to determine the control-plane ownership. The control-plane operation is identical on either of the virtual-switch nodes. Modifying the default switch priority is an optional setting since either of the virtual-switch can provide transparent operation to network and the user.

DTP. OSPF. etc. FWSM) – Remote SPAN Using EtherChannel technology. – Layer 3 Protocols—ICMP. MPLS LDP. the VSS software design provides the flexibility to increase on-demand VSL bandwidth capacity and to protect the network stability during the VSL link failure or malfunction. BGP. it is tailored to carry the following major traffic categories: • Inter-Switch Control Traffic – Inter-Chassis Ethernet Out Band Channel (EOBC) traffic— Serial Communication Protocol (SCP).1x. however. • Network Control Traffic – Layer 2 Protocols —STP BPDU. 802. PagP+.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design VSL can be considered as Layer 1 physical links between two virtual-switch nodes and is designed to not operate any network control protocols. CDP. LLDP. Ten 5/4 VSS-SW2(config-if)# channel-group 2 mode on VSL Design Consideration Implementing VSL EtherChannel is a simple task. and optimized. – Integrated service-module with centralized forwarding architecture (i. BFD. the VSL links cannot establish network protocol adjacencies and are excluded when building the network topology tables. Ten 5/4 VSS-SW1(config-if)# channel-group 1 mode on Standalone Switch 2: VSS-SW2(config)# interface Port-Channel 2 VSS-SW2(config-if)# switch virtual link 2 VSS-SW2(config)# interface range Ten 1/1 . With the customized traffic engineering on VSL. PIM. IGMP. Deploying VSL requires careful planning to keep system virtualization intact during VSS system component failure on either virtual-switch node. availability. EIGRP. Therefore.. • Data Traffic – End-user data application traffic in single-home network designs.e. the VSL design may require proper design with high reliability. LACP. The strategy for reliable VSL design requires the following three categories of planning: • • • VSL Links Diversification VSL Bandwidth Capacity VSL QoS Medium Enterprise Design Profile Reference Guide 2-28 . and ICC. etc. The following sample configuration shows how to configure VSL EtherChannel: Standalone Switch 1: VSS-SW1(config)# interface Port-Channel 1 VSS-SW1(config-if)# switch virtual link 1 VSS-SW1(config)# interface range Ten 1/1 . IPC. UDLD. – Virtual Switch Link Protocol (VSLP) —LMP and RRP control-link packets.

2 x 10GE diversified to same remote peer system. If the same 10G module is shared to connect other network devices. Reduces the single point-of-failure chances as triggering multiple hardware faults on diversified cables.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services VSL Links Diversification Complete VSL link failure may break the system virtualization and create network instability during VSL link failure. Medium Enterprise Design Profile Reference Guide 2-29 .e. Use 10G ports from VSL-capable WS-X6708 or WS-X6716 linecard module to protect against any abnormal failure on supervisor uplink port (i. Designing VSL link redundancy through diverse physical paths on both systems prevents network instability. hence VSL protocols is not designed to operate all Catalyst 6500-E supported linecard module. Therefor. • VSL Bandwidth Capacity From each virtual-switch node. VSL-enabled 10G module boot up rapidly than other installed modules in system. Designing the network with single-homed devices connectivity (no MEC) will force at least half of the downstream traffic to flow over the VSL link. then depending on the network module type and slot bootup order. GBIC failure). it is possible to minimize traffic losses during system initialization process. VSL EtherChannel can bundle up to 8 physical member-links. GBIC and hardware modules are rare conditions. All the traffic traverses over the VSL are encoded with special encapsulation header. VSL EtherChannel can bundle 10G member-links with any of following next-generate hardware modules: • • • Sup720-10G WS-X6708 WS-X6716 (must be deployed in performance mode to enable VSL capability) Figure 2-26 shows an example of how to build VSL EtherChannel with multiple diverse physical fiber paths from supervisor 10G uplink ports and the VSL-capable 10G hardware modules. reduces single point of failure conditions and optimizes bootup process. and user data traffic. Figure 2-26 Recommended VSL Links Design Sup720-10GE 6708/6716 SW1 Ten5/4 Ten1/1 VSL Ten5/4 Ten1/1 Sup720-10GE SW2 228956 6708/6716 Deploying VSL with multiple diversified VSL-link design offers the following benefits: • • • • Leverage 10G port from supervisor and use remaining available ports for other network connectivity. This type of connectivity is highly discouraged. VSL can be bundled up to 80G of bandwidth capacity. The next-generation specialized Catalyst 6500-E 10G based supervisor and linecard modules are fully capable and equipped with modern hardware ASICs to build VSL communication. For example. This software design is required to initialize VSL protocols and communication during bootup process.. the requirement on exact capacity may truly depend on number of the following factors: • • Aggregated network uplink bandwidth capacity on per virtual-switch node basis. Use 4 class built-in QoS model on each VSL member-links to optimize inter-chassis communication traffic. network control.

all 1-Gbps ports are disabled. then depending on the service module forwarding design. WiSM. Independent of global QoS settings. • For an optimal traffic load-sharing between VSL member-links. etc. During network protocol graceful-recovery process the forwarding information remains non-disrupted to continue nonstop packet switching in hardware. etc.).. all ports must follow a single queuing mode. it is recommended to bundle VSL member-link in the power of 2 (i. configuration. the VSL member-links are automatically configured with system generated QoS settings to protect different class of applications. 2. The QoS implementation on VSL EtherChannel operates in restricted mode as it carries critical inter-chassis backplane traffic.e. Adding a link increases the chance of distributing the normal traffic that was hashed on the same link carrying the SPAN traffic. The SPANed traffic is considered as a single flow. Cisco VSS is designed with application intelligence and automatically enables QoS on VSL interface to provide bandwidth and resource allocation for different class-of-service traffic.e. the remaining ports (10 Gbps or 1Gbps) follow the same CoS-mode of queuing for any other non-VSL connectivity because VSL only allows class of service (CoS)-based queuing. SSO-enabled active supervisor is tightly synchronized with standby supervisor with several components (protocol state-machine. Even if only one 10G port used as VSL link. The SSO operation on active supervisor holds control-plane ownership and communicates with remote Layer 2 and Layer 3 neighbors to build distributed forwarding information. If the VSS is carrying the services hardware (such as FWSM. thus the traffic hashes only over a single VSL link that can lead to oversubscription of a particular link. Unified Control-Plane Deploying redundant supervisor with common hardware and software components into single standalone Cisco Catalyst 6500-E platform automatically enables the Stateful Switch Over (SSO) capability to provide in-chassis supervisor redundancy in highly redundant network environment. if an active supervisor fails. Deploying VSS network based on Cisco’s recommendation significantly reduces VSL link utilization. still both 10-Gbps ports are restricted to CoS-based trust model. The only way to improve the probability of traffic distribution is to have an additional VSL link. however. and 8). it may be carried over the VSL.). Medium Enterprise Design Profile Reference Guide 2-30 . 4. which may then be sent over a different link. forwarding information. • Implementing 10G mode may assist in increasing the number of transmit and receive queue depth level. Non-blocking (10G-only mode)—In this mode. the Sup720-10G uplink ports can be configured in one of the following two QoS modes: • Default (Non-10G-only mode)—In this mode. out-of-band network management port).. As a result. VSL QoS The network infrastructure and the application demands of next-generation enterprise networks have tremendous amount of dependencies on the strong and resilient network for constant network availability and on-demand bandwidth allocation to provide services compromising performance. If any 10-Gbps port is used for the VSL link. To retain system stability. a hot-standby supervisor takes over control-plane ownership and initializes protocol graceful-recovery with peer devices. as the entire supervisor module operates in a non-blocking mode. the inter-switch VSLP protocols the QoS settings are fine tuned to protect high priority traffic with different thresholds even during VSL link congestion. Primary benefit in implementing 10G-only mode is to deploy VSL port in non-blocking mode to dedicate complete 10G bandwidth on port. Capacity planning for each of the supported services blades is beyond the scope of this design guide. restricted VSL QoS prevents reassigning different class-of-service traffic in different queues. To deploy VSL in non-blocking mode and increase the queue depth.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design • Remote SPAN from one switch member to other. thus minimizing the need to implement 10G-only mode and using all 1G ports for other network connectivities (i.

Such network condition is known an dual-active. the Cisco VSS supports inter-chassis SSO redundancy by extending the supervisor redundancy capability from single-chassis to multi-chassis level.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Leveraging the same SSO and NSF technology. Entire virtual-switch node gets reset during abnormal active or hot-standby virtual-switch node failure. VSL Dual-Active Detection and Recovery The preceding section described VSL EtherChannel functions as extended backplane link that enables system virtualization by transporting inter-chassis control traffic. the following criteria must match between both virtual-switch node: • • • • • Identical software version Consistent VSD and VSL interface configuration Power mode and VSL-enabled module power settings Global PFC Mode SSO and NSF-enabled During the bootup process. it will force the virtual-switch node to boot in RPR or cold-standby state that cannot synchronize protocol and forwarding information. Figure 2-27 Inter-Chassis SSO Operation in VSS Switch-1 Switch-2 CFC or DFC Line Cards CFC or DFC Line Cards CFC or DFC Line Cards CFC or DFC Line Cards CFC or DFC Line Cards CFC or DFC Line Cards Active Virtual Switch VSL SF RP PFC SF RP PFC Active Supervisor CFC or DFC Line Cards CFC or DFC Line Cards CFC or DFC Line Cards Standby HOT Supervisor CFC or DFC Line Cards CFC or DFC Line Cards CFC or DFC Line Cards Standby Virtual Switch SF: Switch Fabric RP: Route Processor PFC: Policy Forwarding Card To successfully establish SSO communication between two virtual-switch nodes. If any of the criteria fails to match. Any fault triggered on VSL component leads to a catastrophic instability in VSS domain and beyond. where both virtual switches get split with common configuration and takes Medium Enterprise Design Profile Reference Guide 228957 CFC: Centralized Forwarding Card DFC: Distributed Forwarding Card 2-31 . the SSO synchronization checks all the above criteria with remote virtual-system. Cisco VSS uses VSL EtherChannel as a backplane path to establish SSO communication between active and hot-standby supervisor deployed in separate physical chassis. The virtual-switch member that assumes the role of hot-standby keeps constant communication with the active switch. See Figure 2-27. network control plane and user data traffic. The role of the hot-standby switch is to assume the active role as soon as it detects a loss of communication with its peer via all VSL links without the operational state information of the remote active peer node. The state machine of the unified control-plane protocols and distributed forwarding entries gets dynamically synchronized between the two virtual-switch nodes.

VSS allows configuring up to four dual-active fast-hello links between virtual-switch nodes. Cisco extended the capability of PAgP protocol with extra TLVs to signal the dual-active condition and initiate recovery procedure. This condition that can destabilize the campus network communication with two split system advertising duplicate information. – Fast-Hello enables the ability to implement dual active detection in multi-vendor campus or data-center network environments.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design control plane ownership. Most of the Cisco Catalyst switching platforms can be used as trusted PAgP+ partner to deploy indirect detection method. in a VSS network deployment peering with Cisco Catalyst platforms. Figure 2-28 depicts the state of campus topology in a single active-state and during dual-active state. • Indirect Detection Method—This method relies on intermediate trusted L2/L3 MEC Cisco Catalyst remote platform to detect the failure and notify to old-active switch about the dual-active detection. The network protocols detect inconsistency and instability when VSS peering devices detect two split systems claiming the same addressing and identifications. Cisco recommends deploying Fast-Hello and PAgP+ methods for rapid detection. Independent of routing protocols and network topology. Fast-Hello offers faster network recovery. Medium Enterprise Design Profile Reference Guide 2-32 228958 . Cisco recommends deploying Fast-Hello in lieu of BFD for the following reasons: – Fast-Hello can rapidly detects dual-active condition and trigger recovery procedure. To prevent such network instability. to minimize network topology instability. – Fast-Hello supersedes BFD-based detection mechanism. All VSS supported Ethernet media and module can be used to deploy this methods. Figure 2-28 Single Active and Dual-Active Campus Topology Single Active Network State Active SW1 Hot_Standby SW2 Dual-Active Network State Active SW1 Active SW2 The system virtualization gets impacted during the dual-active network state and splits the single virtual system into two identical Layer 2/3 system. For additional redundancy. Dual-Active Fast-Hello (Fast-Hello) and Bidirectional Forwarding Decision (BFD) protocols are specifically designed to detect the dual-active condition and protect network malfunction. and to retain application performance intact. All dual-active detection protocol and methods can be implemented in parallel. Cisco VSS introduces the following two methods to rapidly detect dual-active condition and recover the situation by isolating the old active virtual-switch from network operation before the network gets destabilized: • Direct Detection Method—This method requires extra physical connection between both virtual-switch nodes. – Fast-Hello optimize protocol communication procedure without reserving higher system CPU and link overheads. As depicted in Figure 2-29.

Gig2/5/1 cr23-VSS-Core(config-if-range)# dual-active fast-hello ! Following logs confirms fast-hello adjacency is established on ! both virtual-switch nodes.102 cr23-VSS-Core(config-if-range)#shutdown cr23-VSS-Core(config)#switch virtual domain 20 cr23-VSS-Core(config-vs-domain)#dual-active detection pagp trust channel-group 101 cr23-VSS-Core(config-vs-domain)#dual-active detection pagp trust channel-group 102 cr23-VSS-Core(config)#int range Port-Channel 101 . %VSDA-SW1_SP-5-LINK_UP: Interface Gi1/5/1 is now dual-active detection capable %VSDA-SW2_SPSTBY-5-LINK_UP: Interface Gi2/5/1 is now dual-active detection capable cr23-VSS-Core#show switch virtual dual-active fast-hello Fast-hello dual-active detection enabled: Yes Fast-hello dual-active interfaces: Port Local StatePeer Port Remote State ----------------------------------------------------------------------------Gi1/5/1 Link up Gi2/5/1 Link up • PAgP+ Enabling or disabling dual-active trusted mode on L2/L3 MEC requires MEC to be in administration shutdown state.1 228959 Medium Enterprise Design Profile Reference Guide 2-33 . network administrator must plan for downtime to provision PAgP+-based dual-active configuration settings: cr23-VSS-Core(config)#int range Port-Channel 101 . Prior to implementing trust settings.102 cr23-VSS-Core(config-if-range)#no shutdown cr23-VSS-Core#show switch virtual dual-active pagp PAgP dual-active detection enabled: Yes PAgP dual-active version: 1.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Figure 2-29 Recommended Dual-Active Detection Method Single Active Network State Active SW1 Fast-Hello Link Dual-Active Trusted MEC Hot_Standby SW2 Po101 The following sample configuration illustrates implementing both methods: • Dual-Active Fast-Hello cr23-VSS-Core(config)#interface range Gig1/5/1 .

1 Channel group 102 dual-active detect capability w/nbrs Dual-Active trusted group: Yes Dual-Active Partner Partner Partner Port Detect Capable Name Port Version Te1/1/3 Yes cr24-4507e-MB Te4/2 1. Cisco recommends using the configuration option provided with the VSS in which the MAC address for Layer-2 and Layer-3 interfaces is derived from the reserved pool. Any networking device connected one hop away from the VSS (and any networking device that does not support gratuitous ARP).1 Te2/3/2 Yes cr22-6500-LB Te1/1/4 1.1 Te1/3/2 Yes cr22-6500-LB Te2/1/4 1. However. regardless of the boot order. then the entire VSS domain will use that switch's MAC address pool. which will trigger gratuitous ARP updates to all Layer-2 and Layer-3 interfaces.1 Te2/1/2 Yes cr22-6500-LB Te1/1/2 1. To avoid such a disruption.1 Virtual Routed MAC The MAC address allocation for the interfaces does not change during a switchover event when the hot-standby switch takes over as the active switch. The following configuration illustrates how to configure virtual routed MAC address for Layer 3 interface under switch-virtual configuration mode: cr23-VSS-Core(config)#switch virtual domain 20 cr23-VSS-Core(config-vs-domain)#mac-address use-virtual Deploying Cisco Catalyst 4500-E In a mid-size medium enterprise campus network.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Channel group 101 dual-active detect capability w/nbrs Dual-Active trusted group: Yes Dual-Active Partner Partner Partner Port Detect Capable Name Port Version Te1/1/2 Yescr22-6500-LB Te2/1/2 1. Cisco Catalyst 4500-E Series switches is a multi-slots modular and scalable and high-speed resilient platform. Medium Enterprise Design Profile Reference Guide 2-34 . This takes advantage of the virtual-switch domain identifier to form the MAC address.1 Te1/3/3 Yes cr24-4507e-MB Te3/1 1. core. For Catalyst 4500-E in-chassis supervisor redundancy. Single Catalyst 4500-E Series platform in medium enterprise design is build with multiple redundant hardware components to develop consistent network topology as Catalyst 6500-E VSS based large network design. This means tat the interface will inherit a new MAC address.1 Te2/1/3 Yes cr24-4507e-MB Te4/1 1.1 Te2/3/3 Yes cr24-4507e-MB Te3/2 1. if both chassis are rebooted at the same time and the order of the active switch changes (the old hot-standby switch comes up first and becomes active). it is recommended to deploy single highly redundant Cisco Catalyst 4500-E Series platform in the different campus network tiers-access. This avoids gratuitous ARP updates (MAC address changed for the same IP address) from devices connected to VSS. the network administrators must consider Catalyst 4507R-E or 4510R-E slot chassis to accommodate redundant supervisors and use remaining for LAN network modules. The MAC addresses of the VSS domain remain consistent with the usage of virtual MAC addresses. will experience traffic disruption until the MAC address of the default gateway/interface is refreshed or timed out. distribution.

Chapter 2

Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services

Cisco Catalyst 4500-E Series supports wide-range of supervisor modules designed for high-performance Layer 2 and Layer 3 network. This reference design recommends deploying next-generation Sup6E and Sup6L-E that supports next-generation hardware switching capabilities, scalability, and performance for various types application and services deployed in campus network.

Implementing Redundant Supervisor
Cisco Catalyst 4507R-E supports intra-chassis or single-chassis supervisor redundancy with dual-supervisor support. Implementing single Catalyst 4507R-E in highly resilient mode at various campus layer with multiple redundant hardware components will protect against different types of abnormal failures. This reference design guide recommends deploying redundant Sup6E or Sup6L-E supervisor module to deploy full high-availability feature parity. Mid-size core or distribution layer Cisco Catalyst 4507R-E Series platform currently do not support inter-chassis supervisor and node redundancy with VSS technology. Therefore, implementing intra-chassis supervisor redundancy and initial network infrastructure setup will be simplified for medium and small size campus network. Figure 2-30 illustrates Cisco Catalyst 4500-E-based intra-chassis SSO and NSF capability.
Figure 2-30 Intra-Chassis SSO Operation

Cisco Catalyst 4507R-E/4510R-E

Line Card

Stub Linecards

Line Card Line Card Line Card PP FE CPU FPGA

Sup6E/Sup6L-E

Active Supervisor Standby Supervisor PP FE CPU FPGA

Line Card

PP: Packet Processor FE: Forwarding Engine CPU: Control-Plane Processing FPGA: Hardware Based Forwarding Information

During bootup process, the SSO synchronization checks various criteria to assure both supervisors can provide consistent and transparent network services during failure event. If any of the criteria fails to match, it forces the standby supervisor to boot in RPR or cold-standby state which cannot synchronize protocol and forwarding information from active supervisor. The following sample configuration illustrates how to implement SSO mode on Catalyst 4507R-E and 4510R-E chassis deployed with Sup6E and Sup6L-E redundant supervisors:
cr24-4507e-MB#config t cr24-4507e-MB (config)#redundancy cr24-4507e-MB (config-red)#mode sso cr24-4507e-MB#show redundancy states my state = 13 - ACTIVE peer state = 8 - STANDBY HOT < snippet >

Medium Enterprise Design Profile Reference Guide

228960

2-35

Chapter 2 Deploying Medium Enterprise Network Foundation Services

Medium Enterprise Design Profile (MEDP)—LAN Design

Sup6L-E Enhancement
Starting in IOS Release 12.2(53)SG, Cisco introduced new Catalyst 4500 – Sup6L-E supervisor module that is designed and built on the next-generation supervisor Sup6E architecture. As a cost-effective solution, the Sup6L-E supervisor is built with reduced system resources, but also addresses several types of key business and technical challenges for mid- to small-scale size Layer-2 network design. Initial IP-based IOS Release for Sup6L-E supports SSO capability for multiple types of Layer 2 protocols. To extend its high availability and enterprise-class Layer 3 feature-parity support on Sup6L-E supervisor, it is recommended to deploy IOS Release 12.2(53)SG2 software version with Enterprise license.

Note

This validated design guide provides the Sup6L-E supervisor deployment guidance and validated test results based on the above recommended software version.

Deploying Supervisor Uplinks
Every supported supervisor module in Catalyst 4500-E supports different types of uplink ports for core network connectivity. Each Sup6E and Sup6L-E supervisor module supports up two 10G or can deployed as four different 1G uplinks using Twin-Gigabit converters. To build high speed low-latency campus backbone network, it is recommended to leverage and deploy 10G uplinks to accommodate various types of bandwidth demanding network application operating in the network. Cisco Catalyst 4500-E Series supervisors are designed with unique architecture to provide constant network availability and reliability during supervisor reset. Even during supervisor switchover or administrative reset events, the state-machines of all deployed uplinks remains operation and with centralized forwarding architecture it continue to switch packets without impacting any time-sensitive application like Cisco TelePresence. Such unique architecture protects bandwidth capacity while administrative supervisor switchover is to upgrade IOS software or during abnormal software triggers supervisor reset.

Sup6E Uplink Port Design
Non-Redundant Mode

In non-redundant mode, there is a single supervisor module deployed in Catalyst 4500-E chassis. In non-redundant mode, by default both uplink physical ports can be deployed in 10G or 1G with Twin-Gigabit converters. Each port operates in non-blocking state and can switch traffic at the wire-rate performance.
Redundant Mode

In recommended redundant mode, Catalyst 4507R-E chassis is deployed with dual supervisor. To provide wire-rate switching performance, by default port-group 1 from active and hot-standby supervisor are in active mode and put port-group 2 in the in-active state. The default configuration can be modified by changing Catalyst 4500-E backplane settings to sharing mode. The shared backplane mode enables operation of port-group 2 of both supervisors. Note that sharing the 10G backplane ASIC between two 10G port do not increase switching capacity, it creates 2:1 oversubscription. If the upstream device is deployed with chassis-redundancy (i.e., Catalyst 6500-E VSS), then it is highly recommended to deploy all four uplink ports for the following reasons:
• •

Helps developing full-mesh or V shape physical network topology from each supervisor module. Increases high availability in the network during individual link, supervisor, or other hardware component failure event.

Medium Enterprise Design Profile Reference Guide

2-36

Chapter 2

Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services

Reduces latency and network congestion during rerouting traffic through non-optimal path.

Figure 2-31 summarizes the uplink port support on Sup6E model depends on non-redundant and redundant deployment scenario.
Figure 2-31 Catalyst 4500-E Sup6E Uplink Mode

Non-Redundant Mode Port Group 1 2
WS-X45-Sup6-E SUPERVISOR ENGINE 6-E
X2 10GbE UPLINK TX
1

Redundant Mode Port Group 1 2
“E” SERIES

Redundant Mode (Shared Backplace Mode) Port Group 1 2
“E” SERIES

UPLINKS
X2 10GbE UPLINK RX ACTIVE
SFP 10GbE 3 4 5 6 2

USB CONSOLE
RX

WS-X45-Sup6-E

SUPERVISOR ENGINE 6-E
X2 10GbE UPLINK TX
1

UPLINKS
X2 10GbE UPLINK RX ACTIVE
SFP 10GbE 3 4 5 6 2

WS-X45-Sup6-E

SUPERVISOR ENGINE 6-E
X2 10GbE UPLINK
1

UPLINKS
X2 10GbE UPLINK RX ACTIVE
SFP 10GbE 3 4 5 6 2

“E” SERIES

10GB A SF - 1 X4

TX

10GB ASF - 1 X4

10/100/1000 MGT COMPACT FLASH

USB CONSOLE
RX

USB CONSOLE
RX

10GB A SF - 1 X4

RESET STATUS
ACTIVE SUPERVISOR
1%

UTILIZATION EJECT

COMPACT FLASH

TX

10GB ASF - 1 X4

10/100/1000 MGT RESET STATUS
ACTIVE SUPERVISOR
1%

TX

10GBASF - 1 X4

TX

10GB A SF - 1 X4

10/100/1000 MGT

ACTIVE
SFP 10GbE

RESET STATUS
ACTIVE SUPERVISOR
1%

UTILIZATION EJECT

ACTIVE
SFP 10GbE

UTILIZATION EJECT

COMPACT FLASH

ACTIVE
SFP 10GbE

100%

100%

100%

WS-X45-Sup6-E

SUPERVISOR ENGINE 6-E
X2 10GbE UPLINK TX
1

UPLINKS
X2 10GbE UPLINK RX ACTIVE
SFP 10GbE 3 4 5 6 2

“E” SERIES

WS-X45-Sup6-E

SUPERVISOR ENGINE 6-E
X2 10GbE UPLINK
1

UPLINKS
X2 10GbE UPLINK RX ACTIVE
SFP 10GbE 3 4 5 6 2

“E” SERIES

USB CONSOLE
RX

USB CONSOLE
RX

10GB A SF - 1 X4

TX

10GB ASF - 1 X4

10/100/1000 MGT RESET STATUS
ACTIVE SUPERVISOR
1%

TX

10GBASF - 1 X4

TX

10GB A SF - 1 X4

10/100/1000 MGT

RESET STATUS
ACTIVE SUPERVISOR
1%

UTILIZATION EJECT

COMPACT FLASH

ACTIVE
SFP 10GbE

UTILIZATION EJECT

COMPACT FLASH

ACTIVE
SFP 10GbE

100%

100%

Active Active In-Active Active Active

The following sample configuration provides guideline to modify default backplane settings on Catalyst 4507R-E platform deployed with Sup6E supervisors in redundant mode. The new backplane settings will be effective only after complete chassis gets reset; therefore, it is important to plan the downtime during this implementation:
cr24-4507e-MB#config t cr24-4507e-MB(config)#hw-module uplink mode shared-backplane !A 'redundancy reload shelf' or power-cycle of chassis is required ! to apply the new configuration cr24-4507e-MB#show hw-module uplink Active uplink mode configuration is Shared-backplane

cr24-4507e-MB#show hw-module mod 3 port-group Module Port-group ActiveInactive ---------------------------------------------------------------------3 1 Te3/1-2Gi3/3-6 cr24-4507e-MB#show hw-module mod 4 port-group Module Port-group ActiveInactive ---------------------------------------------------------------------4 1 Te4/1-2Gi4/3-6

Sup6L-E Uplink Port Design The Sup6L-E uplink port function same as Sup6E in non-redundant mode. However, in redundant mode the hardware design of Sup6L-E differs from Sup6E—currently does not support shared backplane mode that allow using all uplink ports actively. The Catalyst 4507R-E deployed with Sup6L-E may use 10G uplink of port group 1 from active and standby supervisor when the upstream device is a single, highly redundant Catalyst 4507R-E chassis. If the upstream device is deployed with chassis-redundancy, (i.e., Cisco VSS), then it is recommended to build full-mesh network design between each supervisor and virtual-switch node. For such design, the network administrator must leverage the existing WS-4606 Series 10G linecard to build full-mesh uplink. Figure 2-32 illustrates the deployment guideline for highly resilient Catalyst 4507R-E-based Sup6L-E uplink.

Medium Enterprise Design Profile Reference Guide

2-37

228961

Chapter 2 Deploying Medium Enterprise Network Foundation Services

Medium Enterprise Design Profile (MEDP)—LAN Design

Figure 2-32

Catalyst 4500-E Sup6L-E Uplink Mode

Non-Redundant Mode Port Group 1 2
WS-X45-Sup6-E SUPERVISOR ENGINE 6-E
X2 10GbE UPLINK TX
1

Redundant Mode Port Group 1 2
“E” SERIES

UPLINKS
X2 10GbE UPLINK RX ACTIVE
SFP 10GbE 3 4 5 6 2

USB CONSOLE
RX

WS-X45-Sup6-E

SUPERVISOR ENGINE 6-E
X2 10GbE UPLINK TX
1

UPLINKS
X2 10GbE UPLINK RX ACTIVE
SFP 10GbE 3 4 5 6 2

“E” SERIES

10GB A SF - 1 X4

TX

10GB ASF - 1 X4

10/100/1000 MGT COMPACT FLASH

USB CONSOLE
RX

10GB A SF - 1 X4

RESET STATUS
ACTIVE SUPERVISOR
1%

UTILIZATION EJECT

COMPACT FLASH

TX

10GB ASF - 1 X4

10/100/1000 MGT

ACTIVE
SFP 10GbE

RESET STATUS
ACTIVE SUPERVISOR
1%

UTILIZATION EJECT

ACTIVE
SFP 10GbE

100%

100%

WS-X45-Sup6-E

SUPERVISOR ENGINE 6-E
X2 10GbE UPLINK TX
1

UPLINKS
X2 10GbE UPLINK RX ACTIVE
SFP 10GbE 3 4 5 6 2

“E” SERIES

USB CONSOLE
RX

10GB A SF - 1 X4

TX

10GB ASF - 1 X4

10/100/1000 MGT

RESET STATUS
ACTIVE SUPERVISOR
1%

UTILIZATION EJECT

COMPACT FLASH

ACTIVE
SFP 10GbE

100%

Active Active In-Active
WS-X4606-X2-E
X2 10GbE 1 10GBASF - 1 X4 RX TX 2 10GB A SF - 1 X4 RX TX 3 10GBA SF - 1 X4 RX X2 10GbE 4 5 6
“E” SERIES

TX

STATUS

SFP GbE

SFP GbE

WS-4606
228962

9

10

11

12

13

14

15

16

Active

Active

Deploying Cisco Catalyst 3750-X StackWise Plus
The next-generation Cisco Catalyst 3750-X switches can be deployed in StackWise mode using special stack cable that develops bidirectional physical ring topology. Up to nine switches can be integrated into a single stack ring that offers robust distributed forwarding architecture and unified single control and management plane. Device level redundancy in StackWise mode is achieved via stacking multiple switches using the Cisco StackWise Plus technology. Single switch from the stack ring is selected in master role that manages centralized control-plane process while keeping all member switches in member role. Cisco StackWise Plus solution is designed based on 1:N redundancy option. Master switch election in stack ring is determined based on internal protocol negotiation. During the active master switch failure, the new master is selected based on reelection process that takes place internally through the stack ring. See Figure 2-33.
Figure 2-33 Cisco StackWise Plus Switching Architecture

Master Catalyst 3750-X Member Switch-1 Stack Ring

Slave Catalyst 3750-X Member Switch-2
229362

Single Virtual Switch

Since Cisco StackWise Plus solution is developed with high redundancy, it offers unique centralized control and management plane with forwarding architecture design. To logically appear as a single virtual switch, the master switch manages complete management-plane and Layer-3 control-plane operations (i.e., IP Routing, CEF, PBR, etc.). Depending on the implemented network protocols, the master switch communicates with rest of the Layer 3 network through stack ring and dynamically develops the best path global routing and updates local hardware with forwarding information. Unlike centralized Layer-3 management function on master switch, the Layer-2 network topology development is completely based on distributed design. Each member switch in the stack ring dynamically discovers MAC entry from the local port and use internal stack ring network to synchronize MAC address table on each member switch in the stack ring. Table 2-2 lists the network protocols that are designed to operate in centralized versus distributed model in Cisco StackWise Plus architecture.

Medium Enterprise Design Profile Reference Guide

2-38

Chapter 2

Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services

Table 2-2

Cisco StackWise Plus Centralized and Distributed Control-Plane

Protocols Layer 2 Protocols MAC Table Spanning-Tree Protocol CDP VLAN Database EtherChannel - LACP Layer 3 Protocols Layer 3 Management Layer 3 Routing

Function Distributed Distributed Centralized Centralized Centralized Centralized Centralized

Using stack ring as a backplane communication path, master switch updates the Layer-3 forwarding information base (FIB) to each member-switch in the stack ring. Synchronizing common FIB in member switch will develop distributed forwarding architecture. Each member switch performs local forwarding physical path lookup to transmit the frame instead of having master switch performing forwarding path lookup, which may cause traffic hair-pinning problem.

SSO Operation in 3750-EX StackWise Plus
Cisco StackWise Plus solution offers network and device resiliency with distributed forwarding, but the control plane is not designed like 1+1 redundant design. This is because Cisco Catalyst 3750-X StackWise switch is not an SSO-capable platform that can synchronize control-plane state-machines to a standby switch in the ring. However, it can be configured in NSF-capable mode to gracefully recover from the network during master switch failure. Therefore, when the master switch failure occurs, all the Layer 3 function that is primarily deployed on the uplink ports may get disrupted until new master election occurs and reforms Layer 3 adjacency. Although the new master switch in the stack ring identification is done in range of 0.7 to 1 second, the amount of time for rebuilding the network and forwarding topology depends on the protocol function and scalability. To prevent Layer 3 disruption in the network caused by master switch failure, the determined master switch with the higher switch priority can be isolated from the uplink Layer 3 EtherChannel bundle path and use physical ports from switches in member role. With the Non-Stop Forwarding (NSF) capabilities in the Cisco StackWise Plus architecture, this network design helps to decrease major network downtime during master switch failure.

Implementing StackWise Mode
As described earlier, Cisco Catalyst 3750-E switch dynamically detects and provision member-switches in the stack ring without any extra configuration. For planned deployment, network administrator can pre-provision the switch in the ring with the following configuration in global configuration mode:
cr36-3750x-xSB(config)#switch 3 provision WS-C3750E-48PD cr36-3750x-xSB#show running-config | include interface GigabitEthernet3/ interface GigabitEthernet3/0/1 interface GigabitEthernet3/0/2

Medium Enterprise Design Profile Reference Guide

2-39

Chapter 2 Deploying Medium Enterprise Network Foundation Services

Medium Enterprise Design Profile (MEDP)—LAN Design

Switch Priority
The centralized control-plane and management plane is managed by the master switch in the stack. By default, the master switch selection within the ring is performed dynamically by negotiating several parameters and capabilities between each switch within the stack. Each StackWise-capable member-switch is by default configured with switch priority 1.
cr36-3750x-xSB#show switch Switch/Stack Mac Address : 0023.eb7b.e580 H/W Current Switch#Role Mac AddressPriorityVersion State -------------------------------------------------------------------------------------------------------* 1 Master 0023.eb7b.e58010 Ready 2 Member 0026.5284.ec80 1 0 Ready

As described in previous section, the Cisco StackWise architecture is not SSO-capable. This means all the centralized Layer-3 functions must be reestablished with the neighbor switch during a master-switch outage. To minimize the control-plane impact and improve network convergence, the Layer 3 uplinks should be diverse, originating from member switches, instead of the master switch. The default switch priority must be increased manually after identifying the master switch and switch number. The new switch priority becomes effective after switch reset.
cr36-3750x-xSB (config)#switch 1 priority 15 Changing the Switch Priority of Switch Number 1 to 15 cr36-3750x-xSB (config)#switch 2 priority 14 Changing the Switch Priority of Switch Number 2 to 14 cr36-3750x-xSB # show switch Switch/Stack Mac Address : 0023.eb7b.e580 H/W Current Switch#Role Mac AddressPriority Version State --------------------------------------------------------------------------------------------------1 Master 0023.eb7b.e580150Ready * 2 Member 0026.5284.ec80140Ready

Stack-MAC Address
To provide a single unified logical network view in the network, the MAC addresses of Layer-3 interfaces on the StackWise (physical, logical, SVIs, port channel) are derived from the Ethernet MAC address pool of the master switch in the stack. All the Layer-3 communication from the StackWise switch to the endpoints (like IP phone, PC, servers, and core network system) is based on the MAC address pool of the master switch.
cr36-3750x-xSB#show switch Switch/Stack Mac Address : 0023.eb7b.e580 H/W Current Switch#Role Mac AddressPriority Version State --------------------------------------------------------------------------------------------------1 Master 0023.eb7b.e580150Ready * 2 Member 0026.5284.ec80140Ready cr36-3750s-xSB #show version . . . Base ethernet MAC Address . . .

: 00:23:EB:7B:E5:80

Medium Enterprise Design Profile Reference Guide

2-40

Chapter 2

Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services

To prevent network instability, the old MAC address assignments on Layer-3 interfaces can be retained even after the master switch fails. The new active master switch can continue to use the MAC addresses assigned by the old master switch, which prevents ARP and routing outages in the network. The default stack-mac timer settings must be changed in Catalyst 3750-X StackWise switch mode using the global configuration CLI mode as shown below:
cr36-3750x-xSB (config)#stack-mac persistent timer 0 cr36-3750x-xSB #show switch Switch/Stack Mac Address : 0026.5284.ec80 Mac persistency wait time: Indefinite H/W Current Switch#Role Mac AddressPriority Version State --------------------------------------------------------------------------------------------------1 Master 0023.eb7b.e580150Ready * 2 Member 0026.5284.ec80140Ready

Deploying Cisco Catalyst 3560-X and 2960-S FlexStack
The Medium Enterprise Reference design recommends deploying fixed configuration Cisco Catalyst 3560-X and 2960 Series platform at the campus network edge. The hardware architecture of access-layer fixed configuration is standalone and non-modular in design. These switches are designed to go above traditional access-layer switching function to provide robust next-generation network services (i.e., edge security, PoE+ EnergyWise, etc.). Cisco Catalyst 3560-X and 2960 Series platform do not support StackWise technology, therefore, these platforms are ready to deploy with a wide-range of network services at the access-layer. All recommended access-layer features and configuration will be explained in following relevant sections. The access-layer Cisco Catalyst 2960-S Series switches can be stacked using Cisco FlexStack technology that allows stacking up to four switches into single stack ring using special properietary cable. Cisco FlexStack leverages several architecture components from Cisco Catalyst 3750-X StackWise Plus. However it offers flexibility to upgrade hardware capability in standalone Cisco Catalyst 2960-S series platform to support FlexStack with hot-swappable FlexStack module. The FlexStack module supports dual on-board StackPort each design to support upto 10G switching capacity. The StackPorts on FlexStack module is not a network ports hence it does not run any Layer 2 network protocols, i.e. STP, to develop virtual-switch environment each participating Cisco Catalyst 2960-S in stack-ring runs FlexStack protocol to keep protocols, ports and forwarding information synchronized within the ring. The port configuration and QoS configuration StackPorts are preset and cannot be modified by user, it is design to minimize the network impact due to misconfiguration. From an operational perspective Cisco Catalyst 2960-S FlexStack technology is identical as Cisco Catalyst 3750-X StackWise Plus. Therefore, all the deployment guidelines and best practices defined in “Deploying Cisco Catalyst 3750-X StackWise Plus” section on page 2-38 must be leverage to deploy Cisco Catalyst 2960-S FlexStack in the campus access-layer.

Designing EtherChannel Network
In this reference design, multiple parallel physical paths are recommended to build highly scalable and resilient medium enterprise network design. Without optimizing the network configuration, by default each interfaces requires network configuration, protocol adjacencies and forwarding information to load-share traffic and provide network redundancy.

Medium Enterprise Design Profile Reference Guide

2-41

this design principle is applicable to all systems across campus network. scalability. Such network design automatically creates multiple parallel paths to provide load-sharing capabilities and path redundancy during network fault events. redundant (dual-supervisor) or virtual systems (Cisco VSS and StackWise Plus.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design The reference architecture of medium enterprise network is design is built upon small. Depending on the network applications.to mid-size enterprise-class network. Figure 2-34 demonstrates recommended deployment physical network design model for various Catalyst platforms. Deploying single physical connection from a standalone single system to separate redundant upstream systems creates a “V” shape physical network design instead non-recommended partial-mesh “square” network design. Each campus network design offers the following set of operation benefits: • • • • Common network topologies and configuration (all campus network design) Simplifies network protocols (eases network operations) Increase network bandwidth capacity with symmetric forwarding paths Delivers deterministic network recovery performance Diversified EtherChannel Physical Design As a general best practice to build resilient network designs. Medium Enterprise Design Profile Reference Guide 2-42 . platform and technology deployment options in different campus locations and building premises. it is highly recommended to interconnect all network systems with full-mesh diverse physical paths. it offers wide-range of campus network designs. Independent of network tier and platform role. and performance requirement. Cisco recommends building full-mesh fiber path between each Layer 2 or Layer 3 operating in standalone.

Figure 2-35 demonstrates the default network design with redundant and complex control-plane operation with under-utilized forwarding plane design. Medium Enterprise Design Profile Reference Guide 228964 2-43 . Without designing the campus network with EtherChannel technology.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Figure 2-34 Designing Diverse Full-mesh Network Topology Redundant Mode Stackwise Master Catalyst 4507R-E Slave Standalone VSS SW1 SW2 VSS SW1 SW2 Deploying diverse physical network design with redundant mode standalone or the virtual-system running single control-plane will require extra network design tuning to gain all EtherChannel benefits. Such network design cannot leverage distributed forwarding architecture and increase operational and troubleshooting complexities. the individual redundant parallel paths will create network operation state depicted in Figure 2-35.

e. it is highly recommended to prevent the condition where it creates hardware or network protocol-driven asymmetric forwarding design (i. single-home connection or STP block port). the STP blocks the non-preferred individual link path from forwarding state. With the single STP root virtual-switch. To build loop-free network topology.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-35 Non-optimized Campus Network Design VLAN 10 VLAN 20 VLAN 10 VLAN 20 Access Per Physical Port Layer 3 IGP Adjacency STP Primary SW1 Root Per Physical Port Layer 3 IGP Adjacency Per Physical Port Layer 2 STP Operation STP Primary SW1 Root Access SW2 Distribution SW2 Distribution VSS SW1 SW2 Core VSS SW1 SW2 Core The design in Figure 2-35 suffers from the following challenges for different network modes: • Layer 3—Multiple routing adjacencies between two Layer-3 systems. As described in “Deploying Cisco Catalyst 4500-E” section on page 2-34. it is a special inter-chassis backplane connection used to build virtual system and the network must be designed to switch traffic across VSL-only as a last-resort. VSL is not regular network port. It also uses more system resources like CPU and memory to store redundant dynamic-routing information with different Layer-3 next-hop addresses connected to same router. point-to-point topology that helps to eliminate all protocol-driven forwarding restrictions and program hardware for distributed forwarding to fully use all network resources. Bundling multiple parallel paths into single logical connection builds single loop-free. It develops Equal Cost Multi Path (ECMP) symmetric forwarding paths between same Layer 3 peers and offers network scale-dependent Cisco CEF-based network recovery. such network topologies cannot fully use all the network resources as well as it creates non-optimal and asymmetric traffic forwarding design. Medium Enterprise Design Profile Reference Guide 2-44 228965 Layer 2 Trunk Port Layer 3 Routed Port STP Block Port Bi-Directional Traffic Port Asymmetric Traffic Port Non-Forwarding Port .. This configuration doubles or quadruples the control-plane load between each of the Layer-3 devices. VSL Link Utilization—In a Cisco VSS-based distribution network. • • Implementing campus wide MEC or EtherChannel across all the network platforms is the solution for all of the above challenges. Layer 2—Multiple parallel Layer-2 paths between STP Root (distribution) and the access switch will build the network loop.

Detect and remove unidirectional links and multidrop connections from the Etherchannel bundle. data center. the distributed forwarding architecture in MEC helps increasing network bandwidth capacity. Both protocols are designed to provide identical benefits. Dynamically react to runtime changes and failures on local and remote Etherchannel systems. Independent of network scalability. Independent of campus location and the network layer—campus. All the key network devices in the medium enterprise network design support EtherChannel technology. Implementing these protocols provides the following additional benefits: • • • • Ensure link aggregation parameters consistency and compatibility between two systems. Multi-Chassis EtherChannel Fundamentals Cisco’s Multi-Chassis EtherChannel (MEC) technology is a breakthrough innovation that lifts up barrier to create logical point-to-point EtherChannel by distributing physical connection to each highly resilient virtual-switch node in the VSS domain. All the key network devices in the Medium Enterprise Reference design support EtherChannel technology. WAN/Internet edge. WAN/Internet edge. Deploying Layer 2 or Layer 3 MEC with VSS introduces the following benefits: • • • • • In addition to all EtherChannel benefits. all the EtherChannel fundamentals and configuration guideline described in this section remain consistent. Implementing EtherChannel In a standalone EtherChannel mode. data center. Simplifies network control-plane. MEC technology which remains transparent operation to remote peer devices. Port-Aggregation Protocols The member-links of EtherChannel must join the port-channel interface using Cisco PAgP+ or industry standard LACP port-aggregation protocols. Ensure compliance with aggregation requirements. Medium Enterprise Design Profile Reference Guide 2-45 . all the EtherChannel fundamentals and configuration guideline described in this section remain consistent. multiple and diversified member-links are physically connected in parallel between two same physical systems.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services EtherChannel Fundamentals In a standalone EtherChannel mode. Independent of campus location and the network layer-campus. Increases network reliability by eliminating single point-of-failure limitation compare to traditional EtherChannel technology. multiple and diversified member-links are physically connected in parallel between two same physical systems. topology. and system resources with single logical bundled interface instead multiple individual parallel physical paths. MEC provides deterministic hardware-based subsecond network recovery.

network administrator must implement static mode port-channel with special attention that assures no configuration in-compatibility between bundling member-link ports.255.254 ! Bundling single MEC diversed physical ports and module on per node basis. standalone Catalyst 4507R-E system: • MEC—VSS-Core cr23-VSS-Core(config)#interface Port-channel 102 cr23-VSS-Core(config-if)# ip address 10. The following sample configuration provides a guidance to implement single point-to-point Layer-3 MEC from diverse physical ports in different module slots that physically resides in two virtual-switch chassis to a single redundant mode. None or Static Mode EtherChannel configuration must be deployed in exceptional cases when remote node do not support either of the port-aggregation protocols. To prevent network instability. Cisco recommends deploying the port-channel settings specified in Table 2-3. Medium Enterprise Design Profile Reference Guide 2-46 229363 Internet Edge QFP .125.14 255. Table 2-3 MEC Port-Aggregation Protocol Recommendation Port-Agg Protocol PAgP+ LACP None 1 Local Node Desirable Active ON Remote Node Desirable Active ON Bundle State Operational Operational Operational 1. depending on each end of EtherChannel device types. therefore.0. The implementation guidelines to deploy EtherChannel and MEC in Layer 2 or Layer 3 mode are simple and consistent.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-36 Network-Wide Port-Aggregation Protocol Deployment Guidelines Catalyst 4507R-E Catalyst 4507R-E Catalyst 3750-X/2960-S StackWise/FlexStack Catalyst 3560-X/2960 Access PAgP+ VSL PAgP+ LACP LACP Distribution Catalyst 4507-E Sup6E PAgP+ PAgP+ Catalyst 4507-E Sup6L-E PAgP+ LACP Catalyst 3750-X StackWise Catalyst 6500-E Core Catalyst 3750-X Service StackWise Block LACP VSL LACP Catalyst 3750-X StackWise PSTN Gateway Cisco 3800 LACP WAN Edge ON ASR 1006 Port-aggregation protocol support varies on various types of Cisco platforms.255.

0.d8f5. Medium Enterprise Design Profile Reference Guide 2-47 . Ten2/3/3 cr23-VSS-Core(config-if-range)#channel-protocol pagp cr23-VSS-Core(config-if-range)#channel-group 102 mode desirable cr23-VSS-Core#show etherchannel 102 summary | inc Te 102 Po102(RU) PAgP Te1/1/3(P) Te1/3/3(P) cr23-VSS-Core#show pagp 102 neighbor | inc Te Te1/1/3 cr24-4507e-MB 0021. cr24-4507e-MB (config)#interface range Ten3/1 . Ten1/3/3 .0014 Te4/2 cr23-VSS-Core 0200. Table 2-4 summarizes the currently supported EtherChannel load-balancing methods. such tuning optimizes the egress path-selection procedure with multiple levels of variable information that are originated by the source host (i.0014 Te1/3/3 Te2/3/3 Te2/1/3 Te1/1/3 26s 15s 25s 11s SC SC SC SC 660001 660001 660001 660001 EtherChannel Load-Sharing The numbers of applications and their function in campus network design becomes highly variable.45c0 Te3/1 Te2/1/3 cr24-4507e-MB 0021. Ten2/1/3 . especially when the network is provided as a common platform for business operation.15 255.255.. Layer 2 to Layer 4).d8f5.2 cr24-4507e-MB (config-if-range)#channel-protocol pagp cr24-4507e-MB (config-if-range)#channel-group 1 mode desirable cr24-4507e-MB #show etherchannel 101 summary | inc Te 1 Po1 (RU) PAgP Te3/1(P) Te3/2(P) Te4/1(P) Te4/2(P) cr24-4507e-MB#show pagp 1 neighbor | inc Te Te3/1 cr23-VSS-Core 0200. campus security and open accessibility to the users.45c0 Te4/1 Te2/3/3 cr24-4507e-MB 0021.d8f5.0014 Te3/2 cr23-VSS-Core 0200.0014 Te4/1 cr23-VSS-Core 0200.45c0 Te3/2 Te2/1/3(P) 27s 28s 11s 11s SC SC SC SC Te2/3/3(P) 10001 10001 10001 10001 • EtherChannel—Catalyst 4507R-E Distribution cr24-4507e-MB (config)#interface Port-channel 1 cr24-4507e-MB (config-if)# ip address 10.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services cr23-VSS-Core(config)#interface range Ten1/1/3 . It becomes important for the network to become more intelligence-aware with deep packet-inspection and load-share the traffic by fully using all network resources.125.e.0000.2 .0000. Fine tuning EtherChannel and MEC add an extra computing intelligence in the network to make protocol-aware egress forwarding decision between multiple local member-links paths. EtherChannel load-balancing method supports varies on Cisco Catalyst platforms. Ten4/1 . For each traffic flow.0000.45c0 Te4/2 Te1/3/3 cr24-4507e-MB 0021.254 ! Bundling single EtherChannel diversed on per physical ports and per supervisor basis.d8f5.0000.255.

When computing the load-sharing hash. 6500 IP XOR L3 and L4 src-dst-mixed-ip-port (recommended) 6500 Implementing EtherChannel Load-Sharing EtherChannel load-sharing is based on a polymorphic algorithm. All Cisco Catalyst 29xx-S. 6500 IP Layer 3 src-ip dst-ip src-dst-ip (recommended) IP Layer 4 src-port dst-port src-dst-port 4500. load sharing is done based on source XOR destination address or port from Layer 2 to 4 header and ports. each node in VSD uses same polymorphic algorithm to load-share egress Layer 2 or Layer 3 traffic across different member-links from local chassis. and 4500-E switching must be tuned with optimal EtherChannel load-sharing capabilities similar to the following sample configuration: cr24-4507e-MB(config)#port-channel load-balance src-dst-ip cr24-4507e-MB#show etherchannel load-balance EtherChannel Load-Balancing Configuration: src-dst-ip Implementing MEC Load-Sharing The next-generation Catalyst 6500-E Sup720-10G supervisor introduces more intelligence and flexibility to load-share traffic with upto 13 different traffic patterns. each virtual-switch node includes local physical ports of MEC instead remote switch ports.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Table 2-4 EtherChannel Load Balancing Support Matrix Packet Type Non-IP Classification Layer Layer 2 Load Balancing Mechanic src-dst-mac src-mac dst-mac src-dst-mac Supported Cisco Catalyst Platform 29xx. It is recommended to implement the following MEC load-sharing configuration in the global configuration mode: cr23-VSS-Core(config)#port-channel load-balance src-dst-mixed-ip-port cr23-VSS-Core#show etherchannel load-balance EtherChannel Load-Balancing Configuration: src-dst-mixed-ip-port vlan included Medium Enterprise Design Profile Reference Guide 2-48 . 3750. 3xxx-X. 35xx. On per-protocol basis. an EtherChannel can intelligently load-share egress traffic using different algorithms. this customized load-sharing is design to prevent traffic reroute over the VSL. 4500. Independent of virtual-switch role. For the higher granularity and optimal utilization of each member-link port.

for more details. MEC Hash Algorithm Like MEC load sharing. cr23-VSS-Core(config)#interface Port-channel 101 cr23-VSS-Core(config-if)#shutdown cr23-VSS-Core(config-if)#no shutdown cr23-VSS-Core#show etherchannel 101 detail | inc Hash Last applied Hash Distribution Algorithm: Adaptive Network Addressing Hierarchy Developing a structured and hierarchical IP address plan is as important as any other design aspect of the medium enterprise network to create an efficient. a network can create addressing conflicts and overlapping problems.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Note MEC load-sharing becomes effective only when each virtual-switch node have more than one physical path in same bundle interface. • Improved routing efficiencies Medium Enterprise Design Profile Reference Guide 2-49 . Therefore. Cisco Catalyst 6500-E system in VSS mode assigns 8 bits to every MEC. Note This section does not explain the fundamentals of TCP/IP addressing. Keep it default if each virtual-switch node has single local member-link port bundled in same L2/L3 MEC (total 2 ports in MEC). see the many Cisco Press publications that cover this topic. Adaptive—Best practice is to modify to adaptive hash method if each virtual-switch node has greater than or equal to two physical ports in the same L2/L3 MEC. the hash algorithm is computed independently by each virtual-switch to perform load share via its local physical ports. it is recommended to modify default MEC hash algorithm from default settings as shown in the following sample configuration: cr23-VSS-Core(config)#port-channel hash-distribution adaptive Modifying MEC hash algorithm to adaptive mode requires the system to internally reprogram hash result on each MEC. The following are key benefits of using hierarchical IP addressing: • Efficient address allocation – Hierarchical addressing provides the advantage of grouping all possible addresses contiguously. When deploying full-mesh V-shape network VSS-enabled campus core network. plan for additional downtime to make new configuration effective. scalable. Traffic-load share is defined based on number of internal bits allocated to each local member-link ports. – In non-contiguous addressing. which may not allow the network administrator to use the complete address block. Like standalone network design. the 8-bit hash is computed and allocated to each port for optimal load-sharing result. Identifying an IP addressing strategy for the network for the entire medium enterprise network design is essential. Depending on number of local member-link ports in an MEC bundle. and stable network design. 8-bit can be represented as 100 percent switching load. VSS supports the following EtherChannel hash algorithms: • • Fixed—Default setting.

– Becomes easier to manage and troubleshoot. to set the trust boundary to distinguish applications. – Improves overall routing protocol performance by flooding less messages and improves network convergence time. This is designed for critical network edge functions to provide intelligent application and device-aware services. routing principles must be applied. and flexibility in subnet allocation and VLAN usage. provide physical infrastructure services to reduce greenhouse emission. This subsection provides design guidance to enable various types of Layer 1 to 3 intelligent services. provide identity-based network access to protected data and resources. Both routing and switching fundamentals need to be applied. Distribution layer—The distribution block uses a combination of Layer 2 and Layer 3 switching to provide for the appropriate balance of policy and access controls. The following applies to the three layers in a LAN design model: • • Core layer—Because this is a Layer 3 network that interconnects several remote locations and shared devices across the network. Designing the Core Layer Network Because the core layer is a Layer 3 network.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design – Building centralized main and remote campus site networks with contiguous IP addresses provides an efficient way to advertise summarized routes to neighbors. and routing design principles and routing protocol selection criteria are discussed in the following subsections. availability. Network Foundational Technologies for LAN Design In addition to a hierarchical IP addressing scheme. it is also essential to determine which areas of the medium enterprise design are Layer 2 or Layer 3 to determine whether routing or switching fundamentals need to be applied. • Improved system performance – Reduces the memory needed to hold large-scale discontiguous and non-summarized route entries. – Route summarization simplifies the routing database and computation during topology change events. and more. choosing a routing protocol is essential at this layer. • The recommended routing or switching scheme of each layer is discussed in the following sections. – Reduce higher CPU power to re-compute large-scale routing databases during topology change events. Medium Enterprise Design Profile Reference Guide 2-50 . – Reduces network bandwidth utilization used by routing protocols. and to optimize and secure network edge ports. – Helps in overall network and system stability. Choosing a routing protocol is essential. Access layer—This layer is the demarcation point between network infrastructure and computing devices.

Cisco recommends deploying a single routing protocol across the medium enterprise network infrastructure. However. management. configuration. For an optimized routing design.and system-efficient and operate with a minimal number of updates and re-computation. and troubleshooting. link type. independent of the number of routes in the network. Scalability—The routing protocol function must be network. offers rapid network convergence. Open Shortest Path First (OSPF). network architects must consider all the following critical design factors when selecting the right routing protocol to be implemented throughout the internal network: • • Network design—Requires a proven protocol that can scale in full-mesh campus network designs and can optimally function in hub-and-spoke WAN network topologies. OSPF is popular link-state protocol for large-scale enterprise and service provider networks. optimal. the routing blueprint must be well understood and designed before implementation. designated router (DR)/backup designated router (BDR) priority. Medium Enterprise Design Profile Reference Guide 2-51 . Network re-convergence also varies based on network design. and above all is simple to operate and manage. Rapid convergence—Link-state versus DUAL re-computation and synchronization. Enhanced Interior Gateway Routing Protocol (EIGRP). This document provides design guidance for using simplified EIGRP in the medium enterprise campus and WAN network infrastructure. Operational—A simplified routing protocol that can provide ease of configuration. such as OSPF router type. The best convergence time can be achieved from a routing protocol if the network is designed to the strengths of the protocol. The OSPF area function depends on the network connectivity model and the role of each OSPF router in the domain. Other technical factors must be considered when implementing OSPF in the network.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Routing Design Principles Although enabling routing functions in the core is a simple task. independent of scale: • • Hierarchical network addressing—Structured IP network addressing in the medium enterprise LAN and/or WAN design is required to make the network scalable. and resilient. Cisco recommends using EIGRP or OSPF for this network design. OSPF can scale higher but the operation. OSPF enforces hierarchical routing domains in two tiers by implementing backbone and non-backbone areas. and management might become too complex for the medium enterprise LAN network infrastructure. Although all the routing protocols that Cisco IOS currently supports can provide a viable solution. because it provides the end-to-end reachability path of the enterprise network. and Intermediate System-to-Intermediate System (IS-IS). and a multitude of other factors that may be more than a specific routing protocol can handle. • Routing Protocol Selection Criteria The criteria for choosing the right protocol vary based on the end-to-end network infrastructure. and so on. Routing protocol—Cisco IOS supports a wide range of Interior Gateway Protocols (IGPs). Hierarchical routing domain—Routing protocols must be designed in a hierarchical model that allows the network to scale and operate with greater stability. the following three routing components must be identified and designed to allow more network growth and provide a stable network. maximum transmission unit (MTU) considerations. • • Cisco IOS supports a wide range of routing protocols. Building a routing boundary and summarizing the network minimizes the topology size and synchronization procedure. such as Routing Information Protocol (RIP) v1/2. configuration. EIGRP is a popular version of an Interior Gateway Protocol (IGP) because it has all the capabilities needed for small to large-scale networks. which improves overall network resource use and re-convergence.

as shown in Figure 2-37. loops.com/en/US/docs/solutions/Enterprise/Campus/routed-ex. see the following URL: http://www. and other problems that may occur because of misconfiguration. A single EIGRP AS reduces operational tasks and prevents route redistribution. Medium Enterprise Design Profile Reference Guide 2-52 . Figure 2-37 illustrates end-to-end single EIGRP Autonomous network design in medium enterprise network. Designing an End-to-End EIGRP Routing Network EIGRP is a balanced hybrid routing protocol that builds neighbor adjacency and flat routing topology on a per autonomous system (AS) basis.html.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Note For detailed information on EIGRP and OSPF.cisco. Cisco recommends considering the following three critical design tasks before implementing EIGRP in the medium enterprise LAN core layer network: • EIGRP autonomous system—The Layer 3 LAN and WAN infrastructure of the medium enterprise design must be deployed in a single EIGRP AS.

0 Medium Enterprise Design Profile Reference Guide 229364 2-53 .Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Figure 2-37 Sample End-to-End EIGRP Routing Design in Medium Enterprise LAN Network Main Site EIGRP AS 100 VSL VSL QFP EIGRP AS 100 WAN VSL VSL EIGRP AS 100 Remote Large Site EIGRP AS 100 Remote Medium Site EIGRP AS 100 Remote Small Site Implementing EIGRP Routing Protocol The following sample configuration provides deployment guideline for implement EIGRP routing protocol on all Layer-3 network devices into a single Autonomous System (AS): cr23-VSS-Core(config)#router eigrp 100 cr23-VSS-Core(config-router)# network 10.0.0.

0.125. Following recommended EIGRP MD5 adjacency authentication configuration must on each non-passive EIGRP interface to establish secure communication with remote neighbors.13 10.125. This recommended best practice must be enabled on all the EIGRP Layer 3 systems in the network: cr23-VSS-Core(config)#router eigrp 100 cr23-VSS-Core(config-router)# passive-interface default cr23-VSS-Core(config-router)# no passive-interface Port-channel101 cr23-VSS-Core(config-router)# no passive-interface Port-channel102 <snippet> – Network security—Each EIGRP neighbor in the LAN/WAN network must be trusted by implementing and validating the Message-Digest algorithm 5 (MD5) authentication method on each EIGRP-enabled system in the network.0/16 [90/3072] via 10. Port-channel108 • EIGRP adjacency protection—This increases network infrastructure efficiency and protection by securing the EIGRP adjacencies with internal systems.0. Figure 2-38 shows an example of the EIGRP topology for the medium enterprise LAN design.0. 08:41:12. Port-channel103 D 10.0.27.0/16 is a summary. stability.128.23.0.0.125.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design cr23-VSS-Core(config-router)# eigrp router-id 10.126.0. 5 masks D 10. and convergence by hiding the fault of an individual network that requires each router in the network to synchronize the routing topology.125. Route summarization helps improve network performance. 08:33:20.254 cr23-VSS-Core(config-router)# no auto-summary cr23-VSS-Core#show ip eigrp neighbors EIGRP-IPv4 neighbors for process 100 H Address Interface 7 0 1 … 10. 08:33:18.0/20 [90/3072] via 10.0. Each aggregating device must summarize a large number of networks into a single summary route.0.13.0 10.15 10.0.0/0 [170/515072] via 10.17 Po101 Po102 Po103 Hold Uptime (sec) 12 3d16h 10 3d16h 11 3d16h SRTT (ms) 1 1 1 RTO Q Seq Cnt Num 200 0 62 200 0 503 200 0 52 cr23-VSS-Core#show ip route eigrp | inc /16|/20|0.EIGRP devices in the network.125.17.125.0. 41 subnets.125.96. Null0 … D*EX 0.125. Medium Enterprise Design Profile Reference Guide 2-54 . This task involves two subset implementation tasks on each EIGRP-enabled network devices: – Increases system efficiency—Blocks EIGRP processing with passive-mode configuration on physical or logical interfaces connected to non. 08:33:16.108 cr23-VSS-Core(config-if-range)# ip authentication mode eigrp 100 md5 cr23-VSS-Core(config-if-range)# ip authentication key-chain eigrp 100 eigrp-key • Optimizing EIGRP topology—EIGRP allows network administrators to summarize multiple individual and contiguous networks into a single summary network before advertising to the neighbor. The best practice helps reduce CPU utilization and secures the network with unprotected EIGRP adjacencies with untrusted devices. such as PCs. This recommended best practice must be enabled on all the EIGRP Layer 3 systems in the network: cr23-VSS-Core(config)#key chain eigrp-key cr23-VSS-Core(config-keychain)# key 1 cr23-VSS-Core(config-keychain-key)#key-string <password> cr23-VSS-Core(config)#interface range Port-Channel 101 . The following sample configuration provide guidelines to enable EIGRP protocol communication on trusted interface and block on all system interfaces.125.0/8 is variably subnetted. 08:33:15.0.125.0.0/20 [90/3072] via 10.0. Port-channel106 D 10. Port-channel101 D 10.200.125.0.

cr22-6500-LB(config)#interface Port-channel100 cr22-6500-LB(config-if)# ip summary-address eigrp 100 10.125.240.0 Medium Enterprise Design Profile Reference Guide 2-55 . EIGRP route summarization must be implemented on upstream logical port-channel interface to announce single prefix from each block.255.96.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Figure 2-38 EIGRP Route Aggregator Design Main Site Access VSL Aggregator Distribution VSL Core Aggregator QFP WAN Edge WAN Aggregator Aggregator VSL Aggregator Aggregator VSL Aggregator 229365 The following configuration must be applied on each EIGRP route aggregator system as depicted in Figure 2-38.0 255.

and rely on the distribution layer aggregation switch to perform intelligent Layer 3 forwarding and to set policies and access control. The access layer switches in the campus network edge interface with various types of endpoints and provide intelligent Layer 1/2 services. and security challenges. the following two network designs are recommended: • • Multilayer Routed access Designing the Multilayer Network A multilayer network is a traditional.96. The access layer switches interconnect to distribution switches with the Layer 2 trunk. EIGRP speakers transmit Hello packets every 5 seconds.125. Cisco recommends retaining default EIGRP Hello and Hold timers on all EIGRP-enabled platforms. Hybrid—A hybrid logical network design segments VLAN workgroups that do not span different access layer switches. and terminates EIGRP adjacency if the neighbor fails to receive it within 15 seconds of hold-down time.96. and may require extra attention to protect the network against misconfiguration and miswiring that can create spanning-tree loops and de-stabilize the network. The hybrid network design enables flat Layer 2 communication without impacting the network. and widely deployed scenario. and allows certain VLANs (for example. performance. simple. regardless of network scale.0/20 is a summary. Segmented—Provides a unique VLAN for different organization divisions and enterprise business function segments to build a per-department logical network. Designing the Campus Distribution Layer Network This section provides design guidelines for deploying various types of Layer 2 and Layer 3 technology in the distribution layer. • • Figure 2-39 shows the three design variations for the multilayer network. Independent of which implemented distribution layer design model is deployed.125.0/20 for Port-channel100 <snippet> cr22-6500-LB#s ip route | inc Null0 D 10. and also helps reduce the number of subnets used. that net management VLAN) to span across the access-distribution block. In this network design. all variations must be deployed in a V-shape physical network design and must be built to provide a loop-free topology: • Flat—Certain applications and user access requires that the broadcast domain design span more than a single wiring closet switch. There are the following three design variations to build a multilayer network. Such flexibility introduces scalability.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design cr22-6500-LB#show ip protocols … Address Summarization: 10. Null0 • EIGRP Timers—By default. Because the distribution layer can be deployed with both Layer 2 and Layer 3 technologies. Medium Enterprise Design Profile Reference Guide 2-56 . 3d16h. The multilayer network design provides the flexibility to build a single large broadcast domain with an extended star topology. the deployment guidelines remain consistent in all designs. All network communication between various enterprise and administrative groups passes through the routing and forwarding policies defined at the distribution layer.

deletion. and renaming of VLANs on a network-wide basis. It is recommended to deploy VTP in transparent mode. The following sample configuration provides guideline to deploy several types of multilayer network components for hybrid multilayer access-distribution block.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Figure 2-39 Multilayer Design Variations Multi-Layer – Flat Network Single Root Bridge V-Shape Network Single Loop-free Etherchannel VSL Multi-Layer –Segmented VLAN VSL Multi-Layer – Hybrid Network VSL Marketing VLAN 10 Sales VLAN 10 Engineering VLAN 10 Marketing VLAN 10 Sales VLAN 20 Engineering VLAN 30 Marketing VLAN 10 Sales VLAN 20 Engineering VLAN 30 229366 Network Mangement VLAN 900 Cisco recommends that the hybrid multilayer access-distribution block design use a loop-free network topology. VTP can be configured in three modes—server. Cisco's VTP simplifies administration in a switched network. and span a few VLANs that require such flexibility. such as the management VLAN. client. and transparent. All the configuration and best practices remains consistent and can deployed independent of Layer 2 platform type and campus location: VTP VLAN Trunking Protocol (VTP) is a Cisco proprietary Layer -messaging protocol that manages the addition. set the VTP domain name and change the mode to the transparent mode as follows: cr22-3750-LB(config)#vtp domain CCVE-LB cr22-3750-LB(config)#vtp mode transparent cr22-3750-LB(config)#vtp version 2 cr22-3750-LB#show vtp status VTP Version capable:1 to 3 VTP version running:2 VTP Domain Name:CCVE-LB VLAN cr22-3750-LB(config)#vlan 101 cr22-3750-LB(config-vlan)#name Untrusted_PC_VLAN cr22-3750-LB(config)#vlan 102 cr22-3750-LB(config-vlan)#name Lobby_IP_Phone_VLAN cr22-3750-LB(config)#vlan 900 cr22-3750-LB(config-vlan)#name Mgmt_VLAN cr22-3750-LB#show vlan | inc 101|102|900 101 Untrusted_PC_VLANactive Gi1/0/1 Medium Enterprise Design Profile Reference Guide 2-57 .

The default native VLAN must be properly configured to avoid several security risks—Attack. Gig1/0/49 and Gig1/0/50): Access-Layer cr22-3750-LB(config)#vlan 801 cr22-3750-LB(config-vlan)#name Hopping_VLAN cr22-3750-LB(config)#interface Port-channel1 cr22-3750-LB(config-if)#description Connected to cr22-6500-LB cr22-3750-LB(config-if)#switchport cr22-3750-LB(config-if)#switchport trunk encapsulation dot1q cr22-3750-LB(config-if)#switchport trunk native vlan 801 cr22-3750-LB(config-if)#switchport trunk allowed vlan 101-110. filter VLAN list and configure the native-VLAN to prevent attacks and optimize port channel interface. to improve the rapid link bring-up performance.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design 102 900 Lobby_IP_Phone_VLANactive Mgmt_VLANactive Gi1/0/2 Implementing Layer 2 Trunk In a typical campus network design..e. When the following configurations are applied on port-channel interface (i.900 cr22-3750-LB(config-if)#switchport mode trunk cr22-3750-LB#show interface port-channel 1 trunk Port Po1 Port Po1 Mode on Encapsulation 802. The following is the configuration example to implement Layer-2 trunk. Best practice to mitigate this security risk is to implement a unused and unique VLAN ID as a native VLAN on the Layer-2 trunk between the access and distribution switch. they are automatically inherited on each bundled member-link (i. Enabling the Layer-2 trunk on a port-channel automatically enables communication for all of the active VLANs between the access and distribution. Then change the default native VLAN setting in both the switches.. Hence it is important to limit traffic on Layer-2 trunk ports by statically allowing the active VLANS to ensure efficient and secure network performance. The native VLAN remains active on all access switches Layer 2 ports. Port-Channel 1). Any malicious traffic originated in VLAN 1 will span across the access-layer network.1Q trunk encapsulation in static mode instead of negotiating mode. For example.900 Medium Enterprise Design Profile Reference Guide 2-58 . and cannot be disabled or removed from VLAN database. the native VLAN on each Layer 2 trunk port is VLAN 1. worm and virus or data theft. With a VLAN-hopping attack it is possible to attack a system which does not reside in VLAN 1. Allowing only assigned VLANs on a trunk port automatically filters rest. By default on Cisco Catalyst switches. for example a Data VLAN and a Voice VLAN. VLAN 801 must not be used anywhere for any purpose in the same access-distribution block. This may create an adverse impact in the large scale network.1q Status trunking Native vlan 801 Vlans allowed on trunk 101-110. the access-layer switch may receive traffic flood destined to another access switch. The Layer-2 network connection between the distribution and access device is a trunk interface. a single access switch will be deployed with more than singleVLAN. It is recommended to implement 802. VLAN tag is added to maintain logical separation between VLANS across the trunk. configure VLAN 801 in the access-switch and in the distribution switch.e. Thereafter.

Cisco has developed several STP extensions to protect against network malfunctions.1s-MST—Provides up to 16 instances of RSTP (802. In this point-to-point network design. All Cisco Catalyst LAN switching platforms support the complete STP toolkit suite that must be enabled globally on individual logical and physical ports of the distribution and access layer switches.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Port Po1 Port Po1 Vlans allowed and active in management domain 101-110. therefore. Over the years. Although STP behavior is deterministic. Spanning-Tree Protocol (STP) dynamically develops a loop-free multilayer network topology that can compute the best forwarding path and provide redundancy.1w) per VLAN.1w-Rapid PVST+—Provides an instance of RSTP (802. IEEE 802. The medium enterprise LAN network design uses Etherchannel or MEC (point-to-point logical Layer-2 bundle) connection between access-layer and distribution switch which inherently simplifies the STP topology and operation.1D STP for each active VLAN in the network.1w) and combines many VLANs with the same physical and logical topology into a common RSTP instance. It is easy to implement. it will be assigned automatically in forwarding state. proven in large scale networks that support up to 3000 logical ports and greatly improves network restoration time. Figure 2-40 shows an example of enabling various STP extensions on distribution and access layer switches in all campus sites. IEEE 802. the STP protocols have evolved into the following versions: • • Per-VLAN Spanning Tree Plus (PVST+)—Provides a separate 802.900 Spanning-Tree in Multilayer Network Spanning Tree (STP) is a Layer-2 protocol that prevents logical loops in switched networks with redundant links. the STP operation is done on a logical port. Figure 2-40 Protecting Multilayer Network with Cisco STP Toolkit Medium Enterprise Design Profile Reference Guide 2-59 . and to increase stability and availability.900 Vlans in spanning tree forwarding state and not pruned 101-110. it is not optimally designed to mitigate network instability caused by hardware miswiring or software misconfiguration. • The following is the example configuration for enabling STP in multilayer network: Distribution-Layer cr22-6500-LB(config)#spanning-tree mode rapid-pvst cr22-6500-LB #show spanning-tree summary | inc mode !Switch is in rapid-pvst mode Access-Layer cr22-3750-LB(config)#spanning-tree mode rapid-pvst Hardening Spanning-Tree Toolkit Ensuring a loop-free topology is critical in a multilayer network design.

Medium Enterprise Design Profile Reference Guide 2-60 228967 BPDU Guard Root Guard PortFast . see the following URL: http://www.cisco.html. Implementing Layer 3 functions in the access layer replaces Layer 2 trunk configuration to a single point-to-point Layer 3 interface with a collapsed core system in the aggregation layer. optimize distribution performances.com/en/US/tech/tk389/tk621/tsd_technology_support_troubleshooting_technotes_list . Designing the Routed Access Network Routing functions in the access layer network simplify configuration. the access-distribution block can be used. and provide end-to-end troubleshooting tools. Implementing Layer 3 functions in the access switch does not require any physical or logical link reconfiguration. as well as where the Layer 2 and Layer 3 boundaries exist in each network design. Pushing Layer 3 functions one tier down on Layer 3 access switches changes the traditional multilayer network topology and forwarding development path. Figure 2-41 shows the differences between the multilayer and routed access network designs. and is as resilient as in the multilayer network design.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design STP Root Bridge VSL Root Guard UDLD UDLD Edge Port Layer 2 Trunk Port Note For additional STP information.

EIGRP adjacency protection—EIGRP processing must be enabled on uplink Layer 3 EtherChannels. the STP toolkit must be hardened at the access layer. thus minimizing the number of denial-of-service (DoS)/ distributed denial-of-service (DDoS) attacks.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Figure 2-41 Layer 2 and Layer 3 Boundaries for Multilayer and Routed Access Network Design VSL VSL Core Core Routing VSL Distribution Layer 3 Routing VSL Distribution Layer 3 STP Layer 2 Access Marketing VLAN 10 Sales VLAN 20 Engineering VLAN 30 Routing Access Layer 2 Marketing VLAN 10 Sales VLAN 20 Engineering VLAN 30 229367 Multi-Layer Network Routed-Access Network Routed-access network design enables Layer 3 access switches to perform Layer 2 demarcation point and provide Inter-VLAN routing and gateway function to the endpoints. multi-function and policy-based routing and switching decision like distribution-layer switches. the benefits in implementing the routed access design in medium enterprises are as follows: • • • • Eliminates the need for implementing STP and the STP toolkit on the distribution system. and must block remaining Layer 3 ports by default in passive mode. Although Cisco VSS and a single redundant distribution design are simplified with a single point-to-point EtherChannel. As a best practice. Enabling Layer 3 functions in the access-distribution block must follow the same core network designs as mentioned in previous sections to provide network security as well as optimize the network topology and system resource utilization: • • EIGRP autonomous system—Layer 3 access switches must be deployed in the same EIGRP AS as the distribution and core layer systems. Improves overall collapsed core and distribution resource utilization. The Layer 3 access switches makes more intelligent. Bandwidth efficiency—Improves Layer 3 uplink network bandwidth efficiency by suppressing Layer 2 broadcasts at the edge port. Shrinks the Layer 2 fault domain. Access switches must establish secured EIGRP adjacency using the MD5 hash algorithm with the aggregation system. Medium Enterprise Design Profile Reference Guide 2-61 .

Because the distribution switch provides a gateway function to rest of the network. Prefixes: 6 Topology-ids from peer . The Layer 3 access switches must be deployed in EIGRP stub mode for a concise network view.0 Stub Peer Advertising ( CONNECTED ) Routes Suppressing queries Medium Enterprise Design Profile Reference Guide 2-62 . In the three. no configuration changes are required in the distribution system: • Access layer cr22-4507-LB(config)#router eigrp 100 cr22-4507-LB(config-router)# eigrp stub connected cr22-4507-LB#show eigrp protocols detailed Address Family Protocol EIGRP-IPv4:(100) EIGRP metric weight K1=1. the data center. Implementing Routed Access in Access-Distribution Block Cisco IOS configuration to implement Layer 3 routing function on the Catalyst access-layer switch remains consistent. Retrans: 0.0. K2=0. the Layer 3 access switch must always have single physical or logical forwarding to a distribution switch. such as distribution blocks. EIGRP creates and maintains a single flat routing topology network between EIGRP peers. The following is an example configuration to enable EIGRP stub routing in the Layer-3 access-switch. connected Topologies : 0(base) • Distribution layer cr22-6500-LB#show ip eigrp neighbors detail port-channel 101 EIGRP-IPv4 neighbors for process 100 H Address Interface Hold UptimeSRTT RTO Q Seq (sec) (ms) Cnt Num 2 10. Retries: 0. K5=0 EIGRP maximum hopcount 100 EIGRP maximum metric variance 1 EIGRP NSF-aware route hold timer is 240 EIGRP NSF enabled NSF signal timer is 20s NSF converge timer is 120s Time since last restart is 2w2d EIGRP stub. the routing design on the Layer 3 access switch can be optimized with the following two techniques to improve performance and network reconvergence in the access-distribution block. Building a single routing domain in a large-scale campus core design allows for complete network visibility and reachability that may interconnect multiple campus components.1 Po101 13 3d18h 4 2000 98 Version 4.0/3. and so on. as shown in Figure 2-42: • Deploying the Layer 3 access switch in EIGRP stub mode EIGRP stub router in Layer-3 access-switch can announce routes to a distribution-layer router with great flexibility. The Layer 3 access switch dynamically develops the forwarding topology pointing to a single distribution switch as a single Layer 3 next hop. services blocks.125.0.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design • EIGRP network boundary—All EIGRP neighbors must be in a single AS to build a common network topology. K3=1.or two-tier deployment models. Refer to EIGRP routing configuration and best practices defined in Designing End-to-End EIGRP Network section to routing function in access-layer switches. K4=0. the WAN edge.

124.0.0.0.123.126.0.0/16 cr22-6500-LB(config)#router eigrp 100 cr22-6500-LB(config-router)#distribute-list route-map EIGRP_STUB_ROUTES out Port-channel101 cr22-6500-LB(config-router)#distribute-list route-map EIGRP_STUB_ROUTES out Port-channel102 cr22-6500-LB(config-router)#distribute-list route-map EIGRP_STUB_ROUTES out Port-channel103 cr22-6500-LB#show ip protocols Outgoing update filter list for all interfaces is not set Port-channel101 filtered by Port-channel102 filtered by Medium Enterprise Design Profile Reference Guide 2-63 .0.0/16 15 permit 10.0/16 25 permit 10.0.0/16 20 permit 10.0/16 30 permit 10.125.0/0 10 permit 10.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services • Summarizing the network view with a default route to the Layer 3 access switch for intelligent routing functions Figure 2-42 Designing and Optimizing EIGRP Network Boundary for the Access Layer EIGRP Stub Network VSL Summarized EIGRP Route Advertisment VSL EIGRP AS-100 VSL Summarized Network Non-Summarized Connected Network EIGRP Stub Mode Marketing VLAN 10 Sales VLAN 20 Engineering VLAN 30 EIGRP AS-100 Marketing VLAN 10 Sales VLAN 20 Engineering VLAN 30 229368 VSL Aggregator Summarized Network + Default Network Routed-Access Network Routed-Access Network The following sample configuration demonstrate the procedure to implement route filtering at the distribution layer that allows summarized and default-route advertisement to build concise network topology at the access layer: • Distribution layer cr22-6500-LB(config)# cr22-6500-LB(config)# cr22-6500-LB(config)# cr22-6500-LB(config)# cr22-6500-LB(config)# cr22-6500-LB(config)# ip ip ip ip ip ip prefix-list prefix-list prefix-list prefix-list prefix-list prefix-list EIGRP_STUB_ROUTES EIGRP_STUB_ROUTES EIGRP_STUB_ROUTES EIGRP_STUB_ROUTES EIGRP_STUB_ROUTES EIGRP_STUB_ROUTES seq seq seq seq seq seq 5 permit 0.0.122.

0. 12 subnets. Multicast packet replication in the network is done by Cisco routers and switches enabled with Protocol Independent Multicast (PIM) as well as other multicast routing protocols.125. the network may need to be made more efficient by allowing certain applications where the same content or application must be replicated to multiple users. it becomes easier in routing and switching decisions to perform destination address lookup.0. and to switch traffic.0. 4 masks D 10.0 – 238.0. Port-channel1 D *EX 0.0. Port-channel1 Multicast for Application Delivery Because unicast communication is based on the one-to-one forwarding model. 07:49:13. Multicast addresses are assigned in various pools for well-known multicast-based network protocols or inter-domain multicast communications.255 232. Global scope—Group communication between an organization and the Internet. Port-channel1 D 10.0.125.0. Similar to the unicast methods. Port-channel1 D 10.0.255. 07:49:11.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Port-channel103 filtered by • Access layer cr22-4507-LB#show ip route eigrp 10. multicast requires the following design guidelines: • • • Choosing a multicast addressing design Choosing a multicast routing protocol Providing multicast security regardless of the location within the medium enterprise design Multicast Addressing Design The Internet Assigned Numbers Authority (IANA) controls the assignment of IP multicast addresses.122.255. while the destination address of IP multicast traffic is in the multicast group range.0. Table 2-5 Multicast Address Range Assignments Application Reserved—Link local network protocols.0/0 [170/515584] via 10.0.125.125.0.125.255.0/8 Medium Enterprise Design Profile Reference Guide 2-64 . determine the egress path by scanning forwarding tables.255.0/24 224.0.0.0.0. as listed in Table 2-5.126.123.0/16 [90/3840] via 10. 07:49:11.255. Source Specific Multicast (SSM)—PIM extension for one-to-many unidirectional multicast communication. A range of class D address space is assigned to be used for IP multicast applications. 07:49:11. Port-channel1 D 10.0 through 239.0/16 [90/3840] via 10.0. Layer 3 addresses in multicast communications operate differently.0/16 [90/768] via 10.1. Port-channel1 D 10.0. 07:49:13.0.0.0. All multicast group addresses fall in the range from 224.0/16 [90/64000] via 10.124.0.0.0.0/16 [90/3584] via 10.0/8 is variably subnetted. 01:42:22.0.125.0.0. IP multicast delivers source traffic to multiple receivers using the least amount of network resources as possible without placing an additional burden on the source or the receivers. the source IP address is always in the unicast address range.0. Address Range 224. In the unicast routing and switching technologies discussed in the previous section.125.0.

All the recommended platforms in this design support PIM-SM mode on physical or logical (switched virtual interface [SVI] and EtherChannel) interfaces. education.0. medium enterprise network architects must select a range of multicast sources from the limited scope pool (239/8). and it adjusts its behavior to match the characteristics of each receiver group. Commonly deployed in enterprise. as might be the case for most multicasts over the WAN.0. each intermediate system between the multicast receiver and source must support the multicast feature. PIM-SM mode is ideal for a network without dense receivers and multicast transport over WAN environments. shared trees use a single common root placed at a selected point in the network.0/8 During the multicast network design phase. The hosts belonging to the group are widely dispersed. with its root at the source and branches forming a tree through the network to the receivers. This shared root is called a rendezvous point (RP).Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Table 2-5 Multicast Address Range Assignments (continued) GLOP—Inter-domain multicast group assignment with reserved global AS. almost all hosts on the network belong to each multicast group). Sparse mode (SM)—Assumes that relatively few routers in the network are involved in each multicast. A primary goal in distribution trees construction is to ensure that no more than one copy of each packet is forwarded on each branch of the tree. Therefore. The medium enterprise LAN design must be able to build packet distribution trees that specify a unique forwarding path between the subnet of the source and each subnet containing members of the multicast group. • The PIM protocol is divided into the following two modes to support both types of multicast distribution trees: • Dense mode (DM)—Assumes that almost all routers in the network need to distribute multicast traffic for each multicast group (for example. • Selecting the PIM mode depends on the multicast applications that use various mechanisms to build multicast distribution trees.0. PIM-SM begins with an empty distribution tree and adds branches only as the result of explicit Internet Group Management Protocol (IGMP) requests to join the distribution. 233. and other organizations. To enable communication. Because this tree uses the shortest path through the network. Cisco recommends deploying PIM-SM because it is efficient and intelligent in building multicast distribution tree.0. Shared trees—Unlike source trees that have their root at the source. Multicast develops the forwarding table differently than the unicast routing and switching model. it is also referred to as a shortest path tree (SPT). multicast requires specific multicast routing protocols and dynamic group membership. PIM in DM mode builds distribution trees by initially flooding the entire network and then pruning back the small number of paths without receivers. Based on the multicast scale factor and centralized source deployment design for one-to-many multicast communication in medium enterprise LAN infrastructures. Medium Enterprise Design Profile Reference Guide 2-65 . The two basic types of multicast distribution trees are as follows: • Source trees—The simplest form of a multicast distribution tree is a source tree. Limited scope—Administratively scoped address that remains constrained within a local organization or AS.0/8 239. Multicast Routing Design To enable end-to-end dynamic multicast operation in the network.

Figure 2-43 Distributed PIM-SM RP Placement Main Site PIM-SM RP VSL Core Data Center Multicast Source VSL PIM-SM RP Data Center Multicast Source Remote Large Site Data Center PIM-SM RP Data Center PIM-SM RP Multicast Source Remote Medium Site Multicast Source 229369 Remote Small Site PIM-SM RP Mode PIM-SM supports RP deployment in the following three modes in the network: • • Static—In this mode. RP must be statically identified and configured on each PIM router in the network. To prevent network reconfiguration during a change. as part of the PIM version 1 specification. RP load balancing and redundancy can be achieved using anycast RP. and on the collapsed core/distribution system in the two-tier campus design model. Cisco recommends deploying PIM RP on each site for wired or wireless multicast receivers and sources to join and register at the closest RP. In such a distributed multicast network design. Auto-RP implementation is beneficial when there are multiple RPs and groups that often change in the network. Medium Enterprise Design Profile Reference Guide 2-66 . PIM-SM RP Placement It is assumed that each medium enterprise site has a wide range of local multicast sources in the data center for distributed medium enterprise IT-managed media and employee research and development applications. See Figure 2-43. The Medium Enterprise Reference design recommends PIM-SM RP placement on a VSS-enabled and single resilient core system in the three-tier campus design.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Designing PIM Rendezvous Point The following sections discuss best practices in designing and deploying the PIM-SM Rendezvous Point. Auto-RP—This mode is a dynamic method for discovering and announcing the RP in the network. the RP mapping agent router must be designated in the network to receive RP group announcements and to arbitrate conflicts.

Medium Enterprise Design Profile Reference Guide 2-67 . In a small. and an additional simple access control list (ACL) can be applied to deploy RP without compromising multicast network security. Cisco recommends designing the medium enterprise LAN multicast network using the static PIM-SM mode configuration.to mid-sized multicast network. and is part of the PIM version 2 specification. See Figure 2-44. Static RP implementation offers RP redundancy and load sharing. static RP configuration is recommended over the other modes.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services • BootStrap Router (BSR)—This mode performs the same tasks as Auto-RP but in a different way. Auto-RP and BSR cannot co-exist or interoperate in the same network.

To provide transparent PIM-SM redundancy. static PIM-SM RP configuration must be identical across the campus LAN network and on each PIM-SM RP routers.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-44 PIM-SM Network Design in Medium Enterprise Network Main Site PIM-SM Access VSL PIM-SM Distribution PIM-SM RP VSL Core PIM-SM PIM-SM QFP WAN Edge WAN PIM-SM PIM-SM RP VSL PIM-SM RP PIM-SM PIM-SM RP VSL PIM-SM PIM-SM The following is an example configuration to deploy PIM-SM RP on all PIM-SM running systems. • Core layer cr23-VSS-Core(config)#ip multicast-routing cr23-VSS-Core(config)#interface Loopback100 Medium Enterprise Design Profile Reference Guide 2-68 229370 Remote Large Site Remote Medium Site Remote Small Site .

100.100.21 Outgoing interface list: Port-channel101.100.100.100.8). Forward/Sparse.0.40.100.0.100.2.192.100.51. flags: S Incoming interface: Null. next RP-reachable in 00:00:34 Group: 239. expires never cr22-6500-LB#show ip pim interface Address Interface 1 30 Ver/ Mode 1 Nbr Count QueryDR IntvlPrior 10.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services cr23-VSS-Core(config-if)#description Anycast RP Loopback cr23-VSS-Core(config-if)#ip address 10.0. flags: A Incoming interface: Port-channel105. 12 kbps(life avg) • Distribution layer cr23-6500-LB(config)#ip multicast-routing cr23-6500-LB(config)#ip pim rp-address 10. 3d22h/00:03:20.100.1.192.0. RP: 10.8).3.125.1.255.192.0 Outgoing interface list: Port-channel105.100. uptime 00:10:42.100.0.100.13 10.1.3. 00:16:54/00:03:20 cr23-VSS-Core#show ip mroute active Active IP Multicast Sources .100. RP 10.100.153 (?) Rate: 2500 pps/4240 kbps(1sec). next RP-reachable in 00:00:34 cr23-VSS-Core#show ip pim interface Address 10. uptime 00:10:41.125.125.100. (?) Source: 10.0.100. 239. RPF nbr 10. 00:16:56/00:03:20 (10. expires never Group: 239.100.100.13Port-channel100v2/S Medium Enterprise Design Profile Reference Guide 2-69 .13 DR 10.100 255.51.0. next RP-reachable in 00:00:34 Group: 239.51.31.125.255 cr23-VSS-Core(config)#ip pim rp-address 10.125.192.192.147.0.100. Forward/Sparse.100.0.255. expires never Group: 239.15 … Interface Port-channel101 Port-channel102 Ver/ Nbr Query DR Mode Count Intvl Prior v2/S 1 30 1 v2/S 1 30 1 DR cr23-VSS-Core#show ip mroute sparse (*.100. expires never Group: 224. RP: 10.100 cr23-6500-LB(config)#interface range Port-channel 100 – 103 cr22-6500-LB(config-if-range)#ip pim sparse-mode cr23-6500-LB(config)#interface range Vlan 101 – 120 cr22-6500-LB(config-if-range)#ip pim sparse-mode cr22-6500-LB#show ip pim rp Group: 239. Forward/Sparse. 00:16:54/00:02:54 Port-channel101.1. uptime 00:10:42.100.192. RP: 10. 239.2.100 cr23-VSS-Core#show ip pim rp Group: 239. RP: 10.0.125.51.100.100. RP: 10.14 10.100. 00:16:54/00:02:35.192.51.51.100.51. RP: 10. RP: 10.125.51.100.100. uptime 3d22h.12 10. RPF nbr 0.31. 4239 kbps(last 30 secs).100.192.125.125.sending >= 4 kbps Group: 239.192.51.100.

Gig0/2/0 . 239.100.100.5 10.192.65 Interface Mode Count Port-channel1 Vlan101 Vlan110 Ver/ Prior v2/S v2/S v2/S 0 Nbr 1 0 Query 30 30 30 1 DR 1 1 DR 10. RP: 10.2.100.0.100.125.51.125.125. Forward/Sparse. Gig0/2/1.0. flags: SC Incoming interface: Port-channel1. expires never Group: 224. 00:14:23/00:03:10.3. H Vlan120.0 10.0Port-channel101v2/S … 10.125.100.100.100 cr11-asr-we(config)#interface range Port-channel1 .192.192. uptime 5w5d. 00:14:23/00:02:17. Forward/Sparse. 00:14:20/00:02:55.0. RP: 10. RP: 10.1).125. uptime 00:01:36.4 Outgoing interface list: Vlan101.12.101.sending >= 4 kbps Group: 239. uptime 00:01:36. uptime 00:01:36.100. H Port-channel103.100. Forward/Sparse.192.1).192. 239.100.125.1.51.103.100. 00:14:23/00:03:21. RPF nbr 10.1.100.1 … 10. 00:06:06/00:02:59. Forward/Sparse. (?) RP-tree: Rate: 2500 pps/4240 kbps(1sec).129Vlan101v2/S 0 … 1 30 30 1 1 10.102 cr11-asr-we(config-if-range)#ip pim sparse-mode cr11-asr-we(config)#interface Ser0/3/0 cr11-asr-we(config-if)#ip pim sparse-mode Medium Enterprise Design Profile Reference Guide 2-70 .100.65 Intvl cr22-3560-LB#show ip mroute sparse (*.100.125. 00:14:02/00:02:13.51.100.40.100.1 10.192.51. H cr22-6500-LB#show ip mroute active Active IP Multicast Sources .125.103.51.100.100. expires never Group: 239. RP 10.51.100.0.100 cr23-3560-LB(config)#interface range Vlan 101 – 110 cr22-3560-LB(config-if-range)#ip pim sparse-mode cr22-3560-LB#show ip pim rp Group: 239.0.103. RPF nbr 10. 00:06:06/00:02:05 • WAN edge layer cr11-asr-we(config)#ip multicast-routing distributed cr11-asr-we(config)#ip pim rp-address 10. expires never Group: 239.0.125. RP 10.100.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design 10. H Port-channel101. Forward/Sparse.100.0.100.125.0. expires never cr22-3560-LB#show ip pim interface Address 10. H Vlan110. RPF-MFD Outgoing interface list: Port-channel102. 00:06:08/00:02:09 Vlan110.100.103.0.1. 00:13:27/00:03:06. flags: SC Incoming interface: Port-channel100. Forward/Sparse.125. RP: 10. 4240 kbps(last 10 secs). 4011 kbps(life avg) • Access layer cr23-3560-LB(config)#ip multicast-routing distributed cr23-3560-LB(config)#ip pim rp-address 10.129 cr22-6500-LB#show ip mroute sparse (*. Forward/Sparse.5 0.

flags: T Incoming interface: Port-channel1.100. RP: 10.125. Because VSS is logically a single system and provides node protection. MSDP allows each multicast domain to maintain an independent RP that does not rely on other multicast domains.100.125. Large networks typically use Anycast RP for configuring a PIM-SM network to meet fault tolerance requirements within a single multicast domain.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services cr11-asr-we#show ip pim rp Group: 239. expires never Group: 239.1).57.100. Forward/Sparse.100. uptime 00:23:16. the dynamically discovered group-to-RP entries are fully synchronized to the standby switch. expires never cr11-asr-we#show ip mroute sparse (*.192.31. Inter-Site PIM Anycast RP MSDP allows PIM RPs to share information about the active sources. RPF nbr 10. 00:24:08/stopped. there is no need to implement Anycast RP and MSDP on a VSS-enabled PIM-SM RP. RP 10.31.1.0.100. PIM-SM is used to forward the traffic between the multicast domains.22 Outgoing interface list: Serial0/3/0. The medium enterprise LAN multicast network must be designed with Anycast RP.0.1.sending >= 4 kbps Group: 239.156 (?) Rate: 625 pps/1130 kbps(1sec).192. RP: 10. flags: SP Incoming interface: Port-channel1.125. Figure 2-45 shows an example of a medium enterprise LAN multicast network design. 872 kbps(life avg) PIM-SM RP Redundancy PIM-SM RP redundancy and load sharing becomes imperative in the medium enterprise LAN design.22 Outgoing interface list: Null (10. but does enable RPs to forward traffic between domains.125.100. uptime 00:23:16. PIM-SM uses Anycast RP and Multicast Source Discovery Protocol (MSDP) for node failure protection. 239.192. because each recommended core layer design model provides resiliency and simplicity. (?) Source: 10.100. MSDP used with Anycast RP is an intradomain feature that provides redundancy and load sharing capabilities. PIM-SM RPs discover local receivers through PIM join messages.192. uptime 00:23:16. PIM-SM redundancy and load sharing is simplified with the Cisco VSS-enabled core.57. In the Cisco Catalyst 6500 VSS-enabled core layer.3.57. RPF nbr 10.100. In the non-VSS-enabled network design. 00:24:08/00:03:07.100. 1130 kbps(last 40 secs).57.100.100. RP: 10.57. Combining NSF/SSO capabilities with IPv4 multicast reduces the network recovery time and retains the user and application performance at an optimal level. Originally developed for interdomain multicast applications.1). Anycast RP is a useful application of MSDP.156.192.100. 00:24:08/00:02:55 cr11-asr-we#show ip mroute active Active IP Multicast Sources . Medium Enterprise Design Profile Reference Guide 2-71 . PIM-SM RP at the main or the centralized core must establish an MSDP session with RP on each remote site to exchange distributed multicast source information and allow RPs to join SPT to active sources as needed. 239.57. expires never Group: 239.2. while the multicast source can be in a local or remote network domain.192.

200.2 (?).125.200. Resets: 0.100.100.254/32 Anycast RP : 10.100. AS ? State: Up.122.100/32 Loopback PIM-SM RP Remote Medium Site Loopback0 : 10.200.200.254) Remote Large Campus cr14-6500-RLC(config)#ip msdp peer 10.200. Resets: 0.122.1 connect-source Loopback0 description 10.100.100.200.1 (?).125. Connection source: Loopback0 (10.100/32 Loopback Implementing MSDP Anycast RP Main Campus cr23-VSS-Core(config)#ip cr23-VSS-Core(config)#ip cr23-VSS-Core(config)#ip cr23-VSS-Core(config)#ip cr23-VSS-Core(config)#ip cr23-VSS-Core(config)#ip cr23-VSS-Core(config)#ip cr23-VSS-Core(config)#ip msdp msdp msdp msdp msdp msdp msdp msdp peer 10.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-45 Medium Enterprise Inter-Site Multicast Network Design Main Site VSL Loopback0 : 10.254) MSDP Peer 10.123.100/32 Loopback PIM-SM RP MSDP Peering PIM-SM Anycast RP VSL PIM-SM RP Remote Large Site Loopback0 : 10.200. AS ? State: Up. AS ? State: Up.254) MSDP Peer 10.123.122.1 ANYCAST-PEER-4k-RemoteMedCampus peer 10.100.124.2 (?).200. Resets: 0.2/32 Anycast RP : 10.123.125.200.124.122.100.100/32 Loopback PIM-SM RP Remote Small Site 229371 Loopback0 : 10.254 ANYCAST-PEER-6k-MainCampus cr14-6500-RLC(config)#ip msdp cache-sa-state Medium Enterprise Design Profile Reference Guide 2-72 . Connection source: Loopback0 (10.2 connect-source Loopback0 description 10.200.200.1/32 Anycast RP : 10.125.125.2 ANYCAST-PEER-6k-RemoteLrgCampus peer 10.123.100.200.254 connect-source Loopback0 cr14-6500-RLC(config)#ip msdp description 10.125.2 ANYCAST-PEER-4k-RemoteSmlCampus cache-sa-state originator-id Loopback0 cr23-VSS-Core#show ip msdp peer | inc MSDP Peer|State MSDP Peer 10.200.200.2 connect-source Loopback0 description 10.200.124.200. Connection source: Loopback0 (10.200.2/32 Anycast RP : 10.200.124.

254 connect-source Loopback0 description 10. Layer 2 access switches flood the traffic on all ports.125.200.125. Connection source: Loopback0 (10. Resets: 0.124.254 connect-source Loopback0 description 10. AS ? State: Up. IGMP communication is limited between a receiver host and the Layer 3 access switch. the Layer-2 access-switch dynamically detects IGMP hosts and multicast-capable Layer-3 PIM routers in the network. PIM-SM must be enabled at the Layer 3 access switch to communicate with RPs in the network. AS ? State: Up.125. Medium Enterprise Design Profile Reference Guide 2-73 . IGMP is still required when a Layer 3 access layer switch is deployed in the routed access network design.200.125.200. and is globally enabled by default for all the VLANs. Because the Layer 3 boundary is pushed down to the access layer. Because multilayer access switches do not run PIM.200.200.200. In such a situation.200.200. IGMP is an integrated component of an IP multicast framework that allows the receiver hosts and transmitting sources to be dynamically added to and removed from the network. the network is forced to flood rather than multicast the transmissions for each group.254 (?).200.125. Without IGMP. This multilayer limitation in access switches is solved by using the IGMP snooping feature. The multicast system role changes when the access layer is deployed in the multilayer and routed access models.125.254 ANYCAST-PEER-6k-MainCampus cache-sa-state originator-id Loopback0 cr11-4507-RMC#show ip msdp peer | inc MSDP Peer|State|SAs learned MSDP Peer 10. it becomes complex to make forwarding decisions out of the receiver port.2) SAs learned from this peer: 94 Remote Medium Campus cr11-4507-RMC(config)#ip cr11-4507-RMC(config)#ip cr11-4507-RMC(config)#ip cr11-4507-RMC(config)#ip msdp msdp msdp msdp peer 10.1) SAs learned from this peer: 94 Remote Small Campus cr14-4507-RSC(config)#ip cr14-4507-RSC(config)#ip cr14-4507-RSC(config)#ip cr14-4507-RSC(config)#ip msdp msdp msdp msdp peer 10. In addition to the unicast routing protocol.254 (?). Resets: 0. IGMP operates between a multicast receiver host in the access layer and the Layer 3 router at the distribution layer.125.122.254 ANYCAST-PEER-6k-MainCampus cache-sa-state originator-id Loopback0 cr14-4507-RSC#show ip msdp peer | inc MSDP Peer|State|SAs learned MSDP Peer 10.254 (?). Connection source: Loopback0 (10. AS ? State: Up. Resets: 0. Implementing IGMP By default.200.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services cr14-6500-RLC(config)#ip msdp originator-id Loopback0 cr14-6500-RLC#show ip msdp peer | inc MSDP Peer|State|SAs learned MSDP Peer 10. which is enabled by default and is recommended to not be disabled. Connection source: Loopback0 (10.2) SAs learned from this peer: 94 Dynamic Group Membership Multicast receiver registration is done via IGMP protocol signaling. The IGMP snooping and multicast router detection functions on a per-VLAN basis.123.

because the pim accept-register command works on the control plane of the RP.107 00:52:36 02:12 2A Vl110 *. Flags Interface *. and provide a snooped Layer-2 uplink port-channel which is connected to the collapsed core router. The following output from a Layer-3 switch verifies that the local multicast ports are in router mode.3 igmp v2 Gi1/0/20.239.-----103 Router 106 Router 110 Router Designing Multicast Security When designing multicast security in the medium enterprise LAN design.125. PIM operation is performed at the access layer.40 10.103. If the source is not listed in the accept-register filter list (configured on the RP).G) state and sends a PIM source register message to the RP.0.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Multicast routing function changes when the access-switch is deployed in routed-access mode. the RP rejects the register and sends back an immediate Register-Stop message to the DR.3 10.51. the PIM-SM (S. the first-hop router (DR) creates the (S.51. two key concerns are preventing a rogue source and preventing a rogue PIM-RP.239. this can be used to overload the RP with fake register messages and possibly cause a DoS condition. When the source traffic hits the first-hop router.103.------110 Po1(dynamic) Layer 3 Access cr22-3560-LB#show ip igmp membership Channel/Group Reporter Uptime Exp.109 00:52:35 02:16 2A Vl110 *.2 10.129 4w4d 02:33 2LA Vl103 cr22-3560-LB#show ip igmp snooping mrouter Vlan ports ------.192.192.2 igmp v2 Gi1/0/20. Po1 110 239.0. Furthermore.4 3d22h 02:04 2A Po1 *.1 igmp v2 Gi1/0/20. therefore.224.51. Po1 110 239.239.51. for multicast routing: The IGMP configuration can be validated using the following show command on the Layer-2 and Layer-3 access-switch: Layer 2 Access cr22-3750-LB#show ip igmp snooping groups Vlan Group Type Version Port List ----------------------------------------------------------------------110 239.51.125.125.192. Po1 cr22-3750-LB#show ip igmp snooping mrouter Vlan ports ------.192.1. The drawback with this method of source filtering is that with the pim accept-register command on the RP.40 10.192.0.106 00:52:36 02:09 2A Vl110 *.G) state is still created on the first-hop router of the source.224.101. multicast router detection process is eliminated. Medium Enterprise Design Profile Reference Guide 2-74 .125.125.1. This can result in traffic reaching receivers local to the source and located between the source and the RP.51. an unwanted traffic source can be controlled with the pim accept-register command.1 10. Preventing Rogue Source In a PIM-SM network.192.103.

and particularly video-oriented media applications. are evolving as the enterprise networks enters the digital era of doing business. high-definition room-based conferencing applications. Integrating video applications in the medium enterprise LAN network exponentially increases bandwidth utilization and fundamentally shifts traffic patterns. It is also possible to filter the source and the group using of an extended ACL on the RP: cr23-VSS-Core(config)#ip access-list extended PERMIT-SOURCES cr23-VSS-Core(config-ext-nacl)# permit ip 10.255 cr23-VSS-Core(config-ext-nacl)# deny ip any any cr23-VSS-Core(config)#ip pim accept-register list PERMIT-SOURCES Preventing Rogue PIM-RP Like the multicast source.255 239.0 0.0 0.0.0. Converging media applications onto an IP network is much more complex than converging voice over IP (VoIP) alone. any router can be misconfigured or can maliciously advertise itself as a multicast RP in the network with the valid multicast group address.0. as well as the increased campus network and asset security requirements. The following is the sample configuration that must be applied to each PIM-enabled router in the campus network.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services The following is the sample configuration with a simple ACL that has been applied to the RP to filter only on the source address.31.39 cr23-VSS-Core(config-std-nacl)# permit 224. each PIM-enabled router in the network can be configured to use static RP for the multicast source and override any other Auto-RP or BSR multicast router announcement from the network.120. and social networking phenomena are crossing over into enterprise settings.100.255.192.192.1. digital signage applications. Besides internal and enterprise research applications. and many different types of media applications exist. With a static RP configuration. requiring the ongoing development of converged network designs.0 0.0. as well as an infinite array of data-oriented applications.40 cr23-VSS-Core(config-std-nacl)# permit 239. Application and device awareness has become a key tool in providing differentiated service treatment at the campus LAN edge.0.0. High-definition media is transitioning from the desktop to conference rooms.255 cr23-VSS-Core(config-std-nacl)# deny any cr23-VSS-Core(config)#ip pim rp-address 10. media applications are fueling a new wave of IP convergence.0. Business drivers behind this media application growth include remote learning. as well as leveraging the network as a platform to build an energy-efficient network to minimize cost and go "green".1. to accept PIM announcements only from the static RP and ignore dynamic multicast group announcement from any other RP: cr23-VSS-Core(config)#ip access-list standard Allowed_MCAST_Groups cr23-VSS-Core(config-std-nacl)# permit 224. applications can include live and on-demand streaming media applications.7. By Medium Enterprise Design Profile Reference Guide 2-75 .100.100 Allowed_MCAST_Groups override QoS for Application Performance Optimization The function and guaranteed low latency bandwidth expectation of network users and endpoints has evolved significantly over the past few years.255. Media applications are generally bandwidth-intensive and bursty (as compared to VoIP). in addition to IP telephony. Media applications.

Deploying QoS technologies in the campus allows different types of traffic to contend inequitably for network resources.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design embracing media applications as the next cycle of convergence. The policy for providing network resources to an internal application is further complicated when interactive video and real-time VoIP applications are converged over the same network that is switching mid-to-low priority data traffic. Real-time applications such as voice. respectively). as well as how should these individual classes should be implemented to deliver differentiated services consistently in main and remote campus sites. To this end. and to keep the network protected from threats. with the aim of improving QoS consistency. These guidelines are to be viewed as industry best-practice recommendations. to extend the effectiveness of your QoS policies beyond your direct administrative control. interactive. The characteristic of network services and applications must be well understood. Cisco has made a minor modification to its adoption of RFC 4594. because these guidelines are not standards. compatibility. medium enterprise IT departments can think holistically about their network design and its readiness to support the coming tidal wave of media applications. the medium enterprise LAN QoS framework is developed based on RFC4594 that follows industry standard and guidelines to function consistently in heterogeneous network environment. so that policies can be defined that allow network resources to be used for internal applications. Medium Enterprise LAN QoS Framework Each group of managed and un-managed applications with unique traffic patterns and service level requirements requires a dedicated QoS class to provision and guarantee these service level requirements. users and endpoints to prevent contention. and develop a network-wide strategy to ensure high quality end-user experiences. modifications can be made to these recommendations as specific needs or constraints require. RFC 4594 outlines twelve classes of media applications that have unique service level requirements. but not to the point that data applications are starving for bandwidth. namely the switching of call-signaling and broadcast video markings (to CS3 and CS5. Medium Enterprise Design Profile Reference Guide 2-76 . to meet specific business requirements. and physical security video can be given priority or preferential services over generic data applications. and interoperability. Enterprise organizations and service providers are encouraged to adopt these marking and provisioning recommendations. With minor changes. The medium enterprise LAN infrastructure must set the administrative policies to provide differentiated forwarding services to the network applications. to provide best-effort services for external traffic. The medium enterprise LAN network architect may need to determine the number of classes for various applications. However. Cisco recommends following relevant industry standards and guidelines whenever possible. as shown in Figure 2-46.

and Cisco IP Video Surveillance. Broadcast video—This service class is intended for broadcast TV.729a. live events. admission to this class should be controlled (admission control is discussed in the following section). and similar inelastic streaming video flows. Gaming. Whenever technically possible and administratively feasible. as such. video surveillance flows. CRM Apps E-mail. • • • Medium Enterprise Design Profile Reference Guide 2-77 . H.323 SNMP. Traffic in this class should be marked CS4 and may be provisioned with an EF PHB. Traffic in this class should be marked class selector 5 (CS5) and may be provisioned with an EF PHB.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Figure 2-46 Campus 12-Class QoS Policy Recommendation Media Application Examples Cisco IP Phone Cisco IPVS. HSRP. live Cisco Enterprise TV (ETV) streams. admission to this class should be controlled. SSH. Examples of this type of traffic include G. admission to this class should be controlled. Traffic assigned to this class should be marked EF. IP/TV EIGRP. Whenever technically possible and administratively feasible. P2P PHB EF CS5 CS4 AF4 AF3 CS6 CS3 CS2 AF2 AF1 DF CS1 Admission Control Required Required Required Required Recommended Queuing and Dropping Priority Queue (PQ) (Optional) PQ (Optional) PQ BW Queue + DSCP WRED BW Queue + DSCP WRED BW Queue BW Queue BW Queue BW Queue + DSCP WRED BW Queue + DSCP WRED Default Queue + RED Min BW Queue 228497 Application Class VoIP Telephony Broadcast Video Real-Time Interactive Multimedia Conferencing Multimedia Streaming Network Control Call-Signaling Ops/Admin/Mgmt (OAM) Transactional Data Bulk Data Best Effort Scavenger The twelve classes are as follows: • VoIP telephony—This service class is intended for VoIP telephony (bearer-only) traffic (VoIP signaling traffic is assigned to the call-signaling class). Traffic in this class should be marked assured forwarding (AF) Class 4 (AF41) and should be provisioned with a guaranteed bandwidth queue with Differentiated Services Code Point (DSCP)-based Weighted Random Early Detection (WRED) enabled. IKE SCCP. This class is provisioned with expedited forwarding (EF) per-hop behavior (PHB). Admission to this class should be controlled.711 and G. high-definition interactive video applications and is intended primarily for voice and video components of these applications. SIP. WebEx Cisco DMS. as such. Real-time interactive—This service class is intended for (inelastic) room-based. Syslog ERP Apps. OSPF. FTP. as such. data sub-components of this class can be separated out and assigned to the transactional data traffic class. data sub-components of this class can be separated out and assigned to the transactional data traffic class. A sample application is Cisco TelePresence. Enterprise TV Cisco TelePresence Cisco CUPC. Examples of this traffic include live Cisco Digital Media System (DMS) streams to desktops or to Cisco Digital Media Players (DMPs). Backup Default Class YouTube. The EF PHB-defined in RFC 3246 is a strict-priority queuing service and. which are highly drop sensitive and have no retransmission and/or flow control capabilities. Multimedia conferencing—This service class is intended for desktop software multimedia collaboration applications and is intended primarily for voice and video components of these applications.

Sample traffic includes EIGRP. excessive latency directly impacts user productivity). because OAM traffic should not be dropped (if this class is experiencing drops. Sample traffic includes Secure Shell (SSH). and management traffic. Traffic in this class should be marked CS3 and provisioned with a (moderate. • • • • • • Medium Enterprise Design Profile Reference Guide 2-78 . Traffic in this class should be marked AF Class 2 (AF21) and should be provisioned with a dedicated bandwidth queue with DSCP-WRED enabled. Sample applications include E-mail. because call-signaling traffic should not be dropped (if this class is experiencing drops. Traffic in this class should be marked AF Class 3 (AF31) and should be provisioned with a guaranteed bandwidth queue with DSCP-based WRED enabled. but dedicated) guaranteed bandwidth queue. This traffic class may be subject to policing and re-marking. WRED should not be enabled on this class. WRED should not be enabled on this class. Syslog. Bulk data (or high-throughput data)—This service class is intended for non-interactive “background” data applications (background refers to applications from which users are not awaiting a response via the network to continue with their tasks. Admission control is recommended on this traffic class (though not strictly required) and this class may be subject to policing and re-marking. WRED should not be enabled on this class. because network control traffic should not be dropped (if this class is experiencing drops. database applications. in general. Call-signaling—This service class is intended for signaling traffic that supports IP voice and video telephony. Transactional data (or low-latency data)—This service class is intended for interactive. This class is critical to the ongoing maintenance and support of the network. but dedicated) guaranteed bandwidth queue. Sample applications include Cisco Digital Media System VoD streams. Session Initiation Protocol (SIP). Simple Network Management Protocol (SNMP). administration. the bandwidth allocated to it should be re-provisioned). • Multimedia streaming—This service class is intended for video-on-demand (VoD) streaming video flows.323. the bandwidth allocated to it should be re-provisioned). Customer Relationship Management (CRM) applications. video and content distribution. Enterprise Resource Planning (ERP) applications. Sample applications include data components of multimedia collaboration applications. WRED is recommended to be enabled on this class. FTP/SFTP transfers. this default class should be adequately provisioned. Cisco Unified Video Advantage. Sample applications include Cisco Unified Personal Communicator. as such. Internet Key Exchange (IKE). and the Cisco Unified IP Phone 7985G. which. and so on. and so on. Traffic in this class is marked default forwarding (DF or DSCP 0) and should be provisioned with a dedicated queue. H. and so on. backup operations. OSPF. Best effort (or default class)—This service class is the default class. Traffic in this class should be marked AF Class 1 (AF11) and should be provisioned with a dedicated bandwidth queue with DSCP-WRED enabled. Border Gateway Protocol (BGP). traffic in this class may be subject to policing and re-marking. and so on. Sample traffic includes Skinny Call Control Protocol (SCCP). This traffic class may be subject to policing and re-marking. Operations/administration/management (OAM)—This service class is intended for network operations. and so on. The vast majority of applications will continue to default to this best-effort service class. excessive latency in response times of background applications does not directly impact user productivity). the bandwidth allocated to it should be re-provisioned). HSRP.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design additionally. but dedicated) guaranteed bandwidth queue. are more elastic than broadcast/live streaming flows. Network control—This service class is intended for network control plane traffic. Traffic in this class should be marked CS2 and provisioned with a (moderate. “foreground” data applications (foreground refers to applications from which users are expecting a response via the network to continue with their tasks. Traffic in this class should be marked CS6 and provisioned with a (moderate. which is required for reliable operation of the enterprise network.

such as data or video applications that are entertainment and/or gaming-oriented. Bi-directional network communication between applications. and must be taken into account when designing the trust model between network endpoints and core and edge campus devices. and forwarding paths. and data applications.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services • Scavenger (or low-priority data)—This service class is intended for non-business-related traffic flows. Figure 2-47 shows the QoS trust model setting that sets the QoS implementation guidelines in medium enterprise campus networks. Traffic in this class should be marked CS1 and should be provisioned with a minimal bandwidth queue that is the first to starve should network congestion occur. as soon as the network experiences congestion. The trust or un-trust model simplifies the rules for defining bi-directional QoS policy settings. it is important to create an blueprint of the network. Sample traffic includes YouTube. Xbox Live/360 movies. However. endpoints. Medium Enterprise Design Profile Reference Guide 2-79 . or other network devices requires the same treatment when traffic enters or leaves the network. and then define common QoS policy settings independent of how QoS is implemented within the system. BitTorrent. political compromise. Designing Medium Enterprise LAN QoS Trust Boundary and Policies To build an end-to-end QoS framework that offers transparent and consistent QoS service without compromising performance. as long as resources are always available for business-critical voice. The approach of a less-than Best-Effort service class for non-business applications (as opposed to shutting these down entirely) has proven to be a popular. this class is the first to be penalized and aggressively dropped. it is important that other LAN network devices in the campus trust the marking and apply the same policy to retain the QoS settings and offer symmetric treatment. video. classifying a set of trusted applications. and so on. devices. These applications are permitted on enterprise networks. To retain the marking set by access layer switches. iTunes. QoS settings applied at the LAN network edge sets the ingress rule based on deep packet classification and marks the traffic before it is forwarded inside the campus core.

This allows complex policies to be applied at line rates even up to Gigabit or 10-Gigabit speeds. and as such do not tax their main CPUs to administer QoS policies. Cisco IOS routers perform QoS in software. perform QoS in dedicated hardware application-specific integrated circuits (ASICs) on Ethernet-based ports. Conditional-Trusted or Un-Trusted Endpoints QoSTrust Boundary Ingress QoS Ploicy Egress QoS Ploicy 228498 Medium Enterprise LAN QoS Overview With an overall application strategy in place. end-to-end QoS policies can be designed for each device and interface. Marking and Queueing VSL Trust Trust Queueing and WTD Classification. Marking. Classification. on the other hand. because the Cisco QoS toolset provides many QoS design and deployment options. as discussed in the following sections. However. a few succinct design principles can help simplify strategic QoS deployments. Marking and Queueing Trust Trust. Policing and Queueing IP Queueing and WTD Trusted.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-47 Campus LAN QoS Trust and Policies VSL Classification. Medium Enterprise Design Profile Reference Guide 2-80 . which places incremental loads on the CPU. Cisco Catalyst switches. as determined by their roles in the network infrastructure. depending on the complexity and functionality of the policy. Hardware versus Software QoS A fundamental QoS design principle is to always enable QoS policies in hardware rather than software whenever possible.

Therefore. Medium Enterprise Design Profile Reference Guide 2-81 . such as DSCP-based WRED. Policing and Markdown There is little reason to forward unwanted traffic that gets policed and drop by a subsequent tier node. and inter-class relative priority (such as RFC 2597 Assured Forwarding Drop Preference markdown) is not supported. Such abuse can easily ruin the service quality of realtime applications throughout the campus. There is also less marking granularity at Layer 2. only up to eight classes of traffic can be supported at Layer 2. because worm-generated traffic can masquerade under legitimate. Cisco recommends following the IETF standards-based DSCP PHB markings to ensure interoperability and future expansion. Because the medium enterprise voice. which provides more flexibility and is adequate in large-scale deployments and for future requirements. In general. because users can easily abuse provisioned QoS policies if permitted to mark their own traffic. For example. medium enterprises can easily adopt these markings to interface with service provider classes of service. Layer 2 markings are lost when the media changes (such as a LAN-to-WAN/VPN edge). On the other hand. as previously discussed. thus hijacking network priority queues to service non-realtime traffic. if medium enterprise network administrator controls are in place that centrally administer PC QoS markings. Whenever supported. For example. such as RFC 2597 (AF PHB). For example. This common principle applies to campus-to-WAN/Internet edges. markdown should be done according to standards-based rules. where oversubscription ratios create the greater potential for network congestion. it may be possible and advantageous to trust these. Following such markdowns. excess traffic marked to AFx1 should be marked down to AFx2 (or AFx3 whenever dual-rate policing such as defined in RFC 2698 is supported). should be configured to drop AFx3 more aggressively than AFx2. which can result in outages. it is not recommended to trust markings that can be set by users on their PCs or other similar devices. This principle promotes end-to-end differentiated services and PHBs. Queuing and Dropping Critical media applications require uncompromised performance and service guarantees regardless of network conditions. more granular. congestion management policies. and campus interswitch links. 802. and data applications marking recommendations are standards-based. a recommended design principle is to classify and mark applications as close to their sources as technically and administratively feasible. the need for interoperability and complementary QoS markings is critical. As the network border blurs between enterprise network and service providers. where speed mismatches are most pronounced. and more extensible than Layer 2 markings. if an EF PHB has been provisioned over the network. Enabling outbound queuing in each network tier provides end-to-end service guarantees during potential network congestion. because these are end-to-end. it is recommended to use DSCP markings whenever possible. Following this rule. especially when unwanted traffic is the result of DoS or worm attacks in the enterprise network.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Classification and Marking When classifying and marking traffic. Such excesses should be monitored at the source and marked down appropriately. well-known TCP/UDP ports and cause extreme amounts of traffic to be poured into the network infrastructure. a PC user can easily configure all their traffic to be marked to EF. video. Layer 3-based DSCP markings allow for up to 64 classes of traffic. This principle applies also to legitimate flows. as does Multiprotocol Label Switching Experimental (MPLS EXP).1P supports only three bits (values 0-7). Cisco recommends policing traffic flows as close to their sources as possible. which in turn should be dropped more aggressively than AFx1. Excessive volume attack traffic can destabilize network systems.

For example. consider a 45 Mbps DS3 link configured to support two Cisco TelePresence CTS-3000 calls with an EF PHB service. specifically as follows: • • • • Realtime queue (to support a RFC 3246 EF PHB service) Guaranteed-bandwidth queue (to support RFC 2597 AF PHB services) Default queue (to support a RFC 2474 DF service) Bandwidth-constrained queue (to support a RFC 3662 scavenger service) Additional queuing recommendations for these classes are discussed next. assume there are no other realtime applications on this link. video. And finally. Assuming that both systems are configured to support full high definition. non-realtime applications have access to 100 percent of the bandwidth on the link. the medium enterprise network administrator must provision according to their detailed requirements and constraints. destroying the transparency of the converged network. all non-realtime applications are suddenly contending for less than 33 percent of the link. and data applications to transparently co-exist on a single medium enterprise network infrastructure. this design principle applies to the sum of all LLQs to be within one-third of link capacity.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Because each application class has unique service level requirements. so each must be bounded by a limited number of hardware or service provider queues. In such a multiple LLQ context. which usually translates into users calling the IT help desk to complain about the network (which happens to be functioning properly. each such call requires 15 Mbps of strict-priority queuing. Note As previously discussed. Medium Enterprise Design Profile Reference Guide 2-82 . any traffic assigned to a strict-priority queue should be governed by an admission control mechanism. A wide range of platforms in varying roles exist in medium enterprise networks. In such cases. When realtime applications dominate a link. or become stuck in a non-responsive state. after these TelePresence calls are established. and also for non-realtime applications (because these may periodically receive significant bandwidth allocation fluctuations. both for latency. it is important to recognize the tradeoffs involved with over-provisioning strict priority traffic and its negative performance impact. No fewer than four queues are required to support QoS policies for various types of applications. if the majority of bandwidth is provisioned with strict priority queuing (which is effectively a FIFO queue). both on other realtime flows and also on non-realtime-application response times. Strict-Priority Queuing The realtime or strict priority class corresponds to the RFC 3246 EF PHB. The amount of bandwidth assigned to the realtime queuing class is variable. Cisco IOS software allows the abstraction (and thus configuration) of multiple strict priority LLQs. timeout. to simplify the example. However. TCP windowing takes effect and many applications hang. Before the TelePresence calls are placed. albeit in a poorly-configured manner). depending on the instantaneous amount of traffic being serviced by the priority queue).and jitter-sensitive realtime applications (contending with each other within the FIFO priority queue). However. the overall effect is a dampening of QoS functionality. each should be assigned optimally a dedicated queue. However. non-realtime applications fluctuate significantly in their response times. There may be cases where specific business objectives cannot be met while holding to this recommendation. It is vitally important to understand that this strict priority queuing rule is simply a best practice design recommendation and is not a mandate. Remember that the goal of convergence is to enable voice.

Figure 2-48 Compatible 4-Class and 12-Class Queuing Models VoIP Telephony Best Effort Broadcast Video Best Effort Scavenger Bulk Data Scavenger > Realtime Realtime Interactive Guaranteed BW Transactional Data OAM Signaling Network Control Multimedia Streaming Multimedia Conferencing Medium Enterprise Design Profile Reference Guide 228499 2-83 . either because queuing assignments are determined by class of service (CoS) values (and both of these application classes share the same CoS value of 1). These queuing rules are summarized in Figure 2-48. queuing distinctions between bulk data and scavenger traffic flows cannot be made. Cisco recommends reserving at least 25 percent of link bandwidth for the default best effort class. precluding the use of separate dedicated queues for each of these two classes. Therefore. it should be assigned a minimal amount of link bandwidth capacity. or because only a limited amount of hardware queues exist. adequate bandwidth must be provisioned for this class as a whole to handle the number and volume of applications that default to it. where the inner pie chart represents a hardware or service provider queuing model that is limited to four queues and the outer pie chart represents a corresponding. Only if an application has been selected for preferential/deferential treatment is it removed from the default class. more granular queuing model that is not bound by such constraints. or whatever the minimal bandwidth allocation that the platform supports. such as 5 percent. the scavenger/bulk queue can be assigned a moderate amount of bandwidth.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Best Effort Queuing The best effort class is the default class for all traffic that has not been explicitly assigned to another application-class queue. Scavenger Class Queuing Whenever the scavenger queuing class is enabled. In such cases. Because most medium enterprises may have several types of applications running in networks. On some platforms. such as 1 percent.

QoS accomplishes this by creating a more application-aware Layer 2 and Layer 3 network to provide differentiated services to network applications and traffic. To prevent switch fabric and egress physical port congestion. and then attaching the policy-map to an individual physical port or to logical interfaces (SVI or port-channel). while reserving sufficient network resources to service medium to lower non-real-time traffic. but offers no guarantee of delivery. refer to the Enterprise QoS Design Guide at the following URL: http://www. See Figure 2-49. All ingress traffic from edge ports passes through the switch fabric and move to the egress ports.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Deploying QoS in Campus LAN Network All Layer 2 and Layer 3 systems in IP-based networks forward traffic based on a best-effort.cisco. Congestion in access-layer switches can be prevented by tuning queuing scheduler and Weighted Tail Drop (WTD) drop parameters. The Cisco Catalyst switches allow users to create policy-maps by classifying incoming traffic (Layer 2 to Layer 4). There is no difference in the ingress or egress packet classification. For a detailed discussion of QoS. the QoS implementation in hardware and software-based switching platforms vary due to internal system design. For an optimal user-experience the real time applications (such as voice. The routing protocol forwards packets over the best low-metric or delay path. the ingress QoS policing structure can strictly filter excessive traffic at the network edge. providing no differentiated services between different class-of-service network applications. QoS in Catalyst Fixed Configuration Switches The QoS implementation in Cisco Catalyst 2960.html While the QoS design principles across the network are common. Figure 2-49 QoS Implementation in Cisco Catalyst Switches Policer Policer Receive Classify Marker Marker Ingress Queues Normal-Q SRR Priority-Q Internal Ring Egress Queues Q1 Q2 SRR Q3 Q4 Transmit Policer Policer Marker Marker Ingress QoS Egress QoS 228973 Medium Enterprise Design Profile Reference Guide 2-84 . The medium enterprise LAN and WAN is a multi-service network designed to supports a wide-range of low-latency voice and high bandwidth video with critical and non-critical data traffic over a single network infrastructure. jitter. marking. This creates a common QoS policy that may be used in multiple networks. This model works well for TCP-based data applications that adapt gracefully to variations in latency. Cisco quality-of-service (QoS) is a collection of features and hardware capabilities that allow the network to intelligently dedicate the network resources for higher priority real-time applications. where congestion may occur. video) require packets delivered within specified loss. This section discusses the internal switching architecture and the differentiated QoS structure on a per-hop-basis. delay and jitter parameters. queuing and scheduling implementation among these Catalyst platforms. and 3750-X Series switches are similar to one another. 3560-X. and loss.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND/QoS-SRND-Bo ok.

the new 2960-S platform do not support ingress queueing and buffer function in harware. resilient switches for large scale networks. The switching architecture and some of the internal QoS structure also differs between these switches. when Catalyst 2960-S is deployed in FlexStack configuration mode. The medium enterprise LAN network design uses both platforms across the network. • • • The next-generation Cisco Catalyst 2960-S Series platform introduces modified QoS architecture. This buffer allocation is static and cannot be modified by the user. buffer and bandwidth sharing function remain consistent as Catalyst 2960 platform. All other ingress and egress queuing.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services The main difference between these platforms is the switching capacity that ranges from 1G to 10G. all the QoS recommendations in this section for these platforms will remain consistent. Figure 2-50 illustrates QoS architecture on Catalyst 2960-S Series platform Figure 2-50 QoS Implementation in Catalyst 2960-S Switches Policer Policer Receive Classify Marker Marker Egress Queues Q1 Q2 SRR Q3 Transmit Policer Policer Marker Q4 Marker Egress QoS 229372 Ingress QoS QoS in Cisco Modular Switches The Cisco Catalyst 4500-E and 6500-E are high-density. there is a flexibility to assign different buffer size on egress queue of StackPort. The following are some important differences to consider when selecting an access switch: • • The Cisco Catalyst 2960 does not support multilayer switching and does not support per-VLAN or per-port/per-VLAN policies. However. Only the Cisco Catalyst 3560-X and 3750-X support policing on 10-Gigabit Ethernet interfaces. however. Only the Cisco Catalyst 3560-X and 3750-X support IPv6 QoS. Both Catalyst platforms are modular in design. Each physical ports including StackPort have 2 MB buffer capacity to prevent traffic drop during congestion. there are significant internal hardware architecture differences between the two platforms that impact the QoS implementation model. The Cisco Catalyst 2960 can police to a minimum rate of 1 Mbps. Only the Cisco Catalyst 3560-X and 3750-X support SRR shaping weights on 10-Gigabit Ethernet interfaces. therefore. To reduce the latency and improve application performance. all other switches including next-generation Cisco Catalyst 2960-S Series within this product family can police to a minimum rate of 8 kbps. Medium Enterprise Design Profile Reference Guide 2-85 .

converged network services regardless of its place in the network.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Catalyst 4500-E QoS The Cisco Catalyst 4500-E Series platform are widely deployed with classic and next-generation supervisors. secure. This design guide recommends deploying the next-generation supervisor Sup6E and Sup6L-E that offers a number of technical benefits that are beyond QoS. For example. The QoS implementation in Sup-6E and Sup6L-E supports the Modular QoS CLI (MQC) as implemented in IOS-based routers that enhances QoS capabilities and eases implementation and operations. the Sup6-E and Sup6L-E provides sequential classification rather than parallel. Catalyst 4500—Supervisor 6-E and 6L-E QoS Architecture • • Figure 2-51 Ingress QoS Policer Receive Classify Unconditional Marking Marking Forwarding Lookup Egress QoS Q1 Q2 Policer Marking DBL Unconditional Marking Q3 Q4 Q5 Q6 Q7 Q8 228974 Classify Queueing/ Transmit Shaping Catalyst 6500-E QoS The Cisco Catalyst 6500-E Series are enterprise-class switches. DSCP 46 can be classified with ACL and can be matched in PQ class-map of an MQC in Sup-6E and Sup6L-E. with next-generation hardware and software capabilities designed to deliver innovative. Internal DSCP—The queue placement in Sup-6E and Sup6L-E is simplified by leveraging the MQC capabilities to explicitly map DSCP or CoS traffic in a hard-coded egress queue structure. The following are some of the key QoS features that differentiate the Sup-6E versus classic supervisors: • Trust and Table-Map—MQC-based QoS implementation offers a number of implementation and operational benefits over classic supervisors that rely on the Trust model and internal Table-map as a tool to classify and mark ingress traffic. New QoS capabilities in the Sup-6E and Sup6L-E enable administrators to take advantage of hardware-based intelligent classification and take action to optimize application performance and network availability. Sequential vs Parallel Classification—With MQC-based QoS classification. The Cisco Catalyst 6500-E can be deployed as a service-node in the campus Medium Enterprise Design Profile Reference Guide 2-86 . The Cisco Catalyst 4500 with next generation Sup-6E and Sup6L-E (see Figure 2-51) are designed to offer better differentiated and preferential QoS services for various class-of-service traffic. The sequential classification method allows network administrators to classify traffic at the egress based on the ingress markings.

MPLS EXP Mark – set internal DSCP Police – rate limit. The Catalyst 6500-E provides leading-edge Layer 2-Layer 7 services. and the trust model with which the endpoint is deployed. or whether to change them. the platform can be deployed with different types of Supervisor modules—Sup720-10GE. the Policy Feature Card (PFC) that serves as the primary QoS engine. as well as integrated Power-over-Ethernet (PoE). including rich high availability. Figure 2-52 Cisco Catalyst 6500-E PFC QoS Architecture Port Trust State • CoS • IP Prec • DSCP • MPLS EXP Identify traffic based on match criteria: • ACL (L2.e. laptop etc. virtualization. and QoS feature sets. manageability. These supervisors leverage various featured daughter cards. allowing for maximum flexibility in virtually any role within the campus. PQ Queueing Mode: CoS PFC/DFC Egress Port DWRR CoS set on trunk port DSCP set for IP Deploying Access-Layer QoS The campus access switches provide the entry point to the network for various types of end devices managed by medium enterprise IT department or employee's personal devices (i. Depending on the network services and application demands of the Cisco Catalyst 6500-E. robust. Medium Enterprise Design Profile Reference Guide 228975 Action – policy-map Trust – DSCP. Specifically relating to QoS. intelligent application and network awareness services.. the PFC and DFC functions are enabled and active on active and hot-standby virtual-switch nodes. which is built with next-generation hardware allowing administrators to build virtual-network-systems in the enterprise LAN network. The access switch must decide whether to accept the QoS markings from each endpoint. Since Cisco VSS is designed with a distributed forwarding architecture. the PFC sends a copy of the QoS policies to the DFC to provide local support for the QoS policies. DWRR. Sup720 and Sup32.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services network to offer a high performance. This design guide uses the Sup720-10GE supervisor. SP Classification Q1 Policy Result DSCP CoS rewrite Q2 Incoming ToS CoS SP WRR Q1 Q2 Outgoing Scheduler Q3 Q4 Ingress Port Scheduling Rules: WRR. security. which enables the DFCs to support the same QoS features that the PFC supports. This is determined by the QoS policies. Figure 2-52 provides internal PFC based QoS architecture. including the Multilayer Switch Feature Card (MSFC) that serves as the routing engine.). IP Prec. IP) • DSCP • IP Prec • MPLS EXP • Class-map Internal DSCP map Final internal DSCP is mapped to CoS Scheduler operation on WRR. as well as various Distributed Feature Cards (DFCs) that serve to scale policies and processing. drop Scheduler queue and threshold are configurable 2-87 .

it is possible for an unsecured user to take away network bandwidth that may impact network availability and security for other users. guides policy implementations for each device. Otherwise. Even when these devices are network administrator maintained and secured. These deployment scenarios require hybrid QoS policy that intelligently distinguishes and applies different QoS policy to the trusted and untrusted endpoints that are connected to the same port. This includes defining trust points and determining which policies to enforce at each device within the network. or untrusted). switches. employee-owned PC or network printer. • • Medium Enterprise Design Profile Reference Guide 2-88 228976 . Access-layer switches communicate with devices that are beyond the network boundary and within the internal network domain. each with its own unique security and QoS policies to access the network: • Untrusted—An unmanaged device that does not pass through the network security policies. but it is possible that the untrusted user behind the endpoint may or may not be secure (for example. QoS trust boundary at the access-layer communicates with various devices that could be deployed in different trust models (trusted. For example. QoS policies must still be enforced to classify traffic and assign it to the appropriate queue to provide bandwidth assurance and proper treatment during network congestion. The devices (routers. Developing the trust model.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design QoS Trust Boundary QoS needs to be designed and implemented considering the entire network.1p or DSCP marking set by untrusted endpoints are reset to default by the access-layer switch at the edge. and hence are classified as trusted devices. Figure 2-53 illustrates several types of devices in the network edge. conditional-trusted. Conditionally-trusted—A single physical connection with one trusted endpoint and an indirect untrusted endpoint must be deployed as conditionally-trusted model. WLC) within the internal network boundary are managed by the system administrator. Cisco Unified IP Phone + PC). The trusted endpoints are still managed by the network administrator. Trusted—Devices that passes through network access security policies and are managed by network administrator. Figure 2-53 Campus LAN QoS Trust Boundary Access Catalyst 3560 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 15X 17X SERIES PoE-48 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 31X 33X 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 47X SYST RPS STAT DUPLX SPEED POE 1X 1 3 2 2X 16X 18X 32X 34X 48X 4 MODE IP IP UnTrusted PC Cisco IP Phone Trusted Secured Phone + Printer PC Server UnTrusted PC Trusted Device Cisco TelePresence Cisco Cisco Cisco UC Wireless IP Video + Mobile Access Surveillance PC Point Camers UnTrusted Device Conditionally-Trusted Device Enterprise network administrator must identify and classify each of this device type into one of three different trust models. Packets with 802.

Catalyst switches set each port in untrusted mode when QoS is enabled. Additional policing can be applied for known applications. Best practice is to deploy DSCP-based trust mode on all the trusted and conditionally-trusted endpoints. The network administrator must explicitly enable the trust settings on the physical port where trusted or conditionally trusted endpoints are connected. The Catalyst switches can trust the ingress packets based on 802. classification. The following sample DSCP-based trust configuration must be enabled on the access-switch ports connecting to trusted or conditionally-trusted endpoints. This offers a higher level of classification and marking granularity than other methods. simplifies the classification process and improves application and network performance. The following sample QoS configuration must be enabled on all the access-layer switches deployed in campus network LAN network. This classification determines the priority the traffic will receive in the network.1P (CoS-based). the QoS marking is set at the edge before approved traffic enters through the access-layer switching fabric. Upon enabling QoS in the Catalyst switches. • • • Enabling QoS By default. Classification—IETF standard has defined a set of application classes and provides recommended DSCP settings. QoS is disabled on all Catalyst 29xx and 3xxx Series switches and must be explicitly enabled in global configuration mode. and treated with the appropriate priority. Queuing—To provide differentiated services internally in the Catalyst 29xx and 3xxx switching fabric. since this is the trust boundary. Policing—To prevent network congestion. Access-Layer 29xx and 3xxx (Multilayer or Routed Access) cr24-2960-S-LB(config)#mls qos cr24-2960-S-LB#show mls qos QoS is enabled QoS ip packet dscp rewrite is enabled Note QoS function on Catalyst 4500-E with Sup6E and Sup6L-E is enabled with the policy-map attached to the port and do not require any additional global configuration. Using the IETF standard. The following ingress QoS techniques are applied to provide appropriate service treatment and prevent network congestion: • • Trust—After classifying the endpoint the trust settings must be explicitly set by a network administrator. the access-layer switch limits the amount of inbound traffic up to its maximum setting. Ingress queuing architecture assures real-time applications. By default. Marking traffic with the appropriate DSCP value is important to ensure traffic is mapped to the appropriate internal queue. ToS (ip-prec-based) or DSCP (DSCP-based) values. all approved traffic is queued into priority or non-priority ingress queue. Marking—Based on trust model. to ensure the bandwidth of an egress queue is not completely consumed by one application. The QoS configuration is the same for a multilayer or routed-access deployment. where traffic enters the network. and policer settings. all physical ports are assigned untrusted mode. Medium Enterprise Design Profile Reference Guide 2-89 .Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services The ingress QoS policy at the access switches needs to be established. like VoIP traffic. are given appropriate priority (eg transmitted before data traffic).

Refer to the “Implementing Ingress QoS Policing” section on page 2-94 for further details. To appropriate network policy the default settings must be modified by implementing ingress QoS policy-map. Conditionally-Trusted Port cr22-3560-LB(config)#interface Gi0/4 cr22-3560-LB(config-if)# description CONNECTED TO PHONE+PC cr22-3560-LB(config-if)# mls qos trust device cisco-phone cr22-3560-LB(config-if)# mls qos trust dscp cr22-3560-LB#show mls qos interface Gi0/4 GigabitEthernet0/4 trust state: not trusted trust mode: trust dscp trust enabled flag: dis COS override: dis default COS: 0 DSCP Mutation Map: Default DSCP Mutation Map Trust device: cisco-phone qos mode: port-based • 4500-E-Sup6LE (Multilayer or Routed Access) cr22-4507-LB(config)#interface GigabitEthernet3/3 cr22-4507-LB(config-if)# qos trust device cisco-phone cr22-4507-LB#show qos interface Gig3/3 Operational Port Trust State: Trusted Trust device: cisco-phone Default DSCP: 0 Default CoS: 0 Appliance trust: none Medium Enterprise Design Profile Reference Guide 2-90 .Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design QoS Trust Mode (Multilayer or Routed-Access) Trusted Port • 29xx and 3xxx (Multilayer or Routed Access) cr22-3560-LB(config)#interface GigabitEthernet0/5 cr22-3560-LB(config-if)# description CONNECTED TO IPVS 2500 . such configuration leverages internal DSCP mapping table to automatically classify QoS bit settings from incoming traffic and place it to appropriate to queue based on mapping table.CAMERA cr22-3560-LB(config-if)# mls qos trust dscp cr22-3560-LB#show mls qos interface Gi0/5 GigabitEthernet0/5 trust state: trust dscp trust mode: trust dscp trust enabled flag: ena COS override: dis default COS: 0 DSCP Mutation Map: Default DSCP Mutation Map Trust device: none qos mode: port-based • 4500-E-Sup6LE (Multilayer or Routed Access) By default all the Sup6E and Sup6L-E ports are in trusted mode.

therefore. Voice traffic is primarily sourced from Cisco IP telephony devices residing in the voice VLAN (VVLAN). the network administrator needs to consider what applications are present at the access edge (in the ingress direction) and whether these applications are sourced from trusted or untrusted endpoints. thus PCs are considered untrusted endpoints for the remainder of this document. Administration and Management—Primarily generated by network devices (routers. etc. Medium Enterprise Design Profile Reference Guide 2-91 . These are trusted devices. In most deployments. and should be classified with multimedia conferencing streams. Without explicit trust configuration on Gi0/1 port. or a network control center. the following show command verifies current trust state and mode: • 29xx and 3xxx (Multilayer or Routed Access) cr22-3560-LB#show mls qos interface Gi0/1 GigabitEthernet0/1 trust state: not trusted trust mode: not trusted trust enabled flag: ena COS override: dis default COS: 0 DSCP Mutation Map: Default DSCP Mutation Map Trust device: none qos mode: port-based • 4500-E-Sup6LE (Multilayer or Routed Access) QoS trust function on Cisco Catalyst 4500-E with Sup6E and Sup6L-E is enabled by default and must be modified with the policy-map attached to the port. cr22-4507-LB#show qos interface GigabitEthernet3/1 Operational Port Trust State: Trusted Trust device: none Default DSCP: 0 Default CoS: 0 Appliance trust: none Implementing Ingress QoS Classification When creating QoS classification policies.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services UnTrusted Port As described earlier. See Figure 2-54. is present in the ingress direction at the access edge. Broadcast Video—Broadcast video and multimedia streaming server can be distributed across the campus network which may be broadcasting live video feed using multicast streams must be originated from trusted distributed data center servers. as shown in Figure 2-54. or conditionally trusted (if users also attach PCs. • All applications present at the access edge need to be assigned a classification. Since such applications share the same UDP port range as multimedia conferencing traffic (UDP/RTP ports 16384-32767) this soft-phone VoIP traffic is indistinguishable. like Cisco Unified Personal Communicator (CUPC). switches) and collected by management stations which are typically deployed in the trusted data center network. it is not necessary to provision the following application classes at the access-layer: • • Network Control—It is assumed that access-layer switch will not transmit or receive network control traffic from endpoints. as defined in the Cisco-modified RFC 4594-based model.) to the same port. this is not the case. the default trust mode is untrusted when globally enabling QoS function. hence this class is not implemented. then endpoint PCs may be considered trusted endpoints. Operation. If PC endpoints are secured and centrally administered. Voice communication may also be sourced from PCs with soft-phone applications. Not every application class.

Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-54 Ingress QoS Application Model Application PHB Application Examples Present at Campus Access-Edge (Ingress)? Trust Boundary Network Control VoIP Broadcast Video Realtime Interactive Multimedia Conferencing Multimedia Streaming Signaling Transactional Data OAM Bulk Data Best Effort Best Effort Scavenger CS6 EF EIGRP. H. SIP. Gaming. OSPF. Syslog Email. SSH. IP/TV SCCP. WebEx Cisco DMS. The following sample configuration creates an extended access-list for each application and then applies it under class-map configuration mode.323 ERP Apps. IKE Cisco IP Phone Cisco IPVS. 3xxx and 4500-E (MultiLayer and Routed Access) cr22-4507-LB(config)#ip access-list extended MULTIMEDIA-CONFERENCING cr22-4507-LB(config-ext-nacl)# remark RTP cr22-4507-LB(config-ext-nacl)# permit udp any any range 16384 32767 cr22-4507-LB(config-ext-nacl)#ip access-list extended SIGNALING cr22-4507-LB(config-ext-nacl)# remark SCCP cr22-4507-LB(config-ext-nacl)# permit tcp any any range 2000 2002 cr22-4507-LB(config-ext-nacl)# remark SIP cr22-4507-LB(config-ext-nacl)# permit tcp any any range 5060 5061 cr22-4507-LB(config-ext-nacl)# permit udp any any range 5060 5061 cr22-4507-LB(config-ext-nacl)#ip access-list extended TRANSACTIONAL-DATA cr22-4507-LB(config-ext-nacl)# remark HTTPS cr22-4507-LB(config-ext-nacl)# permit tcp any any eq 443 cr22-4507-LB(config-ext-nacl)# remark ORACLE-SQL*NET cr22-4507-LB(config-ext-nacl)# permit tcp any any eq 1521 cr22-4507-LB(config-ext-nacl)# permit udp any any eq 1521 cr22-4507-LB(config-ext-nacl)# remark ORACLE cr22-4507-LB(config-ext-nacl)# permit tcp any any eq 1526 cr22-4507-LB(config-ext-nacl)# permit udp any any eq 1526 cr22-4507-LB(config-ext-nacl)# permit tcp any any eq 1575 cr22-4507-LB(config-ext-nacl)# permit udp any any eq 1575 cr22-4507-LB(config-ext-nacl)# permit tcp any any eq 1630 Medium Enterprise Design Profile Reference Guide 2-92 . • Catalyst 29xx. CRM Apps SNMP. P2P Yes Yes Trusted Untrusted Yes Yes Trusted Untrusted Yes Best Effort Yes Best Effort Yes Untrusted Best Effort Untrusted Best Effort Untrusted 228977 Modular QoS MQC offers scalability and flexibility in configuring QoS to classify all 8-application classes by using match statements or an extended access-list to match the exact value or range of Layer-4 known ports that each application uses to communicate on the network. Enterprise TV Yes Trusted CS4 AF4 AF3 CS3 AF2 CS2 AF1 DF DF CS1 Cisco TelePresence Cisco CUPC. Backups Best Effort Default Class Best Effort YouTube. FTP. HSRP.

Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services cr22-4507-LB(config-ext-nacl)#ip access-list extended BULK-DATA cr22-4507-LB(config-ext-nacl)# remark FTP cr22-4507-LB(config-ext-nacl)# permit tcp any any eq ftp cr22-4507-LB(config-ext-nacl)# permit tcp any any eq ftp-data cr22-4507-LB(config-ext-nacl)# remark SSH/SFTP cr22-4507-LB(config-ext-nacl)# permit tcp any any eq 22 cr22-4507-LB(config-ext-nacl)# remark SMTP/SECURE SMTP cr22-4507-LB(config-ext-nacl)# permit tcp any any eq smtp cr22-4507-LB(config-ext-nacl)# permit tcp any any eq 465 cr22-4507-LB(config-ext-nacl)# remark IMAP/SECURE IMAP cr22-4507-LB(config-ext-nacl)# permit tcp any any eq 143 cr22-4507-LB(config-ext-nacl)# permit tcp any any eq 993 cr22-4507-LB(config-ext-nacl)# remark POP3/SECURE POP3 cr22-4507-LB(config-ext-nacl)# permit tcp any any eq pop3 cr22-4507-LB(config-ext-nacl)# permit tcp any any eq 995 cr22-4507-LB(config-ext-nacl)# remark CONNECTED PC BACKUP cr22-4507-LB(config-ext-nacl)# permit tcp any eq 1914 any cr22-4507-LB(config-ext-nacl)#ip access-list extended DEFAULT cr22-4507-LB(config-ext-nacl)# remark EXPLICIT CLASS-DEFAULT cr22-4507-LB(config-ext-nacl)# permit ip any any cr22-4507-LB(config-ext-nacl)#ip access-list extended SCAVENGER cr22-4507-LB(config-ext-nacl)# remark KAZAA cr22-4507-LB(config-ext-nacl)# permit tcp any any eq 1214 cr22-4507-LB(config-ext-nacl)# permit udp any any eq 1214 cr22-4507-LB(config-ext-nacl)# remark MICROSOFT DIRECT X GAMING cr22-4507-LB(config-ext-nacl)# permit tcp any any range 2300 2400 cr22-4507-LB(config-ext-nacl)# permit udp any any range 2300 2400 cr22-4507-LB(config-ext-nacl)# remark APPLE ITUNES MUSIC SHARING cr22-4507-LB(config-ext-nacl)# permit tcp any any eq 3689 cr22-4507-LB(config-ext-nacl)# permit udp any any eq 3689 cr22-4507-LB(config-ext-nacl)# remark BITTORRENT cr22-4507-LB(config-ext-nacl)# permit tcp any any range 6881 6999 cr22-4507-LB(config-ext-nacl)# remark YAHOO GAMES cr22-4507-LB(config-ext-nacl)# permit tcp any any eq 11999 cr22-4507-LB(config-ext-nacl)# remark MSN GAMING ZONE cr22-4507-LB(config-ext-nacl)# permit tcp any any range 28800 29100 Creating class-map for each application services and applying match statement: cr22-4507-LB(config)#class-map match-all VVLAN-SIGNALING cr22-4507-LB(config-cmap)# match ip dscp cs3 cr22-4507-LB(config-cmap)#class-map match-all VVLAN-VOIP cr22-4507-LB(config-cmap)# match ip dscp ef cr22-4507-LB(config-cmap)#class-map match-all MULTIMEDIA-CONFERENCING cr22-4507-LB(config-cmap)# match access-group name MULTIMEDIA-CONFERENCING cr22-4507-LB(config-cmap)#class-map match-all SIGNALING cr22-4507-LB(config-cmap)# match access-group name SIGNALING cr22-4507-LB(config-cmap)#class-map match-all TRANSACTIONAL-DATA cr22-4507-LB(config-cmap)# match access-group name TRANSACTIONAL-DATA cr22-4507-LB(config-cmap)#class-map match-all BULK-DATA cr22-4507-LB(config-cmap)# match access-group name BULK-DATA cr22-4507-LB(config-cmap)#class-map match-all DEFAULT cr22-4507-LB(config-cmap)# match access-group name DEFAULT Medium Enterprise Design Profile Reference Guide 2-93 .

• In addition to policing. end-station. Table 2-6 provides best practice policing guidelines for different classes to be implemented for trusted and conditional-trusted endpoints at the network edge. and application performance capacities. It is important to police high-priority application traffic which is assigned to the high-priority queue. Bandwidth Security—Well-known applications like Cisco IP telephony. Catalyst 2960 can only police to a minimum rate of 1 Mbps. • Trusted or Conditionally-Trusted Port Policer cr22-2960-LB(config)#policy-map Phone+PC-Policy cr22-2960-LB(config-pmap)# class VVLAN-VOIP cr22-2960-LB(config-pmap-c)# police 1000000 8000 exceed-action cr22-2960-LB(config-pmap-c)# class VVLAN-SIGNALING cr22-2960-LB(config-pmap-c)# police 1000000 8000 exceed-action cr22-2960-LB(config-pmap-c)# class MULTIMEDIA-CONFERENCING cr22-2960-LB(config-pmap-c)# police 5000000 8000 exceed-action cr22-2960-LB(config-pmap-c)# class SIGNALING cr22-2960-LB(config-pmap-c)# police 1000000 8000 exceed-action cr22-2960-LB(config-pmap-c)# class TRANSACTIONAL-DATA drop drop drop drop Medium Enterprise Design Profile Reference Guide 2-94 . The rate-limit value may differ based on several factors—end-to-end network bandwidth capacity. each physical port at the trust boundary must be rate-limited. Table 2-6 Access-Layer Ingress Policing Guidelines Application VoIP Signaling VoIP Bearer Multimedia Conferencing Signaling Transactional Data Bulk Data Best Effort Scavenger Policing Rate <32 kbps <128 kbps <5Mbps 1 Conform-Action Pass Pass Pass Pass Exceed-Action Drop Drop Drop Drop Remark to CS1 Remark to CS1 Remark to CS1 Drop <32 kbps <10 Mbps <10 Mbps <10 Mbps 1 Pass Pass Pass Pass <10 Mbps 1 1 1 1. etc. This table depicts sample rate-limiting value Catalyst 29xx As described earlier. otherwise it could consume too much overall network bandwidth and impact other application performance. The exceed-action for each class must be carefully designed based on the nature of application to provide best-effort service based on network bandwidth availability. based on codec. use a fixed amount of bandwidth per device. Rate varies based on several factors as defined earlier. the rate-limit function also provides the ability to take different actions on the excess incoming traffic which exceeds the established limits.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design cr22-4507-LB(config-cmap)#class-map match-all SCAVENGER cr22-4507-LB(config-cmap)# match access-group name SCAVENGER Implementing Ingress QoS Policing It is important to limit how much bandwidth each class may use at the ingress to the access-layer for two primary reasons: • Bandwidth Bottleneck—To prevent network congestion. all other platforms including next-generation Cisco Catalyst 2960-S within this switch-product family can police to a minimum rate of 8 kbps.

3xxx and 4500-E (Multilayer and Routed-Access) • UnTrusted Port Policer All ingress traffic (default class) from untrusted endpoint be must be policed without explicit classification that requires differentiated services. All classified and policed traffic must be explicitly marked using the policy-map configuration based on an 8-class QoS model as shown in Figure 2-59. The following sample configuration shows how to deploy policing on untrusted ingress ports in access-layer switches: cr22-2960-LB(config)#policy-map UnTrusted-PC-Policy cr22-2960-LB(config-pmap)# class class-default cr22-2960-LB(config-pmap-c)# police 10000000 8000 exceed-action drop Implementing Ingress Marking Accurate DSCP marking of ingress traffic at the access-layer switch is critical to ensure proper QoS service treatment as traffic traverses through the network. The following sample configuration shows how to implement explicit marking for multiple classes on trusted and conditionally-trusted ingress ports in access-layer switches: Trusted or Conditionally-Trusted Port • Catalyst 29xx. The best practice is to use a explicit marking command (set dscp) even for trusted application classes (like VVLAN-VOIP and VVLAN-SIGNALING). and improves the hardware efficiency.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services cr22-2960-LB(config-pmap-c)# police 10000000 cr22-2960-LB(config-pmap-c)# class BULK-DATA cr22-2960-LB(config-pmap-c)# police 10000000 cr22-2960-LB(config-pmap-c)# class SCAVENGER cr22-2960-LB(config-pmap-c)# police 10000000 cr22-2960-LB(config-pmap-c)# class DEFAULT cr22-2960-LB(config-pmap-c)# police 10000000 8000 exceed-action policed-dscp-transmit 8000 exceed-action policed-dscp-transmit 8000 exceed-action drop 8000 exceed-action policed-dscp-transmit Catalyst 2960-S. A trust statement in a policy map requires multiple hardware entries. 3xxx and 4500-E (Multilayer and Routed-Access) cr22-3750-LB(config)#policy-map Phone+PC-Policy Medium Enterprise Design Profile Reference Guide 2-95 . 3xxx and 4500-E (Multilayer and Routed-Access) • Trusted or Conditionally-Trusted Port Policer cr22-4507-LB(config)#policy-map Phone+PC-Policy cr22-4507-LB(config-pmap)# class VVLAN-VOIP cr22-4507-LB(config-pmap-c)# police 128000 8000 exceed-action drop cr22-4507-LB(config-pmap-c)# class VVLAN-SIGNALING cr22-4507-LB(config-pmap-c)# police 32000 8000 exceed-action drop cr22-4507-LB(config-pmap-c)# class MULTIMEDIA-CONFERENCING cr22-4507-LB(config-pmap-c)# police 5000000 8000 exceed-action drop cr22-4507-LB(config-pmap-c)# class SIGNALING cr22-4507-LB(config-pmap-c)# police 32000 8000 exceed-action drop cr22-4507-LB(config-pmap-c)# class TRANSACTIONAL-DATA cr22-4507-LB(config-pmap-c)# police 10000000 8000 exceed-action policed-dscp-transmit cr22-4507-LB(config-pmap-c)# class BULK-DATA cr22-4507-LB(config-pmap-c)# police 10000000 8000 exceed-action policed-dscp-transmit cr22-4507-LB(config-pmap-c)# class SCAVENGER cr22-4507-LB(config-pmap-c)# police 10000000 8000 exceed-action drop cr22-4507-LB(config-pmap-c)# class DEFAULT cr22-4507-LB(config-pmap-c)# police 10000000 8000 exceed-action policed-dscp-transmit Catalyst 29xx. with the use of an explicit (seemingly redundant) marking command. rather than a trust policy-map action.

Medium Enterprise Design Profile Reference Guide 2-96 . Per-Port / Per-VLAN-Based QoS—This is not supported on all the Catalyst platforms and the configuration commands are platform-specific. the service-policy must be applied on the edge interface of the access-layer to enforce the QoS configuration. VLAN-Based QoS—Applying the service-policy on a per VLAN bas requires the policy-map to be attached to a logical Layer 3 SVI interface. Per-Port/Per-VLAN-based QoS create a nested hierarchical policy-map that operates on a trunk interface. depending on the deployment model either of the methods can be implemented: • Port-Based QoS—Applying the service-policy on per physical port basis will force traffic to pass-through the QoS policies before entering in to the campus network. • • See Figure 2-55.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design cr22-3750-LB(config-pmap)# class VVLAN-VOIP cr22-3750-LB(config-pmap-c)# set dscp ef cr22-3750-LB(config-pmap-c)# class VVLAN-SIGNALING cr22-3750-LB(config-pmap-c)# set dscp cs3 cr22-3750-LB(config-pmap-c)# class MULTIMEDIA-CONFERENCING cr22-3750-LB(config-pmap-c)# set dscp af41 cr22-3750-LB(config-pmap-c)# class SIGNALING cr22-3750-LB(config-pmap-c)# set dscp cs3 cr22-3750-LB(config-pmap-c)# class TRANSACTIONAL-DATA cr22-3750-LB(config-pmap-c)# set dscp af21 cr22-3750-LB(config-pmap-c)# class BULK-DATA cr22-3750-LB(config-pmap-c)# set dscp af11 cr22-3750-LB(config-pmap-c)# class SCAVENGER cr22-3750-LB(config-pmap-c)# set dscp cs1 cr22-3750-LB(config-pmap-c)# class DEFAULT cr22-3750-LB(config-pmap-c)# set dscp default All ingress traffic (default class) from an untrusted endpoint must be marked without a explicit classification. A different policy-map can be applied on each logical SVI interface that is associated to same physical port. Port-Based QoS discretely functions on a per-physical port basis even if it is associated with a logical VLAN which is applied on multiple physical ports. Every physical port associated to VLAN requires an extra configuration to ensure all traffic to passes through the QoS policies defined on an logical interface. Cisco Catalyst switches offers three simplified methods to apply service-policies. 3xxx and 4500-E (Multilayer and Routed-Access) cr22-3750-LB(config)#policy-map UnTrusted-PC-Policy cr22-3750-LB(config-pmap)# class class-default cr22-3750-LB(config-pmap-c)# set dscp default Applying Ingress Policies After creating complete a policy-map on all the Layer 2 and Layer 3 access-switches with QoS policies defined. The following sample configuration shows how to implement explicit DSCP marking: Untrusted Port • Catalyst 29xx.

all the packets that meet the specified policy are forwarded to the switching fabric for egress switching. Medium Enterprise Design Profile Reference Guide 2-97 228978 . Figure 2-56 depicts how different class-of-service applications are mapped to the Ingress Queue structure (1P1Q3T) and how each queue is assigned a different WTD threshold. based on DSCP value. the switch drops the packet. The ingress queue inspects the DSCP value on each incoming frame and assigns it to either the normal or priority queue.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Figure 2-55 Depicts all three QoS implementation method Port-Based QoS VLAN Interface VLAN 10 Physical Ports Physical port attached with single service-policy VLAN 20 VLAN-Based QoS VLAN Interface VLAN 10 VLAN 20 Per-Port/Per-VLAN Based QoS VLAN Interface WLAN 10 WLAN 20 DVLAN 100 DVLAN 200 Single Logical port attached with single service-policy Multiple Logical ports attached with different service-policy The following sample configuration provides guideline to deploy port-based QoS on the access-layer switches in campus network: • Catalyst 29xx. WTD drops packets from the queue. Two of the three thresholds are configurable (explicit) and one is not (implicit). like DSCP EF marked packets. High priority traffic. The aggregate bandwidth from all edge ports may exceed the switching fabric bandwidth and cause internal congestion. are placed in the priority queue and switched before processing the normal queue. If the threshold is exceeded for a given internal DSCP value. Each queue has three threshold values. and the associated threshold. The internal DSCP determines which of the three threshold values is applied to the frame. WTD is implemented on queues to manage the queue length. Cisco Catalyst 2960 and 3xxx platforms support two internal ingress queues: normal queue and priority queue. but also internally on the switching fabric. 3xxx and 4500-E (Multilayer and Routed-Access) cr22-2960-LB(config)#interface FastEthernet0/1 cr22-2960-LB(config-if)# service-policy input UnTrusted-PC-Policy cr22-2960-LB#show mls qos interface FastEthernet0/1 FastEthernet0/1 Attached policy-map for Ingress: UnTrusted-PC-Policy trust state: not trusted trust mode: not trusted trust enabled flag: ena COS override: dis default COS: 0 DSCP Mutation Map: Default DSCP Mutation Map Trust device: none qos mode: port-based Applying Ingress Queuing Fixed configuration Cisco Catalyst switches (2960 and 3xxx) not only offer differentiated services on the network ports. This last threshold corresponds to the tail of the queue (100 percent limit). The Catalyst 3750-X family of switches supports the weighted tail drop (WTD) congestion avoidance mechanism. After enabling QoS and attaching inbound policies on the physical ports. Note. Cisco Catalyst 2960-S Series platform do not support ingress queueing and buffer allocation.

CS1 and AF1 are mapped to ingress Q1T1 cr22-3750-LB (config)# mls qos srr-queue input dscp-map queue 1 threshold 1 16 18 20 22 ! DSCP CS2 and AF2 are mapped to ingress Q1T1 cr22-3750-LB (config)# mls qos srr-queue input dscp-map queue 1 threshold 1 26 28 30 34 36 38 ! DSCP AF3 and AF4 are mapped to ingress Q1T1 cr22-3750-LB (config)#mls qos srr-queue input dscp-map queue 1 threshold 2 24 ! DSCP CS3 is mapped to ingress Q1T2 cr22-3750-LB(config)#mls qos srr-queue input dscp-map queue 1 threshold 3 48 56 ! DSCP CS6 and CS7 are mapped to ingress Q1T3 (the tail of Q1) cr22-3750-LB(config)#mls qos srr-queue input dscp-map queue 2 threshold 3 32 40 46 ! DSCP CS4. CS5 and EF are mapped to ingress Q2T3 (the tail of the PQ) cr22-3750-LB#show mls qos input-queue Medium Enterprise Design Profile Reference Guide 2-98 .Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-56 Catalyst 2960 and 3xxx Ingress Queuing Model Application Network Control Internetwork Control VoIP Broadcast Video Multimedia Conferencing Realtime Interactive Multimedia Streaming Signaling Transactional Data Network Management Bulk Data Best Effort Best Effort Scavenger • PHB CS7 CS6 EF CS5 AF4 CS4 AF3 CS3 AF2 CS2 AF1 DF DF CS1 Ingress Queue 1P1Q3T EF CS5 CS4 CS7 CS6 CS3 AF4 AF3 AF2 CS2 AF1 DF CS1 228979 Q2 Priority Queue Q1T3 Q1T2 Q1T1 Queue 1 Normal Queue Catalyst 2960 and 3xxx (Multilayer and Routed-Access) cr22-3750-LB(config)#mls qos srr-queue input priority-queue 2 bandwidth 30 ! Q2 is enabled as a strict-priority ingress queue with 30% BW cr22-3750-LB (config)#mls qos srr-queue input bandwidth 70 30 ! Q1 is assigned 70% BW via SRR shared weights ! Q1 SRR shared weight is ignored (as it has been configured as a PQ) cr22-3750-LB (config)#mls qos srr-queue input threshold 1 80 90 ! Q1 thresholds are configured at 80% (Q1T1) and 90% (Q1T2) ! Q1T3 is implicitly set at 100% (the tail of the queue) ! Q2 thresholds are all set (by default) to 100% (the tail of Q2) ! This section configures ingress DSCP-to-Queue Mappings cr22-3750-LB (config)# mls qos srr-queue input dscp-map queue 1 threshold 1 0 8 10 12 14 ! DSCP DF.

Implementing Access-Layer Egress QoS The QoS implementation of egress traffic towards network edge devices on access-layer switches are much simplified compared to ingress traffic which requires stringent QoS policies to provide differentiated services and network bandwidth protection. Catalyst 2960 and 3xxx Egress QoS Cisco Catalyst 29xx and 3xxx Series platform supports four egress queues that are required to support the variable class QoS policies for the medium enterprise campus LAN network. specifically. Figure 2-57 illustrates the egress bandwidth allocation best practices design for different classes. the Cisco Catalyst switching platforms are bounded by a limited number of hardware queues.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Queue: 12 ---------------------------------------buffers :9010 bandwidth :7030 priority :030 threshold1:80100 threshold2:90100 cr22-3750-LB#show mls qos maps dscp-input-q Dscp-inputq-threshold map: d1 :d2 0 1 2 3 8 9 4 5 6 7 -------------------------------------------------------------------------------------0 : 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 1 : 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 01-01 2 : 01-01 01-01 01-01 01-01 01-02 01-01 01-01 01-01 01-01 01-01 3 : 01-01 01-01 02-03 01-01 01-01 01-01 01-01 01-01 01-01 01-01 4 : 02-03 02-01 02-01 02-01 02-01 02-01 02-03 02-01 01-03 01-01 5 : 01-01 01-01 01-01 01-01 01-01 01-01 01-03 01-01 01-01 01-01 6 : 01-01 01-01 01-01 01-01 Note The ingress queuing function on Catalyst 4500-E Sup6E and Sup6L-E is not supported as described in Figure 2-51. each physical or logical interfaces must be deployed with IETF recommended bandwidth allocations for different class-of-service applications: • • • The real-time queue should not exceed 33 percent of the link's bandwidth. With egress queuing in DSCP mode. the egress QoS model must provide optimal queuing policies for each class and set the drop thresholds to prevent network congestion and prevent an application performance impact. The default queue should be at least 25 percent of the link's bandwidth. Medium Enterprise Design Profile Reference Guide 2-99 . the following queues would be considered a minimum: • • • • Realtime queue (to support a RFC 3246 EF PHB service) Guaranteed bandwidth queue (to support RFC 2597 AF PHB services) Default queue (to support a RFC 2474 DF service) Bandwidth constrained queue (to support a RFC 3662 scavenger service) As a best practice. Unlike the Ingress QoS model. The bulk/scavenger queue should not exceed 5 percent of the link's bandwidth.

A campus egress QoS model example for a platform that supports DSCP-to-queue mapping with a 1P3Q8T queuing structure is depicted in Figure 2-58.e. and transactional data can be mapped to the guaranteed bandwidth queue. selective dropping tools). Congestion avoidance mechanisms (i. can be enabled on this class. signaling. Scavenger/Bulk Queue—Bulk data and scavenger traffic can be mapped to the bandwidth-constrained queue and congestion avoidance mechanisms can be enabled on this class. such as WRED. in the respective order they are listed (such that control plane protocols receive the highest level of QoS within a given queue). congestion avoidance mechanisms can be enabled on this class. multimedia streaming. the following application classes can be mapped to the respective queues: • • Realtime Queue—Voice. Guaranteed Queue—Network/internetwork control. if configurable drop thresholds are supported on the platform.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-57 Class-of-Service Egress Bandwidth Allocations Given these minimum queuing requirements and bandwidth allocation recommendations.. The DSCP-to-queue mapping for egress queuing must be mapped to each egress queues as stated above which allows better queuing-policy granularity. • • Like the ingress queuing structure that maps various applications based on DSCP value into two ingress queues. network management. and realtime interactive may be mapped to the realtime queue (per RFC 4594). Medium Enterprise Design Profile Reference Guide 2-100 . If configurable drop thresholds are supported on the platform. broadcast video. the egress queuing must be similar designed to map with four egress queues. Default Queue—Best-effort traffic can be mapped to the default queue. multimedia conferencing. these may be enabled to provide inter-queue QoS to drop scavenger traffic ahead of bulk data. these may be enabled to provide intra-queue QoS to these application classes. furthermore.

! Q4 Maximum (Overflow) Threshold is set to 400% cr22-3750-LB(config)# mls qos srr-queue output dscp-map queue ! DSCP CS4. ! Q2 Reserve Threshold is set to 100%. 2960-S and 3xxx (Multilayer and Routed-Access) cr22-3750-LB(config)#mls qos queue-set output 1 buffers 15 30 35 20 ! Queue buffers are allocated cr22-3750-LB (config)#mls qos queue-set output 1 threshold 1 100 100 100 100 ! All Q1 (PQ) Thresholds are set to 100% cr22-3750-LB (config)#mls qos queue-set output 1 threshold 2 80 90 100 400 ! Q2T1 is set to 80%. ! Q2 Maximum (Overflow) Threshold is set to 400% cr22-3750-LB (config)#mls qos queue-set output 1 threshold 3 100 100 100 400 ! Q3T1 is set to 100%. as all packets are marked the same weight in Q3 ! Q3 Reserve Threshold is set to 100%. • Catalyst 2960. ! Q3 Maximum (Overflow) Threshold is set to 400% cr22-3750-LB (config)#mls qos queue-set output 1 threshold 4 60 100 100 400 ! Q4T1 is set to 60%. Q2T2 is set to 90%. Egress queuing settings are common between all the trust-independent network edge ports as well as on the Layer 2 or Layer 3 uplink connected to internal network. The following egress queue configuration entered in global configuration mode must be enabled on every access-layer switch in the network. Q4T2 is set to 100% ! Q4 Reserve Threshold is set to 100%. CS5 and EF are mapped to egress Q1T3 (tail of the cr22-3750-LB(config)# mls qos srr-queue output dscp-map queue ! DSCP CS2 and AF2 are mapped to egress Q2T1 cr22-3750-LB(config)# mls qos srr-queue output dscp-map queue 38 ! DSCP AF3 and AF4 are mapped to egress Q2T1 1 threshold 3 32 40 46 PQ) 2 threshold 1 16 18 20 22 2 threshold 1 26 28 30 34 36 Medium Enterprise Design Profile Reference Guide 228981 CS5 2-101 .Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Figure 2-58 1P3Q3T Egress QoS Model on Catalyst 29xx and 3xxx platforms Application Network Control Internetwork Control VoIP Broadcast Video Multimedia Conferencing Realtime Interactive Multimedia Streaming Signaling Transactional Data Network Management Bulk Data Best Effort Best Effort Scavenger PHB CS7 CS6 EF CS5 AF4 CS4 AF3 CS3 AF2 CS2 AF1 Egress Queue 1P3Q3T AF1 CS1 DF CS7 CS6 CS3 AF4 AF3 AF2 CS2 EF Queue 1 Priority Queue (30%) Q2T2 Queue 2 (30%) Q2T1 Queue 4 (5%) Queue 3 (35%) Q2T3 Q4T2 Q4T1 DF DF CS1 CS4 DSCP marked packets are assigned to the appropriate queue and each queue is configured with appropriate WTD threshold as defined in Figure 2-58.

and flexibilities to provide for a well diverse queuing structure for multiple class-of-service traffic types.0) The port is mapped to qset : 1 • Catalyst 4500-E Sup6E and Sup6L-E Egress QoS The enterprise-class 4500-E switch with next-generation supervisor hardware architecture are designed to offers better egress QoS techniques. Deploying the next-generation Sup-6E and Sup6L-E in the campus network provides more QoS granularity to map the 8-class traffic types to hardware-based egress-queues as illustrated in Figure 2-59. When the queue length of a flow exceeds its limit. namely Dynamic Buffer Limiting (DBL). DBL drops packets or sets the Explicit Congestion Notification (ECN) bits in the TCP Medium Enterprise Design Profile Reference Guide 2-102 . Figure 2-59 8 Class-of-Service Egress Bandwidth Allocations The Cisco Catalyst 4500-E Sup-6E and Sup6L-E supervisor supports platform-specific congestion avoidance algorithms to provide Active Queue Management (AQM). DBL tracks the queue length for each traffic flow in the switch. capabilities.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design cr22-3750-LB(config)#mls qos srr-queue output dscp-map queue 2 threshold 2 24 ! DSCP CS3 is mapped to egress Q2T2 cr22-3750-LB(config)#mls qos srr-queue output dscp-map queue 2 threshold 3 48 56 ! DSCP CS6 and CS7 are mapped to egress Q2T3 cr22-3750-LB(config)#mls qos srr-queue output dscp-map queue 3 threshold 3 0 ! DSCP DF is mapped to egress Q3T3 (tail of the best effort queue) cr22-3750-LB(config)#mls qos srr-queue output dscp-map queue 4 threshold 1 8 ! DSCP CS1 is mapped to egress Q4T1 cr22-3750-LB(config)# mls qos srr-queue output dscp-map queue 4 threshold 2 10 12 14 ! DSCP AF1 is mapped to Q4T2 (tail of the less-than-best-effort queue) ! This section configures edge and uplink port interface with common egress queuing parameters cr22-3750-LB(config)#interface range GigabitEthernet1/0/1-48 cr22-3750-LB(config-if-range)# queue-set 1 ! The interface(s) is assigned to queue-set 1 cr22-3750-LB(config-if-range)# srr-queue bandwidth share 1 30 35 5 ! The SRR sharing weights are set to allocate 30% BW to Q2 ! 35% BW to Q3 and 5% BW to Q4 ! Q1 SRR sharing weight is ignored. as it will be configured as a PQ cr22-3750-LB(config-if-range)# priority-queue out ! Q1 is enabled as a strict priority queue cr22-3750-LB#show mls qos interface GigabitEthernet1/0/27 queueing GigabitEthernet1/0/27 Egress Priority Queue : enabled Shaped queue weights (absolute) : 25 0 0 0 Shared queue weights : 1 30 35 5 The port bandwidth limit : 100 (Operational Bandwidth:100.

Figure 2-60 provides the new recommended bandwidth allocation. Implementing QoS policies on Sup-6E-based Catalyst 4500 platform follows the IOS (MQC) based configuration model instead of the Catalyst OS-based QoS model. the following configuration use the new egress policy-map with queuing and DBL function implemented on the Catalyst 4500-E deployed with a Sup6E and SupL-E supervisor module. Based on Figure 2-60. the queuing function using MQC must be applied on per member-link of the EtherChannel interface. To take advantage of hardware-based QoS egress. the bandwidth distribution for different classes change. With 8 egress (1P7Q1T) queues and DBL capability in the Sup-6E-based supervisor. load-sharing egress per-flow traffic across EtherChannel links offers the advantage to optimally use distributed hardware resources. All network edge port and core-facing uplink ports must use a common egress policy-map.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services packet headers. Recommended DSCP markings for each traffic class can be classified in a different class-map for egress QoS functions. • Catalyst 4500 Sup-6E and SupL-E (MultiLayer and Routed-Access) ! Creating class-map for each classes using match dscp statement as marked by edge systems cr22-4507-LB(config)#class-map match-all PRIORITY-QUEUE cr22-4507-LB(config-cmap)# match dscp ef cr22-4507-LB(config-cmap)# match dscp cs5 cr22-4507-LB(config-cmap)# match dscp cs4 cr22-4507-LB(config-cmap)#class-map match-all CONTROL-MGMT-QUEUE cr22-4507-LB(config-cmap)# match dscp cs7 cr24-4507-LB(config-cmap)# match cr24-4507-LB(config-cmap)# match cr24-4507-LB(config-cmap)# match dscp cs6 dscp cs3 dscp cs2 Medium Enterprise Design Profile Reference Guide 2-103 . Figure 2-60 1P7Q1T Egress QoS Model on Catalyst 4500-E with Sup6E and Sup6L-E Application Network Control Internetwork Control VoIP Broadcast Video Multimedia Conferencing Realtime Interactive Multimedia Streaming Signaling Transactional Data Network Management Bulk Data Best Effort Scavenger Best Effort PHB CS7 CS6 EF CS5 AF4 CS4 AF3 CS3 AF2 CS2 AF1 AF1 DF CS1 DF CS1 DF AF2 AF4 AF3 EF CS5 CS4 Egress Queue 1P7Q1T (+DBL) Priority Queue (30%) CS7 & CS6 CS3 & CS2 Q7 (10%) Q6 (10%) Q5 (10%) Q4 (10%) Q3 (4%) Q2 (1%) Q1 (25%) 228983 The QoS architecture and implementation procedure are identical between Sup-6E and Sup6L-E modules. Therefore.

To mitigate this challenge. Ten5/1 . it is recommended to implement an additional policy-map to rate-limit the priority class traffic and must be attached on the EtherChannel to govern the aggregated egress traffic limits. Te4/1 .6 cr24-4507-DO(config-if-range)# service-policy output EGRESS-POLICY Policing Priority-Queue EtherChannel is an aggregated logical bundle of interfaces that do not perform queuing and rely on individual member-links to queue egress traffic by using hardware-based queuing.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design cr24-4507-LB(config-cmap)#class-map match-all MULTIMEDIA-CONFERENCING-QUEUE cr24-4507-LB(config-cmap)# match dscp af41 af42 af43 cr24-4507-LB(config-cmap)#class-map match-all MULTIMEDIA-STREAMING-QUEUE cr24-4507-LB(config-cmap)# match dscp af31 af32 af33 cr24-4507-LB(config-cmap)#class-map match-all TRANSACTIONAL-DATA-QUEUE cr24-4507-LB(config-cmap)# match dscp af21 af22 af23 cr24-4507-LB(config-cmap)#class-map match-all BULK-DATA-QUEUE cr24-4507-LB(config-cmap)# match dscp af11 af12 af13 cr24-4507-LB(config-cmap)#class-map match-all SCAVENGER-QUEUE cr24-4507-LB(config-cmap)# match dscp cs1 ! Creating policy-map and configure queueing for class-of-service cr22-4507-LB(config)#policy-map EGRESS-POLICY cr22-4507-LB(config-pmap)# class PRIORITY-QUEUE cr22-4507-LB(config-pmap-c)# priority cr22-4507-LB(config-pmap-c)# class CONTROL-MGMT-QUEUE cr22-4507-LB(config-pmap-c)# bandwidth remaining percent 10 cr22-4507-LB(config-pmap-c)# class MULTIMEDIA-CONFERENCING-QUEUE cr22-4507-LB(config-pmap-c)# bandwidth remaining percent 10 cr22-4507-LB(config-pmap-c)# class MULTIMEDIA-STREAMING-QUEUE cr22-4507-LB(config-pmap-c)# bandwidth remaining percent 10 cr22-4507-LB(config-pmap-c)# class TRANSACTIONAL-DATA-QUEUE cr22-4507-LB(config-pmap-c)# bandwidth remaining percent 10 cr22-4507-LB(config-pmap-c)# dbl cr22-4507-LB(config-pmap-c)# class BULK-DATA-QUEUE cr22-4507-LB(config-pmap-c)# bandwidth remaining percent 4 cr22-4507-LB(config-pmap-c)# dbl cr22-4507-LB(config-pmap-c)# class SCAVENGER-QUEUE cr22-4507-LB(config-pmap-c)# bandwidth remaining percent 1 cr22-4507-LB(config-pmap-c)# class class-default cr22-4507-LB(config-pmap-c)# bandwidth remaining percent 25 cr22-4507-LB(config-pmap-c)# dbl ! Attaching egress service-policy on all physical member-link ports cr24-4507-DO(config)#int range Ten3/1 . Ten5/4. The hardware-based priority-queue implementation on the Catalyst 4500-E does not support a built-in policer to restrict traffic during network congestion. Ten Gi1/1 . The following additional policy-map must be created to classify priority-queue class traffic and rate-limit up to 30 percent egress link capacity: cr22-4507-LB(config)#class-map match-any PRIORITY-QUEUE cr22-4507-LB (config-cmap)# match dscp ef cr22-4507-LB (config-cmap)# match dscp cs5 cr22-4507-LB (config-cmap)# match dscp cs4 cr22-4507-LB (config)#policy-map PQ-POLICER cr22-4507-LB (config-pmap)# class PRIORITY-QUEUE cr22-4507-LB (config-pmap-c)# police cir 300 m conform-action transmit exceed-action drop cr22-4507-LB (config)#interface range Port-Channel 1 cr22-4507-LB (config-if-range)#service-policy output PQ-POLICER Medium Enterprise Design Profile Reference Guide 2-104 .

Trust Trust Classification None 8 Class Model Yes Yes No No No Marking None Yes Yes Yes No No No Policing Yes Yes Yes Yes No No No Ingress Queuing 1 Yes Yes Yes Yes Yes Yes Yes Conditionally-Tru Trust sted Trusted Trusted Trusted Trust Trust Trust 1. printers etc Managed secured devices.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Table 2-7 Summarized Access-Layer Ingress QoS Deployment Guidelines End-Point Unmanaged devices. it is recommended to implement bidirectional QoS policies on distribution and core layer systems. Default. and virtualization. Servers etc Phone Phone + Mobile PC IP Video surveillance Camera Digital Media Player Core facing Uplinks Trust Model UnTrusted Trusted Trusted Conditionally-Truste d Trusted Trusted Trusted Classification / Marking / Policing None None None None None None Yes (PQ Policer) Egress Queuing Yes Yes Yes Yes Yes Yes Yes Bandwidth Share Yes Yes Yes Yes Yes Yes Yes Deploying Network-Layer QoS Campus network systems at the main site and remote campus are managed and maintained by the enterprise IT administration to provide key network foundation services such as routing. Medium Enterprise Design Profile Reference Guide 2-105 . Catalyst 29xx and 3xxx only Table 2-8 Summarized Access-Layer Egress QoS Deployment Guidelines End-Point Unmanaged devices. To allow for consistent application delivery through the network. printers etc Managed secured devices. In a best practice network environment. QoS. Servers etc Phone Phone + Mobile PC IP Video surveillance Camera Digital Media Player Core facing Uplinks Trust Model UnTrusted Trusted Trusted DSCP Trust Don’t Trust. these systems must be implemented with the recommended configuration to provide differentiated network services on per-hop basis. switching.

there is no need to reclassify the same class-of-service at the campus distribution and core layer. the Catalyst 4500-E deployed with either a Sup6E or Sup6L-E supervisor module in the distribution or core layer will automatically sets the physical ports in the trust mode. Based on global network QoS policy each class-of-service applications get common treatment. Implementing Network-Layer Ingress QoS As described earlier. Independent of enterprise network tier—LAN/WAN. However the default QoS function on campus distribution or core platforms like the Catalyst 3750-X and 6500-E Series switches is disabled. The network administrator must manually enable QoS globally on the switch and explicitly enable DSCP trust mode on each logical EtherChannel and each member-link interface connected to upstream and downstream devices. Distribution-Layer Catalyst 3750-X and 6500-E • 3750-X and 6500-E (Multilayer or Routed Access) cr22-6500-LB(config)#mls qos cr22-6500-LB#show mls qos Medium Enterprise Design Profile Reference Guide 2-106 . the distribution and core network must be deployed to trust incoming pre-marked DSCP traffic from the downstream Layer 2 or Layer 3 network device. The Catalyst 4500-E by default will perform DSCP-CoS or CoS-DSCP mappings to transmit traffic transparently without any QoS bits rewrites. platform type and their capabilities— each devices in the network will protect service quality and enable communication across the network without degrading the application performance. and egress. switching fabric. therefore. Cisco Catalyst access-layer switches must classify the application and device type to marks DSCP value based on the trust model with deep packet inspection using access-lists (ACL) or protocol-based device discovery. The following sample QoS configuration must be enabled on all the distribution and core layer switches deployed in campus LAN network.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design QoS Trust Boundary All medium enterprise IT managed campus LAN and WAN network systems can be classified as trusted device and must follow same QoS best practices recommended in previous subsection. This medium enterprise LAN network design recommends deploying a broad-range of Layer-3 Catalyst switching platforms in the campus distribution and core layer. The campus core and distribution network devices should rely on the access-layer switches to implement QoS classification and marking based on a wide-range of applications and IP-based devices deployed at the network edge. the hardware architecture of each switching platform is different. the internal campus core network must be considered to be trusted. Based on the simplified internal network trust model. To provide consistent and differentiated QoS services on per-hop basis across the network. The next-generation Cisco Catalyst access-layer platform must be deployed with more application-aware and intelligence at the network edge. the ingress QoS configuration also becomes more simplified and manageable. The campus distribution and core layers can trust DSCP markings from access-layer and provide QoS transparency without modifying the original parameters unless the network is congested. based on the platform capabilities and resources. It is recommended to avoid deploying trusted or untrusted endpoints directly to the campus distribution and core layer systems. This subsection provides common ingress QoS deployment guidelines for the campus distribution and core for all locations: QoS Trust Mode As described earlier. The distribution layer QoS trust configuration is the same for a multilayer or routed-access deployment. This will change how each various class-of-service traffic will be handled in different directions: ingress. As mentioned in the previous section.

Both Catalyst platforms support up to two ingress queues but how they are implemented differs. Ten2/0/1 . Implementing Catalyst 3750-X Ingress Queuing The ingress queuing function in the distribution-layer Catalyst 3750-X StackWise Plus must be deployed to differentiate and place the normal versus high-priority class traffic in separate ingress queue before forwarding it to the switching fabric.2 . Refer to the “Applying Ingress Queuing” section on page 2-97 for implementation detail. then depending on the DSCP and CoS markings it can queue the traffic prior sending it to the switching fabric in a FIFO manner. network administrator must apply this command on each bundled member-links. For consistent QoS within the campus network. cr36-3750x-xSB(config)#interface range Ten1/0/1 . Implementing Catalyst 6500-E Ingress Queuing There are two main considerations relevant to ingress queuing design on the Catalyst 6500/6500-E: • • The degree of oversubscription (if any) of the linecard Whether the linecard requires trust-CoS to be enabled to engage ingress queuing Medium Enterprise Design Profile Reference Guide 2-107 .Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services QoS is enabled globally … Implement DSCP Trust Mode • Catalyst 6500-E (Multilayer or Routed Access) cr22-6500-LB(config)#interface Port-channel100 cr22-6500-LB(config-if)# description Connected to cr22-4507-LB cr22-6500-LB(config-if)# mls qos trust dscp Catalyst 6500-E will automatically replicate “mls qos trust dscp” command from port-channel interface to each bundled member-links. the core and access layers should map DSCP-marked traffic into ingress queues the same way. therefore.2 cr36-3750x-xSB(config-if-range)# description Connected to cr23-VSS-Core cr36-3750x-xSB(config-if-range)# mls qos trust dscp cr36-3750x-xSB#show mls qos interface Ten1/0/1 TenGigabitEthernet1/0/1 trust state: trust dscp trust mode: trust dscp … Applying Ingress Queuing When Cisco Catalyst 3750-X and 6500-E switching platforms receive various class-of-service requests from different physical ports. cr22-6500-LB#show queueing interface Ten1/1/2 | inc QoS|Trust Port QoS is enabled Trust boundary disabled Trust state: trust DSCP Catalyst 3750-X (Multilayer or Routed Access) Catalyst 3750-X does not support mls qos trust dscp command on port-channel interface. The Cisco Catalyst 4500-E deployed with a Sup6E or a Sup6L-E supervisor module does not support ingress queuing.

In Performance mode. it is not recommended to enable CoS-based ingress queuing on the Catalyst 6500-E. To manage application-class service levels during such extreme scenarios. it is often more cost-effective to use linecards that have a degree of oversubscription within the campus network. a second important consideration that many Catalyst 6500-E linecards only support CoS-based ingress queuing models that reduces classification and marking granularity—limiting the administrator to an 8-class 802. Table 2-9 summarizes recommended linecards consideration by listing and oversubscription ratios and whether the ingress queuing models are CoS or DSCP-based.html Medium Enterprise Design Profile Reference Guide 2-108 . Since such a scenario is extremely unlikely. it is recommended to enable 1P7Q2T DSCP-based ingress queuing on this linecard in Oversubscription Mode. rather. if this design choice has been made. ingress queuing models may be enabled. Therefore. While the presence of oversubscribed linecard architectures may be viewed as the sole consideration as to enabling ingress queuing or not. it is important for network administrators to recognize the potential for drops due to oversubscribed linecard architectures. limit such linecards and deploy either non-oversubscribed linecards and/or linecards supporting DSCP-based queuing at the distribution and core layers of the campus network. However. only one port in every group of four is operational (while the rest are administratively shut down). In Oversubscription Mode (the default mode). Table 2-9 Catalyst 6500-E Switch Module Ingress Queuing Architecture Switch Module WS-6724-SF P WS-6704-10 GE WS-6708-10 GE WS-6716-10 GE Maximum Input 24 Gbps (24 x GE ports) 40 Gbps (4 x 10GE ports) 80 Gbps (8 x 10GE ports) 160 Gbps (16 x 10GE ports) Maximum Output (To Backplane) 40 Gbps (2 x 20 Gbps) Oversubscription Ratio 2:1 Ingress Queuing Structure 1P3Q8T 8Q8T 8Q4T CoS / DSCP Based CoS based CoS or DSCP based CoS or DSCP based CoS or DSCP based Ingress Queuing Recommendations Not Required Not Required Use DSCP-based 8Q4T ingress queuing Use DSCP-based 1P7Q2T ingress queuing 4:1 8Q4T / 1P7Q2T* Note The Catalyst WS-X6716-10GE can be configured to operate in Performance Mode (with an 8Q4T ingress queuing structure) or in Oversubscription Mode (with a 1P7Q2T ingress queuing structure). all ports are operational and the maximum oversubscription ratio is 4:1. Additional details on these WS-X6716-10GE operational modes can be found at the following URL: http://www. DSCP values are overwritten (via the CoS-to-DSCP mapping table) and application classes sharing the same CoS values are longer distinguishable from one another.com/en/US/prod/collateral/switches/ps5718/ps708/qa_cisco_catalyst_6500_series_1 6port_10gigabit_ethernet_module. Therefore. which eliminates any oversubscription on this linecard and as such ingress queuing is not required (as only 4 x 10GE ports are active in this mode and the backplane access rate is also at 40 Gbps). Once CoS is trusted.1Q/p model.cisco. given this classification and marking limitation and the fact that the value of enabling ingress queuing is only achieved in extremely rare scenarios.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Some linecards may be designed to support a degree of oversubscription that theoretically offers more traffic to the linecard than the sum of all GE/10GE switch ports than can collectively access the switching backplane at once.

10% BW to Q4. 10% to Q4. therefore. ! Allocates 10% to Q5. 10% BW to Q6.8 . 10% to Q3. 2/1/2-8 cr22-vss-core(config-if-range)# mls qos queue-mode mode-dscp ! Enables DSCP-to-Queue mapping ! This section configures the receive queues BW and limits cr22-vss-core(config-if-range)# rcv-queue queue-limit 10 25 10 10 10 10 10 15 ! Allocates 10% to Q1. 25% BW to Q2. Figure 2-61 depicts how different class-of-service applications are mapped to the Ingress Queue structure (8Q4T) and how each queue is assigned a different WTD threshold. • Distribution and Core-Layer Catalyst 6500-E in VSS mode ! This section configures the port for DSCP-based Ingress queuing cr22-vss-core(config)#interface range TenGigabitEthernet 1/1/2 . Figure 2-61 Catalyst 6500-E Ingress Queuing Model Application Network Control Internetwork Control VoIP Broadcast Video Realtime Interactive Multimedia Conferencing Multimedia Streaming Signaling Transactional Data Network Management Bulk Data Best Effort Scavenger Best Effort phb CS7 CS6 EF CS5 CS4 AF4 AF3 CS3 AF2 CS2 AF1 DF CS1 DF Ingress Queue 1P7Q4T EF CS5 CS4 CS7 CS6 CS3 CS2 AF4 AF3 AF2 AF1 CS1 DF Q7 (10%) Priority Queue Q8 (30%) Q6 (10%) Q5 (10%) Q4 (10%) Q3 (4%) Q2 (1%) Q1 (25%) 228984 The corresponding configuration for 8Q8T (DSCP-to-Queue) ingress queuing on a Catalyst 6500-E VSS in distribution and core layer is shown below. PFC function is active on active and hot-standby virtual-switch nodes. These queuing models are detailed in the following sections. then 8Q4T DSCP-based ingress queuing and 1P7Q2T DSCP-based ingress queuing (respectively) are recommended to be enabled. 25% to Q2. 10% BW to Q7 & 30% BW to Q8 ! This section enables WRED on all queues except Q8 cr22-vss-core(config-if-range)# rcv-queue random-detect 1 ! Enables WRED on Q1 cr22-vss-core(config-if-range)# rcv-queue random-detect 2 Medium Enterprise Design Profile Reference Guide 2-109 . ! Allocates 10% BW to Q5. ingress queuing must be configured on each distributed member-links of Layer 2 or Layer 3 MEC. 4% BW to Q3. 10% to Q7 and 15% to Q8 cr22-vss-core(config-if-range)# rcv-queue bandwidth 1 25 4 10 10 10 10 30 ! Allocates 1% BW to Q1. 10% to Q6.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services If 6708 and 6716 linecards (with the latter operating in oversubscription mode) are used in the distribution and core layers of the campus network.

Chapter 2 Deploying Medium Enterprise Network Foundation Services

Medium Enterprise Design Profile (MEDP)—LAN Design

! Enables WRED on Q2 cr22-vss-core(config-if-range)# ! Enables WRED on Q3 cr22-vss-core(config-if-range)# ! Enables WRED on Q4 cr22-vss-core(config-if-range)# ! Enables WRED on Q5 cr22-vss-core(config-if-range)# ! Enables WRED on Q6 cr22-vss-core(config-if-range)# ! Enables WRED on Q7 cr22-vss-core(config-if-range)# ! Disables WRED on Q8

rcv-queue random-detect 3 rcv-queue random-detect 4 rcv-queue random-detect 5 rcv-queue random-detect 6 rcv-queue random-detect 7 no rcv-queue random-detect 8

! This section configures WRED thresholds for Queues 1 through 7 cr22-vss-core(config-if-range)# rcv-queue random-detect max-threshold ! Sets all WRED max thresholds on Q1 to 100% cr22-vss-core(config-if-range)# rcv-queue random-detect min-threshold ! Sets Q1T1 min WRED threshold to 80% cr22-vss-core(config-if-range)# rcv-queue random-detect min-threshold ! Sets Q2T1 min WRED threshold to 80% cr22-vss-core(config-if-range)# rcv-queue random-detect max-threshold ! Sets all WRED max thresholds on Q2 to 100% cr22-vss-core(config-if-range)# rcv-queue random-detect min-threshold ! Sets WRED min thresholds for Q3T1, Q3T2, Q3T3 to 70 %, 80% and 90% cr22-vss-core(config-if-range)# rcv-queue random-detect max-threshold ! Sets WRED max thresholds for Q3T1, Q3T2, Q3T3 to 80%, 90% and 100% cr22-vss-core(config-if-range)# rcv-queue random-detect min-threshold ! Sets WRED min thresholds for Q4T1, Q4T2, Q4T3 to 70 %, 80% and 90% cr22-vss-core(config-if-range)# rcv-queue random-detect max-threshold ! Sets WRED max thresholds for Q4T1, Q4T2, Q4T3 to 80%, 90% and 100% cr22-vss-core(config-if-range)# rcv-queue random-detect min-threshold ! Sets WRED min thresholds for Q5T1, Q5T2, Q5T3 to 70 %, 80% and 90% cr22-vss-core(config-if-range)# rcv-queue random-detect max-threshold ! Sets WRED max thresholds for Q5T1, Q5T2, Q5T3 to 80%, 90% and 100% cr22-vss-core(config-if-range)# rcv-queue random-detect min-threshold ! Sets WRED min thresholds for Q6T1, Q6T2, Q6T3 to 70 %, 80% and 90% cr22-vss-core(config-if-range)# rcv-queue random-detect max-threshold ! Sets WRED max thresholds for Q6T1, Q6T2, Q6T3 to 80%, 90% and 100% cr22-vss-core(config-if-range)# rcv-queue random-detect min-threshold ! Sets WRED min thresholds for Q7T1, Q7T2, Q7T3 and Q7T4 ! to 60%, 70%, 80% and 90%, respectively cr22-vss-core(config-if-range)# rcv-queue random-detect max-threshold ! Sets WRED max thresholds for Q7T1, Q7T2, Q7T3 and Q7T4 ! to 70%, 80%, 90% and 100%, respectively ! This section configures the DSCP-to-Receive-Queue mappings cr22-vss-core(config-if-range)# rcv-queue dscp-map 1 1 8 ! Maps CS1 (Scavenger) to Q1T1 cr22-vss-core(config-if-range)# rcv-queue dscp-map 2 1 0 ! Maps DF (Best Effort) to Q2T1 cr22-vss-core(config-if-range)# rcv-queue dscp-map 3 1 14 ! Maps AF13 (Bulk Data-Drop Precedence 3) to Q3T1 cr22-vss-core(config-if-range)# rcv-queue dscp-map 3 2 12 ! Maps AF12 (Bulk Data-Drop Precedence 2) to Q3T2 cr22-vss-core(config-if-range)# rcv-queue dscp-map 3 3 10 ! Maps AF11 (Bulk Data-Drop Precedence 1) to Q3T3 cr22-vss-core(config-if-range)# rcv-queue dscp-map 4 1 22 ! Maps AF23 (Transactional Data-Drop Precedence 3) to Q4T1 cr22-vss-core(config-if-range)# rcv-queue dscp-map 4 2 20 ! Maps AF22 (Transactional Data-Drop Precedence 2) to Q4T2 cr22-vss-core(config-if-range)# rcv-queue dscp-map 4 3 18 ! Maps AF21 (Transactional Data-Drop Precedence 1) to Q4T3

1 100 100 100 100 1 80 100 100 100 2 80 100 100 100 2 100 100 100 100

3 70 80 90 100 3 80 90 100 100 4 70 80 90 100 4 80 90 100 100 5 70 80 90 100 5 80 90 100 100 6 70 80 90 100 6 80 90 100 100 7 60 70 80 90

7 70 80 90 100

Medium Enterprise Design Profile Reference Guide

2-110

Chapter 2

Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services

cr22-vss-core(config-if-range)# rcv-queue dscp-map 5 1 30 ! Maps AF33 (Multimedia Streaming-Drop Precedence 3) to Q5T1 cr22-vss-core(config-if-range)# rcv-queue dscp-map 5 2 28 ! Maps AF32 (Multimedia Streaming-Drop Precedence 2) to Q5T2 cr22-vss-core(config-if-range)# rcv-queue dscp-map 5 3 26 ! Maps AF31 (Multimedia Streaming-Drop Precedence 1) to Q5T3 cr22-vss-core(config-if-range)# rcv-queue dscp-map 6 1 38 ! Maps AF43 (Multimedia Conferencing-Drop Precedence 3) to Q6T1 cr22-vss-core(config-if-range)# rcv-queue dscp-map 6 2 36 ! Maps AF42 (Multimedia Conferencing-Drop Precedence 2) to Q6T2 cr22-vss-core(config-if-range)# rcv-queue dscp-map 6 3 34 ! Maps AF41 (Multimedia Conferencing-Drop Precedence 1) to Q6T3 cr22-vss-core(config-if-range)# rcv-queue dscp-map 7 1 16 ! Maps CS2 (Network Management) to Q7T1 cr22-vss-core(config-if-range)# rcv-queue dscp-map 7 2 24 ! Maps CS3 (Signaling) to Q7T2 cr22-vss-core(config-if-range)# rcv-queue dscp-map 7 3 48 ! Maps CS6 (Internetwork Control) to Q7T3 cr22-vss-core(config-if-range)# rcv-queue dscp-map 7 4 56 ! Maps CS7 (Network Control) to Q7T4 cr22-vss-core(config-if-range)# rcv-queue dscp-map 8 4 32 40 46 ! Maps CS4 (Realtime Interactive), CS5 (Broadcast Video), ! and EF (VoIP) to Q8 cr23-VSS-Core#show queueing interface Ten1/1/2 | begin Rx Queueing Mode In Rx direction: mode-dscp Receive queues [type = 8q4t]: Queue Id Scheduling Num of thresholds ----------------------------------------01 WRR 04 02 WRR 04 03 WRR 04 04 WRR 04 05 WRR 04 06 WRR 04 07 WRR 04 08 WRR 04 WRR bandwidth ratios: 1[queue 1] 25[queue 2] 10[queue 6] 10[queue 7] 30[queue 8] queue-limit ratios: 10[queue 1] 25[queue 2] 10[queue 6] 10[queue 7] 15[queue 8] queue tail-drop-thresholds -------------------------1 70[1] 80[2] 90[3] 100[4] 2 100[1] 100[2] 100[3] 100[4] 3 100[1] 100[2] 100[3] 100[4] 4 100[1] 100[2] 100[3] 100[4] 5 100[1] 100[2] 100[3] 100[4] 6 100[1] 100[2] 100[3] 100[4] 7 100[1] 100[2] 100[3] 100[4] 8 100[1] 100[2] 100[3] 100[4] queue random-detect-min-thresholds ---------------------------------1 80[1] 100[2] 100[3] 100[4] 2 80[1] 100[2] 100[3] 100[4] 3 70[1] 80[2] 90[3] 100[4] 4 70[1] 80[2] 90[3] 100[4] 5 70[1] 80[2] 90[3] 100[4] 6 70[1] 80[2] 90[3] 100[4] 7 60[1] 70[2] 80[3] 90[4] 8 100[1] 100[2] 100[3] 100[4] 4[queue 3] 10[queue 3] 10[queue 4] 10[queue 4] 10[queue 10[queue

5] 5]

Medium Enterprise Design Profile Reference Guide

2-111

Chapter 2 Deploying Medium Enterprise Network Foundation Services

Medium Enterprise Design Profile (MEDP)—LAN Design

queue random-detect-max-thresholds ---------------------------------1 100[1] 100[2] 100[3] 100[4] 2 100[1] 100[2] 100[3] 100[4] 3 80[1] 90[2] 100[3] 100[4] 4 80[1] 90[2] 100[3] 100[4] 5 80[1] 90[2] 100[3] 100[4] 6 80[1] 90[2] 100[3] 100[4] 7 70[1] 80[2] 90[3] 100[4] 8 100[1] 100[2] 100[3] 100[4] WRED disabled queues: … queue thresh dscp-map --------------------------------------1 1 1 2 3 4 5 6 7 8 9 11 13 15 17 19 21 23 25 27 29 31 33 39 41 42 43 44 45 47 1 1 1 2 2 2 2 3 3 3 3 4 4 4 4 5 5 5 5 6 6 6 6 7 7 7 7 8 8 8 8 … Packets dropped on Receive: BPDU packets: 0 queue dropped [dscp-map] --------------------------------------------1 0 [1 2 3 4 5 6 7 8 9 11 13 15 17 19 21 23 25 27 29 31 33 39 41 42 43 44 45 47 ] 2 0 [0 ] 3 0 [14 12 10 ] 4 0 [22 20 18 ] 5 0 [30 35 37 28 26 ] 6 0 [38 49 50 51 52 53 54 55 57 58 59 60 61 62 63 36 34 ] 7 0 [16 24 48 56 ] 8 0 [32 40 46 ] 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 8

0

14 12 10 22 20 18 30 35 37 28 26 38 49 50 51 52 53 54 55 57 58 59 60 61 62 63 36 34 16 24 48 56

32 40 46

Medium Enterprise Design Profile Reference Guide

2-112

Chapter 2

Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services

Implementing Network Core Egress QoS
The QoS implementation of egress traffic towards network edge devices on access-layer switches are much simplified compared to ingress traffic which requires stringent QoS policies to provide differentiated services and network bandwidth protection. Unlike the Ingress QoS model, the egress QoS model must provides optimal queuing policies for each class and sets the drop thresholds to prevent network congestion and an application performance impact. With egress queuing in DSCP mode, the Cisco Catalyst switching platforms and linecards are bounded by a limited number of egress hardware queues.
Catalyst 3750-X and 4500-E

The configuration and implementation guideline for egress QoS on Catalyst 3750-X StackWise and Catalyst 4500-E with Sup6E and Sup6L-E in distribution and access-layer roles remains consistent. All conformed traffic marked with DSCP values must be manually assigned to each egress queue based on a four class-of-service QoS model. Refer to the “Implementing Access-Layer Egress QoS” section on page 2-99 for the deployment details.
Catalyst 6500-E – VSS

The Cisco Catalyst 6500-E in VSS mode operates in a centralized management mode but uses a distributed forwarding architecture. The Policy Feature Card (PFC) on active and hot-standby is functional on both nodes and is independent of the virtual-switch role. Like ingress queuing, the network administrator must implement egress queuing on each of the member-links of the Layer 2 or Layer 3 MEC. The egress queuing model on the Catalyst 6500-E is based on linecard type and its capabilities, when deploying Catalyst 6500-E in VSS mode only the WS-67xx series 1G/10G linecard with daughter card – CFC or DFC3C/DFC3CXL is supported. Table 2-10 describes the deployment guidelines for the Catalyst 6500-E Series linecard module in the campus distribution and core layer network. In the solutions lab, the WS-6724-SFP and WS-6708-10GE was validated in the campus distribution and core layers. Both modules supports different egress queuing models, this sub-section will provide deployment guidelines for both module types.
Table 2-10 Catalyst 6500-E Switch Module Egress Queuing Architecture

Switch Module WS-6724-SFP WS-6704-10GE WS-6708-10GE WS-6716-10GE

Daughter Card CFC or DFC3 CFC DFC3 DFC3 DFC3

Egress Queue and Drop Thresholds 1P3Q8T 1P7Q8T 1P7Q4T 1P7Q8T (Oversubscription and Perf. Mode)

Egress Queue Scheduler DWRR DWRR DWRR SRR

Total Buffer Size 1.3 MB 16 MB 198 MB 198 MB1 91 MB2

Egress Buffer Size 1.2 MB 14 MB 90 MB 90 MB 1 1 MB2

1. Per Port Capacity in Performance Mode 2. Per Port Capacity in Oversubscription Mode

WS-6724-SFP – 1P3Q8T Egress Queuing Model

On the WS-6724-SFP module the egress queuing functions on per physical port basis and independent of link-layer and above protocols settings, these functions remain consistent when the physical port is deployed in standalone or bundled into an EtherChannel. Each 1G physical port support 4 egress queues

Medium Enterprise Design Profile Reference Guide

2-113

Chapter 2 Deploying Medium Enterprise Network Foundation Services

Medium Enterprise Design Profile (MEDP)—LAN Design

with default CoS based on the transmit side. This module is a cost-effective 1G non-blocking high speed network module but does not provide deep application granularity based on different DSCP markings. It does not have the flexibility to use various class-of-service egress queue for applications. Campus LAN QoS consolidation to a 4 class model occurs on the physical paths that connects to the WAN or Internet Edge routers, which forwards traffic across a private WAN or the Internet. Deploying the WS-6724-SFP module in 4 class model would be recommended in that design. Figure 2-62 illustrates 1P3Q8T egress queuing model to be applied on Catalyst 6500-E – WS-6724-SF module.
Figure 2-62 1P3Q8T Egress Queuing Model

Application Network Control Internetwork Control VoIP Broadcast Video Multimedia Conferencing Realtime Interactive Multimedia Streaming Signaling Transactional Data Network Management Bulk Data Best Effort Scavenger Best Effort

PHP CS7 CS6 EF

CoS CoS 7 CoS 6 CoS 5

Egress Queue 1P3Q8T CoS 5 Priority Queue (30%) CoS 4 CoS 7 CoS 6 Q3T4 Q3T3 Q3T2 Queue 3 (40%) Q3T1

CS5 AF4 CoS 4 CS4 AF3 CoS 3 CS3 AF2 CoS 2 CS2 AF1 DF CS1 DF CoS 1 DF

CoS 3 CoS 2

CoS 0

Queue 2 (25%)

CoS 1 CoS 0

The following corresponding 1P3Q8T egress queuing configuration must be applied on each member-links of MEC.

Catalyst 6500-E VSS (Distribution and Core)

cr23-vss-core(config)#interface range GigabitEthernet 1/2/1-24 , Gi2/2/1 - 24 cr23-vss-core(config-if-range)# wrr-queue queue-limit 20 25 40 ! Allocates 20% of the buffers to Q1, 25% to Q2 and 40% to Q3 cr23-vss-core(config-if-range)# priority-queue queue-limit 15 ! Allocates 15% of the buffers to the PQ cr23-vss-core(config-if-range)# wrr-queue bandwidth 5 25 40 ! Allocates 5% BW to Q1, 25% BW to Q2 and 30% BW to Q3 ! This section enables WRED on cr23-vss-core(config-if-range)# ! Enables WRED on Q1 cr23-vss-core(config-if-range)# ! Enables WRED on Q2 cr23-vss-core(config-if-range)# ! Enables WRED on Q3 Queues 1 through 3 wrr-queue random-detect 1 wrr-queue random-detect 2 wrr-queue random-detect 3

! This section configures WRED thresholds for Queues 1 through 3

Medium Enterprise Design Profile Reference Guide

2-114

228985

Queue 1 (5%)

Chapter 2

Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services

cr23-vss-core(config-if-range)# 100 100 100 100 ! Sets all WRED max thresholds cr23-vss-core(config-if-range)# 100 100 100 ! Sets Q1T1 min WRED threshold cr23-vss-core(config-if-range)# 100 100 100 100 ! Sets all WRED max thresholds cr23-vss-core(config-if-range)# 100 100 100 ! Sets Q2T1 min WRED threshold cr23-vss-core(config-if-range)# 100 100 100 ! Sets Q3T1 max WRED threshold ! Sets Q3T3 max WRED threshold cr23-vss-core(config-if-range)# 100 100 100 ! Sets Q3T1 min WRED threshold ! Sets Q3T3 min WRED threshold

wrr-queue random-detect max-threshold 1 100 100 100 100 on Q1 to 100% wrr-queue random-detect min-threshold 1 80 100 100 100 100 to 80%; all others set to 100% wrr-queue random-detect max-threshold 2 100 100 100 100 on Q2 to 100% wrr-queue random-detect min-threshold 2 80 100 100 100 100 to 80%; all others set to 100% wrr-queue random-detect max-threshold 3 70 80 90 100 100 to 70%; Q3T2 max WRED threshold to 80%; to 90%; Q3T4 max WRED threshold to 100% wrr-queue random-detect min-threshold 3 60 70 80 90 100 to 60%; Q3T2 min WRED threshold to 70%; to 80%; Q3T4 min WRED threshold to 90%

! This section configures the CoS-to-Queue/Threshold mappings cr23-vss-core(config-if-range)# wrr-queue cos-map 1 1 1 ! Maps CoS 1 (Scavenger and Bulk Data) to Q1T1 cr23-vss-core(config-if-range)# wrr-queue cos-map 2 1 0 ! Maps CoS 0 (Best Effort) to Q2T1 cr23-vss-core(config-if-range)# wrr-queue cos-map 3 1 2 ! Maps CoS 2 (Network Management and Transactional Data) to Q3T1 cr23-vss-core(config-if-range)# wrr-queue cos-map 3 2 3 ! Maps CoS 3 (Signaling and Multimedia Streaming) to Q3T2 cr23-vss-core(config-if-range)# wrr-queue cos-map 3 3 6 ! Maps CoS 6 (Internetwork Control) to Q3T3 cr23-vss-core(config-if-range)# wrr-queue cos-map 3 4 7 ! Maps CoS 7 (Network Control) to Q3T4 cr23-vss-core(config-if-range)# priority-queue cos-map 1 4 5 ! Maps CoS 4 (Realtime Interactive and Multimedia Conferencing) to PQ ! Maps CoS 5 (VoIP and Broadcast Video) to the PQ cr23-VSS-Core#show queueing interface GigabitEthernet 1/2/1 Interface GigabitEthernet1/2/1 queueing strategy: Weighted Round-Robin Port QoS is enabled Trust boundary disabled Trust state: trust DSCP Extend trust state: not trusted [COS = 0] Default COS is 0 Queueing Mode In Tx direction: mode-cos Transmit queues [type = 1p3q8t]: Queue Id Scheduling Num of thresholds ----------------------------------------01 WRR 08 02 WRR 08 03 WRR 08 04 Priority 01 WRR bandwidth ratios: queue-limit ratios: 5[queue 1] 20[queue 1] 25[queue 2] 25[queue 2] 40[queue 3] 40[queue 3]

15[Pri Queue]

queue tail-drop-thresholds -------------------------1 70[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8] 2 70[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8] 3 100[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8]

Medium Enterprise Design Profile Reference Guide

2-115

Chapter 2 Deploying Medium Enterprise Network Foundation Services

Medium Enterprise Design Profile (MEDP)—LAN Design

queue random-detect-min-thresholds ---------------------------------1 80[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8] 2 80[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8] 3 60[1] 70[2] 80[3] 90[4] 100[5] 100[6] 100[7] 100[8] queue random-detect-max-thresholds ---------------------------------1 100[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8] 2 100[1] 100[2] 100[3] 100[4] 100[5] 100[6] 100[7] 100[8] 3 70[1] 80[2] 90[3] 100[4] 100[5] 100[6] 100[7] 100[8] WRED disabled queues: queue thresh cos-map --------------------------------------1 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 2 1 0 2 2 2 3 2 4 2 5 2 6 2 7 2 8 3 1 2 3 2 3 3 3 6 3 4 7 3 5 3 6 3 7 3 8 4 1 4 5 …

WS-6708-10GE and WS-6716-10GE – 1P7Q4T Egress Queuing Model

The hardware design of the next-generation 10G linecards are designed with advanced ASICs and higher capacity to ensure the campus backbone of large enterprise networks are ready for future. Both modules support DSCP based on the 8 queue model to deploy flexible and scalable QoS in the campus core. With 8-egress queue support the WS-6708-10G and WS-6716-10G modules increased application granularity based on various DSCP markings are done at the network edge. Figure 2-63 illustrates DSCP-based 1P7Q4T egress queuing model.

Medium Enterprise Design Profile Reference Guide

2-116

! Allocates 10% to Q5. 10% to Q3. 25% to Q2. 10% BW to Q4.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Figure 2-63 P7Q4T Egress Queuing Model Application Network Control Internetwork Control VoIP Broadcast Video Realtime Interactive Multimedia Conferencing Multimedia Streaming Signaling Transactional Data Network Management Bulk Data Best Effort Scavenger Best Effort phb CS7 CS6 EF CS5 CS4 AF4 AF3 CS3 AF2 CS2 AF1 DF CS1 DF Ingress Queue 1P7Q4T EF CS5 CS4 CS7 CS6 CS3 CS2 AF4 AF3 AF2 AF1 CS1 DF Q7 (10%) Priority Queue Q8 (30%) Q6 (10%) Q5 (10%) Q4 (10%) Q3 (4%) Q2 (1%) Q1 (25%) 228984 The following corresponding 1P7Q4T egress queuing configuration must be applied on each member-links of MEC.8 cr23-vss-core(config-if-range)# wrr-queue queue-limit 10 25 10 10 10 10 10 ! Allocates 10% of the buffers to Q1. • Catalyst 6500-E VSS (Distribution and Core) cr23-vss-core(config)#interface range TenGigabitEthernet 1/1/2 . 4% BW to Q3. ! Allocates 10% BW to Q5. 10% to Q4. 2/1/2 . 25% BW to Q2. 10% to Q6 and 10% to Q7 cr23-vss-core(config-if-range)# wrr-queue bandwidth 1 25 4 10 10 10 10 ! Allocates 1% BW to Q1.8 . 10% BW to Q6 and 10% BW to Q7 cr23-vss-core(config-if-range)# priority-queue queue-limit 15 ! Allocates 15% of the buffers to the PQ ! This section enables WRED on cr23-vss-core(config-if-range)# ! Enables WRED on Q1 cr23-vss-core(config-if-range)# ! Enables WRED on Q2 cr23-vss-core(config-if-range)# ! Enables WRED on Q3 cr23-vss-core(config-if-range)# ! Enables WRED on Q4 cr23-vss-core(config-if-range)# ! Enables WRED on Q5 cr23-vss-core(config-if-range)# ! Enables WRED on Q6 cr23-vss-core(config-if-range)# ! Enables WRED on Q7 Queues 1 through 7 wrr-queue random-detect 1 wrr-queue random-detect 2 wrr-queue random-detect 3 wrr-queue random-detect 4 wrr-queue random-detect 5 wrr-queue random-detect 6 wrr-queue random-detect 7 ! This section configures WRED thresholds for Queues 1 through 7 cr23-vss-core(config-if-range)# wrr-queue random-detect max-threshold 1 100 100 100 100 Medium Enterprise Design Profile Reference Guide 2-117 .

Q3T3 to 80%. Q4T3 to 70 %. Q7T2. 80% and 90% cr23-vss-core(config-if-range)# wrr-queue random-detect min-threshold ! Sets WRED min thresholds for Q4T1. Q6T2. Q5T2. 70%. Q6T3 to 70 %. Q5T3 to 70 %. 80% and 90% cr23-vss-core(config-if-range)# wrr-queue random-detect max-threshold ! Sets WRED max thresholds for Q4T1. 80%. Q4T2. 90% and 100% cr23-vss-core(config-if-range)# wrr-queue random-detect min-threshold ! Sets WRED min thresholds for Q3T1. 90% and 100% cr23-vss-core(config-if-range)# wrr-queue random-detect min-threshold ! Sets WRED min thresholds for Q6T1. 90% and 100% cr23-vss-core(config-if-range)# wrr-queue random-detect min-threshold ! Sets WRED min thresholds for Q5T1. Q3T2. Q5T3 to 80%. 90% and 100%. 90% and 100% cr23-vss-core(config-if-range)# wrr-queue random-detect min-threshold ! Sets WRED min thresholds for Q7T1. Q6T2. 80% and 90% cr23-vss-core(config-if-range)# wrr-queue random-detect max-threshold ! Sets WRED max thresholds for Q6T1. respectively cr23-vss-core(config-if-range)# wrr-queue random-detect max-threshold ! Sets WRED max thresholds for Q7T1. Q4T3 to 80%. Q4T2. Q7T2.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design ! Sets all WRED max thresholds on Q1 to 100% cr23-vss-core(config-if-range)# wrr-queue random-detect min-threshold ! Sets Q1T1 min WRED threshold to 80% cr23-vss-core(config-if-range)# wrr-queue random-detect max-threshold ! Sets all WRED max thresholds on Q2 to 100% cr23-vss-core(config-if-range)# wrr-queue random-detect min-threshold ! Sets Q2T1 min WRED threshold to 80% cr23-vss-core(config-if-range)# wrr-queue random-detect max-threshold ! Sets WRED max thresholds for Q3T1. 80% and 90%. Q7T3 and Q7T4 ! to 60%. Q5T2. Q6T3 to 80%. 80% and 90% cr23-vss-core(config-if-range)# wrr-queue random-detect max-threshold ! Sets WRED max thresholds for Q5T1. Q3T2. Q3T3 to 70 %. respectively 1 80 100 100 100 2 100 100 100 100 2 80 100 100 100 3 80 90 100 100 3 70 80 90 100 4 70 80 90 100 4 80 90 100 100 5 70 80 90 100 5 80 90 100 100 6 70 80 90 100 6 80 90 100 100 7 60 70 80 90 7 70 80 90 100 ! This section configures the DSCP-to-Queue/Threshold mappings cr23-vss-core(config-if-range)# wrr-queue dscp-map 1 1 8 ! Maps CS1 (Scavenger) to Q1T1 cr23-vss-core(config-if-range)# wrr-queue dscp-map 2 1 0 ! Maps DF (Best Effort) to Q2T1 cr23-vss-core(config-if-range)# wrr-queue dscp-map 3 1 14 ! Maps AF13 (Bulk Data-Drop Precedence 3) to Q3T1 cr23-vss-core(config-if-range)# wrr-queue dscp-map 3 2 12 ! Maps AF12 (Bulk Data-Drop Precedence 2) to Q3T2 cr23-vss-core(config-if-range)# wrr-queue dscp-map 3 3 10 ! Maps AF11 (Bulk Data-Drop Precedence 1) to Q3T3 cr23-vss-core(config-if-range)# wrr-queue dscp-map 4 1 22 ! Maps AF23 (Transactional Data-Drop Precedence 3) to Q4T1 cr23-vss-core(config-if-range)# wrr-queue dscp-map 4 2 20 ! Maps AF22 (Transactional Data-Drop Precedence 2) to Q4T2 cr23-vss-core(config-if-range)# wrr-queue dscp-map 4 3 18 ! Maps AF21 (Transactional Data-Drop Precedence 1) to Q4T3 cr23-vss-core(config-if-range)# wrr-queue dscp-map 5 1 30 ! Maps AF33 (Multimedia Streaming-Drop Precedence 3) to Q5T1 cr23-vss-core(config-if-range)# wrr-queue dscp-map 5 2 28 ! Maps AF32 (Multimedia Streaming-Drop Precedence 2) to Q5T2 cr23-vss-core(config-if-range)# wrr-queue dscp-map 5 3 26 ! Maps AF31 (Multimedia Streaming-Drop Precedence 1) to Q5T3 cr23-vss-core(config-if-range)# wrr-queue dscp-map 6 1 38 ! Maps AF43 (Multimedia Conferencing-Drop Precedence 3) to Q6T1 cr23-vss-core(config-if-range)# wrr-queue dscp-map 6 2 36 ! Maps AF42 (Multimedia Conferencing-Drop Precedence 2) to Q6T2 cr23-vss-core(config-if-range)# wrr-queue dscp-map 6 3 34 ! Maps AF41 (Multimedia Conferencing-Drop Precedence 1) to Q6T3 cr23-vss-core(config-if-range)# wrr-queue dscp-map 7 1 16 ! Maps CS2 (Network Management) to Q7T1 cr23-vss-core(config-if-range)# wrr-queue dscp-map 7 2 24 Medium Enterprise Design Profile Reference Guide 2-118 . Q7T3 and Q7T4 ! to 70%.

Some of the high availability techniques can be achieved with the LAN network design inherent within the medium enterprise network design. a non-responsive supervisor. the minimum threshold needs to be configured before the maximum (as is the case on queues 4 through 7 in the example above). such as software crashes. Networks that are built on these three fundamentals. and resilient next-generation IP network. the resiliency option appropriate to the role and network service type must be deployed: • • • Network resiliency—Provides redundancy during physical link failures.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services ! Maps CS3 (Signaling) to Q7T2 cr23-vss-core(config-if-range)# wrr-queue dscp-map 7 3 48 ! Maps CS6 (Internetwork Control) to Q7T3 cr23-vss-core(config-if-range)# wrr-queue dscp-map 7 4 56 ! Maps CS7 (Network Control) to Q7T4 cr23-vss-core(config-if-range)# priority-queue dscp-map 1 32 40 46 ! Maps CS4 (Realtime Interactive). the network architects builds strong. the critical network systems that are deployed in the main campus that provide global connectivity may require additional hardware and software components to provide non-stop communications. High-Availability in LAN Network Design Network reliability and availability is not a new demand. To prevent a catastrophic network failure during an unplanned network outage event. it is important to identify network fault domains and define rapid recovery plans to minimize the application impact during minor and major network outage conditions. However. at times the maximum threshold needs to be configured before the minimum (as is the case on queues 1 through 3 in the example above). and so on. Device resiliency—Protects the network during abnormal node failure triggered by hardware or software. Medium Enterprise Design Profile Reference Guide 2-119 . Operational resiliency—Enables resiliency capabilities to the next level. scalable. Medium Enterprise High-Availability Framework Independent of the business function. without making major network changes. and so on. using In Service Software Upgrade (ISSU) features. Because every tier of the LAN network design can be classified as a fault domain. The following three major resiliency requirements encompass most of the common types of failure conditions. incorrect cablings. such as fiber cut. at other times. Cisco high availability technologies can be deployed based on critical versus non-critical platform roles in the network. this introduces a new set of challenges. but is well planned during the early network design phase. However. such as higher cost and the added complexity of managing more systems. ! and EF (VoIP) to the PQ Note Due to the default WRED threshold settings. CS5 (Broadcast Video). providing complete network availability even during planned network outage conditions. Network reliability and availability can be simplified using several Cisco high availability technologies that offer complete failure transparency to the end users and applications during planned or unplanned network outages. deploying redundant systems can be effective. bad transceivers. offers high availability to use network as a core platform that enables flexibility to overlay advanced and emerging technologies and provide non-stop network communications. depending on the LAN design tier. The medium enterprise campus network must be build based on same fundamentals that can provide constant “on” network service for uninterrupted business operations and protects campus physical security and assets.

. congestion and application retries will impact the performance and alerts the user about the network faults. For example failure of 1-Gigabit Ethernet backbone connection for 10 seconds can the drop network information for more than 1Gig. Baselining Campus High Availability Typical application response time is in milliseconds when the campus network is build with high speed backbone connection and is in fully-operational state. When constantly working in deterministic network response time environment the learning and work practice of end-users is rapid. Every protocol operation is different in the network. Network failures can be classified in one of the following two ways: • • Planned Failure—Planned network outage occurs when any network systems is administratively planned to disable inthe network for scheduled event (i. Unplanned Failure—Any unforeseen failures of network elements can be considered as unplanned failure. which can be triggered by system. Several high availability technologies must be deployed at each layer to provide higher network availability and Medium Enterprise Design Profile Reference Guide 2-120 . however. or link transceiver failures conditions. user determines network connection problem based on routine experience even before an application protocols determines connection problem (i. During the major network fault event. they are designed to minimize overall productivity impact and allows network to gracefully adjust and recover during minor failure conditions. or even by nature. which may include critical medium enterprise data or video surveillance captured data. human. while the retries for non-critical data traffic is acceptable the applications running in real-time may not.e. slow internet browsing response time).. Such failures can include internal faults in the network device caused by hardware or software malfunctions which includes software crash. Protocol-based delayed failure detection are intentional.). The fault levels can range from network interruption to disaster.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Network faults domains in this reference architecture are identifiable but the failure conditions within the domains are un-predicted.e. Figure 2-64 provides a sample real-time VoIP application in campus network and sequence of user experience in different phases during minor and major unplanned network outage: Figure 2-64 50 45 40 35 30 sec 25 20 15 10 5 No Impact Minimal Voice Impact User Hangs Up Phone Reset 228971 VoIP Impact During Minor and Major Network Outage Major Network Outage Data Loss (seconds) Minor Network Outage 0 This high availability framework is based on the three major resiliency strategies to solve a wide-range of planned and unplanned network outage types described in the previous section. during abnormal network failure causing traffic loss. software upgrade etc. linecard. Improper network design or non-resilient network systems can experience higher number of faults that not only degrades user experience but may severely impact application performance and may not capture the critical physical security video information.

Deploy IP event dampening as an tool to prevent the control and forwarding plane impact caused by physical topology instability. and acts as a backup to the native Layer 1 unidirectional link detection capabilities provided by 802. UDLD can be deployed on ports implemented in Layer 2 or Layer 3 modes. In the modular platform design the redundant parallel physical links between distributed modules between two systems reduces fault probabilistic and can increase network availability. Ensure that the network design is self-stabilizing. An example of this is configuring the UniDirectional Link Detection (UDLD) protocol. (See Figure 2-65. Implement a defense-in-depth approach to failure detection and recovery mechanisms. and Technologies Resilient Goal Network Service Availability Resilient Strategies Network Resiliency Device Resiliency Operational Resiliency EtherChannel/MEC Resilient Technologies NSF/SSO UDLD Stack Wise IP Event Dampening eFSU 228500 ISSU Network Resiliency Overview The most common network fault occurrence in the LAN network is a link failure between two systems.3z and 802. which uses a Layer 2 keep-alive to test that the switch-to-switch links are connected and operating correctly. In the same network design. Implementing route summarization advertises a concise topology view to the network. Strategy. which prevents core network instability.) Figure 2-65 High-Availability Goals. Link failures can be caused by issues such as a fiber cut. the flood may not be protected. to prevent communication failure or degraded network-wide application performance. It is critical to simplify the control plane and forwarding plane operation by bundling all physical paths into a single logical bundled interface (EtherChannel). To develop a consistent network resiliency service in the centralized main and remote campus sites. However. Hardware or software errors may cause ports to flap. linecard module failure and so on. • Medium Enterprise Design Profile Reference Guide 2-121 .Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services rapid recovery during failure conditions. Deploying redundant parallel paths in the recommended medium enterprise LAN design by default develops a non-optimal topology that keeps the network underutilized and requires protocol-based network recovery. it operates independently over each individual physical port at Layer 2 and remains transparent to the rest of the port configuration.3ae standards. which creates false alarms and destabilizes the network topology. Therefore. within the summarized boundary. the routed access model eliminates such limitations and enables the full load balancing capabilities to increase bandwidth capacity and minimize the application impact during a single path failure. UDLD is not an EtherChannel function. It is important to remember how multiple parallel paths between two systems also changes overall higher layer protocols construct the adjacency and loop-free forwarding topology. miswiring. the following basic principles apply: • Deploying redundant parallel paths are the basic requirement to employ network resiliency at any tier.

To prevent network outage on fixed configuration the Catalyst switches they must be deployed with Cisco StackPower technology. • Redundant Control Plane Device or node resiliency in modular Cisco Catalyst 6500-E/4500-E platforms and Cisco StackWise provides a 1+1 redundancy option with enterprise-class high availability and deterministic network recovery time. and so on. The following subsections provide high availability design details. Redundant Power System Redundant power supplies for network systems protect against power outages. power outages. causing complete or partial network outage. Deploying an internal and external power supply solution protects critical access layer switches during power outages. To protect against common network faults or resets. and so on. The network recovery time can remain undeterministic. power supply failures. the power supply operates in redundant mode. Some of the common internal failures are a software-triggered crash. Medium Enterprise Design Profile Reference Guide 2-122 . By default. but may not be able to offer power redundancy. line card failures. offering the 1+1 redundant option. and can deliver power to multiple switches. as well as graceful network recovery techniques that do not impact the control plane and provide constant forwarding capabilities during failure events. A single Cisco RPS 2300 power supply uses a modular power supply and fan for flexibility. Overall power capacity planning must be done to dynamically allow for network growth. Redundant hardware components for device resiliency vary between fixed configuration and modular Cisco Catalyst switches. Lower power supplies can be combined to allocate power to all internal and external resources. all critical medium enterprise campus network devices must be deployed with a similar device resiliency configuration. Redundant power systems can be deployed in the two following configuration modes: • Modular switch—Dual power supplies can be deployed in modular switching platforms such as the Cisco Catalyst 6500-E and 4500-E Series platforms. depending on the network design. Device Resiliency Overview Another major component of an overall campus high availability framework is providing device or node level protection that can be triggered during any type of abnormal internal hardware or software process within the system. This subsection provides basic redundant hardware deployment guidelines at the access layer and collapsed core switching platforms in the campus network. Fixed configuration switch—Depending on the Catalyst switch capability the fixed configuration switches offers wide range of power redundancy options includes the latest innovation Cisco StackPower in Catalyst 3750-X series platform. and serve primarily to reinforce good resilient design practices. an internal redundant power supplies on Catalyst 3560-X and use Cisco RPS 2300 external power supplies solution on Catalyst 2960-S Series switches. and provides completes fault transparency and constant network availability. LAN network devices can be considered as a single-point-of-failure and are considered to be major failure condition because the recovery type may require a network administrator to mitigate the failure and recover the system. It is important not only to protect the internal network system but also the endpoints that rely on power delivery over the Ethernet network.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design These principles are intended to be a complementary part of the overall structured modular design approach to the campus design.

thus. Deploying redundant supervisors in the mission-critical distribution and core system provides non-stop communication throughout the network. Non-Stop Forwarding Cisco VSS and the single highly resilient-based campus system provides uninterrupted network availability using non-stop forwarding (NSF) without impacting end-to-end application performance. To provide 99. the Catalyst 4500 must be equipped with redundant supervisors to critical endpoints. Deploying Cisco StackWise according to the recommended guidelines protects against network interruption. synchronize. such as Cisco TelePresence.999 percent service availability in the access layer. Cisco StackWise is designed with unique hardware and software capabilities that distribute. and IP video surveillance cameras do not freeze. Users of realtime applications such as VoIP do not hang up the phone. By default. and protect common forwarding information across all member switches in a stack ring. The Cisco VSS and redundant supervisor system is an NSF-capable platform. During master switch failure.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Stateful Switchover The stateful switchover (SSO) capability in modular switching platforms such as the Cisco Catalyst 4500 and 6500 provides complete carrier-class high availability in the campus network. and recovers the network in sub-seconds during master switch re-election. Cisco StackWise is an low-cost solution to provide device-level high availability. most Cisco Layer 3 network devices are NSF-aware systems that operate in NSF helper mode for graceful network recovery. Cisco recommends distribution and core layer design model be the center point of the entire enterprise communication network. (See Figure 2-66. the new master switch re-election remains transparent to the network devices and endpoints. every network device that connects to VSS or the redundant supervisor system must be NSF-aware to provide optimal resiliency.) Medium Enterprise Design Profile Reference Guide 2-123 . Bundling SSO with NSF capability and the awareness function allows the network to operate without errors during a primary supervisor module failure.

Figure 2-67 demonstrates platform-independent Cisco IOS software upgrade flow process using ISSU technology.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Figure 2-66 Medium Enterprise NSF/SSO Capable and Aware Systems Edge NSF-Capable QFP NSF-Aware Switch-1 Active Core VSL Switch-2 Standby NSF-Capable Switch-1 Active Distribution VSL Switch-2 Standby NSF-Capable Standby Active Access NSF-Aware NSF-Capable 228501 Operational Resiliency Overview Designing the network to recover from failure events is only one aspect of the overall campus non-stop design. complemented with the system software capabilities. 6500-E and ASR 1000 series platform support realtime upgrade software in the campus. The Cisco In-Service Software Upgrade (ISSU) and Enhanced Fast Software Upgrade (eFSU) leverages NSF/SSO technology to provide continuous network availability while upgrading the critical systems that eliminates network services downtime planning and maintenance window. configuration changes. and software and hardware upgrades without disrupting network services. Upgrading individual devices without taking them out of service is similarly based on having internal component redundancy (such as with power supplies and supervisors). Medium Enterprise Design Profile Reference Guide 2-124 . Converged network environments are continuing to move toward requiring true 7x24x365 availability. The medium enterprise LAN network is part of the backbone of the enterprise network and must be designed to enable standard operational processes. The Cisco Catalyst 4500-E. upgrade software. and replace or upgrade hardware becomes challenging without a redundant system in the campus core. The ability to make changes.

along with the necessary software control mechanisms. the VSS can continue to provide network services during the upgrade. With the Enhanced Fast Software Upgrade (eFSU) feature. the ISSU process requires three sequential upgrade events for error-free software install on both virtual switch systems. Having the ability to operate the campus as a non-stop system depends on the appropriate capabilities being designed-in from the start. This leverages the NSF/SSO capabilities and unique uplink port capability to keep in operational and forwarding state even when supervisor module gets reset. in-place Cisco IOS upgrade. VSS offers unmatched network availability to the core.2(53)SG1 for example. such as VoIP. causing sub-second traffic loss that does not impact realtime network applications. the network devices can gracefully restore control and forwarding information during the upgrade process.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Figure 2-67 Cisco ISSU Software Process Cycle 1 ACTIVE OLD STANDBY issu loadversion STANDBY Sup/RP reboots with software version OLD 5 ion STANDBY 2 ACTIVE iss ACTIVE ers NEW OLD STANDBY bo ua abo NEW issu commitversion rtv NEW New software version becomes effective with current ACTIVE issu runversion supervisor switchover running old image ion rtv ers Commit and reboot the STANDBY with new IOS Software Version iss u 4 STANDBY 3 STANDBY OLD ACTIVE OLD ACTIVE NEW NEW issu acceptversion Acknowledge successful new software activation and stops ISSU roll-over timer Catalyst 4500—ISSU Full-image ISSU on the Cisco Catalyst 4500-E leverages dual redundant supervisors to allow for a full. For a hitless software update. the VSS network upgrade remains transparent and hitless to the applications and end users. such as moving from IOS Release 12.2(53)SG to 12. Because eFSU works in conjunction with NSF/SSO technology. such design helps in retaining bandwidth capacity while upgrading both supervisor modules at the cost of less than sub-second of traffic loss during a full Cisco IOS upgrade. Each upgrade event causes traffic to be re-routed to a redundant MEC path. Catalyst 6500 VSS—eFSU A network upgrade requires planned network and system downtime. Network and device level redundancy. With the eFSU feature. while concurrently providing the ability to proactively manage the non-stop infrastructure. guarantee controlled and fast recovery of all data flows following any network failure. Medium Enterprise Design Profile Reference Guide 228972 2-125 . while the bandwidth capacity operates at 50 percent and the data plane can converge within sub-seconds.

Some of the high-availability techniques can be achieved with inherent campus network design without making major network changes. however. Power Supplies 2 Red. it introduces the new set of challenges – higher cost and complexities to manage more number of systems. Standalone systems Cisco StackPower NSF-Capable and Aware Red. To prevent catastrophic network failure during un-planned network outage event. Linecard modules 2 Stackwise Plus ISSU Red. The network survivability strategy can categorized in following three major resiliency requirements that can encompass most of the common types of failure conditions. the critical network systems that is deployed in the center of the network to provide global connectivity may require additional hardware and software component to offer non-stop communication. Supervisor modules 3 SSO/NSF Capable & Aware 2 VSS eFSU Core Medium Enterprise Design Profile Reference Guide 2-126 . See Table 2-11. Table 2-11 Medium Enterprise Network High Availability Strategy Platform Catalyst 2960-S FlexStack Role Access Network Resiliency EtherChannel UDLD Dampening 1 Device Resiliency RPS 2300 NSF-Aware Redundant Power Supplies Operational Efficiency Cisco FlexStack Catalyst 3560-X Catalyst 3750-X Catalyst 3750ME Catalyst 3750-X StackWise Catalyst 4500-E WAN Edge Access Distribution Access Distribution Core Catalyst 6500-E Distribution None. role and network service type appropriate resilient option must be deployed. deploying redundant components and systems increases redundancy and load sharing capabilities. it is important to identify network fault domains and define rapid recovery plans to minimize the application impact during minor and major network outage conditions. Minor and major network failure are the broad terms that’s includes several types of network faults that must be taken into consideration and implement the rapid recovery solution. Network reliability and availability can be simplified using several Cisco high-availability and virtual-system technologies like VSS offers complete failure transparency to the end-users and applications during planned or un-planned network outage conditions. However. Depending on the network system tier. it is one of the critical integrated component that gets well planned during early network design phase.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Design Strategies for Network Survivability The network reliability and availability is not a new demand. Cisco high-availability technologies can be deployed based on critical versus non-critical platform role in the network. Each network tier can be classified as a fault domains.

ESP modules Red. The design and implementation considerations for deploying diverse physical connectivity across redundant standalone systems and virtual-systems to create a single point-to-point logical EtherChannel is explained in the “Designing EtherChannel Network” section on page 2-41. Redundant power and hardware components from each 3750-E member switch in Stack ring and 6500-E virtual-switch in VSS domain 3. the Layer 2 and Layer 3 protocols dynamically adjusts the metrics of the aggregated port-channel interfaces. Implementing a resilient hardware and software design increases network resiliency and maintains the availability of all upper layer network services that are deployed in a medium enterprise campus network design. Starting 12. 4. Redundant uplinks from each 3750-E member switch in Stack ring and 6500-E virtual-switch in VSS domain 2. as network protocol remains unaware of the topology changes and allows the hardware to self-recover from faults. Re-routing traffic over an alternate member-link of EtherChannel or MEC is based on minor system internal EtherChannel hash re-computations instead of an entire network topology re-computation. The medium enterprise campus LAN network design deploys EtherChannel and MEC throughout the network to develop a simplified single point-to-point network topology which does not build any parallel routing paths between any devices at any network tiers. the network protocol requires fault detection. Software based SSO redundancy Implementing Network Resiliency The medium enterprise design guide recommends deploying a mix of hardware and software resiliency designed to address the most common campus LAN network faults and instabilities. During individual member-link failures. EtherChannel/MEC Network Recovery Analysis The network recovery with EtherChannel and MEC is platform and diverse physical path dependent instead of Layer 2 or Layer 3 network protocol dependent. EtherChannel or MEC network environments provide significant benefits in such conditions.2(33)SXI4 it is recommended to deploy redundant supervisor on each virtual-switch in a VSS domain. Spanning-Tree updates the port-cost and Layer 3 routing protocols like EIGRP updates the composite metric or OSPF may change the interface cost. Hence an EtherChannel and MEC based network provides deterministic sub-second network recovery of minor to major network faults. Redundant supervisor per VSS Domain (One per virtual-switch node basis). EtherChannel / Multi-Chassis EtherChannel In a non-EtherChannel network environment. and best-path recomputation to reroute traffic which requires variable time to restart the forwarding traffic. Standalone system 1. Conversely. Power Supplies SSO/NSF Capable & Aware 4 ISSU None. In Medium Enterprise Design Profile Reference Guide 2-127 . Power Supplies Red. topology synchronization. Route Processors SSO/NSF Capable & Aware ISSU ASR 1004 Cisco ISR Internet Edge PSTN Gateway Red.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Table 2-11 Medium Enterprise Network High Availability Strategy (continued) ASR 1006 WAN Edge EtherChannel Dampening Red. It is important to analyze the network and the application impacts from a top-down level to adapt and implement the appropriate high availability solution for creating a resilient network.

etc.4 0. Catalyst 6500-E VSS MEC Link Recovery Analysis Several types of network faults can trigger link failures in the network (i. The link failure analysis chart with inter-chassis reroute in Figure 2-68 summarizes several types of faults induced in large scale Cisco lab during developing this validated design guide. but with an additional delay to recompute a new forwarding path through the remote virtual-switch node. GBIC failure. the re-computation to select alternate member-links in EtherChannel and MEC becomes locally significant on each end of the impacted EtherChannel neighbors. Figure 2-68 Catalyst 6500-E VSS Inter-Chassis MEC Link Recovery Analysis 0.e. the EtherChannel recomputation is fairly easy as the alternate member-link resides within the system. However.3 0. Catalyst 4507R-E EtherChannel Link Recovery Analysis In the medium enterprise campus reference design.. The centralized forwarding architecture in Catalyst 4500-Es can rapidly detect link failures and reprogram the hardware with new EtherChannel hash results. The Layer 2 or Layer 3 EtherChannel and MEC re-computation is rapid and network scale independent. with the distributed forwarding architecture in virtual-systems like Catalyst 6500-E VSS and Catalyst 3750-X StackWise Plus may require extra computation to select alternate member-link paths through its inter-chassis backplane interface—VSL or StackRing.1 0 228987 Upstream Downstream Multicast 2960 L2 MEC 3560E L3 MEC 3750E L2 MEC 3750 4500E StackWise L3 MEC L3 MEC The medium enterprise LAN can be designed optimally for deterministic and bidirectional symmetric network recovery for unicast and multicast traffic.Refer to the “Redundant Linecard Network Recovery Analysis” section on page 2-134 for intra-chassis recovery analysis with the same network faults tested in inter-chassis scenarios. The network recovery remains consistent and deterministic in all network fault conditions. the traffic load balancing and rerouting across different EtherChannel member-links occurs within the local chassis. the metric change will require minor update messages in the network and do not require end-to-end topology recomputation that impacts the overall network recovery process.7 0. The test results in Figure 2-69 confirm the deterministic and consistent network recovery during individual Layer 2/3 EtherChannel member-link failures. a single Catalyst 4507R-E with redundant hardware components is deployed in the different campus LAN network tiers.6 0. In standalone or non-virtual systems like Catalyst 2960-S or 4500-E.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design such events. Medium Enterprise Design Profile Reference Guide 2-128 . A Cisco Catalyst 4507R-E can only be deployed in standalone mode with in-chassis supervisor and module redundancy.2 0. Since the network topology remains intact during individual link failures. fiber pullout. EtherChannel re-computation requires recreating new logical hash table and re-programming the hardware to re-route the traffic over the remaining available paths in the bundled interface. However.). Such designs still provides deterministic recovery.5 sec 0.

Copper media ports use Ethernet link pulses as a link monitoring tool and are not susceptible to unidirectional link problems. UDLD will attempt to reestablish the state of the port.2 0. such as detecting the identity of neighbors and shutting down misconnected ports. it is assumed there is no fault in the network. At Layer 1. Failure to reestablish communication with UDLD neighbor will force the port into the err-disable state that must be manually recovered by the user or the switch can be configured for auto recovery within a specified interval of time. When such physical connection errors occur. because one-way communication is possible in fiber-optic environments. However. • The following illustrates a configuration example to implement the UDLD protocol: cr22-6500-LB#config t cr22-6500-LB(config)#interface range gi1/2/3 . auto-negotiation takes care of physical signaling and fault detection. gi2/2/3 cr22-6500-LB(config-if-range)#udld port cr22-6500-LB#show udld neighbors Port Device Name Device ID Port ID Neighbor State -------------------------------------------------------Gi1/2/3 FDO1328R0E2 1 Gi1/0/49 Bidirectional Gi2/2/3 FDO1328R0E2 1 Gi1/0/50 Bidirectional Medium Enterprise Design Profile Reference Guide 2-129 . Aggressive mode—If bidirectional UDLD protocol state information times out.3 Upstream 0. it can cause loops or traffic black holes.4 sec 0. UDLD operates in one of two modes: • Normal mode (Recommended)—If bidirectional UDLD protocol state information times out. When auto-negotiation and UDLD are enabled together. if it detects the link on the port is operational.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Figure 2-69 Catalyst 4507R-E EtherChannel Link Recovery Analysis 0. mismatched transmit/receive pairs can cause a link up/up condition even though bidirectional upper-layer protocol communication has not been established.5 0.1 0 228988 Downstream Multicast 2960 L2 MEC 3560E L3 MEC 3750E L2 MEC 3750 4500E StackWise L3 MEC L3 MEC Unidirectional Link Detection (UDLD) UDLD is a Layer 2 protocol that works with the Layer 1 features to determine the physical status of a link. and no further action is taken. UDLD performs tasks that auto-negotiation cannot perform. The port state for UDLD is marked as undetermined and the port behaves according to its STP state. the Layer 1 and Layer 2 detection methods work together to prevent physical and logical unidirectional connections and prevent malfunctioning of other protocols. UDLD functions transparently on Layer-2 or Layer-3 physical ports.

Redundant Line cards. or port-channels: • Layer 3 Port-Channel cr24-4507e-MB(config)#interface Port-Channel 1 cr24-4507e-MB(config-if)#no switchport cr24-4507e-MB(config-if)#dampening • Layer 2 Port-Channel cr24-4507e-MB(config)#interface Port-Channel 15 cr24-4507e-MB(config-if)#switchport cr24-4507e-MB(config-if)#dampening • SVI Interface cr24-4507e-MB(config)#interface range Vlan101 . IP dampening tracks and records the flap events. To ensure local network domain stability during to port-flaps. It can be implemented on each individual physical or logical Layer 3 interface—physical ports. the device redundancy is divided into four major categories—Redundant Power Supplies. the device resiliency solves the problem by integrating redundant hardware components and software based solutions into single standalone or virtual systems. Redundant Supervisor/RP. On multiple flaps. Depending on the platform architecture of the Cisco router or switch deployed in the campus network design. Each time the Layer 3 interface flaps. IP Event Dampening is a local specific function and does not have any signaling mechanism to communicate with remote systems. and Non-Stop Forwarding (NSF) with Stateful Switchover (SSO). SVI. Route summarization is one technique used to isolate the fault domain and contain local network faults within the domain. a single interface flap can severely impact stability and availability of the entire campus network. Medium Enterprise Design Profile Reference Guide 2-130 . When the medium enterprise network is not deployed using best practice guidelines to summarize the network boundaries at the aggregation layer.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design IP Event Dampening Unstable physical network connectivity with poor signaling or loose connection may cause continuous port-flaps. It uses the same fundamental principles as BGP dampening. a logical penalty is assigned to the port and suppresses link status notifications to IP routing until the port becomes stable. all Layer 3 interfaces can be implemented with IP Event Dampening. Like network resiliency.120 cr24-4507e-MB(config-if-range)#dampening cr24-4507e-MB#show interface dampening Vlan101 Flaps Penalty Supp ReuseTm HalfL ReuseV 3 0 FALSE 0 5 1000 … TenGigabitEthernet3/1 Connected to cr23-VSS-Core Flaps Penalty Supp ReuseTm HalfL ReuseV 10 0 FALSE 0 5 1000 … Port-channel1 Connected to cr23-VSS-Core Flaps Penalty Supp ReuseTm HalfL ReuseV 3 0 FALSE 0 5 1000 Port-channel15 Connected to cr24-2960-S-MB Flaps Penalty Supp ReuseTm HalfL ReuseV 3 0 FALSE 0 5 1000 SuppV 2000 MaxSTm 20 MaxP Restart 16000 0 SuppV 2000 MaxSTm 20 MaxP Restart 16000 0 SuppV 2000 SuppV 2000 MaxSTm 20 MaxSTm 20 MaxP Restart 16000 0 MaxP Restart 16000 0 Implementing Device Resiliency Each device in the medium enterprise LAN and WAN network design is connected to a critical system or end-point to provide network connectivity and services for business operations.

Network administrators must identify the network systems that provide network connectivity and services to mission critical servers. Up to four switches can be configured in a StackPower stack with the special Cisco proprietary StackPower cable. With the modular power supply design in Catalyst 3750-X Series platform. FA S T E N E R S M U S T B E FU LLY E N G A G E D P R IO R T O O P E R A T IN G P O W E R S U P P LY 100240V ~ 12A 50/ 60H z O U T P U T FA IL P O E E N A B LE D FA N O K FA N O K 2 3 IN P U T 1 OK IN P U T 1 OK IN P U T 2 OK IN P U T 2 OK 5 100240V ~ 12A 50/ 60H z 4200A C V 100240V ~ 12A 50/ 60H z 4200A C V 6 1 7 Catalyst 4507R-E 2 StackWise Plus SUPERVISOR StackPower Cable RPS Cable Member 8 FAN STATUS 9 3 4 200-240 V 23 A 60/50 Hz 200-240 V 23 A 60/50 Hz Redundant Power Supply Catalyst 3750-X StackWise Plus INPUT OK FAN Power Supply 1 OUTPUT OK FAIL Power Supply 2 INPUT OK FAN OK OUTPUT FAIL 7 Catalyst 6500 SERIES Catalyst 6509-E Catalyst 4507R-E Catalyst 2960-S The following configuration examples provide guidelines to deploy in-chassis and external power redundancy in the Catalyst switching platforms. The Cisco StackPower can be deployed in following two modes: • Sharing mode—All input power is available to be used for power loads. In this mode. Cisco StackPower unifies the individual power supplies installed in the switches and creates a pool of power. If a power supply fails. the defective power supply can be swapped without disrupting network operation. the total available power is used for power budgeting decisions and no power is reserved to accommodate power-supply failures. The next-generation borderless network ready Cisco Catalyst 3750-X introduces latest Cisco StackPower innovation that creates a global pool of power that can provide power load sharing and redundancy option. The StackPower cable is different than the StackWise data cables and is available on all Cisco Catalyst 3750-X models. The total aggregated available power in all switches in the power stack (up to four) is treated as a single large power supply. the in-chassis power redundancy option allows flexibility to deploy dual power supplies into a single system. The Catalyst platforms like the 2960 and 2960-S can be deployed with Cisco RPS 2300 for external power redundancy solution. All switches in stack can share power with available power to all powered devices connected to PoE ports. This would also include Layer 1 services like PoE to boot IP Phone and IP Video Surveillance Cameras for campus physical security and communications. While the Cisco Catalyst 3560-X Series switches are designed to increase device resiliency with dual redundant power supplies and fans.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Redundant Power To provide non-stop network communication during power outages. Catalyst 3750-X—Cisco StackPower Redundancy The next-generation Catalyst 3750-X Series platform introduces innovative Cisco StackPower technology to provide power-redundancy solution for fixed configuration switches. Depending on the Cisco platform design. directing that power where it is needed. Figure 2-70 provides complete power redundancy design and solution on various Cisco Catalyst switching platforms: Figure 2-70 Power Supply Redundancy Design Redundant Internal Power Supply Redundant Dual Power Supply S W IT C H E D S H O U LD B E IN T H E O FF ‘ ’ P O S IT IO N T O IN S T A LL / O R E M O V E P O W E R S U P P LIE S . fault from the stack can regain power from global power pool to provide seamless operation in the network. critical network devices must be deployed with redundant power supplies. This is the default mode. Medium Enterprise Design Profile Reference Guide 2-131 229373 IN AL ST L IN AL ST L N RU N RU SYSTEM 4 Redundant Power Supply Master Cisco 2300 RPS 1 2 3 4 5 Redundant External Power Supply 6 SUPERVISOR Master Member . FA S T E N E R S M U S T B E FU LLY E N G A G E D P R IO R T O O P E R A T IN G P O W E R S U P P LY 100240V ~ 12A 50/ 60H z O U T P U T FA IL P O E E N A B LE D 1 S W IT C H E D S H O U LD B E IN T H E O FF ‘ ’ P O S IT IO N T O IN S T A LL / O R E M O V E P O W E R S U P P LIE S . powered devices and switches could be shut down. During individual power supply.

All the power allocation is assigned from the internal power supply. etc. the possibility of having to shut down switches or powered devices in case of a power failure or extreme power load is reduced. Wireless Access Points. to make new power configuration effective. but provides backup power in case of a power-supply failure. power supplies operate in redundant mode offering a 1+1 redundant option. Enabling redundant mode will offer power redundancy as a backup during one of the power supply unit failure event. cr24-4507e-LB(config)#power redundancy-mode redundant cr24-4507e-LB#show power supplies Power supplies needed by system :1 Power supplies currently available :2 cr22-vss-core(config)#power redundancy-mode redundant switch 1 cr22-vss-core(config)#power redundancy-mode redundant switch 2 cr2-6500-vss#show power switch 1 | inc Switch|mode Switch Number: 1 system power redundancy mode = redundant Medium Enterprise Design Profile Reference Guide 2-132 . Although there is less available power in the pool for switches and powered devices to draw from. Both power supplies must have sufficient power to allocate power to all the installed modules in order to operate in 1+1 redundant mode. it is important that network administrator must plan downtime as all the switches in the stack ring must be reloaded: cr36-3750X-xSB(config)#stack-power stack PowerStack cr36-3750X-xSB(config-stackpower)#mode redundant cr36-3750X-xSB(config)#stack-power switch 1 cr36-3750X-xSB(config-switch-stackpower)#stack-id PowerStack %The change may not take effect until the entire data stack is reloaded cr36-3750X-xSB(config)#stack-power switch 2 cr36-3750X-xSB(config-switch-stackpower)#stack-id PowerStack %The change may not take effect until the entire data stack is reloaded Catalyst 2960 (External Power Redundancy) The Cisco Redundant Power Supply (RPS) 2300 can support up to 6 RPS ports to provide seamless power backup to critical access-layer switches in the campus network. Cisco RPS 2300 can be provisioned for the 3750-E or 3560-E series switches through CLI: Catalyst 4500-E and 6500-E (In-Chassis Power Redundancy) The Cisco Catalyst 4500-E and 6500-E Series modular platforms allocate power to several internal hardware components and external power devices like IP Phones.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design • Redundant mode—The power from the largest power supply in the system is subtracted from the power budget. Since Cisco StackWise Plus can group up to nine 3750-X Series switches in the stack-ring. which reduces the total available power. Additional power resiliency can be added by deploying dual power supply to backup to two devices simultaneously. The system determines power capacity and the number of power supplies required based on the allocated power to all internal and external power components. Dual power supplies in these systems can operate in two different modes as listed below: • Redundant Mode—By default. the Cisco StackPower must be deployed with two power stack group to accommodate up to four switches. Following sample configuration demonstrate deploying Cisco StackPower redundancy mode and grouping the stack-member into power stack group. It is recommended to budget the required power and deploy each Catalyst 3750-X switch in stack with dual power supply to meet the need.

2 sec 0. The Catalyst 3750-X StackWise Plus must be deployed following the same rule. The following global configuration will enable power redundancy mode to operate in combined mode: cr24-4507e-LB(config)#power redundancy-mode combined cr24-4507-LB#show power supplies Power supplies needed by system:2 Power supplies currently available:2 Network Recovery Analysis with Power Redundancy Each campus LAN router and switch providing critical network services must be protected with either the in-chassis or external redundant power supply system. However it may not offer 1+1 power redundancy during a primary power supply failure event. and poor application performance. Each physical Catalyst 6500-E chassis in VSS mode at the campus distribution and core layer must be deployed with a redundant in-chassis power supply. Network modules.. Protecting virtual-systems with redundant power supplies will prevent reducing network bandwidth capacity. the master and member-switches in the stack ring must be deployed with the external redundant power system. The lab test results shown in Figure 2-71 performed on all power redundant campus systems confirms zero-packet loss during individual power supply failure.). PoE+ etc. topology changes. Note that the network administrator must analyze the required power capacity that will be drawn by different hardware components (i. Using internal system protocols. then the network administrator can utilize both power supplies in combined mode to increase capacity. The high speed core design linecards are equipped with special hardware components to build the campus backbone whereas the network edge linecards are developed with more intelligence and application awareness. Figure 2-71 Redundant Power Analysis 0. This best practice is also applicable to the standalone or virtual-systems devices.1 Upstream Downstream Multicast 0 228990 2960 L2 MEC 3560E L3 MEC 3750E L2 MEC 3750 4500E StackWise L3 MEC L3 MEC Redundant Linecard Modules Modular Catalyst platforms support a wide range of linecards for network connectivity to the network core and edge.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services cr2-6500-vss#show power switch 2 | inc Switch|mode Switch Number: 2 system power redundancy mode = redundant • Combined mode—If the system power requirement exceeds the single power supply capacity. Several power failures on power redundant systems were conducted to characterize overall network and application impact.e. each line card communicates with the Medium Enterprise Design Profile Reference Guide 2-133 .

traffic loss can be minimized and consistent bi-directional sub-second network recovery can be achieved by deploying redundant network modules on a per virtual-switch node basis. Figure 2-72 Intra-Chassis versus Inter-Chassis Traffic Re-route Inter-Chassis Re-Route (Without Linecard Redundancy) Intra-Chassis Re-Route (With Linecard Redundancy) VSL SW1 SW2 SW1 VSL SW2 228991 The single standalone Catalyst 4500-E in distribution or core layer must be deployed with linecard redundancy. Figure 2-72 demonstrates inter-chassis reroute (without linecard redundancy) and intra-chassis re-route (with linecard redundancy). Data traffic traverses the VSL links as a “last-resort” in hardware if either of the virtual-switch nodes lose a local member-link from the MEC link due to a fiber cut or linecard failure. proper Cisco VSS traffic-engineering will prevent traffic routing over the VSL which may cause network congestion during individual link or entire high-speed network module failure. which may lead to the linecard and all the physical ports associated with it to forcibly reset to resynchronize with the supervisor. more importantly.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design centralized control-plane processing supervisor module through the internal backplane. Medium Enterprise Design Profile Reference Guide 2-134 . Redundant Linecard Network Recovery Analysis Catalyst 6500-E VSS Linecard module Recovery Analysis The distributed forwarding architecture in Catalyst 6500-Es operating in VSS mode is designed with unique traffic-engineering capabilities. At the critical large campus LAN core and distribution layer. full-mesh physical design must have quad paths to address multiple types of faults. This design minimizes data traffic re-routing across VSL links. both virtual-switch nodes programs their local linecard modules to switch egress data plane traffic. Any type of internal communication failure or protocol malfunction may disrupt the communication between the linecard and the supervisor. the network administrator must design the network by diversifying the physical cables across multiple linecard modules. Deploying redundant linecards and diversifying paths across the modules will allow for inter-chassis re-route and. The impact on traffic could be in the sub-second to seconds range and may create congestion on the VSL Etherchannel link if rerouting traffic exceeds overall VSL bandwidth capacity. A per system “V”-shaped. Additionally. the Cisco VSS traffic-engineering will prevent VSL reroute which may cause network congestion if there is not sufficient bandwidth to accommodate the rerouted traffic. When the distribution and core layer Catalyst 4500-E and 6500-E systems are deployed with multiple redundant line cards. The campus LAN network may face a complete network outage during linecard failures without deploying linecard redundancy as it can be considered a single point-of-failure. The centralized control-plane design on the active virtual-switch node builds Layer 2/3 peerings with the neighboring devices. Figure 2-73 illustrates intra-chassis network recovery analysis showing symmetric sub-second traffic loss during individual member-links and the entire linecard module at the campus core and distribution-layer. However with MEC.Figure 2-72 provides an example of asymmetric traffic-loss statistics when traffic is rerouted via remote virtual-switch node across VSL links.

All the redundant linecards in the chassis are stub and maintains low level information to handle ingress and egress forwarding information.1 0 228992 Upstream Downstream Multicast 2960 L2 MEC 3560E L3 MEC 3750E L2 MEC 3750 4500E StackWise L3 MEC L3 MEC Catalyst 4507R-E Linecard module Recovery Analysis The centralized forwarding architecture in a Catalyst 4507R-E programs all the forwarding information on the active and standby supervisor Sup6E or Sup6L-E modules. The Cisco Catalyst 4507R-E and 4510R-E Series platforms and all current generation Catalyst 6500-E Series chassis and supervisors support in-chassis redundant supervisor modules.2 0. However. Figure 2-74 Catalyst 4507R-E Linecard Recovery Analysis 0. the new forwarding information gets rapidly reprogrammed on both supervisors in the chassis.5 0.5 0. deploying the EtherChannel utilizing diversified fibers across different linecard modules will provide consistent sub-second network recovery during abnormal failure or the removal of a linecard from the Catalyst 4507R-E chassis. During a link or linecard module failure.3 0. The chart in Figure 2-74 provides test results conducted by removing a linecard from the Catalyst 4507R-E chassis deployed in campus network in various roles.1 0 228993 Downstream Multicast 2960 L2 MEC 3560E L3 MEC 3750E L2 MEC 3750 4500E StackWise L3 MEC L3 MEC Redundant Supervisor Enterprise-class modular Cisco Catalyst 4500-E and 6500-E platforms support dual-redundant supervisor modules to prevent disrupting the network control-plane and topology during abnormal supervisor module failures or when forced by the admin reset.3 Upstream 0.4 sec 0. with Cisco’s latest Virtual-Switching System (VSS) Medium Enterprise Design Profile Reference Guide 2-135 .2 0.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Figure 2-73 Catalyst 6500-E VSS Intra-Chassis Link and Linecard Module Recovery Analysis 0. However.4 sec 0.

The “V”-shaped. distributed. Figure 2-75 Intra-Chassis versus Inter-Chassis SSO Redundancy Intra-Chassis SSO Redundancy Intra-Chassis SSO redundancy in the Catalyst 4500-E switch provides continuous network availability across all the installed modules and the uplinks ports from active and standby supervisor modules.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design innovation and the next-generation Sup720-10GE supervisor module. it is important to remember that both supervisor modules must be identical in type and all the internal hardware components like memory and bootflash must be the same to provide complete operational transparency during failure. Cisco Catalyst 6500-E deployed in standalone mode also synchronizes all the hardware and software state-machine info in order to provide constant network availability during intra-chassis supervisor switchover. supervisor redundancy can be extended across dual chassis by logically clustering them into one single large virtual-switch. This may disrupt the network topology if not deployed with the best practices defined in this design guide. the new active virtual-switch node will perform a Layer 3 protocol graceful recovery with its neighbors in order to provide constant network availability over the local interfaces. See Figure 2-75. The virtual-switch node running in active supervisor mode will be forced to reset during the switchover. Thus. During the failure. The default redundancy mode on Catalyst 4500-E and Catalyst 6500-E series platforms is SSO. Hence it does not require any additional configuration to enable SSO redundancy. The uplink port remains in operation and forwarding state during an active supervisor switchover condition. full-mesh fiber paths combined with single point-to-point EtherChannel or MEC links play a vital role during such type of network events. Note VSS does not currently support intra-chassis supervisor redundancy on each individual virtual nodes. • Inter-Chassis SSO Redundancy The Cisco VSS solution extends supervisor redundancy by synchronizing SSO and all system internal communication over the special VSL EtherChannel interface between the paired virtual systems. • Implementing SSO Redundancy To deploy supervisor redundancy. The following sample configuration illustrates how to implement VSS in SSO mode: cr23-VSS-Core#config t Medium Enterprise Design Profile Reference Guide 2-136 . it provides full network capacity even during SSO switchover.

The control plane is the routing protocol graceful restart. Routing protocol—The motivation behind NSF is route convergence avoidance. The NSF aware function is enabled by default on all Layer 3 platforms. and the forwarding plane switches packets using hardware acceleration where available. A Cisco device that is NSF-capable is also NSF-aware. this requires the adjacent routers to support a routing protocol with special intelligence that allows a neighbor to be aware that NSF-capable routers can undergo switchover so that its peer can continue to forward packets. the network disruption remains transparent and provides seamless availability to the campus users and applications remains during control-plane processing module (Supervisor/Route-Processor) gets reset. and requests routing protocol information to be resynchronized. This service availability significantly lowers the Mean Time To Repair (MTTR) and increases the Mean Time Between Failure (MTBF) to achieve highest level of network availability.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services cr23-VSS-Core(config)#redundancy cr23-VSS-Core(config-red)#mode sso cr23-VSS-Core#show switch virtual redundancy My Switch Id = 1 Peer Switch Id = 2 Configured Redundancy Mode = sso Operating Redundancy Mode = sso Switch 1 Slot 5 Processor Information : ----------------------------------------------Current Software state = ACTIVE <snippet> Fabric State = ACTIVE Control Plane State = ACTIVE Switch 2 Slot 5 Processor Information : ----------------------------------------------Current Software state = STANDBY HOT (switchover target) <snippet> Fabric State = ACTIVE Control Plane State = STANDBY Non-Stop Forwarding (NSF) When implementing NSF technology in SSO redundancy mode systems. The following configuration illustrates how to enable the NSF capability within EIGRP on each Layer 3 campus LAN/WAN systems deployed with redundant supervisor. NSF is an integral part of a routing protocol and depends on the following fundamental principles of Layer 3 packet forwarding: • Cisco Express Forwarding (CEF)—CEF is the primary mechanism used to program the network path into the hardware for packet forwarding. From the protocol operation perspective. • A router that has the capability for continuous forwarding during a switchover is NSF-capable. Cisco VSS and StackWise Plus): Medium Enterprise Design Profile Reference Guide 2-137 .. The NSF capability must be manually enabled on each redundant system on a per routing protocol basis. route-processors or in virtual-switching modes (i. the underlying Layer 3 NSF capable protocols perform graceful network topology re-synchronization and the preset forwarding information in hardware on the redundant processor or distributed linecards remain intact in order to continue switching network packets. but may bring its adjacency to hold-down (NSF recovery mode) for a brief period. NSF relies on the separation of the control plane update and the forwarding plane information. This ability plays a critical role in NSF/SSO failover.e. Table 2-11 describes the Layer 3 NSF-capable and aware platforms deployed in the campus network environment. CEF enables this separation by programming hardware with FIB entries in all Catalyst switches. Devices that support the routing protocol extensions to the extent that they continue to forward traffic to a restarting router are NSF-aware. During a failure..

In both deployment scenarios. the NSF/SSO implementation and its recovery process differs on Catalyst 4507R-E (Intra-Chassis) and Catalyst 6500-E VSS (Inter-Chassis) in the medium enterprise campus LAN network design. and ports to go down core system changed state to down changed state to down ! Downed interfaces are automatically removed from EtherChannel/MEC. NSF/SSO Recovery Analysis As described in the previous section. Lowering the timer values may abruptly terminate graceful recovery causing network instability. the NSF route hold-timer expires on the NSF aware system and clears the stale NSF route marking and continues to use the synchronized routing database.12 (Port-channel100) is resync: peer graceful-restart NSF Timers As depicted in the above show commands. It is recommended to retain the default route hold timers in the network unless it is observed that NSF recovery takes more than 240 seconds. 600 seconds after the protocol graceful-recovery starts.0.125. Cisco validated the network recovery and Medium Enterprise Design Profile Reference Guide 2-138 . %DUAL-5-NBRCHANGE: EIGRP-IPv4:(613) 100: Neighbor 10. ! however additional interface to new active chassis retains port-channel in up/up state %EC-SW1_SP-5-UNBUNDLE: Interface TenGigabitEthernet2/1/2 left the port-channel Port-channel100 %EC-SW1_SP-5-UNBUNDLE: Interface TenGigabitEthernet2/1/4 left the port-channel Port-channel100 ! EIGRP protocol completes graceful recovery with new active virtual-switch. The default timer setting is well tuned for a well structured and concise campus LAN network topology. %LINK-3-UPDOWN: Interface TenGigabitEthernet2/1/4. up to 240 seconds NSF aware system can hold the routing information until routing protocol do not gracefully synchronize routing database.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design cr23-vss-core(config)#router eigrp 100 cr23-vss-core (config-router)#nsf cr23-vss-core #show ip protocols | inc NSF *** IP Routing is NSF aware *** EIGRP NSF-aware route hold timer is 240 EIGRP NSF enabled NSF signal timer is 20s NSF converge timer is 120s cr23-vss-core #show ip protocols | inc NSF *** IP Routing is NSF aware *** EIGRP NSF-aware route hold timer is 240 Graceful Restart Example The following example demonstrates how the EIGRP protocol will gracefully recover when active supervisor/chassis switchover on a Cisco VSS core system is forced by a reset: • NSF Capable System cr23-VSS-Core#redundancy force-switchover This will reload the active unit and force switchover to standby[confirm]y NSF Aware/Helper System ! VSS active system reset will force all linecards !the following logs confirms connectivity loss to %LINK-3-UPDOWN: Interface TenGigabitEthernet2/1/2.

With EIGRP NSF/SSO capability the unicast traffic recovers consistently within 200 msec or less. with Layer 2/3 MEC links. there may be around 2 second multicast traffic loss since the switch has to re-establish all the multicast routing information and forwarding information during the Sup6E or Sup6L-E switchover event. If a user from the remote medium campus location joins the multicast source from the main campus location then during Sup6E switchover there could be around a 3 second multicast packet loss. in that during active virtual-switch node failure the entire chassis and all the linecards installed will reset. Figure 2-76 Catalyst 4507R-E NSF/SSO Recovery Analysis 2. However unicast recovery will still remain in the 200 msec or less range in the same scenario. this event will not trigger protocol graceful recovery or any network topology change.5 Upstream 1 0. The inter-chassis SSO implementation in Catalyst 6500-E VSS differs from the single-chassis redundant implementation.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services application performance by inducing several types of active supervisor faults that trigger Layer 3 protocol graceful recovery. If the standby supervisor gets reset or gets re-inserted.5 0 228995 Downstream Multicast 2960 L2 MEC 3560E L3 MEC 3750E L2 MEC 3750 4500E StackWise L3 MEC L3 MEC In the remote medium campus. However. the network protocols and forwarding information remains protected via the remote virtual-switch node that can provide seamless network availability. the Cisco Catalyst 4507R-E deployed with redundant Sup6E or Sup6L-E will retain the operational and forwarding state of the uplink ports and linecard modules in the chassis. However. The uplink port of the standby supervisor remains in operational and forwarding state and the network bandwidth capacity remains intact during a standby supervisor removal or insertion event. Catalyst 4507R-E NSF/SSO Recovery Analysis Figure 2-76 illustrates intra-chassis NSF/SSO recovery analysis for the Catalyst 4507R-E chassis deployed with Sup6E or Sup6L-E in redundant mode. During the SSO switchover process. Therefore.5 2 sec 1. the switches continued to provide network accessibility during the recovery stage. the Catalyst 4507R-E is also deployed as the PIM-SM RP with MSDP Anycast-RP peering to the Cisco VSS core in the main campus location. Catalyst 4507R-E does not currently support redundancy for Layer 3 multicast routing and forwarding information. Medium Enterprise Design Profile Reference Guide 2-139 . During each test. Catalyst 4507R-E Standby Supervisor Failure and Recovery Analysis The standby Sup6E or Sup6L-E supervisor remains in redundant mode while the active supervisor is in the operational state.

When the upstream device is a Catalyst 6500-E and it is deployed in standalone mode.1 Downstream Multicast 0 228996 2960 L2 MEC 3560E L3 MEC 3750E L2 MEC 3750 4500E StackWise L3 MEC L3 MEC Catalyst 6500-E VSS Standby Failure and Recovery Analysis The network impact during a VSS standby failure is similar to a failure of a VSS active virtual-switch node. Cisco recommends not configuring the port-channel load-defer command under the MEC as it will create an adverse impact to the downstream unicast and multicast traffic: Medium Enterprise Design Profile Reference Guide 2-140 . The primary difference with a standby virtual-switch failure is that it will not trigger a Layer 3 protocol graceful recovery since the active virtual-switch is in an operational state. Each MEC neighbors will lose their physical path to standby switch and re-route traffic to the remaining MEC member-links connected to the active virtual-switch node. the Layer 2/3 remote device perceives this event as a loss of a member-link since the alternate link to the standby switch is in an operational and forwarding state. Since there is no major network topology changes and there are member-links still in an operational state. It is possible to configure the same command line under the MEC interface when the upstream device is Catalyst 6500-E and it is deployed in VSS mode instead of standalone. Additionally.2 sec Upstream 0. boot up ordering etc. the Cisco Catalyst 6500-E supports Multicast Multilayer Switching (MMLS) NSF with SSO enabling the system to maintain the multicast forwarding state in PFC3 and DFC3 based hardware during an active virtual-switch reset.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Catalyst 6500-E VSS NSF/SSO Recovery Analysis As described earlier. See Figure 2-77. The new active virtual-switch reestablishes PIM adjacency while continuing to switch multicast traffic based on pre-switchover programmed information. the NSF/SSO recovery in Catalyst 6500-E VSS system is identical as losing individual links. Figure 2-77 Catalyst 6500-E VSS NSF/SSO Recovery Analysis 0. The VSS standby virtual-switch failure will trigger a bidirectional subsecond loss as illustrated in Figure 2-77. then Cisco recommends configuring the port-channel load-defer command under the port-channel to prevent the traffic loss during the standby initialization state. The standby virtual-switch detects the loss of the VSL Etherchannel and transitions in active role and initializes Layer 3 protocol graceful recovery with the remote devices. Since VSS is developed with the distributed forwarding architecture it can create certain race conditions during a standby re-initialization state since the virtual-switch receives traffic from the network while it is not fully ready to switch the traffic. With a diverse full-mesh fiber network design. the entire chassis and all linecard modules installed gets reset during an active virtual-switch switchover event. The amount and the direction of traffic loss depend on multiple factors – VSL interface. ingress and egress module type.3 0.

Therefore. but the single standalone systems are single points of failure sometimes exist or the network design simply does not allow for access if a critical node is taken out of service. Leveraging enterprise-class high availability features like NSF/SSO in the distribution and core layer Catalyst 4500-E and 6500-E Series platforms supports ISSU to enable real-time network upgrade capability. However. There is no software restriction on turning on the feature on VSS systems. it may degrade performance and scalability. However. the ISSU stored compatibility matrix information is analyzed internally to determine interoperability between the software running on the active and standby supervisors.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services • The port-channel load-defer command is primarily developed for Catalyst 6500-E based standalone systems and does not have much effect when the campus upstream device type is Catalyst 6500-E deployed in VSS mode. depending on the network scale size. the user may experience traffic loss for a long period of time. it may create an adverse impact on downstream multicast traffic. With the default multicast replication configuration. Modifying the default (egress) multicast mode to the ingress replication mode may resolve the multicast traffic loss problem. software bug fixes or critical security fixes in real time. Using ISSU and eFSU technology. • • Implementing Operational Resiliency Path redundancy often is used to facilitate access during periods of maintenance activity. ISSU provides SSO compatibility Medium Enterprise Design Profile Reference Guide 2-141 . Catalyst 4500-E ISSU Software Design and Upgrade Process Figure 2-78 Catalyst 4500-E ISSU Software Upgrade Process ISSU Software Upgrade Pre-Requisite ISSU Compatibility Matrix When a redundant Catalyst 4500-E system is brought up with a different Cisco IOS software version. the MEC may drop multicast traffic until the defer timer expires (120 second default timer). the network administrator can upgrade the Cisco IOS software to implement new features.

collapsed core.2 Medium Enterprise Design Profile Reference Guide 2-142 .122-53. Modify the boot string to point to the new image to boot from new IOS software version after the next reset triggered during ISSU upgrade process. core.2(53)SG Peer Version Compatibility ----------------------------12. Refer to following URL for additional ISSU pre-requisites: http://www. the network administrator must verify ISSU software compatibility with the following command.2/53SG/configuration/issu. it is recommended to copy the old and new Cisco IOS software on Catalyst 4500-E active and standby supervisor into local file systems—Bootflash or Compact Flash.25443451 Aug 22 2009 13:26:52 -04:00 cr24-4507e-MB#dir slaveslot0: Directory of slaveslot0:/ 1 2 -rw.2(44)SG1 Base(2) … Managing System Parameters Software Prior to starting the software upgrade process.2(44)SGBase(2) 12.25443451 Aug 22 2009 13:22:00 -04:00 -rw. cr24-4507e-MB#show module | inc Chassis|Sup|12. Make sure the default setting is not changed and the configuration register is set to 0x2102.25442405 Nov 23 2009 17:56:46 -05:00 cat4500e-entservicesk9-mz. The Slot3 supervisor is in the SSO Active role and the Slot4 supervisor is in Standby role. cr24-4507e-MB#dir slot0: Directory of slot0:/ 1 -rw. and Metro Ethernet WAN edge.cisco. Prior to upgrading the software. distribution.122-53.2(53)SG Cisco IOS software version and is fully synchronized with SSO.122-53.SG  old image cat4500e-entservicesk9-mz.htm l#wp1072849 Catalyst 4500-E ISSU Software Upgrade Procedure This subsection provides the realtime software upgrade procedure for a Catalyst 4500-E deployed in the medium enterprise campus LAN network design in several different roles—access. the Sup6E supervisor is installed in Slot3 and Slot4 respectively.SG1  new image cat4500e-entservicesk9-mz.122-53.com/en/US/partner/docs/switches/lan/catalyst4500/12.SG1  new image cat4500e-entservicesk9-mz. ISSU is supported on Catalyst 4500-E Sup6E and Sup6L-E supervisor running Cisco IOS Enterprise feature set. In the following sample output. Boot Variable and String The system default boot variable is to boot from the local file system. Incompatible software may cause the standby supervisor to boot in RPR mode which may result in a network outage: cr24-4507e-MB#show issu comp-matrix stored Number of Matrices in Table = 1 My Image ver: 12.SG  old image Configuration It is recommended to save the running configuration to NVRAM and other local or remote locations such as bootflash or TFTP server prior upgrading IOS software. Both supervisors are running identical 12.25442405 Nov 23 2009 17:53:48 -05:00 2 -rw.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design between several versions of software releases shipped during a 18 month period.2(46)SG Base(2) 12.

2 Chassis Type : WS-C4507R-E ! Common Supervisor Module Type 3 6 Sup 6-E 10GE (X2).d8f5.d8f5.2(53)SG Ok 4 0021. VLAN database and forwarding information with the standby supervisor and will notify the user to proceed with the next ISSU step.4 12. %C4K_REDUNDANCY-5-CONFIGSYNC: The config-reg has standby supervisor %C4K_REDUNDANCY-5-CONFIGSYNC: The startup-config standby supervisor %C4K_REDUNDANCY-5-CONFIGSYNC: The private-config standby supervisor %C4K_REDUNDANCY-5-CONFIGSYNC_RATELIMIT: The vlan synchronized to the standby supervisor been successfully synchronized to the has been successfully synchronized to the has been successfully synchronized to the database has been successfully %ISSU_PROCESS-7-DEBUG: Peer state is [ STANDBY HOT ]. 1000BaseX (SFP) WS-X45-SUP6-E JAE1132SXRQ ! Mismatch operating system version 3 0021.2(53)SG Ok !SSO Synchronized 3 Active Supervisor SSO Active 4 Standby Supervisor SSO Standby hot The following provides the step-by-step procedure to upgrade the Cisco IOS Release 12. 1000BaseX (SFP) WS-X45-SUP6-E JAE1132SXRQ !Common operating system version 3 0021. cr24-4507e-MB#issu loadversion 3 slot0:cat4500e-entservicesk9-mz.SG1 4 slaveslot0: cat4500e-entservicesk9-mz.2(53)SG1 Cisco IOS release without causing network topology and forwarding disruption. • ISSU loadversion—This first step will direct the active supervisor to initialize the ISSU software upgrade process.SG1 After issuing the above command.2(53)SG Ok 4 0021.2(33r)SG ( 12. Each upgrade steps can be aborted at any stage by issuing the issu abortversion command if software detects any failure.2(53)SG1 Ok !SSO Synchronized 3 Active Supervisor SSO Active 4 Standby Supervisor SSO Standby hot This bootup process will force the active supervisor to re-synchronize all SSO redundancy and checkpoints.4 12.d8f5. ISSU changes the boot variable with the new IOS software version if no errors are found and resets the standby supervisor module.d8f5.d8f5.d8f5.45c6 to 0021.2(33r)SG( 12.45c5 0. Please issue the runversion command Medium Enterprise Design Profile Reference Guide 2-143 . 1000BaseX (SFP) WS-X45-SUP6-E JAE1132SXQ3 4 6 Sup 6-E 10GE (X2).2(53)SG to 12.2(33r)SG( 12.45cb 0.4 12.d8f5. Reason: ISSU Loadversion Note Resetting the standby supervisor will not trigger a network protocol graceful recovery and all standby supervisor uplink ports will remain in operational and forwarding state for the transparent upgrade process.45c5 0.2(33r)SG ( 12.45c0 to 0021.4 12. see the following output.122-53.45c6 to 0021. 1000BaseX (SFP) WS-X45-SUP6-E JAE1132SXQ3 4 6 Sup 6-E 10GE (X2).45c0 to 0021. the active supervisor ensures the new IOS software is downloaded on both supervisors file system and performs several additional checks on the standby supervisor for the graceful software upgrade process.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Chassis Type : WS-C4507R-E !Common Supervisor Module Type 3 6 Sup 6-E 10GE (X2).45cb 0.122-53. %RF-5-RF_RELOAD: Peer reload.d8f5. With the broad range of ISSU version compatibility to form SSO communication the standby supervisor will successfully bootup again in its original standby state. cr24-4507e-MB#show module | inc Chassis|Sup|12.

this is the only step that performs SSO-based network graceful recovery. At this stage. the active supervisor reset caused by the issu runversion command will be no different than similar switchover procedures (i. 1000BaseX (SFP) WS-X45-SUP6-E JAE1132SXQ3 4 6 Sup 6-E 10GE (X2). • NSF-Aware Core cr23-VSS-Core# %DUAL-5-NBRCHANGE: EIGRP-IPv4:(415) 100: Neighbor 10.2(53)SG1 Ok !SSO Synchronized 3 Active Supervisor SSO Standby hot 4 Standby Supervisor SSO Active This safeguarded software design provides an opportunity to roll back to the previous IOS software if the system upgrade causes any type of network abnormalities. network administrators may want to adjust the timer up to 2 hours: cr24-4507e-MB#show issu rollback-timer Rollback Process State = In progress Configured Rollback Time = 45:00 Automatic Rollback Time = 19:51 The system will notify the network administrator with the following syslog to instruct them to move to the next ISSU upgrade step if no stability issues are observed and all the network services are operating as expected. Medium Enterprise Design Profile Reference Guide 2-144 .d8f5.15 (Port-channel102) is resync: peer graceful-restart • NSF-Aware Layer 3 Access cr24-3560-MB# %DUAL-5-NBRCHANGE: EIGRP-IPv4:(100) 100: Neighbor 10. In small to mid size network designs.4 12.45c6 to 0021.45cb 0.125.10 (Port-channel1) is resync: peer graceful-restart The previously active supervisor module will boot up in the standby role with the older IOS software version instead the new IOS software version. the network administrator must proceed to the second step.2(33r)SG( 12. cr24-4507e-MB#show module | inc Chassis|Sup|12.125.e.d8f5.2 Chassis Type : WS-C4507R-E ! Common Supervisor Module Type 3 6 Sup 6-E 10GE (X2). However. administrator-forced switchover or supervisor online insertion and removal).2(53)SG Ok 4 0021. During the entire software upgrade procedure.0. for large networks. however the uplink ports of the active supervisor remains intact and the data plane will remain un-impacted during the switchover process. cr24-4507e-MB#issu runversion 4 This command will reload the Active unit.. the default timer may be sufficient. ISSU automatically starts internal rollback timers to re-install old IOS image.4 12.d8f5. Reload reason: Admin ISSU runversion This step will force the current active supervisor to reset itself which will trigger network protocol graceful recovery with peer devices.2(33r)SG( 12.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design • ISSU runversion—After performing several steps to assure the new loaded software is stable on the standby supervisor.0. Proceed ? [confirm]y %RF-5-RF_RELOAD: Self reload. Reason: Admin ISSU runversion CLI %SYS-5-RELOAD: Reload requested by console.d8f5.45c5 0. From the overall network perspective. The following syslog on various Layer 3 systems confirm stable and EIGRP graceful recovery with the new supervisor running the new Cisco IOS software version.45c0 to 0021. 1000BaseX (SFP) WS-X45-SUP6-E JAE1132SXRQ ! Mismatch operating system version 3 0021. The default rollback timer is up to 45 minutes which provides a network administrator an opportunity to perform several sanity checks.

45c0 to 0021.d8f5. Please issue the commitversion command.d8f5.45cb 0.d8f5.4 12. cr24-4507e-MB#show issu rollback-timer Rollback Process State = Not in progress Configured Rollback Time = 45:00 cr24-4507e-MB#show module | inc Chassis|Sup|12.d8f5.d8f5. Reason: ISSU Commitversion cr24-4507e-MB#show module | inc Chassis|Sup|12. 1000BaseX (SFP) WS-X45-SUP6-E JAE1132SXQ3 4 6 Sup 6-E 10GE (X2). then it is recommended to perform an ISSU-based downgrade procedure to retain the network operational state without any downtime planning.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services %ISSU_PROCESS-7-DEBUG: Peer state is [ STANDBY HOT ]. This step stops the rollback timer and instructs the network administrator to issue the final commit command However.45c5 0. cr24-4507e-MB#issu commitversion 3 Building configuration.2(33r)SG( 12.45cb 0.2(33r)SG( 12. If for some reason the network administrator wants to rollback to the older image. This stage concludes the ISSU upgrade procedure and the new IOS version is permanently committed on both supervisor modules. Compressed configuration from 24970 bytes to 10848 bytes[OK] %C4K_REDUNDANCY-5-CONFIGSYNC: The private-config has been successfully synchronized to the standby supervisor %RF-5-RF_RELOAD: Peer reload. 1000BaseX (SFP) WS-X45-SUP6-E JAE1132SXQ3 4 6 Sup 6-E 10GE (X2).45c6 to 0021.2(53)SG1 Ok !SSO Synchronized 3 Active Supervisor 4 Standby Supervisor SSO Standby hot SSO Active Medium Enterprise Design Profile Reference Guide 2-145 .2 Chassis Type : WS-C4507R-E ! Common Supervisor Module Type 3 6 Sup 6-E 10GE (X2).2(33r)SG( 12.2(53)SG1 Ok !SSO Synchronized 3 Active Supervisor SSO Standby hot 4 Standby Supervisor SSO Active • ISSU commitversion—This final ISSU step forces the active supervisor to synchronize its configuration with the standby supervisor and force it to reboot with the new IOS software.45c6 to 0021. it does not perform any additional steps to install the new software on standby supervisor cr24-4507e-MB#issu acceptversion 4 % Rollback timer stopped.4 12.. Please issue the acceptversion command • ISSU acceptversion—This step provides confirmation from the network administrator that the system and network is stable after the IOS install and they are ready to accept the new IOS software on the standby supervisor.4 12.2(53)SG Ok 4 0021.d8f5.2 Chassis Type : WS-C4507R-E ! Common Supervisor Module Type 3 6 Sup 6-E 10GE (X2).2(33r)SG( 12. 1000BaseX (SFP) WS-X45-SUP6-E JAE1132SXRQ ! Mismatch operating system version 3 0021. 1000BaseX (SFP) WS-X45-SUP6-E JAE1132SXRQ ! Common new operating system version 3 0021.d8f5..d8f5.4 12.45c0 to 0021.2(53)SG1 Ok 4 0021.45c5 0.

a VSS capable Sup720-10G supervisor module is installed in Slot5 of virtual-switch SW1 and SW2 respectively. In addition. most of the eFSU pre-requisites and IOS upgrade procedures remain consistent as explained in previous sub-section. However. In the initial introduction. eFSU is supported on the Catalyst 6500-E Sup720-10GE supervisor module running Cisco IOS release with the Enterprise feature set. while the software upgrade procedure for inter-chassis eFSU upgrades is similar. In the following sample output. with MEC and the distributed forwarding architecture. The virtual-Switch SW1 supervisor is in the SSO Active role and the SW2 supervisor is in the Standby hot role.2(33)SXI.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design Catalyst 6500-E VSS eFSU Software Design and Upgrade Process Cisco Catalyst VSS was introduced in the initial IOS Release 12. it had limited high-availability consideration to upgrade the IOS software release.2(33)SXH that supported Fast Software Upgrade (FSU). the Cisco VSS technology enables inter-chassis SSO communication between two virtual-switch nodes. Starting with the IOS Release 12.2(33)SXI2a software version and is fully synchronized with SSO. the Catalyst 6500-E supports true hitless IOS software upgrade in standalone and virtual-switch network designs. Both supervisor are running identical the Cisco IOS Release 12. cr23-VSS-Core#show switch virtual redundancy | inc Mode|Switch|Image|Control ! VSS switch node with control-plane ownership Medium Enterprise Design Profile Reference Guide 2-146 . This may not be a desirable solution when deploying Catalyst 6500-E in the critical aggregation or core network tier. Catalyst 6500-E VSS eFSU Software Design and Upgrade Process Figure 2-79 Catalyst 6500-E VSS eFSU Software Upgrade Process Since eFSU in the Catalyst 6500-E system is built on the ISSU infrastructure. the forwarding plane is in an active state on both virtual-switch nodes. Catalyst 6500-E eFSU Software Upgrade Procedure This subsection provides the software upgrade procedure for Catalyst 6500-Es deployed in VSS mode in the medium enterprise campus LAN network design. the network operation slightly differs compared to ISSU implemented on intra-chassis based SSO design. Enhanced Fast Software Upgrade (eFSU) made it completely ISSU infrastructure compliant and enhances the software and hardware design to retain its functional state during the graceful upgrade process. The ISSU mismatched software version compatibility was not supported by the FSU infrastructure which could cause network down time. As described earlier.

cr23-VSS-Core#issu loadversion 1/5 disk0: s72033-adventerprisek9_wan-mz. s72033_rp Software (s72033_rp-ADVENTERPRISEK9_WAN-M).SXI3 After issuing the above command. VLAN database and forwarding information with the standby virtual-switch and the network administrator is notified to proceed with the next ISSU step.2(33)SXI2a Control Plane State = STANDBY The following provides a step-by-step procedure to upgrade from Cisco IOS Release 12.122-33. It will remain in operational and forwarding state for the transparent upgrade process. Version 12.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services My Switch Id = 1 Peer Switch Id = 2 ! SSO Synchronized Configured Redundancy Mode = sso Operating Redundancy Mode = sso ! Common operating system version Switch 1 Slot 5 Processor Information : Image Version = Cisco IOS Software. RELEASE SOFTWARE (fc2) Control Plane State = ACTIVE Switch 2 Slot 5 Processor Information : Image Version = Cisco IOS Software. With the broad range of ISSU version compatibility to form SSO communication the standby supervisor will successfully bootup again in its original standby state. RELEASE SOFTWARE (fc2) Control Plane State = STANDBY To rejoin the virtual-switch domain.2(33)SXI3. s72033_rp Software (s72033_rp-ADVENTERPRISEK9_WAN-M).2(33)SXI3 without causing network topology and forwarding disruption. Version 12. the active virtual-switch ensures the new IOS software is downloaded on both supervisors file system and performs several additional checks on the standby supervisor on the remote virtual-switch for the graceful software upgrade process.From Active Switch (Reload peer unit). s72033_rp Software (s72033_rp-ADVENTERPRISEK9_WAN-M).2(33)SXI2a Control Plane State = ACTIVE Switch 2 Slot 5 Processor Information : Image Version = Cisco IOS Software. • ISSU loadversion—This first step will direct the active virtual-switch node to initialize the ISSU software upgrade process. Reason: ISSU Loadversion %SYS-SW2_SPSTBY-5-RELOAD: Reload requested . Medium Enterprise Design Profile Reference Guide 2-147 . Version 12. s72033_rp Software (s72033_rp-ADVENTERPRISEK9_WAN-M). Each upgrade step can be aborted at any stage by issuing the issu abortversion command if the software detects any failures. cr23-VSS-Core#show switch virtual redundancy | inc Mode|Switch|Image|Control ! VSS switch node with control-plane ownership My Switch Id = 1 Peer Switch Id = 2 ! SSO Synchronized Configured Redundancy Mode = sso Operating Redundancy Mode = sso ! Mismatch operating system version Switch 1 Slot 5 Processor Information : Image Version = Cisco IOS Software. Version 12.2(33)SXI2a to 12.2(33)SXI2a. %RF-SW1_SP-5-RF_RELOAD: Peer reload. ISSU changes the boot variable to the new IOS software version if no error is found and resets the standby virtual-switch and installed modules.122-33. Note Resetting standby virtual-switch node will not trigger the network protocol graceful recovery process and will not reset the linecards on the active virtual-switch.SXI3 2/54 slavedisk0: s72033-adventerprisek9_wan-mz. both nodes will reestablish the VSL EtherChannel communication and force the active supervisor to resynchronize all SSO redundancy and checkpoints. see the following output.

cr23-VSS-Core#show switch virtual redundancy | inc Mode|Switch|Image|Control ! VSS switch node with control-plane ownership changed to SW2 My Switch Id = 2 Peer Switch Id = 1 ! SSO Synchronized Configured Redundancy Mode = sso Operating Redundancy Mode = sso ! Mismatch operating system version Switch 2 Slot 5 Processor Information : Image Version = Cisco IOS Software. From the network perspective.0.125. The following syslogs confirm stable and EIGRP graceful recovery on the virtual-switch running the new Cisco IOS software version. RELEASE SOFTWARE (fc2) Control Plane State = ACTIVE Switch 1 Slot 5 Processor Information : Image Version = Cisco IOS Software.Chapter 2 Deploying Medium Enterprise Network Foundation Services Medium Enterprise Design Profile (MEDP)—LAN Design %HA_CONFIG_SYNC-6-BULK_CFGSYNC_SUCCEED: Bulk Sync succeeded %PFREDUN-SW2_SPSTBY-6-STANDBY: Ready for SSO mode %ISSU_PROCESS-SW1_SP-7-DEBUG: Peer state is [ STANDBY HOT ]. The default rollback timer is up to 45 minutes which provides the network administrator an opportunity to perform several sanity checks. the network administrator may want to adjust the timer up to 2 hours: cr23-VSS-Core#show issu rollback-timer Rollback Process State = In progress Medium Enterprise Design Profile Reference Guide 2-148 . Version 12.2(33)SXI3. Please issue the runversion command • ISSU runversion—After performing several steps to assure the new loaded software is stable on the standby virtual-switch.. however the linecard on the current standby virtual-switch (SW2) will remain intact and the data plane traffic will continue get switched during the switchover process. cr23-VSS-Core#issu runversion 2/5 This command will reload the Active unit. s72033_rp Software (s72033_rp-ADVENTERPRISEK9_WAN-M). eFSU also provides a safeguarded software design for additional network stability and opportunity to roll back to the previous IOS software if the system upgrade causes any type of network abnormalities. %issu runversion initiated successfully Proceed ? [confirm]y %RF-SW1_SP-5-RF_RELOAD: Self reload. administration-forced switchover or supervisor online insertion and removal). In small to mid size network designs. At this stage. the rebooted virtual-switch module boots up in the standby role with the older IOS software version instead the new IOS software version. s72033_rp Software (s72033_rp-ADVENTERPRISEK9_WAN-M). Reason: Admin ISSU runversion CLI This step will force the current active virtual-switch (SW1) to reset itself which will trigger network protocol graceful recovery with peer devices. In the entire eFSU software upgrade procedure.14 (Port-channel1) is resync: peer graceful-restart After re-negotiating and establishing the VSL EtherChannel link and going through the VSLP protocol negotiation process. this is the only time that the systems will perform an SSO-based network graceful recovery. ISSU automatically starts internal rollback timers to re-install old IOS image if there are any problems.e.2(33)SXI2a. RELEASE SOFTWARE (fc2) Control Plane State = STANDBY Like intra-chassis ISSU implementation. the network administrator is now ready to proceed to the runversion step. Version 12. NSF-Aware Distribution cr24-4507e-MB# %DUAL-5-NBRCHANGE: EIGRP-IPv4:(100) 100: Neighbor 10. the affects of the active supervisor resetting during the ISSU runversion step will be no different than the normal switchover procedure (i. However for large networks. the default timer may be sufficient.

%issu commitversion executed successfully cr23-VSS-Core#show switch virtual redundancy | inc Mode|Switch|Image|Control ! VSS switch node with control-plane ownership My Switch Id = 2 Peer Switch Id = 1 ! SSO Synchronized Configured Redundancy Mode = sso Operating Redundancy Mode = sso ! Common operating system version Switch 2 Slot 5 Processor Information : Medium Enterprise Design Profile Reference Guide 2-149 . However. This step stops the rollback timer and instructs the network administrator to continue to the final commit state. %ISSU_PROCESS-SW2_SP-7-DEBUG: Peer state is [ STANDBY HOT ]. cr23-VSS-Core#show issu rollback-timer Rollback Process State = Not in progress Configured Rollback Time = 00:45:00 cr23-VSS-Core#show switch virtual redundancy | inc Mode|Switch|Image|Control ! VSS switch node with control-plane ownership changed to SW2 My Switch Id = 2 Peer Switch Id = 1 ! SSO Synchronized Configured Redundancy Mode = sso Operating Redundancy Mode = sso ! Mismatch operating system version Switch 2 Slot 5 Processor Information : Image Version = Cisco IOS Software. cr23-VSS-Core#issu commitversion 1/5 Building configuration.. Reason: Proxy request to reload peer %SYS-SW1_SPSTBY-5-RELOAD: Reload requested . cr23-VSS-Core#issu acceptversion 2/5 % Rollback timer stopped. it does not perform any additional steps to install the new software on standby supervisor. s72033_rp Software (s72033_rp-ADVENTERPRISEK9_WAN-M). Version 12. Version 12.2(33)SXI3. s72033_rp Software (s72033_rp-ADVENTERPRISEK9_WAN-M). then it is recommended to perform the eFSU-based downgrade procedure to maintain the network operational state without any downtime planning.Chapter 2 Medium Enterprise Design Profile (MEDP)—LAN Design Deploying Medium Enterprise Network Foundation Services Configured Rollback Time = 00:45:00 Automatic Rollback Time = 00:36:08 The system will notify the network administrator with following syslog to continue to the next ISSU upgrade step if no stability issues are observed and all the network services are operating as expected.. Please issue the acceptversion command • ISSU acceptversion—This eFSU step provides confirmation from the network administrator regarding the system and network stability after installing the new software and confirms they are ready to accept the new IOS software on the standby supervisor. [OK] %RF-SW2_SP-5-RF_RELOAD: Peer reload. RELEASE SOFTWARE (fc2) Control Plane State = STANDBY • ISSU commitversion—The final eFSU step forces the active virtual-switch to synchronize the configuration with the standby supervisor and force it to reboot with the new IOS software. This stage concludes the eFSU upgrade procedure and the new IOS version is permanently committed on both virtual-switches. If for some reason the network administrator needs to rollback to the older image.From Active Switch (Reload peer unit). Please issue the commitversion command. RELEASE SOFTWARE (fc2) Control Plane State = ACTIVE Switch 1 Slot 5 Processor Information : Image Version = Cisco IOS Software.2(33)SXI2a.

2(33)SXI3. and secure classrooms. QoS.Chapter 2 Summary Medium Enterprise Design Profile (MEDP)—LAN Design Image Version = Cisco IOS Software. virtual learning environments. Version 12. key network foundation services such as routing. This chapter reviews the two LAN design models recommended by Cisco. as well as where to apply these models within the various locations of a medium enterprise network. s72033_rp Software (s72033_rp-ADVENTERPRISEK9_WAN-M). mobility. RELEASE SOFTWARE (fc2) Control Plane State = STANDBY Summary Designing the LAN network aspects for the medium enterprise network design establishes the foundation for all other aspects within the service fabric (WAN. Medium Enterprise Design Profile Reference Guide 2-150 . Version 12. operational efficiencies.2(33)SXI3. and high availability best practices are given for the entire medium enterprise design. security. and UC) as well as laying the foundation to provide safety and security. s72033_rp Software (s72033_rp-ADVENTERPRISEK9_WAN-M). Each of the layers is discussed and design guidance is provided on where to place and how to deploy these layers. RELEASE SOFTWARE (fc2) Control Plane State = ACTIVE Switch 1 Slot 5 Processor Information : Image Version = Cisco IOS Software. Finally. switching. multicast.

Medium Enterprise Design Profile Reference Guide 3-1 . The sites are interconnected through various WAN transports as shown in Figure 3-1.CH A P T E R 3 Medium Enterprise Design Profile (MEDP)—WAN Design WAN Design The Medium Enterprise WAN Design Profile is a multi-site design where a site consists of multiple buildings and services.

the service fabric network provides the foundation on which all the solutions and services are built upon to solve the business challenges.Chapter 3 WAN Design Medium Enterprise Design Profile (MEDP)—WAN Design Figure 3-1 Medium Enterprise WAN Design Diagram Large Building Medium Building Small Building Extra Small Building Services Block Data Center QFP Main Site Internet Edge QFP WAN PSTN Internet Private WAN Services Block Services Block Services Block Data Center Data Center Data Center Remote Small Site Remote Large Site Remote Medium Site Within the Medium Enterprise Design Profile. Medium Enterprise Design Profile Reference Guide 3-2 229374 Large Building Medium Building Small Building Medium Building Small Building . This service fabric consists of four distinct components as shown in Figure 3-2.

and the justification for choosing a platform.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design WAN Design Figure 3-2 The Service Fabric Design Model Service Fabric Design Model Mobility Security Unified Communications This chapter discusses the WAN design component of the Medium Enterprise Design Profile. the video applications. and general Internet access for the entire enterprise. video. These locations have similar architecture as the main site. The main components of Medium Enterprise Design Profile for WAN architecture are as follows: • • • WAN transport WAN devices Network Foundation services—Routing. This communication could be with voice. The WAN design should not be viewed merely for providing access. and partners. Moreover. highly performing WAN designs are required. it is important for communication to exist between the employees. a WAN network that can support the following requirements is needed: • • • • • High performance Support different classes of traffic Native routing Multicast capability Security To support these requirements enterprises need to have a private WAN service to provide connectivity between remote sites. QoS. may possess. Therefore. customers. but mainly to see how the business requirements can be met. the platforms chosen. these sites need to collaborate with each other to meet the business objectives. the assumptions made. Private WAN Service The Medium Enterprise Design Profile consists of several locations. flavors ranging from desktop video to real-time video. and main site. Medium Enterprise Design Profile Reference Guide 228505 Local Area Network (LAN) Wide Area Network (WAN) 3-3 . This section discusses how the WAN design is planned for medium enterprises. Therefore. or data applications. highly resilient and. and multicast WAN Transport This section discusses the different WAN transports present in the Medium Enterprise Design Profile. However. The WAN design is highly critical to provide network access for remote sites to the main site. To provide this collaborative environment. as well as connectivity to other networks. See Figure 3-3.

Therefore. and data applications that provide QoS service to customers. which makes this transport highly scalable. it is similar to a situation where a customer is connected to different service providers. The advantages of using this WAN transport are as follows: • Scalability and reachability – The services offered would scale from 1Mbps to 10Gbps. Medium Enterprise Design Profile Reference Guide 3-4 229375 . QoS. however. • Performance. both circuits are logically separated using different subinterfaces. See Figure 3-4. ability to provide different SLAs based on voice. it is available at large number of places. – Service providers worldwide are migrating their networks to provide metro services.Chapter 3 WAN Design Medium Enterprise Design Profile (MEDP)—WAN Design Figure 3-3 Medium Enterprise Connectivity to Other Remote Sites Using Private WAN Remote Site 2 Remote Site 3 Remote Site 1 Medium Enterprise Private WAN Site Network Remote Site 4 QFP Remote Site X Internet Service The physical connection for reaching the Internet and the private WAN network is same. thereby. Figure 3-4 Medium Enterprise Internet Service Private WAN Medium Enterprise Site Network 229376 QFP Internet Metro Service Metro Ethernet is one of the fastest growing WAN transport technologies in the telecommunications industry. and suitability for convergence – Inherently Ethernet networks require less processing to operate and manage and operate at higher bandwidth than other technologies. – The granular options in bandwidth. and beyond in granular increments. video.

and the multiple circuits are identified as VLANs by way of an 802. which is also known as Ethernet Virtual Private Line (EVPL) provides a point-to-point service.1q trunk. like Frame Relay. identifying the multiple virtual circuits or connections. and data. – Enables new applications requiring high bandwidth. Medium Enterprise Design Profile Reference Guide 3-5 . • Cost savings – Metro Ethernet brings the cost model of Ethernet to the WAN. the physical link is Ethernet.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design WAN Design – Low latency and delay variation make it the best solution for video. It passes 802. provides any-to-any connectivity within the Metro area. the access link is a serial interface to a Frame Relay switch with individual data-link connection identifiers (DLCIs). also known as Virtual Private LAN Services (VPLS). • Expediting and enabling new applications – Accelerates implementations with reduced resources for overburdened IT departments. E-LAN which provides multipoint or any-to-any connectivity. voice. In the case of Frame Relay. and low latency that were previously not possible or prohibited by high cost. typically FastEthernet or Gigabit Ethernet. E-LAN. Figure 3-5 shows the difference between these services. EVPL. There are two popular methods of service for Metro Ethernet: 1. which allows flexibility. E-line. provides for multiplexing multiple point-to-point connections over a single physical link. 2.q trunks across the SP network known as Q-in-Q. In the case of EVPL.

Chapter 3 WAN Design Medium Enterprise Design Profile (MEDP)—WAN Design Figure 3-5 Different Services Available E-LAN E-Line This section discusses how the Metro service is designed in the Medium Enterprise Design Profile. making the centralized administration applicable. where as. Figure 3-6 shows how the remote site locations are connected to main site using Metro service. The key reasons for recommending Metro service for Medium Enterprise are as follows: • Centralized administration and management—E-line service provides point-to-point connectivity. Performance—Since all the application services are centrally located at main site. E-LAN provides point-to-multipoint connectivity. and more if needed in the future. • Therefore. Having a point-to-point connectivity mandates that all the remote site sites need to traverse the main site to reach the other. it is recommended that the remote large and medium remote site locations use E-line service to connect to the main site. The Metro service is used to provide connectivity between the remote sites to the main site. the WAN bandwidth required for remote sites to main site should be at least 100 Mbps. The Metro transport can provide 100Mbps. in this design. Medium Enterprise Design Profile Reference Guide 3-6 227581 .

Medium Enterprise Design Profile Reference Guide 229377 Cisco 4800 Switch Cisco 3800 Router 3-7 . choosing the appropriate WAN aggregation router is essential. The leased-line service is more readily available for these type of locations and the bandwidth is sufficient for the small remote site application requirements. WAN Aggregation Platform Selection in the Medium Enterprise Design Profile In addition to selecting the WAN service for connectivity between remote site locations and access to the Internet. Cisco recommends that the small remote site connect to the main site using a private leased-line service.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design WAN Design Figure 3-6 The Metro Transport Deployment in Medium Enterprise WAN Design Main Site Site Network ASR 1006 QFP SONET/SDH Metro Cisco 3750 Metro Switch Large Site Medium Site Small Site Leased-Line Service The WAN bandwidth requirement for a small remote site is assumed to be 20Mbps. For each location in the Medium Enterprise Design Profile various WAN aggregation platforms are selected based on the requirements.

integrated Cisco ASR 1000 Series Shared Port Adapter Interface Processor (SIP). The Cisco ASR 1006 Router is a 12-SPA. and two SIP slots. • • In Medium Enterprise Design Profile. 2-rack-unit (RU) chassis with one Embedded Services Processor (ESP) slot that comes with an integrated Router Processor (RP).Chapter 3 WAN Design Medium Enterprise Design Profile (MEDP)—WAN Design Main Site WAN Aggregation Platform Selection A WAN aggregation router aggregates all the incoming WAN circuits from various locations in the network as well as the Internet and also provides the proper QoS required for application delivery. The first place is where the main site location connects to outside world using private WAN and Internet networks. hardware redundant chassis with two ESP slots. 4-RU chassis with one ESP slot. there are two places where the WAN aggregation occurs in the main site location. The Cisco ASR 1004 Router is an 8-SPA. The Cisco ASR 1000 Series Router family consists of three different models: • The Cisco ASR 1002 Router is a 3-SPA. Medium Enterprise Design Profile Reference Guide 3-8 . The second place is where all the remote sites connect to the main site. Cisco recommends the Cisco ASR family of routers as the WAN aggregation platform for the main site location. 6-RU. and integrated four Gigabit Ethernet ports. two RP slots and three SIP slots. Figure 3-7 shows the two different WAN aggregation devices. one RP slot.

Moreover. routing. and resiliency—that are essential requirements for WAN aggregation router. QoS. This choice was made considering the cost and required features—performance. this platform contains built-in resiliency capabilities such as ISSU and IOS-based redundancy. Medium Enterprise Design Profile Reference Guide 229378 Large Building Medium Building Small Building Medium Building Small Building 3-9 .Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design WAN Design Figure 3-7 The WAN Aggregation Points in Medium Enterprise WAN Design Large Building Medium Building Small Building Extra Small Building Services Block Data Center QFP Main Site Internet Edge QFP WAN Aggregation 1 WAN Aggregation 2 WAN PSTN Internet Private WAN Services Block Services Block Services Block Data Center Data Center Data Center Remote Small Site Remote Large Site Remote Medium Site WAN Aggregation 1 A Cisco ASR 1004 Series router is recommended as the WAN aggregation platform for private WAN/Internet connectivity.

at the large remote site. Therefore. which can be an ASR. Large Remote Site WAN Aggregation Platform Selection The WAN connectivity between the large remote site to the main site is fairly simpler because of the lack of requirements of advanced encryption technologies. the Cisco 3750ME switch was selected to perform the WAN aggregation. The Cisco 3750 Metro switch has the following features/capabilities to adequately meet the requirements: • • • • Hierarchical QoS Routing support: OSPF. VSS has been chosen as technology on the distribution switch. For this design. this router would also support EtherChannel load balancing feature. as per the site LAN design document. a dedicated WAN aggregation device is needed to perform that functionality.” the medium remote site collapses the WAN edge and core-layer LAN functionality into a single switch to provide cost effectiveness to meet the budget needs for this size location. considering the cost/performance criteria. and VSS does not support WAN functionality. However. EIGRP. and dual ESP modules to support the hardware redundancy. Out of these choices.Chapter 3 WAN Design Medium Enterprise Design Profile (MEDP)—WAN Design WAN Aggregation 2 The second WAN aggregation device provides connectivity to the large and medium remote sites to the main site. the Cisco Catalyst 3750 ME. The remote medium site is connected to the main site location through Metro service. the main purpose is to reduce the cost and try to consolidate the WAN functionality into the distribution device at the large site. At the remote medium site. or 3750ME switches. This switch has the necessary features to perform as WAN router. Therefore. the highest port density solution of the three Cisco ASR 1000 routers Resiliency—Cisco ASR 1006 router supports hardware redundancy and in-service software upgrades (ISSU). in addition to its role as core-layer LAN switch. This chassis would support dual route processors. To perform this aggregation. Cisco ISR Series router or upgrading to the Cisco Catalyst 6500 series could be explored as an option. “Medium Enterprise Design Profile (MEDP)—LAN Design. the Cisco Catalyst 4500 Series switches has been chosen to perform the dual functionality as WAN router. Moreover. and BGP Multicast support: PIM Redundant power supply Medium Remote Site WAN Aggregation Platform Selection As discussed in Chapter 2. However. if there is the need for advanced WAN features such as MPLS. 7200. Medium Enterprise Design Profile Reference Guide 3-10 . the Cisco ASR 1006 router with redundant route processors and redundant ESP’s has been recommended for the following reasons: • • • Performance—Up to 20 Gbps throughput Port density—Up to 12 shared port adapters (SPAs). the WAN and LAN aggregation platform is the Cisco Catalyst 4507 switch.

Since it is a leased-line circuit. The large remote site. is recommended to have 1Gbps Metro service to the main site where as the small remote site location is recommended to have at least 20Mbps of bandwidth to main site. The large remote site and medium remote site would connect to main site using Metro Ethernet services. The WAN speed between the small remote site and the main site location is assumed to be around 20Mbps. WAN devices such as Cisco 3750 Metro or 4507 switch cannot be used. WICs. VWICs. Therefore.255. The following section provides the configuration details of all the WAN devices needed to establish the WAN connectivity. For this reason. The small remote site uses a leased-line service to connect to the main site location.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design WAN Design Small Remote Site WAN Aggregation Platform Selection The small remote site is connected to main site using a private leased-line service.126.1 255. The main advantages of using the Cisco 3845 Series router are as follows: • • • • • Enhanced Network Module Slot Support for over 90 existing and new modules Voice Features: Analog and digital voice call support and optional voice mail support Support for majority of existing AIMs.255.0. and this service is provided by a traditional leased line. which aggregates all the connections from the remote site locations to the main site: interface GigabitEthernet0/2/0 description Connected to cr11-3750ME-RLC ip address 10.254 ! interface GigabitEthernet0/2/1 description Connected to cr11-4507-RMC dampening no ip address load-interval 30 carrier-delay msec 0 Medium Enterprise Design Profile Reference Guide 3-11 . The major components of the implementation are the following: • • • • • WAN infrastructure design Routing QoS Resiliency Multicast WAN Infrastructure Design As explained in the design considerations (where??? in chapter 1??). the Medium Enterprise Design Profile uses two different services to connect the remote site locations to the main site location. due to its size. NMs. the Cisco 3845 Series router is chosen as the WAN platform for the small remote site. an integrated services router is needed to meet the requirement. Configuration of WAN Interfaces at WAN Aggregation Router 2 The following is configuration of WAN interfaces on WAN aggregation router 2. and VICs Integrated GE ports with copper and fiber support Implementation of WAN Reference Design The following section discusses the implementation details for the Medium Enterprise Design Profile.

a serial SPA is needed on the ASR 1006 WAN aggregation router at the main site and this SPA needs to be enabled for T3 interface type.0 255. The following configuration steps are needed to build the lease-line service between the main site and small remote site: Medium Enterprise Design Profile Reference Guide 3-12 .255.0.255.126.255.254 ! ! Configuration of WAN Interface at 3750 Large Remote Site The following is configuration of WAN interface at the 3750 large remote site switch.3 255.254 load-interval 30 carrier-delay msec 0 Leased-Line Service The WAN bandwidth requirement for a small remote site is assumed to be 20Mbps.126. Cisco recommends that the small remote site connect to the main site using a private leased-line service.255. The leased-line service is more readily available for these type of locations and the bandwidth is sufficient for the small remote site application requirements.254 Configuration of WAN interface at 4500 Medium Remote Site The following is the configuration of WAN interface at the medium remote site connected to the main site: interface GigabitEthernet4/1 description link connected to cr13-6500-pe2 gi3/2 switchport trunk native vlan 802 switchport trunk allowed vlan 102 switchport mode trunk logging event link-status load-interval 30 carrier-delay msec 0 no cdp enable spanning-tree portfast trunk spanning-tree guard root ! interface Vlan102 description Connected to cr11-ASR-WE dampening ip address 10.0. The configuration below illustrates how to enable and configure the T3 interface. which is connected to main site: interface GigabitEthernet1/1/1 description Connected to cr11-ASR-WE no switchport dampening ip address 10.2 255.126. To implement this design.Chapter 3 WAN Design Medium Enterprise Design Profile (MEDP)—WAN Design negotiation auto cdp enable service-policy output PARENT_POLICY hold-queue 2000 in hold-queue 2000 out ! interface GigabitEthernet0/2/1.0.255.255.102 encapsulation dot1Q 102 ip address 10.

Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design WAN Design Step 1 Enable the T3 interface on the SPA on ASR1006: card type t3 0 3 Step 2 Configure the WAN interface: interface Serial0/3/0 dampening ip address 10.0 5 load-interval 30 carrier-delay msec 0 dsu bandwidth 44210 Routing Design This section discusses how routing is designed and implemented in the Medium Enterprise Design Profile.0. and the Internet service.124.126.255.5 255. To provide connectivity using these transport services we have designed two distinct routing domains – external and internal. Metro Service. and the internal routing domain design. Internet. the external routing domain would connect with different service providers.255.0.4 255. Internet service would help the medium enterprise to reach Internet.0.0. Private WAN.255. because it the only router which interfaces with the external domain. The following section discusses about the external routing domain design. and the internal routing domain is where the entire routing domain is within single autonomous system.254 Configuration of WAN Interface at Small Remote Site Location The following is configuration of WAN interface at the small remote site location: interface Serial2/0 dampening ip address 10. External Routing Domain As indicated above. and leased-line services. The external routing domain is where the medium enterprise would connect with external autonomous system. As indicated in the WAN transport design.254 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 eigrp-key ip pim sparse-mode service-policy output RSC_PARENT_POLICY ip summary-address eigrp 100 10. The main design considerations for routing for the Internet/private WAN edge router are as follows: • • • Scale up to large number of routes Support for multi-homing—connection to different service providers Ability to implement complex polices—Have separate policies for incoming and outgoing traffic Medium Enterprise Design Profile Reference Guide 3-13 .0 255.255. This is applicable only to the WAN aggregation router 1. which interfaces with both Private WAN. the Medium Enterprise Design Profile has multiple transports—Private WAN.126. The private network would provide access to reach other remote sites globally.255. and the Internet service. Metro/leased-line service would help to connect remote site locations to the main site.

BGP supports having different policies for incoming and outgoing prefixes. It is important to design EIGRP routing domain in site infrastructure with all the design principles defined earlier in this section. BGP Design in Medium Enterprise Figure 3-8 AS 65011 Private WAN AS 30000 Medium Enterprise Site Network AS 30001 Internet QFP For more information on designing and configuring BGP on the Internet border router. BGP has is chosen as the routing protocol because of the following reasons: • • Scalability—BGP is far superior when routing table entries is quite large. and optimize the network performance. Figure 3-9 depicts the design of EIGRP for internal network. Complex policies—IGP protocol is better in environments where the neighbors are trusted. refer to the SAFE Reference Design at the following link: http://www.cisco. The Medium Enterprise Design Profile network infrastructure must be deployed in recommended EIGRP protocol design to secure. Medium Enterprise Design Profile Reference Guide 3-14 229379 . whereas when dealing with different service providers’ complex policies are needed to deal with incoming and outgoing entries.com/en/US/netsol/ns954/index. which is basically connecting all the devices in the site network. Figure 3-8 shows the BGP design. EIGRP is a balanced hybrid routing protocol that builds neighbor adjacency and flat routing topology on per autonomous-system (AS)-basis. simplify.Chapter 3 WAN Design Medium Enterprise Design Profile (MEDP)—WAN Design To meet the above requirements.html#~five Internal Routing Domain EIGRP is chosen as the routing protocol for designing the internal routing domain.

3.254 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 eigrp-key ! Medium Enterprise Design Profile Reference Guide 229380 Cisco 4800 Switch Cisco 3800 Router 3-15 .255. which is link between the ASR1006 router and the core The 1Gbps Metro link to large remote site location The 100Mpbs Metro link to medium remote site location 20Mbps leased-line service to small remote Site location Configure the neighbor authentication on interface links: interface Port-channel1 ip address 10.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design WAN Design Figure 3-9 EIGRP Design Diagram Main Site Site Network EIGRP AS 100 ASR 1006 QFP SONET/SDH Metro EIGRP AS 100 EIGRP AS 100 EIGRP AS 100 Cisco 3750 Metro Switch Large Site Medium Site Small Site EIGRP Configuration on WAN Aggregation Router2 –ASR1006 The EIGRP is used on the following links: 1.255. 4.255.0.125. 2. Step 1 Port-channel link.255.23 255.1 255.254 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 eigrp-key ! interface GigabitEthernet0/2/0 description Connected to cr11-3750ME-RLC ip address 10.0.126.

0 255.0.255.254 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 eigrp-key ! interface Serial0/3/0 dampening ip address 10.200.0.102 encapsulation dot1Q 102 ip address 10.255.102 encapsulation dot1Q 102 ip address 10.255.0.254 ip summary-address eigrp 100 10.0.3 255.0.0.0.125.0 255.255.255.0 ! interface Serial0/3/0 ip address 10.3 255.0 ! interface GigabitEthernet0/2/0 description Connected to cr11-3750ME-RLC ip address 10.126.0.0.0 ! interface GigabitEthernet0/2/1 description Connected to cr11-4507-RMC ! interface GigabitEthernet0/2/1.126.0 255.255.255.0.255.102 no passive-interface Serial0/3/0 no passive-interface Port-channel1 nsf The ASR1006 router is enabled with nonstop forwarding feature.125.0 255.254 ip summary-address eigrp 100 10.255.0 eigrp router-id 10.126.254 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 eigrp-key Step 2 Configure the summarization on the member links: interface Port-channel1 ip address 10.0.255.254 ip summary-address eigrp 100 10.0.126.255.0.Chapter 3 WAN Design Medium Enterprise Design Profile (MEDP)—WAN Design interface GigabitEthernet0/2/1 description Connected to cr11-4507-RMC dampening no ip address load-interval 30 carrier-delay msec 0 negotiation auto cdp enable hold-queue 2000 in hold-queue 2000 out ! interface GigabitEthernet0/2/1.0 5 5 5 5 Step 3 Configure EIGRP routing process: router eigrp 100 network 10.255.126.126.126.126.255.255.1 255.254 ip summary-address eigrp 100 10.126.24 no auto-summary passive-interface default no passive-interface GigabitEthernet0/2/0 no passive-interface GigabitEthernet0/2/1. The following command is used to verify the status: cr11-asr-we#show ip protocols Medium Enterprise Design Profile Reference Guide 3-16 .0.0.255.5 255.5 255.255.0.23 255.

4 90 1d17h 10.0.126. GigabitEthernet0/2/1.0 passive-interface default no passive-interface Port-channel1 Medium Enterprise Design Profile Reference Guide 3-17 .0.0.0.102 Serial0/3/0 Summarizing with metric 2816 Maximum path: 4 Routing for Networks: 10. K2=0.126. GigabitEthernet0/2/0.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design WAN Design *** IP Routing is NSF aware *** Routing Protocol is "eigrp 100" Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Default networks flagged in outgoing updates Default networks accepted from incoming updates EIGRP metric weight K1=1.254 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 eigrp-key router eigrp 100 network 10.126.126. K4=0. K3=1.0 255.125.22 90 1d17h 10.0/16 for Port-channel1. K5=0 EIGRP maximum hopcount 100 EIGRP maximum metric variance 1 Redistributing: eigrp 100 EIGRP NSF-aware route hold timer is 240s EIGRP NSF enabled NSF signal timer is 20s NSF converge timer is 120s Time since last restart is 2w1d Automatic network summarization is not in effect Address Summarization: 10. Step 1 Enable authentication on the link: interface GigabitEthernet1/1/1 description Connected to cr11-ASR-WE no switchport dampening ip address 10.255.126.0 Passive Interface(s): GigabitEthernet0/2/1 GigabitEthernet0/2/2 GigabitEthernet0/2/3 GigabitEthernet0/2/4 Serial0/3/1 Group-Async0 Loopback0 Tunnel0 Routing Information Sources: Gateway Distance Last Update (this router) 90 2w1d 10.0.0.0.0.0.2 90 1d17h Distance: internal 90 external 170 cr11-asr-we# EIGRP Configuration on 3750 Large Remote Site Switch The EIGRP configuration at the 3750 large remote site also has similar steps compared to main site.255.0.0 90 1d17h 10.

255.126.255.0 255.0 network 10.0.0.0.4 255.0.200.0.1 Step 2 Configure summarization on the link: interface GigabitEthernet1/1/1 description Connected to cr11-ASR-WE no switchport dampening ip address 10.254 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 eigrp-key Medium Enterprise Design Profile Reference Guide 3-18 .255 nsf ! EIGRP Configuration at 3800 Small Remote Site Router Step 1 Configure link authentication: interface Serial2/0 dampening ip address 10.255.0 0.1 network 10.255.255.255.0.0 255.0.255.0.126.0 Step 3 Configure EIGRP routing process: router eigrp 100 network 10.255.126.0.255.0.0.0 255.0.1 ! EIGRP Configuration at 4750 Medium Site Switch Step 1 Enable authentication on the WAN link: interface Vlan102 description Connected to cr11-ASR-WE dampening ip address 10.98.Chapter 3 WAN Design Medium Enterprise Design Profile (MEDP)—WAN Design no passive-interface GigabitEthernet1/1/1 eigrp router-id 10.122.254 ip summary-address eigrp 100 10.255.0.126.123.200.0 0.123.122.255 network 10.0.254 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 eigrp-key Step2) Enable summarization on the WAN links interface Vlan102 ip summary-address eigrp 100 10.0 passive-interface default no passive-interface Port-channel1 no passive-interface GigabitEthernet1/1/1 eigrp router-id 10.1 0.0.2 255.0 5 load-interval 30 carrier-delay msec 0 Step 2 Enable EIGRP routing process: router eigrp 100 passive-interface default no passive-interface Vlan102 no auto-summary eigrp router-id 10.122.0.200.123.

each of these applications require different performance characteristics on the network. As shown in Figure 3-10. the bandwidth of the WAN transport dictates the amount of traffic received at each remote site. and data together with newer applications such as broadcast video. For example.255.0. QoS QoS is a part of foundation services. Moreover. voice applications need constant low bandwidth and low delay performance.124. This problem would be exacerbated if there were more centralized applications. • Bandwidth—Lack of proper bandwidth can cause applications from performing poorly.124. Before discussing the QoS design.0 no auto-summary eigrp router-id 10.0. refer to the “Designing an End-to-End EIGRP Routing Network” section on page 2-52. delay.1 ! To obtain more information about EIGRP design. Cisco IOS has several robust QoS tools such as classification and marking.0 5 load-interval 30 carrier-delay msec 0 dsu bandwidth 44210 Step 2 Configure EIGRP process: router eigrp 100 network 10. Bandwidth Constraint Due to Difference in Speeds Figure 3-10 • Jitter—Occurs when there are bandwidth mismatches between the sender and receiver. data applications may need only high throughput. shaping.0.0. WRED. Traffic Characteristics The main traffic characteristics are bandwidth. loss. policing. Medium Enterprise Design Profile Reference Guide 228512 3-19 . real-time video. The bandwidth constraint occurs because of the difference between the bandwidth available at LAN and the WAN.0 255. Applications are constrained by the amount of WAN bandwidth. the following subsection provides a brief introduction on these characteristics. The traditional applications such as voice. To cater to these performance characteristics.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design WAN Design Step2) Configure Summarization interface Serial2/0 dampening ip summary-address eigrp 100 10. which could result in poor performance of delay sensitive applications like voice and video. video. and many other applications have all converged into IP networks. video surveillance. and many other tools to effect the traffic characteristics. and jitter. queuing. Similarly. but are tolerant to delay and loss.200. which is very critical to the application performance.

For WAN speeds between 1Mpbs to 100Mbps. Figure 3-11 illustrates the recommended markings for different application traffic. or data. Cisco QoS tools help to optimize these characteristics so that voice. coherent QoS scheme across all network layers. the traffic characteristics discussed above need to be fully understood before making any decisions on WAN transport or the platforms needed to deploy these services. QoS design is the most significant factor in determining the success of network deployment. the congestion can occur when there are speed mismatches. Class-based Weighted-Fair Queuing (CBWFQ). Therefore. Whether the service provider will provide four classes of traffic Whether the service provider will only provide one class of traffic The general guidelines for deploying the WAN edge device considerations are as follows: • • When designing the QoS for WAN architecture. To prevent that from occurring. and there is not enough bandwidth to send the packets. it is important to have a good QoS policy to accommodate these applications. Therefore. The voice applications have a constant and low bandwidth requirement. QoS must always be considered in the design choice. which is used for highest-priority traffic (voice/ video). it helps to mitigate network attacks and manage the control plane traffic. SILVER. GOLD. video. but the difference lies in the bandwidth requirement. and DEFAULT. For WAN speeds between 100Mbps to 10Gbps. For a properly designed voice network. which can be used for guaranteeing bandwidth to data applications. when the platforms are selected at each network layer. which plays a large role in determining the performance of the applications. but the video applications have variable bandwidth requirements.Chapter 3 WAN Design Medium Enterprise Design Profile (MEDP)—WAN Design • • Loss—occurs when the queues become full. and data applications performance is optimized. use ASR1000 with QFP or hardware queuing via Cisco Catalyst 3750-Metro and 6500/7600 WAN modules. voice. the following two major tools can be used: • • Low-Latency Queuing (LLQ). there are two main considerations to start with: • • This document assumes that the service provider will support at least 4 classes of traffic such as REAL_TIME. use hierarchical policies for sub-line-rate Ethernet connections to provide shaping and CBWFQ/LLQ. There are many benefits in deploying a consistent. The Medium Enterprise site LAN supports 12 classes of traffic. It helps not only in optimizing the network performance. In the WAN links. Regardless of the WAN transport chosen. which will be mapped to 4 classes of traffic on the WAN side. QoS Design for WAN Devices For any application regardless of whether it is video. Medium Enterprise Design Profile Reference Guide 3-20 . the one-way delay must be less than 150 msec. This may occur because there is significant difference between LAN speeds and WAN speeds. The voice and video applications are highly delay-and drop-sensitive. Delay—Is an important characteristic.

Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design QoS Implementation Figure 3-11 Mapping of 12-Class Model to 4-Classes 4-Class Model 8-Class Model Voice Interactive Video 12-Class Model Voice Realtime Interactive Realtime Multimedia Conferencing Broadcast Video Streaming Video Signaling/Control Call Signaling Network Control Critical Data Critical Data Multimedia Streaming Call Signaling Network Control Network Management Transactional Data Bulk Data Best Effort Best Effort Scavenger Scavenger Once the QoS policy is designed.Real-Time SP-Critical 1 Bandwidth Allocated 30% 20% Actual Bandwidth 33 Mbps 36 Mbps SP-Critical 2 20% 25 Mbps SP-Best Effort 30% 6 Mbps QoS Implementation This section discusses how QoS is implemented in Medium Enterprise Design Profile. Broadcast Video. the following methods are used to implement QoS policy: Medium Enterprise Design Profile Reference Guide 228513 Best Effort 3-21 . As explained in the QoS design considerations. each class must received the guaranteed minimum bandwidth. Real Time Interactive Network Control Signaling Transactional Data Multi-media Conferencing Multimedia streaming OAM Bulk data Scavenger Best Effort 4-class SP Model SP. and actual bandwidth allocated for each class of traffic. the percentage. Each class should receive the adequate bandwidth. Table 3-1 describes the different classes. Table 3-1 Classes of Traffic Class of Traffic Voice. the next pertinent question is the appropriate allocation of bandwidth for the 4 classes of traffic. To accomplish this objective. the main objective of the QoS implementation is to ensure that the 12 classes of LAN traffic is mapped into 4 classes of WAN traffic. and during congestion.

It is assumed that the aggregate bandwidth is 100Mbps that should be shared between both services—50Mbps is dedicated for private WAN network and 50Mbps is dedicated for Internet traffic. For example. As explained in the previous section. and queuing within the reserved policy. Single-layer design—If the interface bandwidth. to implement this granular policy. and the SLA bandwidth of the provider are equal then we can use a single QoS policy to share the bandwidth among the classes of traffic. Figure 3-12 The Bandwidth Allocation at WAN Aggregation Router 1 100 Mbps WAN pipe 50M Private with 4 classes Private WAN Medium Enterprise Site Network QFP Internet 50M Internet with 4 classes Medium Enterprise Design Profile Reference Guide 3-22 229381 . and each site needs dedicated bandwidth. a three-layer hierarchical QoS design needs to be used. Two-layer hierarchical design—This design is needed when the interface bandwidth is higher than the SLA bandwidth allocated by the service provider. • This section describes detailed implementation of QoS policies at various parts of the network. Figure 3-12 depicts the bandwidth allocation at the WAN aggregation router 1.Chapter 3 QoS Implementation Medium Enterprise Design Profile (MEDP)—WAN Design • • Three-layer hierarchical design—This is needed when multiple sites need to share a common bandwidth. The devices that need QoS design are as follows: • • • • • WAN aggregation router 1 for connection to the Internet and PRIVATE WAN network WAN aggregation router 2 for connection to remote site Cisco 3750 Metro switch at the large remote site Cisco 4500 switch at the medium remote site Cisco 3800 router at the small remote site QoS Implementation at WAN Aggregation Router 1 The WAN aggregation router 1 connects to two different providers: private WAN network and Internet. but the service provider has only allocated 50 Mbps. In this scenario we need two policies. which is four in our design. The first policy. if the physical link is 100Mbs. which is parent policy would shape the entire traffic to 50Mbs then the child policy would queue and allocated bandwidth for each class.

Step 3 Medium Enterprise Design Profile Reference Guide 229382 PARENT_POLICY 3-23 . queue. and allocate bandwidth within each subparent policy. For example. Within each of the subparent policies. BEST_EFFORT. PRIVATE WAN_PARENT is a policy dedicated for PRIVATE WAN traffic. which would further shape it to 50Mbps. and SCAVENGER classes. This is like a grandfather of policy. The following diagram shows the hierarchical allocation. Define the child policies—Classifies.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design QoS Implementation To implement a three-layer hierarchical QoS policy on the WAN aggregation1 router. For example. then subparent policies are defined. CRITICAL_DATA. and allocate the bandwidth within each allocated bandwidth. queues. there are four defined classes: REALTIME. a higher-level parent policy is defined that would shape the aggregate WAN speed to 100Mbps. Figure 3-13 Hierarchical QoS Design IE_CHILD_POLICY WE_CHILD_POLICY IE_PARENT_POLICY WE_PARENT_POLICY The hierarchical three-layer QoS policy is implemented in three steps as follows: Step 1 Step 2 Define parent policy—Enforces the aggregate bandwidth policy for the entire interface. and PRIVATE WAN_Internet is specific to Internet traffic. Define the individual subparent policies—These would be specific to each service type. PRIVATE WAN_PARENT would have a PRIVATE WAN_Child policy that would classify. Figure 3-13 depicts this hierarchical QoS design.

class-map match-all REALTIME match ip dscp cs4 af41 cs5 ef class-map match-all CRITICAL_DATA match ip dscp af11 af21 cs3 cs6 class-map match-all BEST_EFFORT match ip dscp default class-map match-all SCAVENGER match ip dscp cs2 228926 Step 2 Define the child policy maps.Chapter 3 QoS Implementation Medium Enterprise Design Profile (MEDP)—WAN Design REALTIME CRITICAL DATA BEST EFFORT SCAVENGER REALTIME CRITICAL DATA BEST EFFORT SCAVENGER VLAN_WE NLR_Parent Policy VLAN_INTERNET Internet_Parent Policy Bandwidth Sharing Equally Shape Rate 50 Mbps Parent Policy Main Interface Shape Rate of 100 Mbps Shape Rate 50 Mbps Implementation Steps for QoS Policy at WAN Aggregation Router 1 This section would describes the detailed steps needed to implement the three-layer QoS policy in the WAN_Aggregation_router1. Step 1 Define the class-maps. Medium Enterprise Design Profile Reference Guide 3-24 229383 .

policy-map NLR_PARENT_POLICY class class-default fragment share shape average 50000000 service-policy NLR_CHILD_POLICY policy-map IE_PARENT_POLICY class class-default fragment share shape average 50000000 service-policy IE_CHILD_POLICY ! 228927 Parent policy allocates 50% of bandwidth Child policy gets attached to parent policy Step 4 Apply the policy maps created in Steps 1 to 3. class-map match-all dummy ! policy-map PARENT_POLICY class dummy service-fragment share shape average 10000000 Dummy class does not classify anything Defining service-fragment would allow other policies to point for share of bandwidth. The parent policy would shape to 100 Mbps. Medium Enterprise Design Profile Reference Guide 228928 3-25 .Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design QoS Implementation policy-map IE_CHILD_POLICY class REALTIME priority percent 33 class CRITICAL_DATA bandwidth remaining ratio 6 class SCAVENGER bandwidth remaining ratio 1 class BEST_EFFORT bandwidth remaining ratio 4 policy-map NLR_CHILD_POLICY class REALTIME priority percent 33 class CRITICAL_DATA bandwidth remaining ratio 6 class BEST_EFFORT bandwidth remaining ratio 4 class SCAVENGER bandwidth remaining ratio 1 Step 3 Define the parent policy maps.

255.252 service-policy output NLR_PARENT_POLICY ! Aggregate policy (grand-father) applied on main interface The parent policy applied on sub-interface QoS Policy Implementation for WAN Aggregation Router 2 QoS configuration at WAN aggregation router 2 is more complex than the QoS configuration of WAN aggregation router 1 because of different speeds connected to the router.255.255.10.252 service-policy output IE_PARENT_POLICY ! interface GigabitEthernet1/0/0.113 255.10.104.75 ip address 64.Chapter 3 QoS Implementation Medium Enterprise Design Profile (MEDP)—WAN Design interface GigabitEthernet1/0/0 dampening no ip address load-interval 30 carrier-delay msec 0 negotiation auto service-policy output PARENT_POLICY hold-queue 2000 in hold-queue 2000 out ! interface GigabitEthernet1/0/0.65 description link to 6500 encapsulation dot 1Q.65 ip address 64.75 description link to 6500 encapsulation dot 1Q.255. Figure 3-14 depicts the different types of WAN speeds Medium Enterprise Design Profile Reference Guide 3-26 228929 .104.125 255.

Since the physical link speed and the actual WAN speed is 1Gbps. requiring a three-layer hierarchical QoS policy is needed. a single-level QoS policy can be applied on each of the links. there is an assumption that there could be more than one remote medium site present in this design.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design QoS Implementation Figure 3-14 WAN Link Speeds at WAN Aggregation Router 2 Device Main Site Site Network 2 Gbps Link Resiliency ASR 1006 QFP 20 Mbps Metro 1 Gbps 100 Mbps SONET/SDH Cisco 3750 Metro Switch Large Site Medium Site Small Site The requirements of the QoS design at the WAN aggregation router 2 are as follows: • • The link speed between the main site and large site is 1Gbps. In addition. The EtherChannel link between the ASR router and the core is 2Gbps. The SLA between the main site and remote medium site is assumed to be 100Mbps. a single-layer QoS policy can be defined on the link. the link speed is assumed to be 1Gbps. Therefore. The link between the main site and small remote site is 20Mbps. • Table 3-2 describes the different QoS policy names applied at the WAN aggregation router 2. which contains two links of 1Gbps link speeds. Medium Enterprise Design Profile Reference Guide 229384 Cisco 4507 Switch Cisco 3800 Router 3-27 . requiring a two-level hierarchical QoS policy is needed. Therefore. each medium remote site would connect to the main site using these 100Mbps links. however. The physical link speed is 44Mbps.

2Gbps and core Applied on link between Main Site 20Mbps and small site Figure 3-15 depicts the various points where QoS policies are applied. Applied on link between Main Site. 1Gbps and Large Remote Site Hierarchical Qos Policy between 100 Mbps the Main Site.Chapter 3 QoS Implementation Medium Enterprise Design Profile (MEDP)—WAN Design Table 3-2 QoS Policy for WAN Aggregation Route 2 QoS Policy Name RLC_POLICY PARENT_POLICY RMC_PARENT_POLICY RMC_CHILD_POLICY WAN_Upstream RSC_PARENT_POLICY RSC_POLICY Description WAN Speed Applied on link between Main Site. Figure 3-15 The allocation of QoS Policy at Different Places on WAN Aggregation Router 2 Main Site Site Network WAN_Upstream Link Resiliency ASR 1006 QFP RSC_POLICY Metro RLC_POLICY RMC_PARENT_POLICY SONET/SDH Cisco 3750 Metro Switch Large Site Medium Site Small Site Medium Enterprise Design Profile Reference Guide 3-28 229385 Cisco 4507 Switch Cisco 3800 Router . and Medium Remote Site location.

policy-map RLC_POLICY class REALTIME priority percent 33 set cos 5 class CRITICAL_DATA bandwidth remaining ratio 6 set cos 3 class SCAVENGER bandwidth remaining ratio 1 set cos 0 class BEST_EFFORT bandwidth remaining ratio 4 set cos 2 ! Step 3 Apply the class-maps and policy map defined in Steps 1 and 2 on the interface connected between the main site to the large site.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design QoS Implementation QoS Policy Between the Main Site and Large Remote Site The WAN physical link speed is 1Gbs. Also. a single-layer QoS policy is implemented in this scenario. 228933 228932 Medium Enterprise Design Profile Reference Guide 3-29 . class-map match-all REALTIME match ip dscp cs4 af41 cs5 ef class-map match-all CRITICAL_DATA match ip dscp af11 af21 cs3 af31 cs6 class-map match-all BEST_EFFORT match ip dscp default class-map match-all SCAVENGER match ip dscp cs2 Step 2 Define the policy map. the actual SLA between the main site and the large remote site is assumed to be 1Gbps. Step 1 Define the class-maps. Therefore.

Figure 3-16 The WAN Link Design for Connectivity Between Main Site and Medium Remote Site Main Site ASR 1006 QFP 1 Gbps Metro 100 Mbps Links Large Site Medium Site Small Site Here. the implementation details are provided for only a single medium site location.255.255. because there could be a couple of remote medium site locations connected on a single metro link to the main site.254 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 eigrp-key ip pim sparse-mode ip summary-address eigrp 100 10.Chapter 3 QoS Implementation Medium Enterprise Design Profile (MEDP)—WAN Design interface GigabitEthernet0/2/0 description Connected to cr11-3750ME-RLC ip address 10.0.0 255.5 logging event link-status load-interval 30 negotiation auto service-policy output RLC_POLICY ! Main Campus QFP Metro Large Campus QoS Policy Between the Main Site and Medium Remote Site Location A three-layer QoS design is needed between the main site and large remote medium site location. however.126.0.0.126.0.255. Figure 3-16 shows how this design looks like when there are more than one remote medium site. if desired. more medium site locations could be added.1 255. Medium Enterprise Design Profile Reference Guide 3-30 229386 228934 .

class-map match-all dummy ! policy-map PARENT_POLICY class dummy service-fragment share shape average 10000000 228936 Sets the total bandwidth to 1G policy-map RMC_PARENT_POLICY class class-default fragment share shape average 10000000 service-policy RMC_CHILD_POLICY Step 3 Apply the policy maps. policy-map RMC_CHILD_POLICY class REALTIME priority percent 33 set cos 5 class CRITICAL_DATA bandwidth remaining ratio 6 set cos 3 class SCAVENGER bandwidth remaining ratio 1 set cos 0 class BEST_EFFORT set cos 2 Step 2 Define the parent policy maps. Medium Enterprise Design Profile Reference Guide 228937 Sets the bandwidth for single medium campus to 100Mbps 3-31 .Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design QoS Implementation The following are implementation steps for this QoS policy: Step 1 Define the child policy maps.

254 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 eigrp-key ip pim sparse-mode ip summary-address eigrp 100 10.126. The actual WAN speed is 44Mbps. a two-layer hierarchical QoS design is needed to implement the above policy.3 255. Step 1 Define the policy map.0 5 service-policy output RMC_PARENT_POLICY Large Campus QFP First level policy applied to main interface Second level policy applied to sub-interface Metro Medium Campus Third level policy applied to main parent policy QoS Policy Between Main Site and Small Remote Site Location The following is the QoS policy implementation steps between main site and small remote site location. policy-map RSC_POLICY class REALTIME priority percent 33 class CRITICAL_DATA bandwidth remaining ratio 6 class SCAVENGER bandwidth remaining ratio 1 class BEST_EFFORT bandwidth remaining ratio 4 ! policy-map RSC_PARENT_POLICY class class-default shape average 20000000 service-policy RSC_POLICY This is child policy This is parent policy 228939 Step 2 Apply the policy map to the interface. however.126.0 255.Chapter 3 QoS Implementation Medium Enterprise Design Profile (MEDP)—WAN Design interface GigabitEthernet0/2/1 description Connected to cr11-4507-RMC dampening no ip address load-interval 30 carrier-delay msec 0 negotiation auto cdp enable service-policy output PARENT_POLICY hold-queue 2000 in hold-queue 2000 out ! interface GigabitEthernet0/2/1.255.0. the SLA is assumed to be 20Mbps.0.102 encapsulation dot1Q 102 ip address 10.255. Medium Enterprise Design Profile Reference Guide 3-32 228938 policy-map RMC_PARENT_POLICY class class-default fragment share shape average 100000000 service-policy RMC_CHILD_POLICY . Therefore.255.0.

126.0 5 logging event link-status load-interval 30 carrier-delay msec 0 Apply parent policy dsu bandwidth 44210 framing c-bit to interface cablelength 10 service-policy output RSC_PARENT_POLICY end ASR 1006 QFP SONET/SDH . There are two links between the ASR 1006 and core.0.5 255. Step 1 Define the policy-map. QoS policy needs to be configured on both links. which is VSS.255. policy-map WAN_Upstream class REALTIME priority percent 33 class CRITICAL_DATA bandwidth remaining ratio 6 class SCAVENGER bandwidth remaining ratio 1 class BEST_EFFORT bandwidth remaining ratio 4 Step 2 Apply the policy-map on both interfaces going up to the core.0 255.254 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 eigrp-key ip pim sparse-mode ip summary-address eigrp 100 10.0. 228941 Medium Enterprise Design Profile Reference Guide 3-33 228940 interface Serial0/3/0 dampening ip address 10.126.255.255.0.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design QoS Implementation Small Campus cr11-asr-we# QoS Policy Implementation Between the Main Site and Core The following is the QoS policy implementation between main site and core.

class-map match-all REALTIME match ip dscp cs4 af41 cs5 ef class-map match-all CRITICAL_DATA match ip dscp af11 cs2 af21 cs3 af31 cs6 class-map match-all BEST_EFFORT match ip dscp default class-map match-all SCAVENGER match ip dscp cs1 Step 2 Define the policy-map.Chapter 3 QoS Implementation Medium Enterprise Design Profile (MEDP)—WAN Design policy-map WAN_Upstream class REALTIME priority percent 33 class CRITICAL_DATA bandwidth remaining ratio 6 class SCAVENGER bandwidth remaining ratio 1 class BEST_EFFORT bandwidth remaining ratio 4 interface GigabitEthernet0/2/3 dampening no ip address load-interval 30 carrier-delay msec 0 negotiation auto cdp enable service-policy output WAN_Upstream channel-group 1 mode active hold-queue 2000 in hold-queue 2000 out ! interface GigabitEthernet0/2/4 dampening no ip address load-interval 30 carrier-delay msec 0 negotiation auto cdp enable service-policy output WAN_Upstream channel-group 1 mode active hold-queue 2000 in hold-queue 2000 out Main Campus Campus Network ASR 1006 QFP QoS Policy Between Large Remote Site and Main Site Location The WAN interface between the large remote site and main site is 1 Gbps. Step 1 Define the class-maps. a single-layer QoS policy map can be created. which is also equal to the link speed. Medium Enterprise Design Profile Reference Guide 3-34 228943 228942 . therefore.

255. interface GigabitEthernet1/1/1 description Connected to cr11-ASR-WE no switchport dampening ip address 10.122.0.0.0 255.0.0 load-interval 30 carrier-delay msec 0 srr-queue bandwidth share 1 30 35 5 priority-queue out mls qos trust dscp service-policy output ME_POLICY hold-queue 2000 in hold-queue 2000 out ! Large Campus Main Campus QFP Metro 228944 Medium Enterprise Design Profile Reference Guide 228945 3-35 .Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design QoS Implementation policy-map ME_POLICY class REALTIME priority police 220000000 8000 exceed-action drop set cos 5 class CRITICAL_DATA bandwidth remaining ratio 40 set cos 3 class BEST_EFFORT bandwidth remaining ratio 35 set cos 2 class SCAVENGER bandwidth remaining ratio 25 set cos 0 ! ! Step 3 The realtime traffic get 330 Mbps Apply the QoS policy-map to the WAN interface.126.0 255.255.255.254 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 eigrp-key ip pim sparse-mode ip summary-address eigrp 100 10.

a single-layer QoS policy meets the requirement. The physical link speed is 100Mbps and the actual SLA is also 100Mbps. Therefore. policy-map RMC_POLICY class REALTIME priority police cir 33000000 conform-action transmit exceed-action drop set cos 5 class CRITICAL_DATA set cos 3 bandwidth percent 36 class SCAVENGER bandwidth percent 5 set cos 0 class BEST_EFFORT set cos 2 bandwidth percent 25 ! Step 3 Apply the defined class and policy maps to the interface. class-map match-all REALTIME match ip dscp cs4 af41 cs5 ef class-map match-all CRITICAL_DATA match ip dscp af11 cs2 af21 cs3 af31 cs6 class-map match-all BEST_EFFORT match ip dscp default class-map match-all SCAVENGER match ip dscp cs1 Step 2 Define the policy-maps. Step 1 Define the class-maps. Medium Enterprise Design Profile Reference Guide 3-36 228947 228946 . which uses 4500-E supervisor.Chapter 3 QoS Implementation Medium Enterprise Design Profile (MEDP)—WAN Design QoS Policy Between Remote Medium Site and Main Site Location The remote medium site location uses 4500 as WAN device.

Therefore. but the SLA is 20 Mbps. class-map match-all REALTIME match ip dscp cs4 af41 cs5 ef class-map match-all CRITICAL_DATA match ip dscp af11 af21 cs3 af31 cs6 class-map match-all BEST_EFFORT match ip dscp default class-map match-all SCAVENGER match ip dscp cs2 Step 2 Define the child policy map. which is 45Mbps. The parent policy shapes the link speed to 20Mbps and the child policy would queue and allocate the bandwidth within the 20Mbps. policy-map RSC_POLICY class REALTIME priority percent 33 class CRITICAL_DATA bandwidth remaining percent 40 class SCAVENGER bandwidth remaining percent 25 class BEST_EFFORT bandwidth remaining percent 35 Step 3 Define the parent policy map.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design QoS Implementation Main Campus ASR 1006 interface GigabitEthernet4/1 description link connected to cr13-6500-pe2 gi3/2 switchport trunk native vlan 802 switchport trunk allowed vlan 102 switchport mode trunk logging event link-status load-interval 30 carrier-delay msec 0 no cdp enable spanning-tree portfast trunk spanning-tree guard root service-policy output RMC_POLICY ! QFP Metro QoS Policy Implementation Between Small Remote Site and Main Site Location This section describes the QoS policy implementation between the small remote site location and the main site. Step 1 Define the class-maps. a hierarchical two-layer QoS policy is implemented. The physical link speed is T3. 228950 228949 Medium Enterprise Design Profile Reference Guide 228948 Cisco 4507 Switch Medium Campus 3-37 .

126.255.4 255.9999% of availability. Some of the following failures can occur over a period of time: route flaps.255. To meet these challenges. Figure 3-17 shows where this feature is enabled. The following are some of the ways to support redundancy: • NSF/SSO—For networks to obtain 99.254 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 eigrp-key ip pim sparse-mode service-policy output RSC_PARENT_POLICY ip summary-address eigrp 100 10. The probability of these occurring over a short period of time is low. fibers being cut.0.0.0. • • Medium Enterprise Design Profile Reference Guide 3-38 228952 interface Serial2/0 dampening ip address 10. it is likely that network will be subjected to different kinds of failures occurring all the time.0 255. 228951 Small Campus Redundancy Redundancy must be factored into the WAN design for a number of reasons. while packet forwarding continues with minimal interruption. technologies such as NSF/SSO are needed. brownouts. Service Software Upgrade (ISSU) allows software to be updated or modified. Ether channel load balancing—Enabling this feature provides link resiliency and load balancing of traffic. whereas SSO allows standby RP to take immediate control and maintain connectivity protocols. Since the WAN may span across several service provider networks.124. The NSF would route packets until route convergence is complete.255.Chapter 3 QoS Implementation Medium Enterprise Design Profile (MEDP)—WAN Design policy-map RSC_PARENT_POLICY class class-default shape average 20000000 service-policy RSC_POLICY Step 4 Apply the policy map to interface.0 5 load-interval 30 carrier-delay msec 0 dsu bandwidth 44210 ASR 1006 QFP SONET/SDH . but the occurrence is highly likely over a long period of time. different kind of redundancy should be planned. and device failures. This feature is enabled on the WAN aggregation 2 device.

Table 3-3 WAN Devices Device WAN aggregation 1 WAN aggregation 2 WAN Transport Private WAN/Internet Metro This section discusses how to incorporate the resiliency principle in Cisco Medium Enterprise Design Profile for the WAN design. However. Similarly. When the ASR router interfaces with the private WAN. Medium Enterprise Design Profile Reference Guide 229387 Cisco 4500 Switch Cisco 3800 Router Resiliency Feature ISSU. resiliency has been added at certain places where it is absolutely critical to the network architecture rather than designing redundancy at every place of the network. Enabling resiliency adds cost and complexity to the design. there are different models at both WAN aggregation locations. Therefore. ASR routers have been selected at both WAN aggregation locations. the redundancy is planned at both WAN aggregation router1 and WAN aggregation router 2 in the main site location. Internet networks the ASR 1004 with IOS-based redundancy. the ASR 1006 with dual RP and dual ESP has been chosen to provide for hardware-based redundancy. As explained in the “WAN Aggregation Platform Selection in the Medium Enterprise Design Profile” section on page 3-7. RP 3-39 . IOS based redundancy Redundant ESP. In the Cisco Medium Enterprise Design Profile.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design QoS Implementation Figure 3-17 Link Resiliency Main Site Site Network Link Resiliency ASR 1006 QFP SONET/SDH Metro Cisco 3750 Metro Switch Large Site Medium Site Small Site Table 3-3 shows the various WAN devices that are designed for resiliency. for the ASR router that interfaces with Metro connections.

Configuration register is 0x2102 CR11-ASR-IE# Step 2 Enable the redundancy: redundancy mode sso ! Step 3 Verify that redundancy is enabled: Medium Enterprise Design Profile Reference Guide 3-40 . Compiled Tue 02-Mar-10 09:51 by mcpre Cisco IOS-XE software. see the ASR page at following URL: http://www. ROM: IOS-XE ROMMON CR11-ASR-IE uptime is 3 weeks. Certain components of Cisco IOS-XE software are licensed under the GNU General Public License ("GPL") Version 2. 2 hours. 4 minutes Uptime for this control processor is 3 weeks.03.2(33)XND3.cisco.0.XND3. 15641929K bytes of USB flash at usb1:. For more details.cisco. 4194304K bytes of physical memory. All rights reserved.02. Version 12.122-33.com/go/asr1000 Implementing IOS-based Redundancy at WAN Aggregation Router 1 The key requirement for implementing software-based redundancy on the ASR1004 is that it must have 4GB DRAM on ASR1004. 39004543K bytes of SATA hard disk at harddisk:. Inc. CR11-ASR-IE#show version Cisco IOS Software.0 is free software that comes with ABSOLUTELY NO WARRANTY.com/techsupport Copyright (c) 1986-2010 by Cisco Systems. To obtain more information on ASR resiliency capabilities. 5 Gigabit Ethernet interfaces 32768K bytes of non-volatile configuration memory. RELEASE SOFTWARE (fc1) Technical Support: http://www.0. Inc. 6 days. 2 hours.bin" Last reload reason: redundancy force-switchover cisco ASR1004 (RP1) processor with 736840K/6147K bytes of memory.04. 6 minutes System returned to ROM by SSO Switchover at 14:41:38 UTC Thu Mar 18 2010 System image file is "bootflash:asr1000rp1-adventerprise. The software code licensed under GPL Version 2. The following are steps for implementing the IOS-based redundancy: Step 1 Check the memory on ASR 1004 router. see the documentation or "License Notice" file accompanying the IOS-XE software. or the applicable URL provided on the flyer accompanying the IOS-XE software. 6 days. Copyright (c) 2005-2010 by cisco Systems.Chapter 3 QoS Implementation Medium Enterprise Design Profile (MEDP)—WAN Design Both of these models support In Service Software Upgrade (ISSU) capabilities to allow a user to upgrade Cisco IOS XE Software while the system remains in service. 937983K bytes of eUSB flash at bootflash:. You can redistribute and/or modify such GPL code under the terms of GPL Version 2. IOS-XE Software (PPC_LINUX_IOSD-ADVENTERPRISE-M).

122-33. 6 days.1.1.cisco. 2 hours.XND3.04. RELEASE SOFTWARE (fc1) Technical Support: http://www.bin. Therefore.XND3. 0 minutes Image Version = Cisco IOS Software.2(33)XND3.2(33)XND3. the WAN aggregation router 2 has redundant RPs and redundant ESPs. Inc. with this configuration. 59 minutes Image Version = Cisco IOS Software.03.04. 6 days.com/techsupport Copyright (c) 1986-2010 by Cisco Systems. CONFIG_FILE = Configuration register = 0x2102 CR11-ASR-IE# Implementation of Hardware-based Redundancy at WAN Aggregation Router 2 As explained in the design considerations documents. IOS-XE Software (PPC_LINUX_IOSD-ADVENTERPRISE-M). Compiled Tue 02-Mar-10 09:51 by mcpre BOOT = bootflash:asr1000rp1-adventerprise.cisco. we nonstop forwarding of data can be achieved even when there are failures with either ESP or RPs. 6 days.02. Compiled Tue 02-Mar-10 09:51 by mcpre BOOT = bootflash:asr1000rp1-adventerprise.02. Version 12. RELEASE SOFTWARE (fc1) Technical Support: http://www.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design QoS Implementation CR11-ASR-IE#show redun CR11-ASR-IE#show redundancy Redundant System Information : -----------------------------Available system uptime Switchovers system experienced Standby failures Last switchover reason Hardware Mode Configured Redundancy Mode Operating Redundancy Mode Maintenance Mode Communications = = = = = = = = = 3 weeks. IOS-XE Software (PPC_LINUX_IOSD-ADVENTERPRISE-M). CONFIG_FILE = Configuration register = 0x2102 Peer Processor Information : ---------------------------Standby Location = slot 6 Current Software state = STANDBY HOT Uptime in current state = 3 weeks.03. 11 minutes 3 0 active unit removed Duplex sso sso Disabled Up Current Processor Information : ------------------------------Active Location = slot 7 Current Software state = ACTIVE Uptime in current state = 3 weeks.bin. The following steps are needed to enable hardware redundancy on WAN aggregation router 2: Step 1 Configuration of SSO redundancy: redundancy mode sso Medium Enterprise Design Profile Reference Guide 3-41 .com/techsupport Copyright (c) 1986-2010 by Cisco Systems. 1 hour.122-33. 2 hours. Inc. Version 12.

Chapter 3 QoS Implementation Medium Enterprise Design Profile (MEDP)—WAN Design Step 2 Verify the redundancy information: cr11-asr-we#show redundancy Redundant System Information : -----------------------------Available system uptime Switchovers system experienced Standby failures Last switchover reason Hardware Mode Configured Redundancy Mode Operating Redundancy Mode Maintenance Mode Communications = = = = = = = = = 3 weeks. 1 day. Inc. IOS-XE Software (PPC_LINUX_IOSD-ADVENTERPRISEK9-M). 18 hours.cisco. 3 minutes Image Version = Cisco IOS Software. RELEASE SOFTWARE (fc1) Technical Support: http://www.com/techsupport Copyright (c) 1986-2009 by Cisco Systems. 3 hours.2(33)XND2.cisco. 52 minutes Image Version = Cisco IOS Software. RELEASE SOFTWARE (fc1) Technical Support: http://www. Inc. 32 minutes 4 0 active unit removed Duplex sso sso Disabled Up Current Processor Information : ------------------------------Active Location = slot 6 Current Software state = ACTIVE Uptime in current state = 2 weeks.2(33)XND2. Version 12. Compiled Wed 04-Nov-09 18:53 by mcpre BOOT = CONFIG_FILE = Configuration register = 0x2102 cr11-asr-we# Implementation of Link Resiliency Between the WAN Aggregation Router 2 and VSS Core The following are the implementation steps to deploy link resiliency: Step 1 Configure the EtherChannel between the ASR1006 and the VSS core: interface GigabitEthernet0/2/3 dampening no ip address load-interval 30 carrier-delay msec 0 negotiation auto cdp enable service-policy output WAN_Upstream Medium Enterprise Design Profile Reference Guide 3-42 .com/techsupport Copyright (c) 1986-2009 by Cisco Systems. 1 day. 6 days. IOS-XE Software (PPC_LINUX_IOSD-ADVENTERPRISEK9-M). Compiled Wed 04-Nov-09 18:53 by mcpre BOOT = CONFIG_FILE = Configuration register = 0x2102 Peer Processor Information : ---------------------------Standby Location = slot 7 Current Software state = STANDBY HOT Uptime in current state = 2 weeks. 19 hours. Version 12.

0. Step 1 Enable multicast routing: ip multicast-routing distributed Medium Enterprise Design Profile Reference Guide 3-43 . The platform chosen must support the number of required groups. IGMP QoS policy must be configured for multicast traffic.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design QoS Implementation channel-group 1 mode active hold-queue 2000 in hold-queue 2000 out ! interface GigabitEthernet0/2/4 dampening no ip address load-interval 30 carrier-delay msec 0 negotiation auto cdp enable service-policy output WAN_Upstream channel-group 1 mode active hold-queue 2000 in hold-queue 2000 out ! Step 2) Configure the port-channel interface interface Port-channel1 ip address 10.254 ip authentication mode eigrp 100 md5 ip authentication key-chain eigrp 100 eigrp-key ip pim sparse-mode ip summary-address eigrp 100 10.255.0 5 logging event link-status load-interval 30 carrier-delay msec 0 negotiation auto ! Multicast The main design considerations for multicast are as follows: • • • • The number of groups supported by the WAN edge device. the multicast design looks at only between the main site and small remote site locations. and not external enterprise/WAN networks.0 255. it is assumed that multicast traffic would be present only within the site. so that this traffic does not affect the unicast traffic In the Medium Enterprise Design Profile. and what interfaces to be enabled with PIM-Sparse mode on the WAN aggregation router 2 that connects to different remote sites. or Anycast with BSR Multicast protocols—PIM-Sparse mode. The placement of the RP—There are couple of options available with RP placement. Anycast with Auto-RP.0.126.255. refer to the“Multicast for Application Delivery” section on page 2-64. The implementation section in the document shows how to enable multicast on the WAN device only. This is scalability factor of the WAN edge device. to obtain more information about multicast design for site.125. Therefore.23 255. Therefore.255. which include Anycast with Static.0. Multicast Configuration on WAN Aggregation Router 2 This section shows how to enable multicast routing.

255.0.0.23 255.100.255.255.5 255.255.254 ip pim sparse-mode logging event link-status load-interval 30 negotiation auto ! interface GigabitEthernet0/2/1 description Connected to cr11-4507-RMC dampening no ip address load-interval 30 carrier-delay msec 0 negotiation auto cdp enable hold-queue 2000 in hold-queue 2000 out ! interface GigabitEthernet0/2/1. The following are implementation steps: Step 1 Enable multicast routing: ip multicast-routing distributed Medium Enterprise Design Profile Reference Guide 3-44 .255.0.254 ip pim sparse-mode load-interval 30 carrier-delay msec 0 dsu bandwidth 44210 framing c-bit cablelength 10 ! Step 3) Configure the RP location ip pim rp-address 10.255.126.100.0.126.Chapter 3 QoS Implementation Medium Enterprise Design Profile (MEDP)—WAN Design Step 2 Enable PIM-Spare mode on the following WAN interfaces: – Port-channel—Connects to the VSS core – Gi0/2/0—Connects to Large Remote Site site – Gi0/2/1—Connects to Medium Remote Site site – S0/3/0—Connects to Small Remote Site site interface Port-channel1 ip address 10.254 ip pim sparse-mode ! ! interface Serial0/3/0 dampening ip address 10.255.100 Configuration of Multicast on Large Remote Site This section discusses how to implement multicast on large remote site.1 255.3 255.125.254 ip pim sparse-mode negotiation auto ! interface GigabitEthernet0/2/0 description Connected to cr11-3750ME-RLC ip address 10.102 encapsulation dot1Q 102 ip address 10.255.126.

255.0 255.254 ip pim sparse-mode load-interval 30 carrier-delay msec 0 dsu bandwidth 44210 Step 3 Configure the RP location: ip pim rp-address 10.100.Chapter 3 Medium Enterprise Design Profile (MEDP)—WAN Design QoS Implementation Step 2 Enable PIM-Sparse mode on the WAN interface that connects to main site.0.255.126.254 ip pim sparse-mode load-interval 30 carrier-delay msec 0 Configuration of Multicast on Small Remote Site This section discusses on how to implement multicast on small remote site.126.0.255. Step 1 Enable multicast routing: ip multicast-routing Step 2 Enable PIM -pare mode on the WAN interface: interface Serial2/0 dampening ip address 10.126.255.0.100 Allowed_MCAST_Groups override Step 4 Configure the multicast security: ip pim spt-threshold infinity ip pim accept-register list PERMIT-SOURCES ! ip access-list standard Allowed_MCAST_Groups Medium Enterprise Design Profile Reference Guide 3-45 .254 ip pim sparse-mode hold-queue 2000 in hold-queue 2000 out ! Configuration of Multicast on Medium Remote Site This section discusses on how to implement multicast on medium remote site. interface GigabitEthernet1/1/1 description Connected to cr11-ASR-WE no switchport dampening ip address 10.255.255.100.4 255. Step 1 Enable multicast routing: ip multicast-routing Step 2 Enable PIM-Spare mode on the WAN interface: interface Vlan102 description Connected to cr11-ASR-WE dampening ip address 10.2 255.

0.1. scalable for future grown.0 0.1.0 0.31.255 239. QoS.Chapter 3 Summary Medium Enterprise Design Profile (MEDP)—WAN Design permit 224. This chapter reviewed the WAN design models recommended by Cisco and where to apply these models within the various locations within a medium enterprise network.40 permit any ! ip access-list extended PERMIT-SOURCES permit ip 10.255 deny any ip access-list standard Deny_PIM_DM_Fallback deny 224.0. and redundancy best practices are discussed for the entire Medium Enterprise Design Profile.0.125. simplified to deploy and manage.0 0. Designing the WAN network of a medium enterprise using these recommendations and best practices will establish a network that is resilient in case of failure. multicast.0.0.0.192.39 permit 224. operational efficiencies. Medium Enterprise Design Profile Reference Guide 3-46 .192.40 permit 239.0.1.255.39 deny 224.0. virtual learning environments. Key WAN design principles such as WAN aggregation platform selection. and secure classrooms.0. and cost efficient to meet the budget needs of a medium enterprise.1.255.0.255 deny ip any any ! Summary Designing the WAN network aspects for the Cisco Medium Enterprise Design Profile interconnects the various LAN locations as well as lays the foundation to provide safety and security.

reliable wireless LANs (WLANs) are present at all medium enterprise environments. demanding connectivity. mobile. and technology-savvy. Today’s enterprise worker is dynamic. high-speed multimedia applications Simplified management tools to facilitate system-wide mobility maintenance The use of tools and applications for mobile conferencing. When at the enterprise site. mobility-enabled network that supports their requirements at a cost that makes good business sense. At the heart of the Medium Enterprise Design Profile is the network service fabric. using mobility-enabled devices and mobile applications A scalable design model that can easily accommodate the addition of new local and remote buildings as well as modifications to existing buildings Support for bandwidth-intensive. which is a collection of products. collaboration.CH A P T E R 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Mobility Design The Cisco Medium Enterprise Design Profile is intended to assist enterprises in the design and deployment of advanced network-based solutions within twenty-first century business environments. they move about while equipped with an array of mobility-enabled devices including PDAs. Operating on top of the network service fabric are all the services used within the medium enterprise network to solve business problems. and technologies that provide a robust routing and switching foundation upon which all solutions and services are built. phones. end-to-end. and operations Effective communication and inter operation with public safety first responders in the event of an emergency. This connected generation of professionals is untethered from wired networks and typically assume that high-performance. and laptops. The challenge facing a medium enterprise is to create a robust. Prospective employees want to be part of medium enterprises that provide services relevant to the way Medium Enterprise Design Profile Reference Guide 4-1 . Medium enterprises should be equipped with mobility solutions that support the following: • • • • • • Secure communications between local and remote sites to support employees. Business professionals tend to use state of the art applications and the enterprise network for many aspects of their lives. Medium enterprises must remain competitive and must differentiate themselves from their peers. The mobility design implemented by a medium enterprise must meet the needs of these mobile workers while also addressing the requirements of guests and visitors. performance and network flexibility wherever they may be located. guests and visitors. both for competitive customer marketing purposes as well as to attract and retain the best employee talent. features.

medium enterprises must evolve into mobility-enabled local and remote sites and twenty-first century business centers. expectations and trade-offs that must be taken into account when integrating mobility into the Cisco Medium Enterprise Design Profile. scalable wireless networks with a low total cost of ownership. These design considerations form a critical part of the overall service fabric design model. this chapter discusses design considerations surrounding the requirements. vendors. and other guests of the medium enterprise has become a standard and expected part of modern-day mobile business environments. and improve productivity. Figure 4-2 shows a high-level topology of the Cisco Unified Network. and even in employee homes. as well as access to mobile voice capabilities throughout medium enterprise sites. alternate hardware platforms include the Cisco ISR router Wireless LAN Controller Module (WLCM) or the Cisco Catalyst 6500 Wireless Services Module (WiSM). work. as shown in Figure 4-1. which includes access points that use the Control and Provisioning of Lightweight Access Points (CAPWAP) protocol. Authorization. secure wireless technologies can enable “virtual offices” even in non-traditional settings such as leased space in professional buildings. In support of this. and high-performance wireless guest access for contractors. records. guests. The Cisco Unified Wireless Network (Cisco UWN) is a unified solution that addresses the wireless network security. and visitors. high-speed wireless network not only provides technological leadership and innovation. In addition to the traditional standalone WLAN controller. in ways that serve to enhance both their quality of life and their individual success potential. and resources. Keep in mind that traditional offices and conference rooms are by no means the only environments seen within medium enterprises any longer. management. reliable. Secure. To meet these needs. the Cisco Wireless Control System (WCS). In fact. deployment. high performance. and the Cisco Wireless LAN Controller (WLC). The Cisco Access Control Server (ACS) and its Authentication. and control aspects of deploying a wireless network. and Accounting (AAA) features complete the solution by providing Remote Authentication Dial-In User Service (RADIUS) services in support of user authentication and authorization. It combines the best elements of wireless and wired networking to deliver secure. Figure 4-1 Service Fabric Design Model Service Fabric Design Model Mobility Security Unified Communications Given the mobility requirements of medium enterprise professionals. but enables the deployment of innovative applications that streamline operations. Medium Enterprise Design Profile Reference Guide 4-2 228517 Local Area Network (LAN) Wide Area Network (WAN) . wireless LANs have emerged as one of the most effective and high performance means for these mobile users to access the medium enterprise network. temporary office spaces. They want to take full advantage of what the medium enterprise has to offer. A medium enterprise with a pervasive. Administrators need secure access to tools. This mobile enterprise lifestyle helps to drive the need for careful wireless capacity and coverage planning. enhance collaboration. and spend their free time.Chapter 4 Mobility Design Medium Enterprise Design Profile (MEDP)— Mobility Design they live.

11n) Cisco Compatible Wi-Fi Tags Cisco Compatible Client Devices Cisco Aironet Wireless LAN Client Adapters Cisco Aironet 1500 Series Lightweight Outdoor Mesh Access Points 225263 The Cisco Medium Enterprise Design Profile accommodates a main site and one or more remote sites interconnected over a metro Ethernet or managed WAN service. Medium Enterprise Design Profile Reference Guide 4-3 .Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Mobility Design Figure 4-2 Cisco Unified Wireless Network Overview Cisco Catalyst 3750G Integrated Cisco WCS Wireless LAN Navigator Controller Browser Based W N S E Cisco Wireless Control System (WCS) Cisco WCS Cisco WCS Cisco Mobile Services Engine Third Party Integrated Applications: E911. as shown in Figure 4-3.11a/b/g and 802. Workflow Automation Cisco Wireless LAN Controller Module (WLCM) Cisco Wireless LAN Controller Cisco Catalyst 6500 Series Wireless Services Module (WiSM) Cisco Aironet Wireless Bridge Chokepoint 125 kHz Cisco Aironet Lightweight Access Points (802. Asset Tracking. Each of these sites may contain one or more buildings of various sizes. ERP.

The topologies and platforms are carefully selected to increase productivity while minimizing the overall cost and complexity of operation. The Cisco mobility approach within the Cisco Medium Enterprise Design Profile focuses on the following key areas: • Accessibility Medium Enterprise Design Profile Reference Guide 4-4 229388 . In certain instances. video surveillance equipment. enhance security. These centralized systems and applications are served by a data center at the main site. As Figure 4-3 shows. and this document helps to point out and clarify some of these trade-offs. with the overall WLAN management function (the Cisco WCS) located at the main site. allowing each remote site to reduce the need for separate services to be operated and maintained. trade-offs are necessary to reach these goals. and so on. The core of these services are deployed and managed at the main (or headquarters) site building. in some cases. enhance network maintainability. be limiting factors for medium enterprises. The key feature of this integration is the use of one or more WLAN controllers at each site. The Cisco Medium Enterprise Design Profile takes into account that cost and limited network administrative resources can. the Cisco Medium Enterprise Design Profile uses a centralized approach in which key resources are centrally deployed. This approach simplifies the deployment and operation of the network. and reduce overall operating costs. maximize network availability. helping to ensure smooth performance.Chapter 4 Mobility Design Medium Enterprise Design Profile (MEDP)— Mobility Design Figure 4-3 Main Large Site Medium Enterprise Design Profile Overview Large Building WLAN Access Points Medium Building WLAN Access Points Small Building WLAN Access Points Extra Small Building WLAN Access Points LWAPP LWAPP LWAPP LWAPP Service Block WAE Wireless LAN Controller NAC Server Internet Data Center www M V SRST/Video Cisco ACS Gateway Appliance NAC Manager Video Surveillance Media Server WCS Server Web Security Core Cisco UCM Email Security Web Email Server Server Internet Edge MetroE HDLC Service Block Core Core Service Block Small Data Center Small Data Center Service Block LWAPP WLAN Access Points Large Building LWAPP WLAN Access Points Medium Building LWAPP WLAN Access Points Small Building LWAPP WLAN Access Points Medium Building LWAPP WLAN Access Points Small Building LWAPP WLAN Access Points Small Building Serverfarm Remote Large Site Remote Medium Site Remote Small Site Operating on top of this network are all the services used within the medium enterprise environment such as safety and security systems. voice communications.

contractors.11n technology. • Usability In addition to extremely high WLAN transmission speeds made possible by the current generation of IEEE 802. administrators. medium. helping to ensure that video and audio information arrives on time. Note For information on how security design is addressed within the Cisco Medium Enterprise Design Profile. such as the following: • • WLAN controller location WLAN controller connectivity Medium Enterprise Design Profile Reference Guide 4-5 . and manage hundreds of access points that may reside within a multisite medium enterprise. and visitors. • • Reliability – Providing adequate capability to recover from a single-layer fault of a WLAN access component or controller wired link.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Accessibility – Enabling mobile professionals. see Chapter 5. regardless of whether they are in a traditional office setting. vendors. – Ensuring that WLAN accessibility is maintained for employees. reliability.” Manageability A relatively small team of network administrators should be able to easily deploy. easy-to-understand WLAN management framework provides small. and ease of deployment required in the medium enterprise domain. A single. operate. guests and visitors to be accessible and productive on the network.1x and Extensible Authentication Protocol (EAP). staff. future employees. Accessibility This section provides a brief introduction to the fundamental protocol used for communication between access points and WLAN controllers. This gives preferential treatment to real-time traffic. or simply enjoying a breath of fresh air outside on-site buildings – Enabling easy. having lunch with colleagues within enterprise site dining areas. with all information sent and received on the WLAN being encrypted. administrators. followed by a discussion of mobility design considerations pertaining to those aspects of the Cisco Medium Enterprise Design Profile relevant to accessibility. latency-sensitive applications (such as IP telephony and video conferencing) are supported over the WLAN using appropriately applied quality-of-service (QoS) classification. guests. collaborating in a conference room. • Security – Segmenting authorized users and blocking unauthorized users – Extending the services of the network safely to authorized parties – Enforcing security policy compliance on all devices seeking to access network computing resources. “Medium Enterprise Design Profile (MEDP)—Network Security Design. and other visitors. in the event of common failures. Staff enjoy rapid and reliable authentication through IEEE 802. secure guest access to guests such as prospective customers. and large sites with the level of WLAN management scalability.

Figure 4-4 CAPWAP Access Point to WLC Communication AP LWAPP Network LWAP P/CAP WAP PWAP LWAPP/CA WLC AP LWAPP AP LWAPP AP LW A P/C AP PW CAPWAP enables the controller to manage a collection of wireless access points.txt. In controller software Release 5. In this arrangement. access points provide the radio connection to wireless clients. Note that most CAPWAP-enabled access points are also compatible with the preceding LWAPP protocol. An exception is that the Cisco Aironet 1140 Series Access Point supports only CAPWAP. The mobility approach in the Cisco Medium Enterprise Design Profile is based on the feature set available in Cisco Wireless LAN Controller software Release 6.ietf.Chapter 4 Accessibility Medium Enterprise Design Profile (MEDP)— Mobility Design • Access points The basic mobility components involved with providing WLAN access in the Cisco Medium Enterprise Design Profile consists of WLAN controllers and access points that communicate with each other using the IETF standard CAPWAP protocol.org/rfc/rfc5415.2 or later. Figure 4-4 shows the use of CAPWAP by access points to communicate with and tunnel traffic to a WLAN controller.11 data for overall WLAN system management CAPWAP is also intended to provide WLAN controllers with a standardized mechanism with which to manage radio-frequency ID (RFID) readers and similar devices.2 use the Lightweight Access Point Protocol (LWAPP) for these communications. and WLAN controllers manage the access points and provide connectivity to the wired network. which uses CAPWAP. and has the following three primary functions in the mobility design: • • • Control and management of the access point Tunneling of WLAN client traffic to the WLAN controller Collection of 802. Cisco lightweight access points use CAPWAP to communicate between the controller and other lightweight access points on the network. Controller software releases before Release 5. as well as enable controllers to interoperate with third-party access points in the future. For detailed CAPWAP protocol information. Medium Enterprise Design Profile Reference Guide 4-6 227453 .0. see the following URL: http://www.

the CAPWAP tunnels formed between access points and WLAN controllers are typically fully contained within the confines of the building. switching. only one integration point must be administered. Some of the advantages underlying the decision to centralize the deployment of WLAN controllers on a per-site basis include the following: • Reduced acquisition and maintenance costs—By servicing the needs of all wireless users from a central point. When integrating the WLAN controller with the Network Admission Control (NAC) appliance on any given site. Reduced component interaction points—Centralizing WLAN controllers minimizes the number of integration points that must be managed when interfacing the controller with other devices. incremental software licensing costs associated with WLAN controllers are reduced as well. large remote. the CAPWAP tunnels formed between them must traverse the site backbone network. the controller management burden imposed on site network administrators is minimized. Reduced administrative requirements—By minimizing the total number of WLAN controllers deployed. CAPWAP tunneling between access points and WLAN controllers is not normally required to traverse WAN links (except during controller fail over). Cost-effective capacity management—The use of a centralized WLAN controller model allows the designer the ability to centrally service access points located in multiple building locations and efficiently manage controller capacity. and follows established best practices. These economies of scale typically increase with the size of the enterprise WLAN. In addition. there is also an incremental economy of scale that occurs as the network grows larger. Figure 4-3 shows the planned deployment of WLAN controllers within distinct per-site service blocks. • The Cisco Medium Enterprise Design Profile is based on the centralization of WLAN controllers. and small remote sites respectively. Service blocks tend to be deployed at locations in the network where high availability routing.com/en/US/solutions/ns340/ns414/ns742/ns820/landing_ent_mob_design. these areas tend to be locally or remotely managed by network staff possessing higher skill sets. each associated with the main (headquarters). and are responsible for managing the access points resident in a given building. This technique is commonly used to connect controllers to the medium enterprise network using distribution routers located within each building. In the distributed deployment model.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Accessibility WLAN Controller Location WLAN deployments are typically categorized into two main categories. the number of WLAN controller hardware platforms deployed can be reduced compared to that required for a distributed. • • • • • Medium Enterprise Design Profile Reference Guide 4-7 . and power is present. per-building design. thereby conserving WAN bandwidth and improving performance overall.html. For large sites. medium remote. such as those contained in Chapter 2 of the Enterprise Mobility 4. for example. without the expense of 1:1 controller duplication. Simplified network management and high availability—Centralized WLAN controller designs simplify overall network management of controllers. typically on a per-building basis.cisco. WLAN controllers are placed at a centralized location within the enterprise.1 Design Guide at the following URL: http://www. Because centralized WLAN controllers are typically not located in the same building as the access points they manage. WLAN controllers are located throughout the medium enterprise network. This can protect sites from a loss of WLAN access in the rare event of a controller failure. Increased performance and reliability—Centralized WLAN controller deployments usually lead to highly efficient inter-controller mobility. Similarly. By centralizing WLAN controllers on a per-site basis. distributed and centralized: • Distributed controller—In this model. as well as facilitate cost-effective controller high availability approaches. Centralized controller—In this model. on a per-site basis.

The choice of WLAN controller for the Cisco Medium Enterprise Design Profile is the Cisco 5508 Wireless Controller. or load sharing/high availability is required. an 802.cisco. Base access point controller licensing provides the flexibility to purchase only the number of access point licenses required.com/en/US/prod/collateral/wireless/ps6302/ps8322/ps10315/data_sheet_c78-521631.11n performance and maximum scalability.cisco. including the following: • • • • • • Controller connectivity to the wired network Controller connectivity to the wireless devices Defining WLANs and Service Set Identifiers (SSIDs) WLAN controller mobility groups WLAN controller access point groups WLAN controller RF groups Controller Connectivity to the Wired Network WLAN controllers possess physical entities known as ports that connect the controller to its neighboring switch (the Cisco 5508 Wireless Controller supports up to eight Gigabit Ethernet Small Form-Factor Pluggable [SFP] ports). Designed for 802. In sites requiring more than 250 total access points. More information on the Cisco 5508 Wireless Controller can be found at the following URL: http://www.Chapter 4 Accessibility Medium Enterprise Design Profile (MEDP)— Mobility Design Note For additional information on inter-controller mobility and roaming. Each physical port on the controller supports. with the ability to add additional access point licenses in the future when medium enterprise site growth occurs. see the following URL: http://www.html#w p1028197.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/ch2_Arch. Figure 4-5 Cisco 5508 Wireless Controller The Cisco 5508 Wireless Controller is a highly scalable and flexible platform that enables system-wide services for mission-critical wireless in medium to large-sized enterprise environments.1Q VLAN trunk. WLAN Controller Connectivity This section discusses WLAN controller connectivity. multiple controllers can be deployed as necessary. by default. as shown in Figure 4-5. the Cisco 5508 Wireless Controller offers the ability to simultaneously manage from 12 to a maximum of 250 access points per controller. with fixed trunking characteristics. html. Medium Enterprise Design Profile Reference Guide 4-8 .

For more information. The AP manager interface communicates through a distribution system port by listening across the Layer 3 network for CAPWAP “join” messages generated by access points seeking to communicate with and “join” the controller. the system dynamically manages port redundancy and load balances traffic transparently to the user. Figure 4-6 WLAN Controller Link Aggregation to Services Block Services Block In this way.0/configuration/guide/Controller60CG. These Gigabit Ethernet connections should be distributed among different modular line cards or switch stack members as much as possible. This design can make use of up to eight Gigabit Ethernet connections from the Cisco 5508 Wireless Controller to the services block. Release 6. the Cisco 5508 Wireless Controllers are interconnected with the modular switches or switch stacks found in the services block using link aggregation and EtherChannel exclusively. Note For more information concerning the various types of interfaces present on Cisco WLAN controllers. and Dynamic Host Configuration Protocol (DHCP) server. one or more centralized WLAN controllers are connected via the services block to the site core.0/configuration/guide/c60mint. Each interface is mapped to at least one primary port. VLAN identifier.com/en/US/docs/wireless/controller/6. thereby reducing the number of IP addresses needed to configure the ports on your controller.com/en/US/docs/wireless/controller/6.3ad port channel.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Accessibility Note For more information concerning the various types of ports present on Cisco WLAN controllers. An interface may have multiple parameters associated with it.cisco. Link aggregation (LAG) is a partial implementation of the 802. and as the destination for CAPWAP packets from the access point to the controller.0 at the following URL: http://www.com/en/US/docs/wireless/controller/6.0/configuration/guide/Controller60CG. including an IP address. Currently published best practices specify either multiple AP manager interfaces (with individual Ethernet links to one or more switches) or link aggregation (with all links destined for the same switch or switch stack) as the recommended methods of interconnecting WLAN controllers with wired network infrastructure.html#wp12776 59. which are used for all Layer 3 communications between the controller and its joined access points. see the Cisco Wireless LAN Controller Configuration Guide. The IP address of the AP manager interface is used as the tunnel source for CAPWAP packets from the controller to the access point. A special type of controller interface is known as the AP manager interface. Interfaces are logical entities found on the controller. optional secondary physical port.html. In the Cisco Medium Enterprise Design Profile. default gateway.cisco. primary physical port.0 at the following URL: http://www. When LAG is enabled. and multiple interfaces can be mapped to a single controller port.html.cisco. It bundles all of the controller distribution system ports into a single 802. as shown in Figure 4-6. so as to ensure that the failure of a single line card or switch stack failure does not result in total failure of the 228520 CT5508 WLC Medium Enterprise Design Profile Reference Guide 4-9 . Release 6. LAG bundles all the enabled distribution ports on the WLAN controller into a single EtherChannel interface. see the following URL: http://www.3ad port aggregation standard. see the Cisco Wireless LAN Controller Configuration Guide. A controller has one or more AP manager interfaces.

such as the administrators. provides redundancy and ensures that connectivity between the services block switch and the controller is maintained in the rare event of a failure. or different switch stack members (as shown in Figure 4-6). The switch features required to implement this connectivity between the WLAN controller and the services block are the same switch features that would otherwise be used for EtherChannel connectivity between switches in general. One of the basic building blocks used in the WLAN controller to address this need is the ability to provision logical WLANs. Link aggregation also offers simplicity in controller configuration. the value chosen for the SSID should bear some direct relationship to the intended purpose of the WLAN. for example. With link aggregation. To promote ease of administration. various user groups will likely require access to the WLAN for a variety of different purposes. These considerations include the WLAN controllers deployed in the services blocks. Terminating on different modules within a single Catalyst modular switch. Several BSSs can be joined together to form one logical WLAN segment. access points remain connected to the network. traffic is automatically migrated to one of the other controller ports. it is safe to assume that a large portion of these groups will likely want access to the WLAN at more or less the same time. • Controller Connectivity to Wireless Devices This section deals with the design considerations that involve provisioning wireless access for the various user groups that reside within the medium enterprise. referred to as an extended service set (ESS). Medium Enterprise Design Profile Reference Guide 4-10 . and guests. For this reason. page 4-35. These WLANs are configured and assigned a unique SSID. Although usage peaks may occur. configuring primary and secondary ports for each interface is not required. link aggregation provides very high traffic bandwidth between the controller and the site network. As long as at least one controller port is functioning. An SSID is simply the 1–32 byte alphanumeric name given to each ESS.Chapter 4 Accessibility Medium Enterprise Design Profile (MEDP)— Mobility Design WLAN controller connection to the site network. as well as the access points that are located in buildings. employees. Thus. if any of the controller ports fail. the wireless infrastructure must support logical segmentation in such a fashion that a reasonable proportion of all users can be serviced simultaneously and with an appropriate degree of security and performance. and wireless clients continue to send and receive data. the system continues to operate. Defining WLANs and SSIDs In most medium enterprises. each of which are mapped to different wired network interfaces by the WLAN controller. as well as the considerations concerning its implementation in the Cisco Medium Enterprise Design Profile can be found in Controller Link Aggregation. Note Each set of wireless devices communicating directly with each other is called a basic service set (BSS). an SSID is also sometimes referred to simply as a network name. in designing for mobility in the Cisco Medium Enterprise Design Profile. and simplicity: • • With the Ethernet bundle comprising up to eight Gigabit Ethernet links. reliability. The key advantage of using link aggregation in this fashion instead of multiple AP manager interfaces is design performance. Further discussion of the advantages of using controller link aggregation. which is a sequence of characters that uniquely names a WLAN.

Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Accessibility Figure 4-7 provides a high-level illustration of the three logical WLANs that provide mobility within the Cisco Medium Enterprise Design Profile. – Broadcast SSID enabled. a uniform baseline level of authentication and encryption to be deployed for the secured staff WLAN across all such devices. This WLAN would be used by enterprise employees. There is no real disadvantage to enabling broadcast SSID. The secured staff WLAN is designed to provide secure access and good performance for devices supported by the medium enterprise network administration staff. also referred to as CCKM) for enhanced roaming. The addition of Cisco CKM in this case provides for faster roaming by enabling Cisco CKM-equipped clients to securely roam from one access point to another without the need to re-authenticate after the roam completes. Figure 4-7 WLAN SSIDs SSID=Guest SSID=Staff SSID=VoWLAN SSID=Guest SSID=Staff SSID=VoWLAN SSID=Guest SSID=Staff SSID=VoWLAN LWAPP LW AP P or CA Network LWAPP LWAPP or CAPWAP PW AP Tunneled Guest Traffic SSID=Staff SSID=VoWLAN LWAPP AP LW P or P CA P WA In the Medium Enterprise Design Profile. administrators. laptops. Enabling this helps to avoid potential connectivity difficulties with some clients. The characteristics of this WLAN include the following: – Wi-Fi Protected Access 2 (WPA2) encryption with 802. for example. PDAs. For example. and so on. such as laptops. the names chosen for the WLAN SSIDs should be consistent within each site in the medium enterprise system. the set of WLAN SSIDs provide access to the following WLANs: • A secured staff WLAN network with dynamically generated per-user. or voice over WLAN (VoWLAN) phones to use on the secured staff WLAN. For ease of administration and the support of employees. – QoS profile setting of silver (best effort delivery). These employees are typically prohibited from bringing their own personal PDAs. Medium Enterprise Design Profile Reference Guide 229389 4-11 . guests and visitors that frequent multiple sites. This allows. Devices that are used on the secured staff WLAN are usually procured and deployed by (or with the knowledge and cooperation of) the medium enterprise network administration staff on behalf of full-time and temporary employees. An underlying assumption made here is that only devices supporting compatible authentication and encryption would be considered for deployment at all. and Cisco Centralized Key Management (Cisco CKM. Most modern WLAN client devices being produced today support this level of authentication and encryption. in Figure 5-7 employee wireless access is made available anywhere there is WLAN RF coverage using the SSID titled “staff”. and how they are mapped to WLAN controller network interfaces or tunneled to another controller.1x/EAP authentication. per-session encryption keys. administrators and other staff members using managed client devices.

For more information about the 802. Unlike the 802. Eliminating the configuration of static IP addresses helps to mitigate the risk of IP address duplication. – WLAN controller QoS profile setting of platinum. simply stating that a client is 802.11n “dual-band” clients. This allows devices and applications that can support 802.4 GHz industrial. which is recommended as a best practice for the Cisco 7921G and 7925G VoWLAN phones. – Mandatory IP address assignment via DHCP.11a PHYs.4 or 5 GHz frequency bands because they are capable of using any of the three PHYs. – Wi-Fi Multimedia (WMM) policy of allowed. and 802. or they may be 802.11b.Chapter 4 Accessibility Medium Enterprise Design Profile (MEDP)— Mobility Design Note For more details on WLAN QoS.4 and 5 GHz frequency bands.11n. • A secured VoWLAN network that is optimized for VoWLAN usage by employee staff and administrators using managed VoWLAN client devices. – WMM policy is required (this precludes the use of clients that do not support WMM). Enabling the use of WMM in this way is also in compliance with the 802. and managed by (or with the knowledge and cooperation of) the medium enterprise network administration staff. 802.11g physical layers (PHYs) are applied in the unlicensed 2. see the following URL: http://www.11n does not precisely indicate what frequency bands the client is capable of operating within. This allows. this WLAN is designed to provide secure access and good performance when used with VoWLAN devices (such as the Cisco Unified Wireless IP Phone 7925G) that are usually procured.11b and 802.html.11a PHY is applied in the unlicensed 5 GHz ISM band. a baseline level of authentication and encryption to be deployed for this WLAN with the knowledge that the devices using this WLAN will support that level of security. This allows clients that can take advantage of benefits of 5 GHz operation (such as increased capacity and reduced interference) to do so.11a/bg clients are capable of operating in either 2. Clients using the very high speed 802.1e enhanced QoS prioritization to do so. whereas the 802. scientific. Selection between PHYs is typically achieved via software configuration.com/en/US/solutions/collateral/ns340/ns394/ns348/ns767/white_paper_8 0211n_design_and_deployment_guidelines. “Dual-band” 802.11g. As was the case with the secured staff WLAN. – Radio policy set to allow clients to use either 2.4 GHz or 5 GHz to access this WLAN. for example. and medical (ISM) frequency band. To assure proper security and promote effective device management.cisco. deployed.11n PHY may be designed to operate in a single band. Such procurement is usually conducted on behalf of full-time and temporary employee staff users. The key differences between this WLAN and the secured staff WLAN include the following: – The security policy on this WLAN is WPA with Cisco CKM. Medium Enterprise Design Profile Reference Guide 4-12 .11n PHY and its application to the 2. Note The 802. see the references contained at the end of Quality-of-Service. employee staff users are typically prohibited from bringing their own personal VoWLAN phones and using them on this WLAN. page 4-26. which assigns the highest prioritization to voice traffic.

cisco. User names and passwords for authentication can reside on a RADIUS AAA server (Cisco ACS). – The radio policy should be set to allow clients to access only this WLAN using 5 GHz. apart from DHCP and Domain Name Service (DNS). easy-to-implement method for deploying wireless guest access by using Ethernet in IP (RFC3378). is blocked until the user enters a correct user name and password into an authentication web page. However.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/ch10GuAc. mandating the use of 802. and so on) as well as the wide variety of WLAN guest client devices they may bring into the enterprise. there is an option of using a non-controller-based web authentication server. This authentication web page is provided by an internal WLAN controller web server in the Cisco Medium Enterprise Design Profile.cisco. the guest access WLAN authenticates the user via a web portal (web authentication) where all network access.1 Design Guide at the following URL: http://www. The guest access WLAN must be designed to accommodate the needs of enterprise guests (such as customers. Traffic to and from this guest access WLAN is tunneled to the DMZ transparently. vendors. The foreign controller is the controller resident in the respective site services block described earlier. – The guest access WLAN user is re-directed to a web authentication web page whenever the user attempts to open any web page before successful authentication via the web portal.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Accessibility – Load-based Call Admission Control (CAC) should be specified for this WLAN. Characteristics of the guest access WLAN include the following: – To provide access control and an audit trail. see the Voice over Wireless LAN 4.html. contractors. For technical information on Guest Access best practices in wireless networks. whereas the anchor controller is resident within the network DMZ.1 Design Guide at the following URL: http://www. The Cisco Medium Enterprise Design Profile uses the Cisco Unified Wireless Network to provide a flexible. This prevents VoWLAN calls from being added to an access point that is unable to accept them without compromising call quality. The benefit of this approach is that no additional protocols or segmentation techniques must be implemented to isolate guest traffic travelling within the tunnel from all other enterprise traffic. page 4-27 for further information regarding considerations surrounding the products and techniques used to provide guest access when designing for mobility in the Cisco Medium Enterprise Design Profile. – The guest access WLAN uses a QoS profile setting of bronze (less than best effort). with no visibility by. other traffic in the enterprise. such as the Cisco NAC Appliance. – WMM policy is set to allowed. Although their numbers will likely be much less compared to that of employees. – Broadcast SSID is enabled.h tml. This helps to ensure that all secured voice devices take full advantage of the robust call capacity and reduced co-channel interference characteristics associated with 5 GHz. Ethernet in IP is used to create a tunnel across a Layer 3 topology between two WLAN controller endpoints (known as the foreign and anchor controllers). Medium Enterprise Design Profile Reference Guide 4-13 .com/en/US/docs/solutions/Enterprise/Mobility/vowlan/41dg/vowlan41dg-book. See Guest Access.1x authentication and WPA or WPA2 encryption does not usually facilitate a practical guest access solution. see the Guest Access section in the Enterprise Mobility 4. For further information on best practices for voice applications. prospective employee candidates. • A guest access WLAN that uses web authentication for guest users of the enterprise network. the WLAN clients brought into the enterprise environment by guest users are typically not managed or directly supported by medium enterprise network administrative staff. or interaction with. Because of the lack of control over the type of device used.

Assume for the purposes of this example that the access points of each building are joined to a different WLAN controller.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/emob41dg-wrapper.4 GHz or 5 GHz. Figure 4-8 Roaming Main Site Remote Site User Movement Medium Building Large Building User Movement Small Building WLC 1 WLC 2 WLC 3 Figure 4-8 shows that there is overlapping RF coverage between the large and medium buildings. The buildings are in relatively close proximity to one another. access point.1 Design Guide at the following URL: http://www. and vice versa.Chapter 4 Accessibility Medium Enterprise Design Profile (MEDP)— Mobility Design – Radio policy should be set such that client access is allowed to use either 2.ht ml. Because roaming is Medium Enterprise Design Profile Reference Guide 4-14 229390 . Additional information about the definition of controller WLANs and SSIDs can be found in the Enterprise Mobility 4. A given WLAN controller is able to make decisions based on data received from other members of the mobility group. The circular and oval patterns surrounding each building are intended to represent a very simplistic view of hypothetical outdoor RF coverage. it may not make sense to put the WLAN controllers in the same mobility group.cisco. This is because users must leave the main site and traverse through a part of the town to get to the smaller remote site. For example. sharing essential end client. If the possibility of a roaming event does not exist. The WLAN controllers in a mobility group form a mesh of authenticated tunnels between themselves. but not between the small building and any other building. Here we see a large and a medium building located within the same medium enterprise site. affording any member controller the ability to efficiently communicate with any other member controller within the group. Typically. WLAN Controller Mobility Groups A mobility group is a group of WLAN controllers that behave as a single virtual WLAN controller. The primary purpose of a mobility group is to create a virtual WLAN domain (across multiple WLAN controllers) to provide a comprehensive view of a wireless coverage area. and the WLAN controller servicing the smaller building located in the remote site. with a small building located on a remote site some distance away from the main site. rather than relying solely on the information learned from its own directly connected access points and clients. two WLAN controllers should be placed in the same mobility group when an inter-controller roam is possible between access points. consider the scenario illustrated in Figure 4-8. and RF information. with the controllers servicing the large and medium building being located within the main service block at the main site. Mobility groups are used to help facilitate seamless client roaming between access points that are joined to different WLAN controllers.

only the WLAN controllers servicing the medium and large building are required to be in the same mobility group. in our Medium Enterprise Design Profile. consider the following: • Within a medium enterprise comprised of one or more sites. Allowing of course for the rare exception that two sites may be adjacent to one another. Thus. It is also assumed that in the vast majority of cases. all WLAN controllers serving access points deployed on the same site are placed within the same mobility group. However. Medium Enterprise Design Profile Reference Guide 4-15 . • Figure 4-9 provides a high-level illustration of how mobility group assignment can be handled in the Medium Enterprise Design Profile. The WLAN controller servicing the small building may be configured to be a member of the same mobility group. it is assumed that intra-site roaming is possible between all buildings resident within the same site. but not between the small building and any other building on any site. as some sites may have collocated buildings with coverage voids between them. Note that MG refers to the mobility group name assigned for the site. Keep in mind that in reality this may not always be the case.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Accessibility clearly possible between the medium and large building. remote sites are sufficiently distant from the main site (as well as from one another) to render inter-site roaming impractical. assuming that intra-site roaming is possible between all buildings allows us to make a design assumption that is generally applicable to both situations. In applying the concept of mobility groups to the Cisco Medium Enterprise Design Profile. but it is not mandatory that this be done in this case. we assume that roaming between buildings located on different sites is very unlikely.

Because of high-speed WAN/MAN connectivity between sites. access points can be configured to fail over to a WLAN controller outside of their mobility group. If inter-site roaming between multiple sites is possible. • • Medium Enterprise Design Profile Reference Guide 4-16 229391 . the controllers at each sites should be assigned into the same mobility group and defined as peers in the mobility list of all controllers for that mobility group. To support this. This is discussed further in Controller Redundancy. Each controller in the same mobility group is defined as a peer in the mobility list of all controllers for that mobility group. page 4-40. access point fail over to a remote backup controller resident at the main site becomes possible. page 4-38 and AP Controller Failover.Chapter 4 Accessibility Medium Enterprise Design Profile (MEDP)— Mobility Design Figure 4-9 Medium Enterprise Mobility Groups LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP Cisco 6500 VSS Large Building Medium Building Cisco 4500 Small Building Cisco 4500 Extra Small Building Cisco 3750 StackWise Core CUCM ACS NAC Mgr VSOM/VSMS DMM/CVP DHCP/DNS NTP DC Appliance Block WAE ACNS WLC NAC Cisco 6500 VSS ESA DMZ Web/Email Anchored WLC www ASR Cisco 3800 WSA Internet Edge Main Large Site ASR MG = “MAIN” MetroE HDLC PSTN Internet HDLC Cisco 375ME VSOM/VSMS DHCP/DNS NTP WAE/ACNS WLC/NAC Cisco 2800 VSOM/VSMS DHCP/DNS NTP Cisco 6500 VSS WAE/ACNS WLC/NAC Cisco 2800 Cisco 2800 VSOM/VSMS DHCP/DNS WAE/ACNS WLC/NAC NTP Cisco 4500 DC Appliance Block DC Appliance Block DC Appliance Block Large Building Medium Building Small Building Medium Building Small Building Small Building Cisco 6500 VSS Cisco 4500 Cisco 4500 Cisco 4500 Cisco 4500 Cisco 4500 LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP Remote Large Site Remote Medium Site Remote Small Site MG = “LARGE” MG = “MEDIUM” MG = “SMALL” The following are some of the key design considerations concerning mobility groups: • The controllers present at each site are defined as members of a mobility group unique to that site.

This is done by assigning a group of access points to an access point group at the WLAN controller. This is a key point when dealing with medium enterprises that may have limited network administrative staff. AP grouping allows a single WLAN to be supported across multiple dynamic VLAN interfaces on the controller.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/ch2_Arch.000 access points. including best practice information. The advantage of this mobility group approach is clarity and simplicity in deployment and administration. design simplicity is maintained.cisco.1 Design Guide at the following URL: http://www. Assume also that there are 10 users associated to each access point. Figure 4-10 shows the use of AP grouping based on site-specific VLANs. the WLAN can be divided into multiple segments using the AP grouping capability of the WLAN controller. the use of subnets large enough to support 2500 users may not be possible. the limitation on the maximum number of controllers per mobility group is not considered to be a significant trade-off. each WLAN defined on the controller is mapped to a single dynamic interface (as shown earlier for the secure staff. Thus. such as by building or set of buildings. To address this issue. This would result in 2500 users sharing the single VLAN to which the WLAN is mapped. Medium Enterprise Design Profile Reference Guide 4-17 . WLAN Controller Access Point Groups Typically. using the same WLAN and SSID. can be found in the Enterprise Mobility 4. and guest access WLANs).Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Accessibility • A single mobility group can contain a maximum of 72 WLAN controllers. a mobility group can have up to 72 * 250. or 18. The number of access points supported in a mobility group is bound by the number of controllers and the access point capacity of each controller. A potential issue with this approach is that. VoWLAN. and then mapping the group to a specific dynamic interface. Additional information about WLAN controller mobility groups. In this way. Consider the case however. for the Cisco 5508 Wireless Controller. By using mobility groups as indicated in Figure 4-9. depending on the particular overall network design. where the Cisco 5508 Wireless Controller is deployed and licensed for 250 access points. access points can be grouped logically.html#wp102814 3. Given the large capacity of the Cisco 5508 Wireless Controller.

VLAN62 or VLAN63). with up to 16 WLANs defined in each group. or WLANs belonging to another access point group. In implementations of the Cisco Medium Enterprise Design Profile where addressing limitations are present. As such. and 63. a staff member associating to the WLAN using an access point that is part of AP group VLAN61 is assigned an IP address from the VLAN 61 IP subnet. Cisco 5508 Wireless Controllers can contain up to 192 access point group definitions. a staff member associating to the WLAN using an access point that is part of AP group VLAN62 is assigned an IP address from the VLAN 62 IP subnet. Each of these access point groups are denoted by an AP Group Name (AP Group VLAN61. 62. each mapping to a site-specific VLAN: VLANs 61.Chapter 4 Accessibility Medium Enterprise Design Profile (MEDP)— Mobility Design Figure 4-10 Access Point (AP) Groups SSID = “secure” SSID = “secure” AP Group: VLAN 61 AP Group: VLAN 62 SSID = “secure” AP Group: VLAN 63 LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP VLAN 61 VLAN 62 VLAN 63 As shown in Figure 4-10. Likewise. the WLAN client maintains its original IP address. Each access point advertises only the enabled WLANs that belong to its access point group. Roaming between the site-specific VLANs is then handled internally by the WLAN controller as a Layer 3 roaming event. Thus. and so on. three dynamic interfaces are configured. the use of access point grouping to allow a single WLAN to be supported across multiple dynamic VLAN interfaces on the controller can be extremely beneficial. Each site-specific VLAN is mapped to a group of access points that uses the same WLAN/SSID. Access points do not advertise disabled WLANs that are contained within its access point group. Medium Enterprise Design Profile Reference Guide 4-18 229392 .

An exception to this would be in extremely large deployments. A clear advantage to this approach is simplicity of configuration and better support of N+1 controller redundancy (see Controller Redundancy. and thus need not be contained in the same RF domain.cisco. Access Points In the Cisco Medium Enterprise Design Profile. the precise subset of interior and exterior areas requiring WLAN access will likely be better determined instead during the site survey planning process. Grouping WLAN controllers into RF groups in this way allows the dynamic RRM algorithms used by the Cisco Unified Wireless Network to scale beyond a single WLAN controller. An RF group is a cluster of WLAN controllers that collectively coordinate and calculate their dynamic radio resource management (RRM) settings. Note Complete information regarding Cisco Radio Resource Management can be found in the Cisco Radio Resource Management under Unified Wireless Networks at the following URL: http://www. If there is any possibility that an access point joined to one WLAN controller may receive RF transmissions from an access point joined to a different WLAN controller. all WLAN controllers in the Medium Enterprise Design Profile are configured with the same RF group name. Note For more information on site survey planning. and even across sites. Medium Enterprise Design Profile Reference Guide 4-19 .11n access points providing RF coverage in both the 2. the benefits of Cisco RRM for a given RF group can be extended between floors. it is anticipated that each building requiring WLAN access will be outfitted with dual-band 802.4 and 5 GHz bands. RRM can be used to optimize configuration settings to avoid 802. Of course.shtml. to include both controllers and their access points. otherwise known as RF domains. Therefore. Thus. as the maximum number of controllers that can be defined in a single mobility group is twenty. it is important to consider that most buildings will almost certainly contain some areas not intended for human entry or occupancy at any time.html.cisco. the implementation of system-wide RRM is recommended.com/en/US/solutions/collateral/ns340/ns394/ns348/ns767/white_paper_80211n_design_a nd_deployment_guidelines. simplicity is preferred in the configuration of RF groups within the mobility design. In general.1 Design Guide at the following URL: http://www. It is generally assumed that users will require WLAN access in most building interior areas. page 4-38 for further details). for most medium enterprise deployments there is no real disadvantage to doing so. buildings. these vacant areas may not be identified.11n Design and Deployment Guidelines at the following URL: http://www. see the Cisco 802. In this way.11 interference and contention as much as possible. which is typically an integral part of any wireless network deployment.cisco. Similarly. some buildings may possess areas within the aforementioned outdoor perimeter that simply may not be accessible to any users at any time.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/ch2_Arch. plus a 50–75 yard outdoor perimeter area surrounding each building. During your initial mobility design.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Accessibility WLAN Controller RF Groups The strategy behind how RF groups.html#wp102818 4. A more detailed discussion as well as best practice recommendations regarding the use of RF groups can be found in the Enterprise Mobility 4. are deployed within the Cisco Medium Enterprise Design Profile represents another important deployment consideration that can affect overall accessibility.com/en/US/tech/tk722/tk809/technologies_tech_note09186a008072c759. In this case. Although it is true that geographically disparate WLAN controllers have very little chance of experiencing RF interaction. both WLAN controllers should be configured with the same RF group name. In this way.

To assist in addressing these and other rare but still significant deployment challenges that may be encountered within medium enterprise sites.11n access point is recommended (see Figure 4-12). This might include situations where a focused directional antenna pattern is required. the Cisco Aironet 1250 Series 802.11n access point (see Figure 4-11).11n access point recommended for most interior building locations is the AIR-LAP1142N. Ideal for indoor environments such as offices. conference rooms.11n access point contains six integrated omni-directional antenna elements that incorporate the use of three hidden discrete elements for each frequency band. corridors. In the Cisco Medium Enterprise Design Profile. extended operating temperature tolerances beyond that of the Cisco Aironet 1140 Series 802.html Although the Cisco Aironet 1140 Series 802.Chapter 4 Accessibility Medium Enterprise Design Profile (MEDP)— Mobility Design In most medium enterprises. in situations where the results of pre-site survey planning indicate that the use of external antennas are required to best meet specific RF coverage requirements.11n Access Point can be found at the following URL: http://www.11n Access Point (AIR-LAP1142N) To deliver the right mix of style and performance. the vast majority of interior building WLAN access can be provided by the Cisco Aironet 1140 Series 802.11n connections on both of its radios simultaneously.com/en/US/products/ps10092/index.3af power-over-Ethernet (PoE) while sustaining full-performance 802. The Aironet 1140 series 802. Figure 4-11 Cisco Aironet 1140 Series 802. Medium Enterprise Design Profile Reference Guide 4-20 .cisco. perhaps one or more access points will need to be deployed in refrigerated storage. Here. the model of the Cisco 1140 Series 802. In other cases. For example.11n access point may be required. with only a small antenna footprint exposed to public view. Note Complete information (including country-specific ordering information) regarding the Cisco Aironet 1140 series 802.11n access point has a visually pleasing metal housing covered by a white plastic shell that blends with the most elegant environments.11n access point provides the ability to be powered directly from 802. which delivers pervasive wireless connectivity while blending in seamlessly with the aesthetics of modern-day enterprise environments. the Cisco Aironet 1140 Series 802. and so on. there are some trade-offs to consider in specialized situations. an access point that provides antenna connectors is necessary. research or even product testing environments where the anticipated operating temperature extremes are not within common norms. or simply one where aesthetic requirements demand that the access point be completely hidden. the Cisco Aironet 1140 Series 802.11n access point is capable of servicing the bulk of all medium enterprise interior wireless needs.

while drawing only 15.11n access points can power both 802.html. extended operating temperature capabilities or minimal-footprint installations where it is highly preferable that the access point chassis is totally hidden from view.e. A tradeoff associated with the use of Cisco Aironet 1250 Series 802.3af PoE Catalyst switch. The use of a mid-span ePoE injectors (Cisco part number AIR-PWRINJ4).11n access point to deliver full 802.pdf Note that Cisco Aironet 1140 Series 802. This option allows the Cisco Aironet 1250 series 802.5 to 20 watts of power from a switch capable of providing enhanced-PoE (ePoE).11n access point can be found at the following URL: http://www. Keep in mind.com/en/US/products/ps8382/index.4 GHz or 5 GHz) the Cisco Aironet 1250 Series 802. Medium Enterprise Design Profile Reference Guide 4-21 .com/en/US/prod/collateral/wireless/ps7183/ps469/at_a_glance_c45-513837. the Cisco Aironet 1250 Series 802. that if the full performance capability of the Cisco Aironet 1250 series access point is not necessary in your particular deployment. the AIR-LAP1252AG model of the Cisco 1250 Series of access points is recommended for those and other types of demanding deployments. both the Cisco 1140 as well as 1250 Series 802. Additional information concerning the antenna options available for the Cisco Aironet 1250 Series 802.11n access point can be found at the following URL: http://www.11n access point is intended for no-compromise performance in combination with the inherent expand-ability required to address challenging deployment situations. 3750-E.11n performance while connected to any Cisco Catalyst switch.11n radios.cisco.11n access point with 20 watts of input power.11n access point can be used to address situations requiring focused directional coverage patterns. at full transmit power running two spatial streams with encryption.11n access point can also operate with 15.4 watts from a 802.cisco. however.11n access points are manufactured with a security slot machined into the access point casing. model number 64068) into the access point security cable slot. 4500E and 6500E Series. either 2.11n Access Point (AIR-LAP1252AG) Designed with a next-generation ruggedized modular form factor.11n access points is that the AP-1250 Series requires slightly more power to reach its peak levels of performance. You can secure either model access point by installing a standard security cable (such as the Kensington Notebook MicroSaver. or you wish to support only a single RF band (i.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Accessibility Figure 4-12 Cisco Aironet 1250 Series 802. approximately 18.. Power is injected directly onto the wire by the AIR-PWRINJ4 mid-span injector without reliance on the power output level of the switch itself. Cisco recommends the following power options: • • An ePoE Cisco Catalyst switch or switch blade module (such as the 3560-E. To provide the Cisco Aironet 1250 Series 802. In the Cisco Medium Enterprise Design Profile.4 watts of power from an 802. the Cisco Aironet 1250 Series 802. Complete information regarding the Cisco Aironet 1250 series 802.3af PoE Catalyst switch. Note To help discourage theft and vandalism. With robust modularized construction and six RP-TNC antenna jacks that allow antennas to be positioned independently of the access point itself.

large cubicle areas. it is recommended for consistency and accuracy that perform your site survey using the same PoE input power levels.Chapter 4 Accessibility Medium Enterprise Design Profile (MEDP)— Mobility Design Although its deployment flexibility is unparalleled within the marketplace. not just maximum coverage It is a natural tendency to try to squeeze the most coverage from each access point deployed. and facilitates the use of advanced capabilities such as location-based context-aware services.4 GHz band. the installed base of 5 GHz 802. Note For the Cisco Aironet 1250 Series 802.4 GHz 802. This translates into the ability to deploy with density and capacity in mind. cafeterias. In addition. and a heavier mounting weight as compared to the Cisco Aironet 1140 series 802. – The number of non-802. attempting to design for maximum coverage at maximum transmitter output power can be counter-productive. if you plan to deploy Cisco Aironet 1250 Series 802. the successful designer should design for capacity and generally aim to have access points installed closer together at lower power output settings.11n access point is typically only deployed only in those locations where they are necessary to address challenging situations. such false economies often sacrifice the ability to effectively make use of advanced tools such as Cisco RRM to address anomalies such as “coverage holes” and other deficiencies. It also allows the practical use of higher data rates.11n users. in most medium enterprise installations. This approach allows for access point transmitter power to be dynamically managed via Cisco RRM. as the maximum coverage footprint is typically attained using lower data rates and degraded signal-to-noise ratios. and allow background resources such as Cisco RRM to handle channel and power output requirements accordingly. • Design and survey for capacity. When designing networks for high-speed applications.11 interferers (such as cordless phones and wireless personal networks) operating in the 5 GHz band is still just a fraction of the number found within the 2.4 watts of PoE. and especially 802.11n access points with 15.11 wireless LAN technology.11n wireless clients. The characteristics of 5 GHz operation make it advantageous for most users.11n access point. A smaller installed base of users translates into less contention with existing clients and better operation at higher throughput rates. Cisco recommends performing your site survey using the same levels of PoE input power as you expect to use in your final deployment. – The amount of available bandwidth found in the 5 GHz band is much greater than that of the 2.4 GHz band. Instead. there are twenty-one 5 GHz non-overlapping channels that can be deployed.11n as well as pre-802. • Mount access points or antennas on the ceiling when possible Medium Enterprise Design Profile Reference Guide 4-22 .11b and 802. provides RRM with the necessary transmission power “headroom” to allow for the ability to compensate for environmental changes. Other trade offs include a higher total cost per access point because of the added cost of external antennas. thereby servicing as much of the site as possible with the lowest total access point investment. a larger footprint. The following design considerations regarding dual-band access points should be kept in mind when designing networks for dense user environments (for example. In the United States.11g clients. for the following reasons: – Despite the maturity of 802.11a clients generally is not nearly as widespread as 2.11n access point. this applies for both 802. For example. the Cisco Aironet 1250 series 802. and employee auditoriums within site buildings): • Use the 5 GHz band whenever possible In general.

taking into consideration signal loss because of attenuation of the human head and other obstacles. a sensible antenna placement strategy still is very important to ensure a superior deployment. Unless you are aware of specific reasons why one of the data rates described below are required in your deployment (such as the presence of clients that can transmit or receive only at these rates). a good general rule of thumb then is to ensure that all access point antennas are mounted at least five to six inches away from any large metal reflective surfaces. However.ht ml Voice Over Wireless LAN 4.cisco. disable at a minimum the 6 and 9 Mbps rates. nulls. disable the 1. they place the radiating portion of the antenna in open space. ceiling mounting of Cisco Aironet 1250 Series access point antennas is highly recommended.h tml • Medium Enterprise Design Profile Reference Guide 4-23 . By designing for capacity and disabling lower data rates. Ceiling mounting is recommended in general for the types of indoor environments found within medium enterprises. and 11 Mbps 2.4 GHz. aggregate system capacity can be increased.1 Design Guide— http://www. ceiling-mounted antennas typically have better signal paths to handheld phones. Ceiling mounting locations are usually readily available. Because of this. 5. The separation of one or more wavelengths between the antenna and reflective surfaces allows the access point radio a better opportunity to receive a transmission. Only if you completely confident that the situation just described is entirely not applicable in your environment should you consider completely disabling all 802.11n access points can be mounted as deemed necessary during pre-site survey planning or during the actual site survey process.4 GHz is why not disable 802. 2. • Avoid mounting on surfaces that are highly reflective to RF Cisco recommends that all antennas be placed one to two wavelengths from surfaces that are highly reflective to RF. depending on the mix of clients in the environment. and 9 Mbps rates. this approach may not be entirely practical. it may be wiser to simply disable only the three 802. • Disable legacy and low speed data rates Clients operating at low data rates (for example.com/en/US/docs/solutions/Enterprise/Mobility/vowlan/41dg/vowlan41dg-book. Based on this recommendation. and more importantly. especially on guest access WLANs where a visitor might attempt to gain access using a device with embedded legacy radio technology that may not support 802. 6. 2.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Accessibility Cisco Aironet AP-1140 Series 802.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/emob41dg-wrapper. 5.11g users.11n access points should be mounted on ceilings only.5.11g.11b entirely? In other words. and multipath. why not disable the 1. A common question concerning 2. and reduces the creation of nulls when the radio transmits. Note that although recent technological advances have helped greatly in mitigating problems with reflections. and 5. – For 5 GHz.1 Design Guide— http://www. especially when using omni-directional antennas. Additional best practice guidelines for access point and antenna deployments can be found in the following reference documents: • Enterprise Mobility 4. the following actions are recommended: – For 2. 1.11b data rates below 11 Mbps. especially for voice applications. which usually allows for the most efficient signal propagation and reception. Overall system performance in any given access point cell drops significantly when a large percentage of low data rate frames tend to consume available airtime. In the majority of carpeted indoor environments. such as metal.5 Mbps) consume more airtime when compared to clients transmitting the same data payloads at higher data rates such as 36 Mbps and 54 Mbps.5.11b data rates. 2. Cisco Aironet 1250 Series 802.cisco.4 GHz rates altogether? Although this certainly may offer advantages relating to better performance for 802.

If this is the case. located outdoors on each building in such a manner that a satisfactory outdoor perimeter area is established. can significantly enhance the ability of law enforcement and other agencies to locate and combat threats. 1130. The robust. a full outdoor mesh infrastructure is beyond the scope of the Cisco Medium Enterprise Design Profile at this time. Because of the limited number of transmitters and the requirement for licensing. Federal Communications Commission (FCC) allocated 50 MHz of spectrum in the 4.Chapter 4 Accessibility Medium Enterprise Design Profile (MEDP)— Mobility Design To provide outdoor WLAN access around the immediate perimeter area of each building. and should be determined during pre-site survey planning. as well as antenna choices. the Cisco Aironet 1520 Series Lightweight Outdoor Access Point is recommended (see Figure 4-13). Public safety agencies can use this 4.9 GHz band tends to be below that of other bands.S. see the Cisco Aironet 1520. weatherized housing of the Cisco Aironet 1520 Series Lightweight Outdoor Access Point can be painted to adapt to local codes and aesthetics. Figure 4-13 Cisco Aironet 1520 Series Lightweight Outdoor Access Point As part of the Cisco Medium Enterprise Design Profile. In choosing among the various models of Cisco Aironet 1520 Lightweight Outdoor Access Points. Rather.cisco. 1240 Series Wireless Mesh Access Points. the U. or access key safety and security applications. For readers who wish to augment the recommendations made in this design guide and deploy a full site outdoor mesh configuration. Communications using the 4. such as 2. the Cisco Aironet 1520 Series Lightweight Outdoor Access Point provides an outdoor extension to the enterprise wireless network.9 GHz public safety equipment (see note below) in emergency response vehicles. Note In 2003.4 GHz and 5 GHz. the ability to connect to and monitor in-building events. state or other public safety agencies are currently using or otherwise plan to deploy compatible 4.9 GHz band to implement wireless networks with advanced services for the transmission of mission-critical information.0 at the following URL: http://www. municipal.9 GHz Medium Enterprise Design Profile Reference Guide 4-24 . it may be wise to plan ahead in conjunction with on-site and local public safety agencies to accommodate the use of this licensed band for connectivity from properly equipped first responders and emergency vehicles to your WLAN.9 GHz band to public safety services. depends on the characteristics associated with the required coverage area and other particulars. Although the Cisco Aironet 1520 Series Lightweight Outdoor Access Point is part of the outdoor mesh series of Cisco access point products. In the event of a site emergency. Design and Deployment Guide. The precise location of these outdoor access points. with central management provided through WLAN controllers and the Cisco Wireless Control System. A very rugged enclosure allows for deployment outdoors without the need to purchase additional housings or third-party National Electrical Manufacturers Association (NEMA) enclosures to provide protection from extreme weather. in this design Cisco Aironet 1520 Series Lightweight Outdoor Access Points are deployed only as root access points (RAPs).html. Release 6.com/en/US/docs/wireless/technology/meshhttps://www.scribd.com/design/guide/MeshAP_60. readers may also wish to consider whether local. interference on the 4.

11b/g standards (2. the added benefits and advantages afforded by the 1524PS are often considered worthwhile. The entire range of power input options is described in the Cisco Aironet 1520 Series Lightweight Outdoor Access Point Ordering Guide. as well as the configuration of their equipment. depending on the inclusion of 4. VoWLAN.9 GHz public safety licensed operation parameters. Keep in mind that although the Cisco Aironet 1520 Series Lightweight Outdoor Access Point is intended to be installed exposed to outdoor weather elements. The trade offs of deploying this model are the lack of 4.11b/g standards. The Cisco Aironet 1522 Outdoor Lightweight Access Point is a dual-radio.9 GHz is in use among public safety agencies. dual-band product that is compliant with IEEE 802. Medium Enterprise Design Profile Reference Guide 4-25 .com/en/US/prod/collateral/wireless/ps5679/ps8368/product_data_sheet0900aecd806 6a157. The model of Cisco Aironet 1524PS Public Safety Lightweight Outdoor Access Point recommended in the Cisco Medium Enterprise Design Profile is the AIR-LAP1524PS. mobile data. video surveillance. Designed for demanding environments. This access point can support independent data exchanges across all three radios simultaneously. All models of the Cisco Aironet 1520 Series Lightweight Outdoor Access Point can be powered from a multitude of sources. Do not use any other power injector or Ethernet switch PoE capability (including enhanced PoE switches) in an attempt to directly provide PoE to Cisco Aironet 1520 Series Lightweight Outdoor Access Points.11a (5-GHz) and 802. they must also contend for access with other unlicensed users of these frequencies. the particular model of outdoor access point recommended for outdoor perimeter building coverage. Examples include WLANs for incident scene management. Keep in mind that when public safety users access WLANs using unlicensed 2.9 GHz as follows: • The Cisco Aironet 1524PS (Public Safety) Lightweight Outdoor Access Point includes 4.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Accessibility public safety band must be related to the protection of life. The model of Cisco Aironet 1522 Lightweight Outdoor Access Point recommended in the Cisco Medium Enterprise Design Profile for deployments without 4.9 GHz clients.11a and 802.9 GHz licensed public safety support in environments where 4. the Cisco Aironet 1522 provides high performance device access through improved radio sensitivity and range performance. • Cisco offers a wide array of antenna options for the entire range of Cisco Aironet 1520 Series Lightweight Outdoor Access Points. and so on. The Cisco Aironet 1520 Series Lightweight Outdoor Access Point is approved for use only with the Cisco AIR-PWRINJ1500-2 power injector. public safety agencies may still be able to access the WLAN using standard 2. Information on these antenna options can be found in the Cisco Aironet 1520 Series Lightweight Outdoor Access Point Ordering Guide at the following URL: http://www. as well as 4. Note Although the Cisco Aironet 1520 Series Lightweight Outdoor Access Point can be conveniently powered via PoE.9 GHz capability and provides flexible and secure outdoor WLAN coverage for both public safety and mobility services. a power injector (Cisco AIR-PWRINJ1500-2) specific to this product line must be used. health.4 GHz and 5 GHz frequencies.cisco. However.9 GHz access is not available at your site. This depends on whether the emergency response vehicles of the agencies in question are equipped to do so. The Cisco Aironet 1524PS Public Safety Lightweight Outdoor Access Point is a multiple-radio access point that complies with the IEEE 802. in environments where public safety agencies are already equipped with compatible 4. Even if 4. fixed point-to-point. or direct AC.9GHz is the AIR-LAP1522AG. With this in mind.html. The main trade-off with the Cisco Aironet 1524PS Public Safety Lightweight Outdoor Access Point is the added purchase and deployment cost.4-GHz). or property. the AIR-PWRINJ1500-2 power injector is approved for indoor installation only. as well as deal with any interference from other sources located within those bands.4 GHz or 5 GHz unlicensed bands. including PoE. direct DC.

Chapter 4 Usability Medium Enterprise Design Profile (MEDP)— Mobility Design Some Cisco partners and customers may choose instead to integrate a standard access point into their own weatherproof outdoor enclosure. silver. such as the following: • • Quality-of-service (QoS) Guest access Quality-of-Service The WLAN controller should be configured to set the 802. the translated CoS value is 0. because this should already be in alignment with the overall network policy In the Cisco Medium Enterprise Design Profile. if the WLAN controller is connected to a switch that is configured to trust the class-of-service (CoS) and maintain a translation table between CoS and Differentiated Services Code Point (DSCP). To implement this approach. integrating a standard indoor access point into a weatherproof outdoor enclosure in this manner has the disadvantage of lacking 4. the WLAN controller assigns a CoS value of 5 in the header of the frame that carries this data to the wired switch. because it provides both the advantage of initial configuration simplicity as well as ongoing ease of maintenance. However. the WLAN controller should be configured to set the 802. For more information on WLAN QoS. see the following URLs: Medium Enterprise Design Profile Reference Guide 4-26 . which means that client traffic leaving WLAN controllers may need to be reclassified based on network policy.1p marking of frames received and forwarded onto the wired VLAN to reflect the QoS policy used on this WLAN. This translates to a DSCP value of EF. bronze. therefore. Therefore. However. WLAN traffic is prioritized based on the QoS profiles (platinum. For example.9 GHz support in areas where public safety agencies are so equipped. without the need to configure explicit policies on adjacent switches. the translation between wireless QoS policy and wired network QoS policy occurs automatically. the translation between wireless and wired network QoS policy occurs automatically. it is highly recommended that the Cisco Aironet 1250 Series 802. Switches need to be configured to trust only the QoS of frames forwarded to them by the WLAN controller. In this case. this does not change the IP QoS classification (DSCP) of the client traffic carried. Therefore. Similarly.1p marking of packets forwarded onto wired VLANs to reflect the QoS policy used on the specific WLAN from which they were received. if the same packet originates from a WLAN assigned a QoS profile of silver. This may be achieved via one of following approaches: • • Applying policy at each of the switch virtual interfaces (SVIs) connecting the WLAN controller to the wired network Learning the QoS policy that has already been applied by the wireless networking components.11n access point be used as the basis for that integration. and so on) applied to each WLAN. This technique requires only that the QoS profiles be maintained on the WLAN controllers themselves. if the WLAN controller is connected to a switch that is configured to trust CoS and maintain a translation table between CoS and DSCP. In the Cisco Medium Enterprise Design Profile. assume a packet received originates from a WLAN to which a platinum QoS profile has been assigned. as its external antenna capabilities would facilitate connection to external antennas via bulkhead connectors. the plan is to use the latter approach. Usability This section discusses the mobility design considerations pertaining to those aspects of the Cisco Medium Enterprise Design Profile that are relevant to overall usability.

1 Design Guide 4. Enterprise Mobility 4.cisco. The benefit of this approach is that there are no additional protocols or segmentation techniques necessary to achieve guest traffic isolation in relation to other internal traffic. Medium Enterprise Design Profile Reference Guide 4-27 .1 Design Guide— http://www. Figure 4-14 shows a high-level view of guest access using this technique with a centralized WLAN controller design.html • Guest Access The Cisco Medium Enterprise Design Profile uses the Cisco Unified Wireless LAN Guest Access option to offer a flexible.1— http://www.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/ch5_QoS. easy-to-implement method for deploying wireless guest access via Ethernet over IP (EoIP). as described in RFC3378.h tml.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Usability • Voice over Wireless LAN 4. EoIP tunneling is used between two WLAN controller endpoints in the centralized network design.com/en/US/docs/solutions/Enterprise/Mobility/vowlan/41dg/vowlan41dg-book.cisco.

these frames are encapsulated using CAPWAP from the access point to the site WLAN controller. The use of EoIP and an anchor WLAN controller in the DMZ allows guest user traffic to be transported and forwarded to the Internet transparently. a WLAN controller with a specific purpose is located in the main site DMZ. As described in earlier sections of this document. they are encapsulated in EoIP from there to the anchor controller. When an access point receives information from a WLAN client via the guest access WLAN/SSID. When received at the WLAN controller. where it is referred to as an anchor controller.Chapter 4 Usability Medium Enterprise Design Profile (MEDP)— Mobility Design Figure 4-14 Guest Access Solution High-Level Overview Internet Site Building Web Server DMZ Internal User Guest User Anchor WLAN Controller LWAPP LWAPP Services Block WLAN Controller Core Internal Servers Internal WLAN Traffic Guest WLAN Traffic 229393 As shown in Figure 4-14. and interfacing the traffic from these controllers to a firewall or border router. Medium Enterprise Design Profile Reference Guide 4-28 . management. other traffic in the enterprise. the centralized site WLAN controllers are responsible for termination. After reaching the anchor controller. The anchor controller is responsible for terminating EoIP tunnels originating from centralized site WLAN controllers. or interaction with. these frames are de-encapsulated and passed to a firewall or border router via the guest VLAN. Instead of being switched locally to a corresponding VLAN on the site controller. including one or more guest WLANs. and standard operation of the various WLANs provisioned throughout the enterprise. guest WLANs are instead transported via the EoIP tunnel to the anchor controller in the DMZ. with no visibility by.

even in networks where hundreds or thousands of access points may be joined to other Cisco 5508 Wireless Controllers. equally functional solutions are available that combine what is discussed in this section with the use of an access control platform external to the WLAN controller. For example. firewall rules must be established to limit communication between the anchor controller and only those controllers authorized to establish EoIP tunnels to them.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Usability Because the anchor controller is responsible for termination of guest WLAN traffic and is positioned within the Internet DMZ. the wireless guest access topology remains the same. Multicast traffic is not supported over guest tunnels. • • • • Finally. for example. even if multicast is enabled on wireless controllers. although the focus for the Cisco Medium Enterprise Design Profile is on the pure controller-based guest access solution. UDP port 16666 for inter-WLAN controller communication. it can be licensed to support only a minimal number of access points. instead of to a firewall or border router. the anchor controller should not be used to control and manage other access points in the enterprise. the guest VLAN interface on the anchor controller connects to an inside interface on the NAC Appliance. the guest access solution topology described in this section can be integrated with the Cisco NAC Appliance. For example. Other rules that might be needed include the following: • • • • TCP 161 and 162 for SNMP UDP 69 for TFTP TCP 80 or 443 for HTTP. a Cisco CT5508-12 (12 access point-licensed capacity) can function quite well as an anchor controller in the Cisco Medium Enterprise Design Profile. As shown in Figure 4-15. or HTTPS for GUI access TCP 23 or 22 for Telnet. if the medium enterprise has already deployed the Cisco NAC Appliance within their Internet DMZ to support wired guest access services. Cisco strongly recommends that the anchor controller be dedicated to supporting EoIP guest access tunneling only. The mobility group name for every WLAN controller that establishes EoIP tunnels with the anchor controller must be configured as a mobility group member in the anchor controller configuration. and IP protocol ID 97 (Ethernet over IP) for client traffic. The mobility group name of the anchor controller should differ from that configured for site controllers. This might be the case. In particular. except that in this scenario. in addition to its guest access role. When deploying a Cisco 5508 Wireless Controller as an anchor controller. or SSH for command-line interface (CLI) access The following are other important considerations to keep in mind regarding the use of this guest access solution: • For the best possible performance. note that other. do not use the anchor controller for any other purpose but EoIP guest access tunneling. Such rules might including filtering on source or destination controller addresses. Medium Enterprise Design Profile Reference Guide 4-29 . This is done to keep the anchor controllers logically separate from the mobility groups associated with the general wireless deployment. keep in mind that because the anchor controller is not going to be used to manage access points. In other words.

where the NAC appliance is used to actually control guest access. versus the benefits it affords in relation to your particular deployment.Chapter 4 Usability Medium Enterprise Design Profile (MEDP)— Mobility Design Figure 4-15 Cisco UWN Guest Access with Anchor WLC and NAC Appliance Internet Site Building NAC Appliance Web Anchor WLAN Server Controller DMZ Internal User Guest User LWAPP LWAPP Services Block WLAN Controller Core Internal Servers Internal WLAN Traffic Guest WLAN Traffic 229394 Figure 4-15 shows that the NAC Appliance is responsible for redirection. The trade-off here is the added cost of the external access control solution.html#wp99965 9. The NAC Guest Access Server facilitates the creation of guest accounts for temporary network access by permitting provisioning by authorized personnel in a Medium Enterprise Design Profile Reference Guide 4-30 . The Cisco NAC Guest Access Server is another member of the Cisco Network Admission Control solution family that can further enhance the utility of your design by assisting network administrators in the provisioning of guest access user accounts. Note Additional information concerning the design and deployment of the Cisco Unified Wireless Network guest access solution can be found in the Enterprise Mobility 4.cisco. The site and anchor controllers are used only to tunnel guest WLAN traffic across the enterprise into the DMZ. and subsequent access to the Internet.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/ch10GuAc.1 Design Guide at the following URL: http://www. web authentication.

Medium Enterprise Design Profile Reference Guide 228551 4-31 . Figure 4-16 NAC Guest Server with NAC Appliance and WLAN Controller Sponsor Cisco NAC Guest Server 5 6 Active Directory 1 3 1. including creation. WLC authenticates user against Guest server using RADIUS 5. Guest access recorded 6. Guest can now access Internet 6. suspension. the Guest Server receives accounting information from the NAC Appliance to enable full reporting. In addition. including details of the network access activity. the whole process is recorded in a single place and stored for later reporting. allowing for guest accounts to be controlled via the Guest Server user interface. Guest opens Web browser 2. Guest logs in with details provided by sponsor 4.cisco. editing. Cisco NAC Guest Server integrates with Cisco NAC Appliance through an application programming interface (API). the WLAN controller makes use of the NAC Guest Server to authenticate guest users (shown in Figure 4-17).Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Usability simple and secure manner. In addition. In this case. The Cisco NAC Guest Server then controls these accounts on the Cisco NAC Appliance through the API (shown in Figure 4-16). see the following URL: http://www. Guest access recorded 5 228529 2 Wireless LAN Controller Internet Guest Note For more information on the Cisco NAC Guest Server. In addition. the Guest Server receives accounting information from the WLAN controller to enable full reporting. Figure 4-17 NAC Guest Server with WLAN Controller Alone Cisco NAC Guest Server 4 6 Active Directory 1 3 Wireless Access Point 1. including the creation. Guest removed when session time expires 4 Internet Wired or Wireless 2 Cisco NAC Appliance Guest Cisco NAC Guest Server can also integrate directly with Cisco WLAN controllers through the RADIUS protocol. and deletion of accounts.com/en/US/prod/collateral/vpndevc/ps5707/ps8418/ps6128/product_data_sheet0900 aecd806e98c9. Web traffic is intercepted by Network Enforcement Device and redirected to login page (captive portal) 3. Guest can now access the Internet 5. allowing for guest accounts to be controlled via the Guest Server user interface. Guest logs in with details provided by sponsor 4. Guest opens Web browser 2. Web traffic is intercepted by Wireless LAN Controller and redirected to login page (captive portal) 3. editing.html. and deletion of guest accounts.

and report on indoor and outdoor wireless networks. deploy.cisco. WCS also supports a software-based high availability option that provides failover from a primary (active) WCS server to a secondary (standby). Cisco WCS lowers operational costs by addressing the whole range of mobility management requirements (radio frequency. each WLAN controller in the Cisco Medium Enterprise Design Profile provides both a CLI as well as a graphical web user interface. for a full-featured. with built-in tools delivering improved efficiency and helping to reduce training costs. Cisco WCS gives network administrators immediate access to the tools they need when they need them. which are primarily used for controller configuration and management. Adding mobility services such as context-aware software and adaptive wireless intrusion prevention systems (wIPS) is simplified through Cisco WCS integration with the Cisco Mobility Services Engine (MSE). These user interfaces provide ready access to the network administrator. administrators. midsize. Effective management of these networks helps to simplify network operation and improve the productivity of employees. Note A detailed description of each management feature and benefit available in the Cisco Wireless Control System is beyond the scope of this chapter. Operational costs are significantly reduced through a simplified and intuitive GUI. but the information can be found at the following URL: http://www. access points. centralized complete life cycle mobility management solution that enables network administrators to successfully plan.Chapter 4 Manageability Medium Enterprise Design Profile (MEDP)— Mobility Design Manageability As mentioned earlier. configure. Cisco WCS can scale to manage hundreds of Cisco WLAN controllers.html. mobility services. monitor. which in turn can manage thousands of Cisco Aironet access points. and so on) using a single unified management platform deployed in a centralized location. and large-scale WLANs across local and remote sites. controllers. and with minimal impact on staffing requirements. even as the site network grows incrementally larger. wherever they may be located within the enterprise. For installations where network management capabilities are considered mission-critical. The comprehensive Cisco WCS platform scales to meet the needs of small. Medium Enterprise Design Profile Reference Guide 4-32 . the use of the Cisco Wireless Control System (WCS) is highly recommended (see Figure 4-18). guests and site visitors. Figure 4-18 Cisco Wireless Control System The Cisco Wireless Control System allows very effective management of wireless networks supporting high-performance applications and mission-critical solutions.com/en/US/prod/collateral/wireless/ps5755/ps6301/ps6305/product_data_sheet0900a ecd802570d0. However. troubleshoot.

on any site. personnel responsible for local site network administration are restricted to the discrete mobility infrastructure components associated with the virtual domain representing their local site. Note For further information on WCS hardware platforms and requirements. which allow policies to be applied that further limit what actions each may be allowed against any visible resources.html#wp1061082. based on administrative level and assigned site or sites.0/configuration/guide/6_0wst.com/en/US/docs/wireless/wcs/6. In this design. auditing. configuration. and troubleshooting made available by WCS are accessible to any authorized medium enterprise network administrator via standard secured web browser access. However. via their WCS management consoles. WLAN clients. the subset of acceptable actions that are allowed against any visible resources are further regulated by the assignment of appropriate WCS user and group rights. a centralized WCS management server located in the data center block within the main site is used. remote site administrators may be limited by the following: • Site resource management visibility policy—This is performed by assigning the network mobility infrastructure components associated with each site to a WCS virtual domain. However. As such. Key members of the central administrative staff are assigned to the WCS root domain. The planning. the ability to query and manage site mobility resources is regulated using the virtual domain feature of WCS. in conjunction with the appropriate assignment of WCS user rights. it is anticipated that access to WCS will be restricted to network administrators and their staff located at the main and remote sites.cisco. These infrastructure components include WLAN controllers. deployment. Thus. Figure 4-19 provides greater detail and magnification. alarms. as well as local site administrators for sites where network administrators are not present. WCS events. It is anticipated that resource access will be limited further. reports. The data center block was initially shown in Figure 4-3. configuration templates. see the following URL: http://www. reporting. Generally speaking. these groups will most likely not have equivalent resource and functionality access. Site resource management access policy—Although the visibility of a resource is determined by WCS virtual domain assignment. • Medium Enterprise Design Profile Reference Guide 4-33 . granting them overall authority to view and configure all mobility infrastructure resources. although key members of the main site central network administration staff may possess the authority to manage any and all mobility resources located on any site throughout the enterprise. Figure 4-19 WCS Within the Data Center Block Data Center M V 228531 Cisco UCM SRST/Video Gateway WCS Cisco ACS Appliance NAC Manager Video Surveillance Media Server The current upper limit for scaling WCS on a high-end server is up to 3000 Cisco Aironet CAPWAP-based access points.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Manageability In the Cisco Medium Enterprise Design Profile. monitoring. and assigning the virtual domains to appropriate network administrators. most implementations of the Cisco Medium Enterprise Design Profile are well served by a mobility design using a WCS management server located on the main site. access points. and up to 750 Cisco WLAN controllers. and so on.

as a backup means of managing the guest access solution. the only function a lobby ambassador is permitted is to create and assign guest user credentials to controllers that have web-policy configured WLANs. Note Further information regarding how WCS virtual domains may be used to limit individual site network administrator access to segments of the mobility network outside of their scope of responsibility. the Cisco Medium Enterprise Design Profile does not at this time provide for the added cost of a secondary WCS management server in an N+1 software-based high-availability arrangement. The use of a centralized WCS management server in the Cisco Medium Enterprise Design Profile provides key advantages such as reduced initial deployment cost and ease of maintaining server resources in a centralized location. this increases the cost of WCS deployment significantly. Because it is believed that the centralized mobility network management services provided by WCS are not regarded as mission-critical to the majority of medium enterprises. Any downtime realized because of a WCS server failure.cisco. Unrecoverable WAN failure A catastrophic. a network administrator can establish a local administrator account on the anchor WLAN controller. However. However.com/en/US/prod/collateral/wireless/ps5755/ps6301/ps6305/brochure_c02-474335. in the rare event of a WCS server failure. although undoubtedly very inconvenient. while still providing for overall “root” administrator control of the entire wireless network. deployments where WCS management services are critical to the mission of the medium enterprise should instead consider modifying the design to include the services of a secondary WCS management platform configured for N+1 software-based high-availability. it is assumed that direct WLAN controller management work a rounds (such as that described earlier for guest access management) are an acceptable cost compromise. would in most cases not be viewed as entirely catastrophic. coupled with good performance across modern high-speed LANs and WANs. with lobby ambassador privileges. and preferably a Cisco WCS Navigator management aggregation platform located at the main site. certain trade offs exist. requiring one WCS management server per site. see the following URL: http://www. Of course. these decentralized management options are not included in the • Medium Enterprise Design Profile Reference Guide 4-34 . Guest access credentials can be created and managed centrally using the Cisco WCS. such as the following: • WCS server failure In the Cisco Medium Enterprise Design Profile. the centralized mobility network management services provided by WCS are not regarded as being mission-critical for the majority of medium enterprise deployments. may be found at the following URL: http://www. Note For more information on WCS high availability configurations.0/configuration/guide/6_0admin. In the rare event that a centralized WCS management system is not available because of a server failure. and centralize WCS management on a per-site basis.ht ml. unrecoverable WAN failure can interrupt management traffic between WCS and the WLAN controllers that are located on remote sites. One way to protect against this is to distribute the WCS management server function out further into the network. With such an account. Thus.com/en/US/docs/wireless/wcs/6. as with any design choice. A network administrator can create a limited privilege account within WCS that permits “lobby ambassador” access for the purpose of creating guest credentials. This being the case. virtual domains (as well as WCS user rights) can be assigned at the WCS server or using an external security manager such as Cisco Secure ACS.cisco.Chapter 4 Manageability Medium Enterprise Design Profile (MEDP)— Mobility Design Via the WCS GUI interface.html#wp11 32580.

cisco.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Reliability Cisco Medium Enterprise Design Profile at this time. as shown in Figure 4-20.3ad port channel. Note For more information on WCS Navigator. it is assumed that in this type of a rare occurrence. It bundles all the controller distribution system ports into a single 802. all eight ports can be bundled together into a single Gigabit EtherChannel interface. This can be especially important with high capacity controllers licensed for many access points.html. Reliability This section discusses the mobility design considerations pertaining to those aspects of the Cisco Medium Enterprise Design Profile relevant to overall reliability. thereby reducing the number of IP addresses needed to make use of all controller wired ports. With the Cisco 5508 Wireless Controller and the release 6.0 software used in the Cisco Medium Enterprise Design Profile. Instead. should any network management intervention be required in such circumstances. the system dynamically manages port redundancy and load balances access points across each port. LAG is a partial implementation of the 802.3ad port aggregation standard. the aforementioned ability to minimally manage WLAN controllers directly will suffice. such as the Cisco CT5508-250. As mentioned earlier. LAG is effective in distributing access point traffic across all controller ports.com/en/US/products/ps7305/index. without interaction from the network administrator. Medium Enterprise Design Profile Reference Guide 4-35 . When LAG is enabled. and includes the following: • • • Controller link aggregation Controller redundancy AP controller failover Controller Link Aggregation An important capability used to enhance the reliability of WLAN controller interconnection to the wired network is link aggregation (LAG). see the following URL: http://www.

This is done to ensure that the failure of a single line card or switch stack member does not result in total failure of the WLAN controller interconnection to the network. if any switch stack member fails. the system continues to operate. When using a Cisco 5508 Wireless Controller with link aggregation enabled. active. access points remain connected to the network. and wireless clients continue to send and receive data. The Gigabit Ethernet connections comprising the LAG (up to eight on the Cisco 5508 Wireless Controller) should be distributed among different modular line cards or switch stack members in the services block to the greatest degree possible. if there are four switch stack members in the services block and LAG is configured using all eight WLAN controller interfaces. the Gigabit Ethernet links from the services switch block to the WLAN controller should be distributed two per services block switch stack member. and available to pass data. six other Gigabit Ethernet links to the WLAN controller remain ready. traffic is automatically migrated to one of the remaining ports. The switch features required to implement this connectivity between the WLAN controller and the services block are the same switch features that are otherwise generally used for EtherChannel connectivity between switches. In this way.Chapter 4 Reliability Medium Enterprise Design Profile (MEDP)— Mobility Design Figure 4-20 LAG in the Cisco 5508 WLC Cisco 5508 WLAN Controller Management/ AP Manager Interface 1 2 3 4 Ports 5 6 7 8 LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP LWAPP 228532 LAG simplifies controller configuration and improves the overall solution reliability. As long as at least one controller port is functioning. it is important to keep the following considerations in mind: Medium Enterprise Design Profile Reference Guide 4-36 . If any of the controller ports fail. For example.

As mentioned previously. These may be fully deployed to take full advantage of multi layer site design guidelines regarding the oversubscription of access layer uplinks. make sure that at least two or more Gigabit Ethernet interfaces are used to connect the controller to the services block.) Table 4-1 provides information for the Cisco 5508 Wireless Controller deployed with its maximum complement of 250 access points. Cisco recommends that if more than 100 access points are connected to the controller. When you enable link aggregation. When you enable link aggregation or make any changes to the link aggregation configuration. only one AP manager interface is needed because only one logical port is needed. it does not matter if the Cisco Catalyst switch is configured for either Link Aggregation Control Protocol (LACP) or Cisco proprietary Port Aggregation Protocol (PAgP). By doing so. The recommended load balancing method for Cisco Catalyst switches is by use of the CLI command src-dest-ip. Therefore. Only one link aggregation group is supported per controller. Medium Enterprise Design Profile Reference Guide 4-37 .11n throughput of 250 Mbps per access point. oversubscription is not expected to exceed site design guidelines of 8:1 when using all the available controller interfaces with LAG. • You cannot configure the controller ports into separate link aggregation groups. there are eight SFP interfaces on the Cisco 5508 Wireless Controller. • • • • • Table 4-1 Cisco 5508 Wireless Controller Oversubscription Rates Throughput per AP (Mbps) 25 50 100 150 200 250 Cisco 5508 Wireless Controller Oversubscription Rate (8 Gbps) 1:1 2:1 4:1 5:1 7:1 8:1 Table 4-1 shows that even if designing for peak 802. When you enable link aggregation. you can connect a controller in link aggregation mode to only one neighbor switch device (note that this can be a switch stack with multiple member switches).Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Reliability • When the port channel is configured as “on” at both ends of the link. Therefore. The in-band management interface of the Cisco 5508 Wireless Controller can also serve as the AP manager interface. all Cisco 5508 Wireless Controller distribution ports participate in link aggregation by default. Although Cisco 5508 Wireless Controllers have no restrictions on the number of access points per port. When you enable link aggregation. only one functional physical distribution port is needed for the controller to pass client traffic. it is relatively straightforward to design a solution that delivers access layer uplinks from the WLAN controller with an oversubscription rate of between 8:1 and 20:1 (Note that these oversubscription rates are not unique to wireless products and are equivalent with what is typically seen in wired networks as well. you must configure link aggregation for all the connected ports in the neighbor switch that have been outfitted with small form-factor plug-in (SFP) modules. because no channel negotiation occurs between the controller and the switch. you must immediately reboot the controller.

html#wp1062 211. Figure 4-21 General N+1 WLAN Controller Redundancy LWAPP LWAPP LWAPP APs Configured with: Primary: WLAN-Controoler-1 Secondary: WLAN Controller-BKP Centralized Location WLAN Controller-1 LWAPP LWAPP WLAN Controller-BKP WLAN Controller-2 LWAPP APs Configured with: Primary: WLAN-Controoler-2 Secondary: WLAN Controller-BKP LWAPP LWAPP 228533 LWAPP APs Configured with: Primary: WLAN-Controoler-n Secondary: WLAN Controller-BKP WLAN Controller-n The main tradeoff associated with the N+1 redundancy approach is that the redundant controller may become oversubscribed if multiple primary controllers fail simultaneously. This is especially important when there are many users that may rely on a centralized component. for access into the network. An easy solution is to have a “hot” standby secondary controller always at the ready for each primary controller in active service (otherwise known as 1:1 controller redundancy). Controller Redundancy The ability of the solution to recover from a reasonable degree of component failure is important in ensuring the reliability of any WLAN networking solution. especially at geographically separate Medium Enterprise Design Profile Reference Guide 4-38 . Although this offers the highest degree of protection from any number of failed primary controllers. unforeseen controller failures are avoided using an “N+1” controller redundancy model. see Deploying Cisco 440X Series Wireless LAN Controllers at the following URL: http://www. by allowing one centralized redundant controller to serve as the backup for many primary controllers.cisco. In reality. Figure 4-21 provides a general illustration of the principle of N+1 controller redundancy. Thus. In the Cisco Medium Enterprise Design Profile. it is also the most costly approach. experience indicates that the probability of multiple controller failures is low. Each access point is configured with the name or IP address of its primary WLAN controller.Chapter 4 Reliability Medium Enterprise Design Profile (MEDP)— Mobility Design Note For more information concerning WLAN controller link aggregation.com/en/US/docs/wireless/technology/controller/deployment/guide/dep. but is also configured with the name or IP address of the redundant controller as its secondary WLAN controller. such as a WLAN controller. in which the redundant WLAN controller is placed in a central location and acts as a backup for multiple active WLAN controllers. The N+1 controller redundancy approach is based on the assumption that the probability of more than one primary WLAN controller failure occurring simultaneously is very low. high availability controller redundancy can be provided at a much lower cost than in a traditional 1:1 redundancy arrangement.

albeit with associated increases in complexity and equipment investment. other controller redundancy approaches are available that can provide increasingly greater degrees of protection. the available capacity of the primary main site WLAN controllers allow them to act as the secondary destination for the access associated with the largest remote site. In the case of a failure of the largest remote site.com/en/US/docs/wireless/technology/controller/deployment/guide/dep. In this case.cisco. if the main site services block is equipped with two Cisco CT5508-250 WLAN controllers (the “-250” signifies that this particular Cisco 5508 Wireless Controller is licensed for 250 access points). For example. This leaves ample capacity in the main site for one of the following scenarios to occur: • Either of the main site controllers may fail and allow up to 125 joined access points to migrate (fail over) to the other controller in the pair. and the largest of the remote sites also contains 250 combined access points across all remote site buildings. the need to deploy hardware at the main site explicitly for the purposes of controller redundancy may be avoided.ht ml • Further information regarding WLAN controller redundancy may be found in the following documents: • • Medium Enterprise Design Profile Reference Guide 4-39 . in this particular case.com/en/US/docs/wireless/technology/controller/deployment/guide/dep. assume that the main site shown in Figure 4-3 contains a total of 250 combined access points across all main site buildings. In other cases.html#wp 1060810 Enterprise Mobility 4. there may be sufficient capacity on the primary controllers located on the main site themselves to accommodate the access point and user load of a single failed controller on any of the remote sites. However. Deploying Cisco 440X Series Wireless LAN Controllers— http://www.cisco.html#wp1060 810. Thus. Any remote site controller may fail and allow its joined access points to migrate (fail over) to the main site controllers. you should assess the risk of multiple controller failures in your environment as well as the potential consequences of an oversubscribed backup controller.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/emob41dg-wrapper. the access point load of the main site alone can be split equally between the two controllers (125 access points on each controller). this results in each of the main site controllers operating at their full licensed capacity. when designing an N+1 redundant controller solution.1 Design Guide— http://www. see Deploying Cisco 440X Series Wireless LAN Controllers at the following URL: http://www. emulating what is shown in Figure 4-21 by having the access points of the main site as well as all remote sites address a common redundant controller located in the main site services block. In this case. This approach requires that main site controllers be licensed for a greater number of access points than necessary for the support of the main site alone. In some cases. Additional licensing of existing controllers is performed in place of providing a dedicated additional controller platform at the main site for system-wide redundancy.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Reliability site locations. Note For more details on controller redundancy. The configuration of N+1 redundancy in any mobility design depends greatly on the licensed capacity of the controllers used and the number of access points involved.cisco. configuration is rather straightforward. This results in the remaining functional controller bearing the full load of 250 access points. In situations where there is reluctance to assume even this generally small degree of risk.

a high-speed WAN/MAN is present between sites.html. making the WLAN controller an aggregation and control point for WLAN traffic. during which service to wireless clients is interrupted because the access points are busy re-joining the primary controller. there is a brief window of time. WLAN controllers have a configurable parameter known as AP Fallback that causes access points to return to their primary controllers after a failover event. Medium Enterprise Design Profile Reference Guide 4-40 . thus making access point fail over to a remote WLAN controller feasible. in the rare event of a controller failure. AP assignment and WLAN redundancy behavior is deterministic. see the Enterprise Mobility 4.1 Design Guide at the following URL: http://www. The access point can prioritize which controller it attempts to join based on its high availability configuration. leaving this parameter at the default value can have some unintended consequences. the access point might “flap” between the primary controller and the backup. The SSID used to access a particular WLAN throughout the multisite medium enterprise should be the same. Wireless LAN Controller Configuration The core component of the Cisco Unified Wireless architecture is the WLAN Controller (WLAN controller) that provides the interface between the “split-MAC” wireless network and the wired network. This feature is enabled by default. as described in the previous section. regardless of the controller. the WLAN controller is the Layer-2 connection point between WLAN client traffic and the wired network. access points can be configured to fail over to a WLAN controller that is outside their mobility group. a common WLAN SSID naming policy for key WLANs must be implemented to ensure that WLAN clients do not have to be re configured in the event of an access point fail over to the main site backup controller. That is. based on pre-configured priorities. When an access point “falls back” to its primary controller.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/emob41dg-wrapper. usually approximately 30 seconds or so.Chapter 4 Wireless LAN Controller Configuration Medium Enterprise Design Profile (MEDP)— Mobility Design AP Controller Failover The Cisco Unified Wireless Network provides for multiple failover options that can allow access points to determine which WLAN controller to migrate in the event of a controller failure. it learns about all the WLAN controllers in its mobility group. In addition. A common WLAN SSID naming policy is necessary to ensure that WLAN clients do not have to be re configured in the event of an access point fail over to a central backup controller. move the access points back to the primary controller in a controlled fashion during a scheduled service window. or choose a WLAN controller based on loading. For this to be effective. In addition. if connectivity to the primary WLAN controller becomes unstable for some reason. and the IP address of the remote WLAN controller must be provided in the HA configuration. However. For this reason.cisco. however. To accomplish this in the Cisco Medium Enterprise Design Profile. access points should be manually assigned to primary and secondary controllers. When an access point goes through its discovery process. • • Note For more information and best practices regarding AP controller failover. In this scenario. In the Cisco Medium Enterprise Design Profile. after the primary controller comes back online. Best practice considerations regarding to AP controller failover include the following: • After access points initially discover a WLAN controller. it is preferable to disable AP Fallback and. the remote WLAN controller is not in the mobility group that is learned during the AP discovery process. the WLAN controller is the primary control point of AP and RF management. By doing this.

two WLAN controllers are used to illustrate the basic configuration requirements.0. In this example. as shown in Figure 4-22. and it is best that customers use a private address that would not be a valid address within their own network. and the virtual interface is used to support mobility. The two key interfaces are highlighted.1.0. These WLAN controllers provide WLAN services for the entire site. Figure 4-23 cr23-5508-1 Interfaces 228520 CT5508 WLC Medium Enterprise Design Profile Reference Guide 4-41 . The number of WLAN controllers for the main site is driven by the number of APs deployed and the type of fail over support required. as well as fail over support for APs in remote sites. including CAPWAP tunnel termination (there is no AP-manager interface).Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Wireless LAN Controller Configuration The reference design used for testing WLAN services in the Medium Enterprise Design Profile mobility design uses the following four WLAN controllers: • • • Two WLAN controllers (cr23-5508-1. differing only in their IP addressing. Figure 4-23 and Figure 4-24 show the interface summary on the two WLAN controllers.1 address has been used in example mobility configurations. cr23-5508-2) for the main site One WLAN controller (cr14-5508-1) for a remote site One anchor WLAN controller (cr11-5508-wlc) for guest services WLAN Controller and Wired Network Connections The WLAN controllers in the main site are centralized for that site and connected to a 3750E stack in services block connected to the site core. Note Although the 1. in the event of WLAN controller outage at that location. that is the management and virtual interfaces. Figure 4-22 Services Block WLAN Controller Connection Services Block The two main site WLAN controllers share the VLAN and subnet configuration. the 1.0/8 address range has now been assigned. The management interface is used as the interface for in-band communication with the WLAN controller.1.

Note that Link Aggregation (LAG) is enabled on all the WLAN controllers used in the Medium Enterprise Design Profile mobility design. Example 4-1 Example of WLAN Controller 3750 Stack Port Channel Configuration interface Port-channel11 Medium Enterprise Design Profile Reference Guide 4-42 .Chapter 4 Wireless LAN Controller Configuration Medium Enterprise Design Profile (MEDP)— Mobility Design Figure 4-24 cr23-5508-2 Interfaces Figure 4-25 shows the management interface of WLAN controller cr23-5508-1. Figure 4-25 cr23-5508-1 Management Interface Example 4-1 and Example 4-2 show examples of the switch configuration for the 3750 stack switch connecting the main WLAN controllers to the wired network.

117. The configuration is the same. This helps to ensure seamless mobility when clients roam between APs that are connected to WLAN controllers within the same Mobility Group. the details are not duplicated here.117. therefore.117. Medium Enterprise Design Profile Reference Guide 4-43 . Mobility Groups The primary purpose of a Mobility Group in the Cisco Unified Wireless Network (CUWN) is to share client information between WLAN controllers. as shown in Figure 4-26.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Wireless LAN Controller Configuration description cr23-5508-1 switchport trunk encapsulation dot1q switchport trunk native vlan 801 switchport trunk allowed vlan 111-115.313.313.317 switchport mode trunk switchport nonegotiate load-interval 30 carrier-delay msec 0 hold-queue 2000 in hold-queue 2000 out end Example 4-2 Example of WLAN Controller 3750 Stack Interface Configuration interface GigabitEthernet1/0/10 description Connected to cr23-5508-1 port Gi0/0/1 via CG#11 switchport trunk encapsulation dot1q switchport trunk native vlan 801 switchport trunk allowed vlan 111-115. WLAN controller is connected to a 3750E stack that acts as a services block for the remote site. In other words.317 switchport mode trunk switchport nonegotiate load-interval 30 carrier-delay msec 0 udld port mls qos trust cos channel-group 11 mode on hold-queue 2000 in hold-queue 2000 out end Remote Site The remote site WLAN controller and wired network connection is the same as that used in the main site.317 switchport mode trunk switchport nonegotiate load-interval 30 carrier-delay msec 0 udld port mls qos trust cos channel-group 11 mode on hold-queue 2000 in hold-queue 2000 out end interface GigabitEthernet2/0/10 description Connected to cr23-5508-1 port Gi0/0/2 via CG#11 switchport trunk encapsulation dot1q switchport trunk native vlan 801 switchport trunk allowed vlan 111-115. The default Mobility Group Name is created in the Controller General configuration page.313.

Because this design includes supporting guest access tunneling for users at the remote site. This Mobility Group has been configured to provide guest access tunneling and is discussed later in this chapter. The remote site WLAN controller Mobility Group membership configuration uses a different mobility group name. Figure 4-27 cr23-5508-1 Mobility Group Members Medium Enterprise Design Profile Reference Guide 4-44 . It can be seen that the Mobility Group membership has two main members for the two WLAN controllers that are providing WLAN access within the main site. These WLAN controllers are also members of another Mobility Group GUEST_ACCESS. The IP address and MAC address information of other controllers in that Mobility Group must be entered manually. There is no point of providing seamless roaming between controllers when there is no seamless WLAN coverage between APs connected to those controllers. and does not include either of the main site WLAN controllers. Figure 4-27 and Figure 4-28 show the Mobility Group membership information for both main site WLAN controllers. along with the necessary IP address and MAC address information for that controller. The reason for it not including either of the main site WLAN controllers is because it is not expecting to support seamless roaming between the remote site and main site.Chapter 4 Wireless LAN Controller Configuration Medium Enterprise Design Profile (MEDP)— Mobility Design Figure 4-26 cr23-5508-1 Mobility Group Definition The default Mobility Domain Name is automatically entered in the Mobility Group membership for that controller. the GUEST_ACCESS mobility group-member information also appears on the remote site WLAN controller.

and CCKM has been added to 802. Most WLAN clients should now support WPA2. The key point to note on this tab is the security policy that has been set under the security tab. Medium Enterprise Design Profile Reference Guide 4-45 .1X+CCKM. the remainder of the WLAN configuration uses default settings. Figure 4-29 Staff Data WLAN Apart from setting DHCP as required in the advanced settings.1X as it provides faster roaming for WLAN clients that support CCKM. Unless static IP address are needed. and the WLAN controller interface that the WLAN has been mapped to.1X to secure the WLAN connection. obtaining IP addresses using DHCP is recommended as a best practice. while using the AAA features of 802.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Wireless LAN Controller Configuration Figure 4-28 cr23-5508-2 Mobility Group Members WLAN Configuration Staff Data WLAN Figure 4-29 shows the general WLAN configuration for the staff data WLAN network. The security configuration recommended is to use WPA2 with 802.

The QoS requirements for the WLAN are that it be set for the platinum profile and that WMM be required. Apart from the QoS differences. in order to ensure optimal VoWLAN capacity and performance. The WLAN client traffic from the Guest WLAN is tunneled by the WLAN controller to the anchor WLAN. The VoWLAN clients (7921 and 7925) support WPA and CCKM. The security configuration recommended is to use WPA with CCKM. Medium Enterprise Design Profile Reference Guide 4-46 . and the level of security provided by Enterprise WPA is sufficient for VoWLAN traffic. and the WLAN controller interface that the WLAN has been mapped to. The radio policy of this WLAN is to use the 5GHz (802. Figure 4-30 Staff Voice WLAN Guest Access WLAN Although the configuration for the Guest WLAN indicates that it has been assigned to the management interface. the true interface used by the Guest WLAN is on the anchor WLAN controller that is located in the DMZ. The key point to note on this tab is the security policy that has been set under the security tab.11a) band for VoWLAN support. the remainder of the WLAN configuration is the same as the “Staff Data WLAN” section on page 4-45. CCKM provides optimal roaming performance for voice calls.Chapter 4 Wireless LAN Controller Configuration Medium Enterprise Design Profile (MEDP)— Mobility Design Staff Voice WLAN Figure 4-30 shows the general WLAN configuration for the Staff VoWLAN network.

The address chosen for the mobility anchor is the management address of the anchor WLAN controller that is located in the DMZ. the creation of a mobility anchor for the Guest WLAN. Figure 4-32 WLAN Mobility Anchor Selection Medium Enterprise Design Profile Reference Guide 4-47 . namely.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Wireless LAN Controller Configuration Figure 4-31 Guest WLAN Figure 4-32 and Figure 4-33 show the first steps in configuring Guest Access Tunneling for the WLAN.

Figure 4-34 Anchor Guest WLAN Figure 4-35 Anchor WLAN Controller Interfaces Medium Enterprise Design Profile Reference Guide 4-48 . The WLAN configuration must be exactly the same as the home controller.Chapter 4 Wireless LAN Controller Configuration Medium Enterprise Design Profile (MEDP)— Mobility Design Figure 4-33 Mobility Anchor Selection Figure 4-34 shows the DMZ anchor Guest WLAN configuration. and shown in Figure 4-34 and Figure 4-35. except that it has a real local interface.

gold. silver and bronze) on the WLAN controller must have its Wired QoS Protocol Type set to 802. but in this case the Mobility Anchor is its own local management address. There are two ways to achieve this reclassification: 1.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Wireless LAN Controller Configuration The WLAN on the DMZ anchor WLAN controller must also be configured with a mobility anchor. the translation between CUWN policy and network policy will occur automatically. This procedure configures the WLAN controller to set the 802. each of the four QoS profiles (platinum. as shown in Figure 4-36. the CoS value assigned would be 0. Therefore. Learning the QoS policy that was applied within the CUWN. 2. All other QoS profile settings can remain at the defaults (an example is shown in Figure 4-37).com/en/US/docs/solutions/Enterprise/Mobility/vowlan/41dg/vowlan41dg-book.1p marking of the frames sent from the WLAN controller to reflect QoS policy for that WLAN. This means that client traffic leaving the CUWN may need to be reclassified based on the network QoS policy. but it does not change the IP QoS classification (DSCP) of the client traffic. if the IP packet was from a platinum WLAN and had a DSCP value of EF. If the same packet had been on a silver WLAN. The latter method is preferable as it requires less configuration and less policy maintenance (the policy only needs to be maintained on WLAN controllers and not on the connected switches as well). To achieve this. For more information on WLAN QoS refer to the Voice over WLAN Design Guide at the following URL: http://www.1p. For example. as long as the WLAN controller is connected to a switch network that is configured to trust CoS and maintain a translation table between CoS and DSCP for its network.cisco. the WLAN controller would use a CoS of 5 in the frame header.html Medium Enterprise Design Profile Reference Guide 4-49 . because this should be aligned with the network policy. Figure 4-36 Anchor Guest WLAN Mobility Anchor WLAN QoS The Cisco Unified Wireless Network (CUWN) prioritizes traffic based on the QoS profiles applied to each WLAN. Applying policy at each of the network SVIs that connect the WLAN controller to the network.

establishing the connection between APs and the correct WLAN controller is a key component of the design. over the air. the APs used DHCP to discover a WLAN controller appropriate for their location.Chapter 4 Access Point Configuration Medium Enterprise Design Profile (MEDP)— Mobility Design Figure 4-37 Wired QoS Protocol Configuration Access Point Configuration The configuration and software management of Cisco Unified Wireless Network access points is determined by the WLAN controller they ultimately join. or static configuration). secondary. and tertiary WLAN controllers within that mobility group.com/en/US/partner/docs/wireless/technology/controller/deployment/guide/dep. it learns about all of the WLAN controllers in the default mobility group of the discovered WLAN controller.com/en/US/partner/tech/tk722/tk809/technologies_configuration_example09186a00 808714fe. The CUWN provides many different options to allow APs to discover the correct WLAN controller (DHCP.cisco. An AP can be configured for preferred primary.html For the purposes of testing in this design. Medium Enterprise Design Profile Reference Guide 4-50 . and its preferred fail over WLAN controller (secondary controller). DNS. Therefore. These are detailed in the Deploying Cisco 440X Series Wireless LAN Controllers document at the following URL: http://www.shtml Once an AP is in communication with a WLAN controller that has been defined using a discovery mechanism. Figure 4-38 shows an example of this where the AP is configured with its preferred WLAN controller (primary controller).cisco. The configuration of DHCP for APs is discussed in the DHCP OPTION 43 for Lightweight Cisco Aironet Access Points Configuration Example document at the following URL: http://www.

An example of this configuration. In situations where the APs are expected to fail over to a WLAN controller outside of its primary WLAN controllers mobility group. By default. some basic configuration changes must be implemented. with the other WLAN controller used solely as a back-up controller. all the APs on the site could be configured to prefer one WLAN controller as primary. on a per building basis. rather than with one of them sitting idle. thereby ensuring that all controllers are actively engaged in passing traffic. For example. is shown in Figure 4-39. the AP must be configured with the IP address and name of that fail over WLAN controller. The advantage of this approach is that a developing controller failure would potentially be discovered more readily if both controllers were always actively carrying some degree of traffic load. and in order to use these access points to provide outdoor coverage as root access points. An alternative configuration would be to spread the AP load across both WLAN controllers. Figure 4-39 AP Failover to a WLAN Controller Outside the Mobility Group AP 1520 Configuration AP1520 access points require somewhat further configuration over and above what has been shown in the preceding paragraphs. rather than just the WLAN controller name. Medium Enterprise Design Profile Reference Guide 4-51 . AP1520 access points are configured for outdoor mesh operation. from the remote site.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Access Point Configuration Figure 4-38 AP Controller Preferences The configuration of access point WLAN controller preference will determine the fail over models for the WLAN deployment.

Release 6.com/en/US/docs/wireless/technology/meshhttps://www.scribd.com/design/guide/MeshAP_60. once the access point has joined the controller. In the Medium Enterprise Design Profile mobility design. MAPs and RAPs are explained in much more detail in the Cisco Wireless Mesh Access Points Design and Deployment Guide. but any WLAN controllers that are defined as secondary or tertiary as well. as shown in Figure 4-40.0 at the following URL: http://www. Figure 4-40 Adding the AP1520 MAC Address to the WLAN Controller Note that MAC addresses must be defined to all WLAN controllers that an AP1520 access point may join. In order to reconfigure the AP1520 to be a RAP.com/en/US/docs/wireless/technology/meshhttps://www.scribd.com/design/guide/MeshAP_60. You can also validate the MAC addresses of AP1520 access points externally using Cisco ACS.0 at the following URL: http://www. This includes not only WLAN controllers defined as primary controllers. For complete details on how to do this.cisco. This can be done by adding the BVI MAC of the access point (this is the MAC address printed on a label on the outside of the access point) via the Security > AAA > MAC Filtering GUI panel.cisco. None of the other parameters need to be changed on this screen. Release 6.html#wp11941 49 Configuring the AP1520 as a Root Access Point (RAP) AP1520 series access points are shipped with a default outdoor Mesh Access Point (MAP) configuration. refer to the Cisco Wireless Mesh Access Points Design and Deployment Guide. as shown in Figure 4-41. the AP1520 series access point is used as an outdoor root access point (RAP)1.Chapter 4 Access Point Configuration Medium Enterprise Design Profile (MEDP)— Mobility Design Adding the AP1520 MAC Address to the WLAN Controller AP1520 series access points will not join a WLAN controller unless the MAC address of the access point has been defined to the WLAN controller. 1. the AP role is changed to “RootAP” in the Wireless > Access Points > All APs > Details > Mesh configuration panel on the WLAN controller.html#wp1194149 Medium Enterprise Design Profile Reference Guide 4-52 .

Enabling this once on the WLAN controller enables back haul client access for all AP1520 series access points that join this controller. Medium Enterprise Design Profile Reference Guide 4-53 . In order to enable the use of this interface for 5 GHz client traffic. the 5 GHz radio interface on the AP1522 is enabled only as a back haul interface. Failing to find another AP1520 neighbor or failing to connect to a WLAN controller via the 5 GHz interface causes the AP1520 to begin to scan for reassignment of the primary backhaul. if the Ethernet port is “down” on a RAP. Figure 4-42 Enabling Backhaul Client Access Primary Backhaul Scanning Under normal circumstances.Chapter 4 Medium Enterprise Design Profile (MEDP)— Mobility Design Access Point Configuration Figure 4-41 Setting the AP Role 5 GHz Backhaul Client Access By default. and will not allow any 5 GHz clients to associate. However. the AP1520 will attempt to use the 5 GHz radio interface as the primary backhaul for 15 minutes. it must be enabled using the Back haul Client Access check box on the WLAN controller’s Wireless > Mesh configuration panel. as shown in Figure 4-42. beginning with the Ethernet interface. an AP1520 configured as a root AP (RAP) communicates with the WLAN controller via its wired Ethernet interface. or a RAP fails to connect to a controller when its Ethernet port is “up”.

with administrative access granted and privileges assigned as necessary via the use of appropriate WCS user groups settings. maintenance. monitoring. Common sense should be used when assigning user privileges. and detailed administration of WCS). This larger group can be assigned as WCS “admin” users or assigned to the “superuser” group. alternate user credentials should be created. In this case. The password for this root user should be protected and only known by those who are responsible for the overall Medium Enterprise Design Profile mobility design and with a real need to know (for example.cisco.0/configuration/guide/6_0manag. which allows access to all WCS functions. After installing WCS in the main site. This can be especially useful if the neighbor AP1520 is attached to the wired network via a different Ethernet switch. This is an acceptable alternative if there is no need to support 5 GHz clients within the outdoor perimeter of the buildings where AP1520s are installed. • WCS Configuration Configuring WCS to allow basic management of WLAN controllers for each site in the Medium Enterprise Design Profile mobility design is a relatively straightforward process. each WLAN controller must be added to WCS. while only a very small set of key technical personnel should have access to the actual WCS root user ID and password. For example. Release 6.html#wp1041451 Once the WLAN controllers are properly defined and reachable from WCS. those personnel responsible for the actual installation. Within 15 minutes of the failed Ethernet port being repaired.4 GHz is never used for backhaul purposes by the AP1520). Chapter 7 of the Cisco Wireless Control System Configuration Guide.Chapter 4 WCS Configuration Medium Enterprise Design Profile (MEDP)— Mobility Design In most cases we did not find this behavior to cause any issues in our validation and we recommend that it be left as is. the AP1520 should revert back to operation over the Ethernet connection. you may wish to assign the ability to make WCS configuration changes to a somewhat larger audience. but the access points and devices that connect through them. at the above URL. WCS Users and User Groups By default. as described in the Cisco Wireless Control System Configuration Guide at the following URL: http://www.cisco.com/en/US/docs/wireless/wcs/6. These capabilities are far too numerous to be described here.html) provides comprehensive instructions for configuring users and group privileges on the WCS server.com/en/US/docs/wireless/wcs/6. This chapter also contains a complete listing of the user groups available in WCS as well as the privileges contained in each group. Use AP 1250 access points installed within traditional weatherproof outdoor NEMA-rated enclosures (supplied by Cisco partners) to provide outdoor coverage. the network administrator can begin to use the multitude of configuration. the connected AP1520 can establish a connection to another AP1520 in the same building or at an adjacent building using the 5 GHz backhaul. For these users and others who require routine administrative access to WCS. We found this behavior beneficial in that should a switch port for an AP 1520 series access point go down. you may either: • Disable the use of 5 GHz entirely on the AP1520 series access point. backhaul operation will not occur over any wireless medium (2. WCS provides for a single root user. If you do not wish to allow primary backhaul scanning. and reporting options available under the WCS to begin to manage not only the WLAN controllers themselves. Most users who are only interested in viewing the information available to them on WCS will not need more than the ability Medium Enterprise Design Profile Reference Guide 4-54 .0 (http://www. but a comprehensive description of these capabilities and how to enable them can be found in the Cisco Wireless Control System Configuration Guide.0/configuration/guide/6_0ctrlcfg.

Chapter 4

Medium Enterprise Design Profile (MEDP)— Mobility Design WCS Configuration

to simply monitor network activity in WCS. For these users, the privileges accorded to them by the WCS System Monitoring or Monitor Lite user groups may be all that is required, depending upon the specific WCS monitoring functions you wish to grant those users.

WCS Virtual Domains
While WCS user groups define the WCS functionality users have been granted, WCS virtual domains allow the network administrator logically partition the WCS management domain and limit management access. In this way, the group of resources that the WCS functionality assigned to a user group may be exercised against is restricted. A WCS virtual domain consists of a set of assigned devices and maps, and restricts a user's scope to only information that is relevant to those devices and maps. Through an assigned virtual domain, users are only able to use WCS functionality against a predefined subset of the devices managed by WCS. Users can be assigned one or more virtual domains; however, only one assigned virtual domain may be active for a user at WCS login. The user can change the current virtual domain in use by selecting a different permitted virtual domain using the WCS Virtual Domain drop-down menu. The WCS virtual domain can be used to limit the user's ability to even view certain resources inside the WCS that are not contained in their active assigned virtual domain. For example, the site manager for a medium enterprise may have the ability to view and report on certain characteristics of wireless assets for his site due to his WCS user account being assigned to an appropriate user group permitting this level of WCS functionality. However, the virtual domain that this site manager is assigned to may only allow such functionality to be exercised against these assets if they are located within his site. Thus, if the site manager for site “A” attempted to use WCS to discover or manage wireless infrastructure located in site “B”, his assigned virtual domain might not allow the ability to manage or even view resources on site “B”. Administrative personnel with system-wide responsibilities, on the other hand, could be assigned a virtual domain that includes all resources in the system (i.e., all sites), and could exercise the functionality assigned to them by their WCS user group against any of these resources. In this way, WCS virtual domain assignment can be useful in prevent unnecessary inter-site WCS traffic, especially traffic whose nature might be based more upon curiosity rather than actual need.

Note

WCS user groups assign what actions a user can take against a resource, whereas WCS virtual domains determine what resources those user-group actions can be applied towards. There are two basic steps necessary to enable the use of virtual domains within WCS:
1.

A virtual domain must be created, and we must assign the resources we wish to include in the virtual domain. Figure 4-43 provides an illustration of how controller resources were assigned during lab testing for the “main site” virtual domain.

Medium Enterprise Design Profile Reference Guide

4-55

Chapter 4 WCS Configuration

Medium Enterprise Design Profile (MEDP)— Mobility Design

Figure 4-43

Assigning WLAN Controller Resources to the Main Site Virtual Domain

The process for creating and assigning network resources to the virtual domain is detailed in “Chapter 20, “Virtual Domains” of the WCS Configuration Guide, Release 6.0, found at the following URL: http://www.cisco.com/en/US/docs/wireless/wcs/6.0/configuration/guide/6_0virtual.html#wp1040002
2.

The virtual domain must be assigned to the user. The process for assigning the main site virtual domain to the “main1” user is shown in Figure 4-44. This process is detailed in a step-by-step fashion in “Chapter 7, Managing WCS User Accounts” at the following URL:

http://www.cisco.com/en/US/docs/wireless/wcs/6.0/configuration/guide/6_0manag.html#wp1097733
Figure 4-44 Assigning the Virtual Domain to a User

Medium Enterprise Design Profile Reference Guide

4-56

Chapter 4

Medium Enterprise Design Profile (MEDP)— Mobility Design WCS Configuration

Note

It is important to note that in Release 6.0, non-root WCS virtual domain users cannot access WCS functions listed under the Services > Mobility Services main menu. This includes wired-switch and device location. Refer to Understanding Virtual Domains as a User, WCS Configuration Guide 6.0 http://www.cisco.com/en/US/docs/wireless/wcs/6.0/configuration/guide/6_0virtual.html#wp1120787 for a complete list of WCS functions that are not available in non-root virtual domains. Additional information on creating WCS users, user groups, and virtual domains can be found in the “Context-Aware Service Design” chapter of the Cisco Service Ready Architecture for Schools Design Guide at the following URL: http://cisco.com/en/US/docs/solutions/Enterprise/Education/SchoolsSRA_DG/SchoolsSRA_chap6.htm l#wp1054537

Reference Documents
A cornerstone of a successful design relies on the knowledge of established best practices. Thus, it is highly recommended that you become familiar with the following general best practice deployment recommendations for Cisco Unified Wireless Networks:

Enterprise Mobility Design Guide 4.1 http://www.cisco.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/emob41dg-wrapper.ht ml Cisco 802.11n Design and Deployment Guidelines http://www.cisco.com/en/US/solutions/collateral/ns340/ns394/ns348/ns767/white_paper_80211n_ design_and_deployment_guidelines.html Voice over Wireless LAN 4.1 Design Guide http://www.cisco.com/en/US/docs/solutions/Enterprise/Mobility/vowlan/41dg/vowlan41dg-book.h tml Cisco Radio Resource Management http://www.cisco.com/en/US/tech/tk722/tk809/technologies_tech_note09186a008072c759.shtml Cisco Wireless Mesh Access Point Design and Deployment Guide, Release 6.0 http://www.cisco.com/en/US/docs/wireless/technology/meshhttps://www.scribd.com/design/guide/MeshAP_60.html

• •

A successful deployment also involves strong knowledge of how to set key infrastructure configuration procedures. The following documents provide comprehensive configuration guidance and should be referenced as needed:

Cisco Wireless LAN Controller Configuration Guide, Release 6.0 http://www.cisco.com/en/US/docs/wireless/controller/6.0/configuration/guide/Controller60CG.ht ml Cisco Wireless Control System Configuration Guide, Release 6.0 http://www.cisco.com/en/US/docs/wireless/wcs/6.0/configuration/guide/WCS60cg.html

Medium Enterprise Design Profile Reference Guide

4-57

Chapter 4 WCS Configuration

Medium Enterprise Design Profile (MEDP)— Mobility Design

Additional product information on the Cisco wireless infrastructure discussed in this chapter can be found at the following locations:

Cisco 5508 Wireless Controller http://www.cisco.com/en/US/prod/collateral/wireless/ps6302/ps8322/ps10315/data_sheet_c78-521 631.html Cisco 1140 Series 802.11n Access Point http://www.cisco.com/en/US/products/ps10092/index.html Cisco 1250 Series 802.11n Access Point http://www.cisco.com/en/US/products/ps8382/index.html Cisco 1250 Series Antenna Options http://www.cisco.com/en/US/prod/collateral/wireless/ps7183/ps469/at_a_glance_c45-513837.pdf Cisco Aironet 1520 Lightweight Outdoor Access Point Ordering Guide http://www.cisco.com/en/US/prod/collateral/wireless/ps5679/ps8368/product_data_sheet0900aecd 8066a157.html Cisco Wireless Control System (WCS) http://www.cisco.com/en/US/prod/collateral/wireless/ps5755/ps6301/ps6305/product_data_sheet0 900aecd802570d0.html Cisco Wireless Control System Virtual Domains http://www.cisco.com/en/US/prod/collateral/wireless/ps5755/ps6301/ps6305/brochure_c02-47433 5.html Cisco Wireless Control System Navigator http://www.cisco.com/en/US/products/ps7305/index.html

• • • •

Medium Enterprise Design Profile Reference Guide

4-58

CH A P T E R

5

Medium Enterprise Design Profile (MEDP)—Network Security Design
Security Design
As medium enterprises embrace new communication and collaboration tools, transitioning to more Internet-based, media-rich applications, a whole new set of network security challenges arise. Medium enterprise network infrastructures must be adequately secured to protect employees from harmful content, to guarantee confidentiality of private data, and to ensure the availability and integrity of the systems and data. Providing a safe and secure network environment is a top responsibility for enterprise administrators. This chapter describes how the Medium Enterprise Design Profile sets the foundation for safe and secure enterprise networks by leveraging the proven design and deployment guidelines of the Cisco SAFE Security Architecture. The Medium Enterprise Design Profile is a well-designed and validated network reference design that enables medium enterprises to deliver all of the services required for an enhanced business environment. Within the Cisco Medium Enterprise Design Profile, the service fabric network provides the foundation on which all solutions and services are built to solve the business challenges facing medium enterprises. These business challenges include borderless access, secure mobile workforce, operational efficiencies, and user experience. The network fabric consists of four distinct components: LAN/WAN, security, mobility, and unified communications, as shown in Figure 5-1.
Figure 5-1 Service Fabric Design Model

Service Fabric Design Model

Mobility

Security

Unified Communications

Medium Enterprise Design Profile Reference Guide

228538

Local Area Network (LAN)

Wide Area Network (WAN)

5-1

Chapter 5 Security Design

Medium Enterprise Design Profile (MEDP)—Network Security Design

The Medium Enterprise Design Profile includes security to protect the infrastructure and its services to provide a safe and secure online business environment. This design profile leverages the proven design and deployment guidelines of the Cisco SAFE Security Reference Architecture to secure the service fabric by deploying security technologies throughout the entire network solution to protect employees from harmful non-business content, to guarantee the confidentiality of the enterprise and employees private data, and to ensure the availability and integrity of the systems and data. Protecting the infrastructure and its services requires implementation of security controls capable of mitigating both well-known and new forms of threats. Common threats to enterprise environments include the following:

Service disruption—Disruption to the infrastructure, applications, and other business resources caused by botnets, worms, malware, adware, spyware, viruses, denial-of-service (DoS) attacks, and Layer 2 attacks Network abuse—Use of non-approved applications by employees, peer-to-peer file sharing and instant messaging abuse, and access to non-business related content Unauthorized access—Intrusions, unauthorized users, escalation of privileges, IP spoofing, and unauthorized access to restricted resources Data loss—Loss or leakage of private data from servers and endpoints while in transit or as a result of spyware, malware, key-loggers, viruses, and so on Identity theft and fraud—Theft of personal identity or fraud on servers and end users through phishing and E-mail spam

• • • •

The Medium Enterprise Design Profile accommodates a main site and one or more remote sites of various sizes, interconnected over a metro Ethernet or managed WAN service. Each of these sites may contain one or more buildings of varying sizes, as shown in Figure 5-2.

Medium Enterprise Design Profile Reference Guide

5-2

Chapter 5

Medium Enterprise Design Profile (MEDP)—Network Security Design Security Design

Figure 5-2

Medium Enterprise Design Profile Network Overview
Large Building Medium Building Small Building Extra Small Building

Services Block

Data Center

Main Site

QFP

Internet Edge

QFP

WAN

PSTN

Internet

Services Block

Services Block Services Block

Data Center

Data Center Data Center

Remote Small Site

Remote Large Site

Remote Medium Site

Operating on top of this network are all the services used within the enterprise environment, such as safety and security systems, voice communications, business databases, ordering systems, payroll, accounting and customer relationship management (CRM) applications, and so on. The core of these services are deployed and managed at the main site, allowing the enterprise to reduce the need for separate services to be operated and maintained at various remote locations. These centralized systems and applications are served by a data center at the main site.

Medium Enterprise Design Profile Reference Guide

5-3

229404

Large Building

Medium Building

Small Building

Medium Building

Small Building

Chapter 5 Security Design Medium Enterprise Design Profile (MEDP)—Network Security Design The security design uses a defense-in-depth approach where multiple layers of security protection are integrated into the architecture. stateful firewall inspection. Figure 5-3 Main Large Site Medium Enterprise Design Profile Network Security Design Overview Large Building Medium Building Small Building Extra Small Building IP IP IP IP Service Block Secure Mobility WAE Wireless LAN Controller NAC Server QFP Internet Data Center www M V SRST/Video Cisco ACS Gateway Appliance NAC Manager Video Surveillance Media Server Web Security Core QFP Anchor WLC Email Security Web Email Server Server Internet Edge Cisco UCM Cisco Security Intelligence Operation SensorBase MetroE HDLC Service Block Core Core Service Block Small Data Center Small Data Center Service Block Large Building Medium Building Small Building Medium Building Small Building Small Building Remote Large Site Remote Medium Site Remote Small Site The following security elements may be included in the Medium Enterprise Security design as shown in Figure 5-3: • • • • • • • Endpoint security—Desktop and server endpoint protection for day-zero attack protection. control plane. Dynamic ARP inspection. data loss prevention. as shown in Figure 5-3. and system and interface-based redundancy Medium Enterprise Design Profile Reference Guide 5-4 229405 IP IP IP IP IP IP Serverfarm . Various security products and technologies are combined to provide enhanced security visibility and control. and signature-based antivirus Network foundation protection (NFP)—Device hardening. and management plane protection throughout the entire infrastructure to maximize availability and resiliency Catalyst Integrated Security Features—Access layer protection provided by port security. intrusion prevention and global correlation. and DHCP Snooping Threat detection and mitigation—Intrusion prevention and infrastructure based network telemetry to identify and mitigate threats Internet access—E-mail and web security. and granular Internet access control Cisco Video Surveillance—Monitor activities throughout the enterprise environment to prevent and deter safety incidents Enhanced availability and resiliency—Hardened devices and high availability design to ensure optimal service availability. IP Source Guard.

smartphones. tradeoffs are made to simplify operations and reduce costs where needed.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Security Design • • Unified communications—Security and emergency services. and other malicious • software – Protecting employees from harmful content – Enforcing E-mail and web browsing policies to prevent identity theft and fraud – Blocking command and control traffic from infected internal bots to external hosts • Data center protection – Ensuring the availability and integrity of centralized applications and systems – Protecting the confidentiality and privacy of proprietary and sensitive data • Network access security and control – Securing the access edges – Enforcing authentication and role-based access for users residing at the main site and remote sites – Ensuring that systems are up-to-date and in compliance with the enterprise’s network security policies • Secure mobility – Providing secure. Therefore. and role-based access control and device security compliance via Cisco Network Admission Control (NAC) Appliance Secure mobility – Always-on VPN protection for PC-based and smartphone mobile users – Persistent and consistent policy enforcement independently from user location – Enforcement of client firewall policies – Optimal gateway selection to ensure best connectivity – Integration with web security and malware threat defense systems deployed at the enterprise • premises – Consolidated SaaS access control The Medium Enterprise Design Profile recognizes that cost and limited resources may be common limiting factors. and data loss Internet perimeter protection – Ensuring safe connectivity to the Internet – Protecting internal resources and users from botnets. and role-based access to all mobile users Medium Enterprise Design Profile Reference Guide 5-5 . persistent connectivity to all mobile employees on laptops. enhanced 911 support. and other mobile platforms – Enforcing encryption. architecture topologies and platforms are carefully selected to increase productivity while minimizing the overall cost and operational complexities. malware. In certain cases. The Medium Enterprise Design Profile focuses on the following key areas for securing the service fabric within medium enterprises: • Network foundation protection (NFP)—Ensuring the availability and integrity of the network infrastructure by protecting the control and management planes to prevent service disruptions network abuse. viruses. unauthorized access. authentication. conferencing and collaboration for planning and emergency response Network access control—Authentication and policy enforcement via Cisco Identity-Based Networking Services (IBNS).

and accounting (AAA) with Terminal Access Controller Access Control System (TACACS+) or Remote Authentication Dial-In User Service (RADIUS) to authenticate access. see the Cisco SAFE Reference Guide at the following URL: http://www. switches. these key security areas create a defense-in-depth solution for protecting medium enterprises from common security threats such as service disruption. • Device resiliency and survivability – Disable unnecessary services.com/go/safe. botnets. and networks that are not supposed to be propagated are never advertised. – Log status changes of neighbor sessions to identify connectivity problems and DoS attempts on routers. These infrastructure devices must be properly hardened and secured to maintain continued operation and access to these services. authorize actions. To ensure the availability of the medium enterprise network infrastructure. the Medium Enterprise Design Profile leverages the Network Foundation Protection best practices for the following areas: • Infrastructure device access – Restrict management device access to authorized parties and via only authorized ports and protocols. – Enforce authentication. – Enable traffic storm control. – Display legal notification banners. and log all administrative access. – Keep local device statistics. and identity theft and fraud. • Routing infrastructure – Restrict routing protocol membership by enabling Message-Digest 5 (MD5) neighbor authentication and disabling default interface membership. The design guidelines and best practices for each of the above security focus areas are detailed in the following sections. – Enforce idle and session timeouts.cisco. – Implement control plane policing (CoPP). and module redundancy for the resiliency and survivability of routers and switches and to ensure network availability. system. – Disable unused access lines. • Network telemetry Medium Enterprise Design Profile Reference Guide 5-6 .Chapter 5 Network Foundation Protection Medium Enterprise Design Profile (MEDP)—Network Security Design – Delivering consistent protection to all mobile employees from viruses. – Ensure confidentiality by using secure protocols such as Secure Shell (SSH) and HTTPS. and other infrastructure network devices that keep the applications and services running. – Implement topological. For more detailed information on each of these areas. network abuse. – Enforce route filters to ensure that only legitimate networks are advertised. data loss. and other malicious software – Ensuring a persistent enforcement of enterprise network security policies to all users – Making sure systems comply with corporate policies and have up-to-date security Together. malware. authorization. Network Foundation Protection Medium enterprise networks are built with routers. unauthorized access.

using Network Address Translation (NAT) to hide management addresses. – Monitor CPU and memory usage on critical systems.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Network Foundation Protection – Enable Network Time Protocol (NTP) time synchronization. Dynamic ARP Inspection. – Disable VLAN dynamic trunk negotiation on user ports. – Protect the Spanning Tree Protocol (STP) domain with BPDU Guard and STP Root Guard.html. Unicast Reverse Path Forwarding (uRPF). – Secure management servers and endpoints with endpoint protection software and operating system (OS) hardening best practices.cisco. Syslog. – Use a dedicated VLAN ID for all trunk ports. and IP Source Guard. For more detailed information on the NFP best practices including configuration examples. Network Foundation Protection” in the Cisco SAFE Reference Guide at the following URL: http://www. – Explicitly configure trunking on infrastructure ports. – Provide secure in-band management access for systems residing at the remote sites by deploying firewalls and ACLs to enforce access controls.com/en/US/docs/solutions/Enterprise/Security/SAFE_RG/chap2. – Authenticate. – Implement Cisco Catalyst Infrastructure Security Features (CISF) including port security. • Network policy enforcement – Implement access edge filtering. • Switching infrastructure – Implement a hierarchical design. Medium Enterprise Design Profile Reference Guide 5-7 . – Disable unused ports and put them into an unused VLAN. and TACACS+/RADIUS accounting. segmenting the LAN into multiple IP subnets or virtual LANs (VLANs) to reduce the size of broadcast domains.or VLAN-based) to manage systems local to the main site. – Secure the OOB management access by enforcing access controls. using dedicated management interfaces or virtual routing and forwarding (VRF) tables. • Network management – Ensure the secure management of all devices and hosts within the enterprise network infrastructure. see “Chapter 2. DHCP Snooping. and IP Source Guard. – Use Per-VLAN Spanning Tree (PVST) to reduce the scope of possible damage. – Use all tagged mode for the native VLAN on trunks and drop untagged frames. – Collect system status and event information with Simple Network Management Protocol (SNMP). authorize. – If possible. – Ensure time synchronization by using NTP. – Enable NetFlow to monitor traffic patterns and flows. and using secure protocols such as SSH and HTTPS. – Enforce IP spoofing protection with access control lists (ACLs). implement a separate out-of-band (OOB) management network (hardware. and keep records of all administrative access.

prevent unauthorized access and block illegitimate traffic . System and interface-based redundancy Public Services DMZ Endpoint server protection.Chapter 5 Internet Perimeter Protection Medium Enterprise Design Profile (MEDP)—Network Security Design Internet Perimeter Protection The Medium Enterprise Design Profile assumes a centralized connection to the Internet at the headquarters or main site. Internet Access Email and web-security. Enforcement of Client Firewall Policies. control and management plane protection throughout the entireinfrastructure to maximize availability and resiliency Distribution Secure Mobility Always-on VPN protection for mobile users. routing security. Granular access control. Integration with web security and malware threat defense systems Internet Border Router Internet QFP Internet Perimeter Threat Detection and Mitigation Intrusion prevention and infrastructure based telemetry to identify and mitigate threats Core Internet Edge Internet Distribution Switch Cisco ASA Secure Mobility SensorBase WAN Edge www Web Security Anchor WLC Cisco Security Intelligence Operation MetroE QFP HDLC Web Server Email Security Email Server The Internet perimeter provides safe and secure centralized access to the Internet for employees and guest users residing at all locations. intrusion prevention. It also provides access to public services such as the company’s web portal and public services without compromising the confidentiality. Medium Enterprise Design Profile Reference Guide 5-8 229406 Enhanced Availability and Resiliency Hardened devices and high availability design ensures optimal service availability. Persistent and consistent policy enforcement independent of user location. firewall integration and IP spoofing protection to discard anomalous traffic flows. DDoS protection. as shown in Figure 5-4. Edge Protection Traffic filtering. This connection serves users at the main site as well as all remote sites or offices. Inline intrusion prevention and global correlation. Figure 5-4 Access Network Foundation Protection Device hardening. stateful firewall inspection. Common services typically provided by this connection include the following: • • • • E-mail and Internet web browsing for employees Hosting of a company’s web portal accessible to clients and partners over the Internet Secure remote access to the enterprise network for mobile users and remote workers Other services may also be provided using the same infrastructure The part of the network infrastructure that provides connectivity to the Internet is defined as the Internet perimeter. and availability of the resources and data of the enterprise. Stateful firewall inspection. application deep-packet inspection. integrity.

Systems residing within the DMZ should be hardened with endpoint protection software and OS hardening best practices. viruses. A WLC is located in the Internet perimeter DMZ. and to quickly react to contain them. mail server. Ethernet over IP (EoIP) tunneling is used between two wireless LAN controller (WLC) endpoints in the centralized network design. and so on. For more information on the wireless guest access solution. The Cisco ASA is configured to control or prevent incoming access from the Internet. The IPS module or appliance is responsible for identifying and blocking anomalous traffic and malicious packets recognized as well-known attacks. Traffic to and from this guest access WLAN is tunneled to the DMZ transparently. and data loss prevention (DLP) to detect the inappropriate transport of sensitive information. Public services DMZ—The company’s external Internet web portal. In addition. the Botnet Traffic Filter feature monitors network ports for rogue activity and detects and blocks traffic from infected internal endpoints. sending command and control traffic back to a host on the Internet. The WSA may also be configured to block certain Internet applications such as AOL Messenger. Intrusion prevention—An Advanced Inspection and Prevention Security Service Module (AIP SSM) on the Cisco ASA or a separate IPS appliance can be implemented for enhanced threat detection and mitigation. adware. The WSA enforces URL filtering policies to block access to websites containing non-business-related content or that are known sources of spyware. and other public facing servers and services are placed on a demilitarized zone (DMZ) for security and control purposes. the Internet perimeter should incorporate the following security functions: • Internet border router—The Internet border router is the gateway responsible for routing traffic between the enterprise and the Internet. The Internet firewall is responsible for restricting incoming access to the public services in the DMZ. to protect the enterprise web portal and other Internet public services. or other types of malware. and worms. • • • • • • Medium Enterprise Design Profile Reference Guide 5-9 . BitTorrent. The security appliance may also provide secure remote access to employees with the Cisco AnyConnect Secure Mobility client. This router provides the first line of protection against external threats and should be hardened according to the NFP best practices. see the Medium Enterprise Design Profile Mobility Design Guide. Guest access wireless LAN controller—The Cisco Unified Wireless LAN Guest Access option offers a flexible. It may be administered by the company’s IT staff or may be managed by the Internet service provider. preventing external users from directly accessing any internal servers and data. Skype. The ESA appliance also offers E-mail encryption to ensure the confidentiality of messages. easy-to-implement method for deploying wireless guest access via Ethernet over IP (RFC3378). The module or appliance may be configured to participate in Cisco IPS Global Correlation. and so on. and interfacing the traffic from these controllers to a firewall or border router. Internet firewall—A Cisco Adaptive Security Appliance (ASA) provides stateful access control and deep packet inspection to protect enterprise resources and data from unauthorized access and disclosure. with no visibility by. other traffic in the enterprise internal network. The anchor controller is responsible for terminating EoIP tunnels originating from centralized campus WLCs located in the services block. where it is referred to as an anchor controller. The DMZ acts as a middle stage between the Internet and enterprise private resources. the Cisco ASA Botnet Traffic Filter feature can be enabled to defend the enterprise against botnet threats. allowing the IPS to gain visibility on global threats as they emerge in the Internet. botnets. Once enabled. E-mail security—A Cisco IronPort C Series E-Mail Security Appliance (ESA) is deployed in the DMZ to inspect incoming and outgoing E-mails and eliminate threats such as E-mail spam. and controls outbound access from DMZ resources to the Internet. BitTorrent. Web security—A Cisco IronPort S Series Web Security Appliance (WSA) is deployed at the distribution switches to inspect HTTP and HTTPS traffic bound to the Internet. IPS may also be configured to help block certain Internet applications such as AOL Messenger.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Internet Perimeter Protection To provide secure access. and to control user traffic bound towards the Internet. or interaction with. Skype. IPS can be deployed either in inline or promiscuous mode.

DNS to DNS servers. HTTP/SSL from Cisco IronPort ESA). Internet Message Access Protocol (IMAP). Enable stateful inspection for the outbound protocols being used to ensure returning traffic is dynamically allowed by the firewall. and is responsible for the following: • • • • Preventing incoming access from the Internet Protecting public resources deployed in the DMZ by restricting incoming access to the public services and by limiting outbound access from DMZ resources out to the Internet Controlling user Internet-bound traffic Monitoring network ports for rogue activity and preventing infected internal endpoints from communicating with botnet masters or command and control hosts on the Internet The Cisco ASA should be configured to enforce access policies. Examples of the needed access policies include the following: • • • • Deny or control any connection attempts originating from the Internet to internal resources and subnets. keep track of connection status. The Internet Border Router Edge ACL Deployment section provides a sample configuration of an Internet Edge ACL. NetFlow. E-mail. and SNMP should be used to gain visibility on traffic flows. Restrict connections initiated from the DMZ to only necessary protocols and sources (DNS from DNS server. and securing the dynamic exchange of routing information. and other external threats. Allow outbound Internet access for users residing at any of the enterprise locations and for the protocols permitted by the organization’s policies. Syslog. network activity. For more information on how to secure the Internet border router. Allow user access to DMZ services such as the company’s web portal. and so on. that is. • • • Medium Enterprise Design Profile Reference Guide 5-10 . and system status.com/en/US/docs/solutions/Enterprise/Security/SAFE_RG/chap6. and other filtering mechanisms should be implemented for anti-spoofing and to block invalid packets. Simple Mail Transfer Protocol (SMTP). and inspect packet payloads. point-of-presence [POP]. protecting the management and control planes. HTTPS.cisco. SMTP to Mail Transfer Agent. Allow outbound SSL access to the Internet for devices requiring administrative updates such as SensorBase. and so on).Chapter 5 Internet Perimeter Protection Medium Enterprise Design Profile (MEDP)—Network Security Design The following subsections describe the design guidelines for implementing the above security functions.html. HTTP and HTTPs. IPS signature updates. This includes restricting and controlling administrative access. ACLs. The router acts as the first line of defense against unauthorized access. the Internet border router should be hardened and secured following the best practices explained in Network Foundation Protection. page 5-6. Internet Firewall A Cisco ASA firewall should be deployed at the Internet perimeter to protect the enterprise internal resources and data from external threats. Domain Name Service [DNS]). and domain name resolution (HTTP. Restrict inbound Internet access to the DMZ for the necessary protocols and servers (HTTP to web server. Enterprise Internet Edge” in the Cisco SAFE Reference Guide at the following URL: http://www. uRPF. In addition. SMTP from mail server. Internet Border Router Security The Internet border router provides connectivity to the Internet through one or more Internet service providers. distributed DoS (DDoS). see “Chapter 6. and so on.

In the Medium Enterprise Design Profile. • Medium Enterprise Design Profile Reference Guide 5-11 . a dedicated management interface should be used. HTTP. Implement NAT and Port Address Translation (PAT) to shield the internal address space from the Internet. The Botnet Traffic Filter on the Cisco ASA provides reputation-based control for an IP address or domain name. in cases where the firewall is managed in-band. page 5-6. • Note Whenever available. This is an effective way to combat botnets and other malware that share the same phone-home communications pattern. This includes restricting and controlling administrative access. identify the protocols and ports required before configuring the firewall ACLs. and NetFlow. and enabling firewall network telemetry with SNMP. securing dynamic exchange of routing information with MD5 authentication. local black). high availability is achieved by using redundant physical interfaces. Cisco ASA Botnet Traffic Filter The Cisco ASA Botnet Traffic Filter feature can be enabled to monitor network ports for rogue activity and to prevent infected internal endpoints from sending command and control traffic back to an external master host on the Internet. As an alternative. When deploying the Internet firewall. it is important to understand the traffic and policy requirements when selecting a firewall. and inspects traffic traversing the appliance to detect rogue traffic in the network. This represents the most cost-effective solution for high-availability. The Cisco ASA should also be hardened following the NFP best practices as described in Network Foundation Protection. The Cisco ASA Botnet Traffic Filter has three main components: • Dynamic and administrator blacklist data—The Botnet Traffic Filter uses a database of malicious domain names and IP addresses that is provided by Cisco Security Intelligence Operations. similar to the control that Cisco IronPort SensorBase provides for E-mail and web servers. TFTP. The dynamic filter compares the source and destination addresses of traffic against the IP addresses that have been discovered for the various lists available (dynamic black. Administrators can also configure their own local blacklists and whitelists. Traffic classification and reporting—Botnet Traffic Filter traffic classification is configured through the dynamic-filter command on the Cisco ASA. Syslog. SSH). However. a pair of firewall appliances can be deployed in stateful failover using separate boxes at a higher cost. and logs and reports the hits against these lists accordingly. the Botnet Traffic Filter alerts the system administrator of this through the regular logging process and can be automatically blocked. An appropriately-sized Cisco ASA model should be chosen so that it does not become a bottleneck. The Cisco Botnet Traffic Filter is integrated into all Cisco ASA appliances.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Internet Perimeter Protection • Prevent access to the anchor WLC deployed in the DMZ for guest access except for tunneled traffic coming from the centralized campus WLCs (UDP port 16666 and IP protocol ID 97) and traffic needed to manage it (SNMP. The Botnet Traffic Filter monitors all ports and performs a real-time lookup in its database of known botnet IP addresses and domain names. Based on this investigation. the Botnet Traffic Filter determines whether a connection attempt is benign and should be allowed. or is a risk and should be blocked. When internal clients are infected with malware and attempt to phone home to an external host on the Internet. This database is maintained by Cisco Security Intelligence Operations and is downloaded dynamically from an update server on the SensorBase network. local white. HTTPS.

and the Botnet Traffic Filter logs or drops any traffic to that IP address without having to inspect DNS requests. be sure to configure a domain name server for the Cisco ASA so that it can access the URL of the update server. the Cisco ASA uses Botnet Traffic Filter snooping instead of the regular DNS lookup to resolve static blacklist domain names in the following circumstances: • • The Cisco ASA DNS server is unavailable. the Cisco ASA looks inside the DNS packets for the domain name and associated IP address. and then sends a DNS request for that domain name and adds the domain name/IP address pairing to the DNS host cache. This database lists thousands of known bad domain names and IP addresses. This action is a background process. a static database can be used by manually entering domain names or IP addresses (host or subnet) that you want to tag as bad names in a blacklist. In addition to the dynamic database. viruses. The network is composed of the Cisco IronPort appliances. When enabled. DNS packet inspection with Botnet Traffic Filter snooping needs to be enabled. When a domain name is added to the static database. and does not affect your ability to continue configuring the Cisco ASA. Static blacklist entries are always designated with a Very High threat level. the IP address itself is supplied in the dynamic database. Dynamic Filter DNS snooping looks at User Datagram Protocol (UDP) DNS replies and builds a DNS reverse cache (DNSRC). 3. the Cisco ASA sends a syslog message reporting the suspicious activity and optionally drops the traffic if the Cisco ASA is configured to do so. which maps the IP addresses in those replies to the domain names they match. Medium Enterprise Design Profile Reference Guide 5-12 . the Botnet Traffic Filter adds the name and IP address to the DNS reverse lookup cache. Both databases can be used together. Cisco ASA. To use the domain names in the dynamic database. 2. Domain names or IP addresses can also be entered in a whitelist. or the dynamic database can be disabled and the static database can be used alone. Cisco also recommends that DNS packet inspection be enabled with Botnet Traffic Filter snooping. When using the dynamic database. the Botnet Traffic Filter uses DNS snooping in conjunction with DNS inspection. The database can be deleted by disabling and purging the database through the configuration. DNS snooping is configured via the Modular Policy Framework (MPF) policies The Botnet Traffic Filter uses two databases for known addresses. the Botnet Traffic Filter receives periodic updates from the Cisco update server on the Cisco IronPort SensorBase network. When the infected host starts a connection to the IP address of the malware site. and Cisco IPS appliances and modules installed in more than 100. Note The SensorBase network is an extensive network that monitors global E-mail and web traffic for anomalies.Chapter 5 Internet Perimeter Protection Medium Enterprise Design Profile (MEDP)—Network Security Design • Domain Name System (DNS) snooping—To map IP addresses to domain names that are contained in the dynamic database or local lists. The Cisco ASA uses this dynamic database as follows: 1.000 organizations worldwide. When the domain name in a DNS reply matches a name in the dynamic database. The database files are stored in running memory rather than Flash memory. the Cisco ASA waits one minute. malware. Note To use the database. A connection is initiated during the one minute waiting period before the Cisco ASA sends the regular DNS request. In some cases. and other abnormal behavior. providing a large and diverse sample of Internet traffic patterns.

full-featured intrusion prevention services to stop malicious traffic before it can affect the enterprise network. • Medium Enterprise Design Profile Reference Guide 5-13 . can affect throughput if not designed or sized appropriately. and one of the above circumstances occurs.com/en/US/prod/vpndevc/ps6032/ps6094/ps6120/botnet_index. This mode is less secure. see the following URL: http://www. however. If Botnet Traffic Filter snooping is not enabled. Unlike inline mode. when an infected host sends a DNS request for a name on the static database.html.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Internet Perimeter Protection If DNS snooping is used. but has little impact on traffic throughput. Traffic identified for IPS inspection cannot continue through the Cisco ASA without first passing through and being inspected by the AIP SSM. while the AIP SSM is analyzing the traffic. the Cisco ASA looks inside the DNS packets for the domain name and associated IP address and adds the name and IP address to the DNS reverse lookup cache. and so on. the AIP SSM can implement a blocking policy on a packet-by-packet basis. in promiscuous mode the AIP SSM can block traffic only by instructing the Cisco ASA to shun the traffic or by resetting a connection on the Cisco ASA. Intrusion Prevention IPS is responsible for identifying and blocking anomalous traffic and packets recognized as well-known attacks.cisco. The AIP SSM is supported on Cisco ASA 5510 and higher platforms. Skype. that traffic is not monitored by the Botnet Traffic Filter. This mode is the most secure because every packet that has been identified for inspection is analyzed before being allowed through. BitTorrent. An AIP SSM IPS module on the Cisco ASA Internet firewall or a separate IPS appliance can be implemented in the Internet perimeter for enhanced threat detection and mitigation. Integrating IPS on a Cisco ASA appliance using an AIP SSM provides a cost-effective solution for medium enterprise networks. The AIP SSM runs advanced IPS software providing proactive. Also. Also. For more information on the Cisco ASA Botnet Traffic Filter feature. The right side of Figure 5-5 shows the AIP SSM in promiscuous mode. a small amount of traffic might pass through the Cisco ASA before the AIP SSM can shun it. Note It is important to realize that a comprehensive security deployment should include Cisco Intrusion Prevention Systems (IPS) with its reputation-based Global Correlation service and IPS signatures in conjunction with the security services provided by the Cisco ASA security appliance such as Botnet Traffic Filter. IPS may also be configured to help block certain Internet applications such as AOL Messenger. This mode. The AIP SSM may be deployed in inline or promiscuous mode: • Inline mode—The AIP SSM is placed directly in the traffic flow (see the left side of Figure 5-5). Promiscuous mode—A duplicate stream of traffic is sent to the AIP SSM.

the participating IPS sensor receives threat updates from the Cisco SensorBase network at regular intervals. the sensor can look at a ping sweep and know that the source of the ping sweep does not have a negative reputation. IPS incorporates the global threat data into its system to detect and prevent malicious activity even earlier. 4. the Cisco ASA blocks all traffic in case of an AIP SSM failure. 6. Conversely. but later can look at another ping sweep and see that Medium Enterprise Design Profile Reference Guide 5-14 . 5. Although the AIP SSM runs as a separate application within the Cisco ASA. and dark nets. and that traffic is not passed on. IPS Global Correlation is an important improvement in the basic functions of IPS because it enables it to understand the world in which it operates—an understanding of who the attacker is and whether the attacker has a record of bad behavior. it is integrated into the traffic flow. uninspected. 2. 3. The AIP SSM card may be configured to fail open or close when the module becomes unavailable. (Inline mode only) Valid traffic is sent back to the ASA over the backplane. 7. allowing IPS to filter out the worst attackers before they have a chance to attack critical assets.Chapter 5 Internet Perimeter Protection Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-5 IPS Inline and Promiscuous Modes Inline Mode IPS Inspection Diverted Traffic Firewall Policy Outside Promiscuous Mode IPS Inspection Copied Traffic Firewall Policy Outside 227632 VPN Policy Inside VPN Policy Inside The recommended IPS deployment mode depends on the goals and policies of the enterprise. it may impact traffic throughput if not properly designed or sized. Cisco IPS Global Correlation The AIP SSM module on the Cisco ASA (or IPS appliance) may also participate in Cisco Global Correlation for further threat visibility and control. IPS inline mode is more secure because of its ability to stop malicious traffic in real-time. Traffic exits the Cisco ASA. IPS promiscuous mode has less impact on traffic throughput but is less secure because there may be a delay in reacting to the malicious traffic. When traffic is identified for IPS inspection on the Cisco ASA. malware outbreaks. Remote access VPN policies are applied (if configured). except for the management interface on the SSM itself. Traffic enters the ASA. including serial attackers. With Global Correlation. Conversely. Traffic is sent to the AIP SSM over the backplane. botnet harvesters. when configured to fail close. the sensor does not have to rely on just the data in the packet or connection to make a decision about the intent of the activity and determine whether the activity is malicious. The AIP SSM applies its security policy to the traffic and takes appropriate actions. The Cisco SensorBase network contains detailed information about known threats on the Internet. if the AIP SSM becomes unavailable. The AIP SSM contains no external interfaces itself. the AIP SSM might block some traffic according to its security policy. Firewall policies are applied. the Cisco ASA allows all traffic through. When configured to fail open. traffic flows through the Cisco ASA and the AIP SSM in the following sequence: 1. Once enabled. however. Now.

that the header is not incorrectly formed. earn a place on the Cisco IPS reputation filter list. and then anomaly detection. Reputation filters also prevent attempts by botnets to phone home if the botnet controller machine resides in one of these networks. • Reputation filters are used to block a subset of IP networks that are owned wholly by malicious groups or were unused and have been hijacked. If the event is sourced from an attacker with a negative reputation. Global Correlation provides users greater confidence in the actions the sensor takes because these actions are applied to attackers that have shown a predisposition for malicious behavior. The primary purpose of the IPS reputation filters is to provide protection from direct scanning. any actions assigned to alerts are processed and acted upon. Medium Enterprise Design Profile Reference Guide 5-15 . where the source IP address for any alert is checked for negative reputation. When an event is triggered. the sensor must detect some sort of malicious activity and fire an event as a result. This list includes only IP networks consisting entirely of stolen. but the networks that are being blocked get logged by the sensor in the Statistics section of Cisco IPS Manager Express (IME). Because there is no way that a legitimate IP address can go from a positive or neutral reputation and then. Packets that match are discarded immediately. Global Correlation inspection uses reputation scores for normal IP addresses to increase the percentage of attacks that the sensor can block. Next. Cisco IPS 7. including event action overrides to add new actions and event action filters to remove actions. This enables the sensor to deny packets and attackers based on the fact that the event has a negative reputation in addition to a high risk rating calculated on the sensor.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Internet Perimeter Protection the source is a known malicious site with a history of web attacks. then all the signature engines. the packet is sent through the Cisco IPS reputation filters. Packets that match the IPS reputation filters. Note There is currently no capability to view the networks on this list. Packets that do not match go to the inspection engines. are dropped before signature inspection. First. Reputation Filters Cisco IPS reputation filters use a list of hundreds of networks that can be safely blocked because they are not owned by any legitimate source. • After Global Correlation is configured. raising its risk rating and making it more likely that the sensor will deny the event. and the risk rating is modified and actions are added as appropriate. and the sensor can block access to and from that site. “zombie” address blocks and address blocks controlled entirely by malicious organizations. and distributed denial-of-service (DDoS) attacks originating from these malicious address blocks and from connections being attempted back to these networks from systems already infected. because of malicious activity. Global Correlation provides a process through which security data is collected for IP addresses and a reputation score is developed for each IP address globally by Cisco. If any events are triggered. the IPS works in the following manner. which performs Layer 2 packet normalization and atomic signature checks. alerts are sent to the Global Correlation inspection processor. Here the packet header is processed to help ensure that the packet is an IP packet. This first line of defense helps prevent malicious contact ranging from spam to intelligence gathering in preparation for directed attacks. The reputation of the networks on this list can be considered to be –10.0 uses this reputation data in two ways: for its reputation filters and for Global Correlation inspection. spamming. Individual IP addresses are never found on this list. starting with the Layer 3 and 4 normalization engine. the sensor adds risk to the event. botnet harvesting. assuming that the reputation filters are enabled and not in Audit mode. that event is processed to determine whether the attacker’s IP address has a negative reputation and to what degree. users can confidently block all activity to and from networks on this list. Finally. and that the packet does not match any atomic signatures. When a packet enters the sensor. the first check is against the preprocessor.

Network Participation and Correlation Updates The IPS sensor pulls reputation information for addresses on the global Internet from Cisco SensorBase. has no concept of positive reputation. Global Correlation inspection has three modes of primary operation: permissive. it uses that data. this checking occurs entirely on the sensor using data downloaded previously from Cisco SensorBase. the signature inspection occurs. When the sensor is configured initially. the more negative the reputation of the source IP address. Alerts that are created are passed to the Global Correlation inspection process for reputation lookups. unlike E-mail and web security reputation applications. In Audit mode. otherwise. the Global Correlation inspection process performs a local lookup of the source (attacker) IP address of the event in its reputation database. and aggressive. It inspects the data that it has. and adds a Deny Attacker action due to reputation if the risk rating is greater than or equal to 95. the sensor assumes that the address has a neutral reputation. Standard mode tells the sensor to adjust the risk rating and to add a Deny Packet action due to reputation if the risk rating is greater than or equal to 86. The sensor then initiates an HTTP connection that Medium Enterprise Design Profile Reference Guide 5-16 . This reputation score is calculated for Cisco IPS sensors using the data in Cisco SensorBase and is sent to the sensor as a reputation update. Global Correlation Inspection The primary activity of an IPS sensor is detection of malicious behavior. It also adds a Deny Attacker action due to reputation if the risk rating is greater than or equal to 100. the sensor does not send a live request for information about an IP address that it has just seen. you can also select Off: • • Permissive mode tells the sensor to adjust the risk rating of an event. This involves inspection of packets flowing through the sensor by the various engines looking for the various types of malicious behavior. but not to assign separate reputation-only actions to the event. The sensor checks Cisco SensorBase every five minutes for updates. • • If Global Correlation inspection is enabled and an event is generated by an attacker with a negative reputation. This lookup returns the location of the server nearest to the sensor. adds a Deny Packet action due to reputation if the risk rating is greater than or equal 83. the sensor makes an outbound connection to check for the latest updates from Cisco SensorBase. the risk rating for the event is elevated by a certain amount that is determined by a statistical formula. When an event occurs.1 to –10. the sensor reports potential deny actions because of reputation filters instead of actually denying the activity. After the packet goes through the IPS reputation filter process. After the sensor has this information. and if it finds the address. If changes are needed. Aggressive mode also adjusts the risk rating due to reputation. This lookup process returns a value ranging from –. or an HTTP or HTTPS proxy (that has DNS configured) needs to be configured. Cisco IPS. the more negative the value. When an event is checked for reputation. a DNS server needs to be configured for the sensor to use to connect to Cisco SensorBase. It initiates an HTTPS request to Cisco SensorBase update servers and downloads a manifest that contains the latest versions of the files related to Global Correlation. If an IP address returns no value for reputation. Unlike other devices. standard (default). The amount by which the risk rating is raised depends on the original risk rating of the event and the reputation of the attacker. it is considered to be neutral. the sensor performs a DNS lookup of the server name returned in the initial request.Chapter 5 Internet Perimeter Protection Medium Enterprise Design Profile (MEDP)—Network Security Design The only user configuration required for reputation filters is enabling or disabling them and specifying whether Global Correlation is set to Audit mode (a global configuration setting for the entire sensor). Selecting Off in the Global Correlation Inspection window prevents the sensor from using updates from Cisco SensorBase to adjust reputation.

Sensors with very high alert volumes can have average update sizes of approximately 850 KB.html. and worms. Medium Enterprise Design Profile Reference Guide 5-17 .0/configuration/guide/cli/cli_collaboration.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Internet Perimeter Protection actually transfers the data. Partial—The sensor sends back alert information. Full—Adds victim IP address and port information to the information reported with the Partial setting. Global Correlation information begins to time out within days. are at the extreme end of the range. For more information on IPS Global Correlation including configuration information. The mechanism used to update Cisco SensorBase with new attack information is fairly straightforward. these sensors. Therefore. and Cisco IPS performance and deployment mode information. In addition. It sends this data in the form of an HTTPS connection that it initiates on average every 10 minutes.cisco. see the following URL: http://www. with weekly totals of up to 900 MB.5 to 1 MB. viruses. The other component of Global Correlation is network participation. and sensor health changes accordingly. the attacker IP address and port. Some higher-volume sensors have average update sizes of approximately 50 KB. The ESA acts as a firewall and threat monitoring system for SMTP traffic (TCP port 25). • • Note No actual packet content information is sent to Cisco. all events reported to Cisco SensorBase have any such IP address information stripped from the reported data. incremental updates average about 100 KB. the ESA acts as a Mail Transfer Agent (MTA) within the E-mail delivery chain. this information is then packaged in future reputation data downloads from Cisco SensorBase. however. The sensor takes event information. E-Mail Security Guidelines The Medium Enterprise Design Profile implements a Cisco IronPort C Series E-Mail Security Appliance (ESA) in the DMZ to inspect E-mails and prevent threats such as E-mail spam. are not considered interesting. The sensor passes this information back to Cisco SensorBase according to the sensor configuration. the signature ID and risk rating of the event. events having RFC 1918 addresses.com/en/US/docs/security/ips/7. because they are not unique. This feature sends data from events that the sensor fires back to Cisco SensorBase to adjust the reputation of IP addresses. with weekly totals in the 45-MB range. The possible configuration options are as follows: • Off (default)—The sensor does not send back any data. parses out the important pieces of data. The size of a full update is approximately 2 MB. as shown in Figure 5-6. If a sensor loses connection to Cisco SensorBase. and this setting does not affect its use of that data except that the reputations of addresses attacking the network being protected are not influenced by their generation on the sensor. and buffers this data for transmission back to Cisco SensorBase. Logically. This information consists of protocol attributes such as the TCP maximum segment size and TCP options string. with weekly averages of approximately 0. The sensor still receives reputation data. The average size of an update is 2 to 4 KB.

When the ESA receives the E-mails. Medium Enterprise Design Profile Reference Guide 5-18 . This can be implemented physically by either using a single firewall or two firewalls in a “sandwich” configuration. they are evaluated using a reputation score mechanism based on the SensorBase network.000 organizations worldwide. Note Alternatively. are automatically dropped or quarantined by preconfigured reputation filters. and data loss prevention (DLP) for E-mail to detect the inappropriate transport of sensitive information.cisco. and other abnormal behavior. Cisco offers managed hosted and hybrid hosted E-mail security services. The SensorBase network consists of Cisco IronPort appliances. For more information. including anti-virus protection with virus outbreak filters and embedded anti-virus engines (Sophos and McAfee). and therefore with a low reputation score. These services are provided through a dedicated E-mail infrastructure hosted in a network of Cisco data centers. viruses. and IPS appliances installed in more than 100. By leveraging the information in the SensorBase network.com/gohttps://www.scribd.com/designzone. Cisco ASA.Chapter 5 Internet Perimeter Protection Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-6 Logical E-Mail Delivery Chain Internet Firewall Cisco IronPort ESA Email Server Firewall Client 227423 Note Figure 5-6 shows a logical implementation of a DMZ hosting the E-mail server and ESA appliance. see the following URL: http://www. which is an extensive network that monitors global E-mail and web traffic for anomalies. This provides a large and diverse sample of Internet traffic patterns. encryption to ensure the confidentiality of messages. In addition. malware. an enterprise may optionally choose to implement some of the other functions offered by the ESA appliance. messages originating from domain names or servers known to be the source of spam or malware.

The private listener receives E-mail from the internal servers and directs messages to the Internet. The public listener interface would connect to the DMZ and the private listener interface can connect to the inside of the firewall closer to the mail server. The public listener receives E-mail from the Internet and directs messages to the internal mail servers. depending on the number of interfaces used: • Dual-armed configuration—Two physical interfaces are used to serve as a public mail listener and a private mail listener where each interface is configured with a separate logical IP address.x Public Listener Internet Outside DMZ Inside Public Listener IP x.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Internet Perimeter Protection There are two options for deploying the ESA appliance. Figure 5-8 shows the logical location of the ESA within the E-mail flow chain and the typical data flow for inbound E-mail traffic.x. One-armed configuration—A single interface is configured on the ESA with a single IP address and used for both incoming and outgoing E-mail. A public mail listener is configured to receive and relay E-mail on that interface. the Medium Enterprise Design Profiles implements the ESA with a single interface in a single-armed configuration. The best practice is to connect the ESA interface to the DMZ where the E-mail server resides. This also leaves the other data interfaces available for redundancy.x.x. Medium Enterprise Design Profile Reference Guide 5-19 . • Figure 5-7 shows both configurations.x.y Email Server 227424 Email Server For simplicity.y.x Private Listener IP y. Figure 5-7 Common ESA Deployments Dual-Armed Single-Armed Internet Outside DMZ Inside IP x.y.

ESA performs a DNS query on sender domain and checks the received IP address in its reputation database.c. also known as a mail exchange (MX).b.d (public IP address of ESA). quarantines E-mail based on policy. The IP address of the sender is needed to Medium Enterprise Design Profile Reference Guide 5-20 227425 9 . If another MTA sits at your network’s perimeter and handles all external connections. The E-mail server sends message to a. The receiver retrieves E-mail from server using POP or IMAP. and drops.d using SMTP. What’s the IP address of domain X? It is a. The following outlines some of the key deployment guidelines for the ESA within the Medium Enterprise Design Profile: • The ESA appliance needs to be accessible via the public Internet and is the first hop in the E-mail infrastructure. and translates its public IP address. The Cisco IronPort ESA appliance functions as an SMTP gateway. The firewall permits incoming SMTP connection to the ESA.b. The E-mail server stores E-mail for retrieval by receiver. ESA forwards E-mail to preconfigured inbound E-mail server.Chapter 5 Internet Perimeter Protection Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-8 Typical Data Flow for Inbound E-Mail Traffic Mail Server 1 Internet 2 3 DNS Server 4 6 5 ESA 7 8 Mail Server The following steps explain what is taking place in Figure 5-8: Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 Step 8 Step 9 Sender sends an E-mail to xyz@domain X.c. the ESA is not able to determine the sender’s IP address.

Alternative redundant designs include the following: • • Multiple MTAs—Adding a second ESA appliance or MTA and using a secondary MX record with an equal cost to load balance between the MTAs. the IP address and MAC address are moved to the secondary interface. a separate MTA should not be deployed at the network perimeter to handle the external connections.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Internet Perimeter Protection identify and distinguish the senders in the Mail Flow Monitor to query the SensorBase Reputation Service for the SensorBase Reputation Service Score (SBRS) of the sender. Configuration includes the definition of sender groups associating groups or users. the host access table (HAT) must be configured to indicate the hosts that are allowed to send E-mails. Because a failure on the ESA appliance may cause a service outage. A DNS “A” record should be created to map the appliance hostname to its public IP address. However. Medium Enterprise Design Profile Reference Guide 5-21 . a redundant design is recommended. a separate interface for administration should be used. access rule. and on which mail policies can be applied. Policies include the following: – Mail flow policies—A way of expressing a group of HAT parameters. and Sophos Antivirus. • • Define SMTP routes to direct E-mail to the appropriate internal mail servers. All the local domains for which the ESA appliance accepts mail needs to be added to the Recipient Access Table (RAT). Therefore. One way to implement redundancy is to use IronPort NIC pairing. • The ESA needs to be registered in DNS for features such as IronPort Anti-Spam. it does not provide redundancy in case of chassis failure. External E-mail servers connect directly to the ESA appliance to transmit E-mail for the local domains. Domino) via SMTP routes. IronPort NIC pairing is the most cost-effective solution because it does not require the deployment of multiple ESA appliances and other hardware. and an MX record that maps the public domain to the appliance hostname. Primary NIC IP address. For each private listener. GroupWise. If the primary interface fails. The ESA appliance accepts outbound E-mail based on the settings of the HAT table. A priority is specified for the MX record to advertise the ESA appliance as the primary MTA for the domain. A static IP address translation entry on the Internet firewall should be defined to map the public IP address of the ESA to its private internal address if NAT is configured on the Internet firewall. Secondary NIC Internet Firewall DMZ ESA IronPort NIC pairing provides redundancy at the network interface card level by teaming two of the Ethernet interfaces in the ESA appliance. and the ESA appliance relays the mail to the appropriate groupware servers (for example. MacAfee Antivirus. Inbound E-mail destined to domains not listed in the RAT are rejected. Exchange. followed by • • • rate limit parameters and custom SMTP codes and responses – Reputation filtering—Allows the classification of E-mail senders. Virus Outbreak Filters. Figure 5-9 Cisco IronPort ESA NIC Pairing 227426 IP address. Load balancer—Using a load balancer such as the Cisco Application Control Engine (ACE) to load balance traffic across multiple ESA appliances. as shown in Figure 5-9. If an OOB management network is available. and restricting E-mail access based on sender trustworthiness as determined by the IronPort SensorBase Reputation Service.

ironport. • The Medium Enterprise Design Profile assumes a centralized Internet connection implemented at the main site.com and phonehome.html Cisco IronPort ESA User Guide—http://www. as shown in Figure 5-10. see the following guides: • • Cisco SAFE Reference Guide— http://www. SMTP (TCP/25) to E-mail server from any internal client Also. The URL filtering capability defines the handling of each web transaction based on the URL category of the HTTP requests. The WSA should be implemented at the distribution layer in the Internet perimeter network. For more information on how to configure the ESA. Leveraging the SensorBase network. Layer 4 traffic monitoring (L4TM)—Monitors all Layer 4 traffic for rogue activity.com/support Web Security Guidelines The Medium Enterprise Design Profile implements a Cisco IronPort S Series Web Security Appliance (WSA) to block HTTP and HTTPS access to sites on the Internet with non-business-related content and to protect the enterprise network from web-based malware and spyware. the Internet firewall needs to be configured to allow this communication. The anti-malware service leverages anti-malware scanning engines such as Webroot and McAfee to monitor for malware activity. the WSA sits in the path between web users and the Internet. Medium Enterprise Design Profile Reference Guide 5-22 .cisco.com Outbound SSL (TCP/443) from ESA to updates-static. and SYSLOG to/from the ESA. POP (TCP/110). if the ESA is managed in-band. The following are some of the common services required to be allowed through the Internet firewall: • • • • • • Outbound SMTP (TCP/25) from ESA to any Internet destination Inbound SMTP (TCP/25) to ESA from any Internet destination Outbound HTTP (TCP/80) from ESA to downloads. the appropriate firewall rules need to be configured to allow traffic such as SSH. The Cisco IronPort WSA relies on two independent services to protect the network: • Web proxy—Provides URL filtering. NTP. and optionally anti-malware services.com/en/US/docs/solutions/Enterprise/Security/SAFE_RG/SAFE_rg. This allows for the inspection and enforcement of web access polices to all users located at any of the enterprise sites. web reputation filters.org Inbound and outbound DNS (TCP and UDP port 53) Inbound IMAP (TCP/143). and to detect infected clients. Protocols and ports to be allowed vary depending on the services configured on the ESA.Chapter 5 Internet Perimeter Protection Medium Enterprise Design Profile (MEDP)—Network Security Design To accommodate traffic to and from the IronPort ESA provisioned in the DMZ.ironport.senderbase.com and updates.ironport.ironport. Logically. the web reputation filters analyze the web server behavior and characteristics to identify suspicious activity and protect against URL-based malware.

The Cisco Catalyst 3750 switch uses WCCP version 2. the Medium Enterprise Design Profile implements transparent proxy mode with WCCP. Both WCCP and Layer 4 load balancer options provide for redundancy and load balancing. transparent proxy mode provides transparent integration of WSA without requiring any configuration control over the endpoints. Per the WCCPv2 specifications. WPAD allows the browser to determine the location of the PAC file using DHCP and DNS lookups. such as web browsers. Medium Enterprise Design Profile Reference Guide 5-23 . After failure. In the Medium Enterprise Design Profile. In addition. This mode requires the implementation of a Web Cache Communications Protocol (WCCP)-enabled device or a Layer 4 load balancer to intercept and redirect traffic to the WSA before going to the Internet. which may not be always possible. WCCP takes the entire service group offline and subsequent requests bypass redirection. Transparent proxy—Client applications are unaware of the web proxy and do not have to be configured to connect to the proxy. smart phones. the traffic is redirected across the remaining active appliances. the Web Proxy Auto-discovery Protocol (WPAD) can be used to automate the deployment of PAC files. Manual configuration does not allow for redundancy. the Cisco Catalyst 3750 Stackwise distribution switches deployed in the Internet perimeter can be leveraged as the WCCP server while the WSA acts as a WCCP traffic processing entity. The web browsers can be configured either manually or by using proxy auto configuration (PAC) files. WCCPv2 supports MD5 authentication for the communication between the WCCP server and the WSA appliances. For example. If supported by the browser.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Internet Perimeter Protection Figure 5-10 Cisco IronPort WSA Internet Firewall www Cisco IronPort WSA Client 227427 There are two deployment modes for enabling the Cisco IronPort WSA Web Proxy service: • Explicit forward proxy—Client applications. or other devices outside the company’s administration. Conversely. The WCCP server (Cisco Catalyst 3750 switch) monitors the availability of each appliance in the group and can identify the appliance failures in 30 seconds. the enterprise may allow the use of personal laptops. transparent proxy also eliminates the possibility of users reconfiguring their web browsers to bypass the WSA appliance without the knowledge of the administrators. In the case where no appliances are active. In addition. HTTP and HTTPS traffic is load balanced across the active WSA appliances based on source and destination IP addresses. are aware of the web proxy and must be configured to point to the WSA as its proxy. For these reasons. while the use of PAC files allows the definition of multiple WSAs for redundancy and load balancing. which has a built-in failover and load balancing mechanism. • Explicit forward proxy mode requires the enterprise to have control over the configuration of the endpoints. multiple appliances (up to 32 entities) can be configured as part of the same service group.

4. 2. 3. and allows/denies the request accordingly. the following steps take place: 1. Medium Enterprise Design Profile Reference Guide 5-24 228541 . Figure 5-11 WCCP Redirection Website. The Cisco Catalyst 3750 Internet perimeter distribution switch intercepts and redirects HTTP/HTTPS requests to WSA via Layer 2 redirection.com.Chapter 5 Internet Perimeter Protection Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-11 shows how WCCP redirection works in conjunction with the Cisco Catalyst 3750 StackWise distribution switches. WSA fetches the content from the destination website. 5. WSA performs a DNS query on the destination site and checks the received IP address against URL and reputation rules. If the content is not present in the local cache. If allowed. The client browser requests a connection to http://website. The content is inspected and then delivered to the requesting client.com Internet 4 2 3 www WSA 5 1 As shown in Figure 5-11.

therefore. Use inbound redirection only.cisco. The WSA and switches in the same service group must be in the same subnet directly connected to the switch that has WCCP enabled.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Internet Perimeter Protection Note In the event that the entire service group fails.html. WCCP does not have visibility into traffic that is being used by the virtual routing tables with VRFs. Use redirect-lists to specifically control what hosts/subnets should be redirected.com/en/US/docs/switches/lan/catalyst3750e_3560e/software/release/12. WCCP GRE forwarding method for packet redirection is not supported. For these reasons. Medium Enterprise Design Profile Reference Guide 5-25 . The ACL may also have to be configured to permit HTTP/HTTPS access from IPS and other systems requiring direct access to the Internet without going through the WSA proxy. WCCP and policy-based routing (PBR) on the same switch interface are not supported. no counters increment when the command show ip wccp is issued on the switch. the WSA(s). which is an important component of the design. WCCP is not compatible with VRF-Lite. The following describes some of the design considerations and caveats for implementing a Cisco IronPort WSA with WCCP on a Cisco Catalyst 3750 switch: • • • • • • • • • • • • The WSA must be Layer 2-adjacent to the Cisco Catalyst 3750 switch. If a Cisco Catalyst 4500 is implemented as the distribution layer switch. deploy the WSA downstream from the existing proxy servers (closer to the clients). WCCP automatically bypasses redirection. should be used as the WCCP server. Use MD5 authentication to protect the communication between the Cisco Catalyst 3750 switches and the WSA(s). and to block any direct requests from clients. Configure the switch interfaces that are facing the downstream web clients. In an existing proxy environment. Therefore. If it is desired to handle a group failure by blocking all traffic. and the web servers as Layer 3 interfaces (routed ports or switch virtual interfaces [SVIs]). and the redirection is supported in hardware. The Cisco Catalyst 6500 and 3750 switches support Layer 2-based redirection. the WSA must be directly connected to the switch running WCCP. Note The Cisco Catalyst 4500 does not provide the ability to create WCCP traffic redirect exception lists. allowing users to browse the Internet without the web controls.2_46_se/con figuration/guide/swwccp. an inbound ACL may be configured on the Cisco ASA inside interface to permit only HTTP/HTTPS traffic originated from the WSA appliance itself. WCCPv2 supports Generic Route Encapsulation (GRE) and Layer 2-based redirection. Cisco Catalyst 3750 switches support switching in hardware only at Layer 2. another device. WSA should connect directly to the Internet perimeter distribution switch using a VLAN that is different than the VLAN from where the client traffic is coming. WCCP is supported only on the ingress of an interface. such as the Cisco ASA. use a separate interface for WSA administration. see the following URL: http://www. For more information on WCCP in relation to the Cisco Catalyst 3750 switch. In addition. If an OOB management network is available.

Depending on the need and the size of the enterprise network.html.com/en/US/docs/solutions/Enterprise/Security/SAFE_RG/SAFE_rg. application acceleration devices. The infrastructure supporting them may include application servers. Applications access can be controlled based on applications. a single data center may be deployed at the main site. they may also host foundational services as part of the enterprise network such as identity and security services. Note Peer-to-peer file sharing and Internet instant messaging applications can also be blocked using Cisco IPS appliances and modules and the Cisco ASA firewall (using modular policy framework). and other services. mobility services. and objects.cisco. URL categories. L4TM monitors network traffic for rogue activity and for any attempts to bypass port 80. The L4TM internal database is continuously updated with periodic updates from the Cisco IronPort update server (https://update-manifests. • In the medium enterprise design. or custom categories defined by the administrator. Applications are matched based on their user agent pattern.com). Kazaa.Chapter 5 Data Center Protection Medium Enterprise Design Profile (MEDP)—Network Security Design Note WCCP. BitTorrent. It works by listening to all UDP and TCP traffic and by matching domain names and IP addresses against entries in its own database tables to determine whether to allow incoming and outgoing traffic. URLs can be blocked based on specific categories. The WSA L4TM service is deployed independently from the web proxy functionality.ironport. firewall. the WSA handles these applications as follows: • Port 80—Applications that use HTTP tunneling on port 80 can be handled by enforcing access policies within the web proxy configuration.ironport. switches. Skype. In addition. Ports other than 80—Applications using ports other than 80 can be handled with the L4TM feature. such as predefined chat and peer-to-peer categories.com/support. the storage media. Depending on the port used for transport. and other systems. This prevents users from bypassing the WSA to browse the Internet. Care should be taken when implementing active-active firewall pairs because they may introduce asymmetric paths. video services. The WSA appliance may also be configured to control or block peer-to-peer file sharing and instant messaging applications such as AOL Messenger. see the following guides: • • Cisco SAFE Reference Guide— http://www. L4TM can block access to specific applications by preventing access to the server or IP address blocks to which the client application must connect. unified communication services. the Internet perimeter firewall can be configured to allow only web traffic (HTTP and HTTPS) outbound to the Internet from only the WSA. off-loaders. routers. If needed. IronPort WSA User Guide—http://www. Data Center Protection Medium enterprise networks typically include a data center at the main site that hosts the systems that serve business applications and store the data accessible to internal users. Medium Enterprise Design Profile Reference Guide 5-26 . partner applications. load balancers. Peer-to-peer access can also be filtered based on object and Multipurpose Internet Mail Extensions (MIME) types. smaller data centers or server farms may also be deployed in remote sites. and so on. and the use of regular expressions. For more information on how to configure the L4TM feature on Cisco IronPort WSA. and other stateful features typically require traffic symmetry where traffic in both directions should flow through the same stateful device.

all services are hosted in a shared physical server farm. and other switch security features may be leveraged to mitigate spoofing. In the collapsed design.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Data Center Protection The data center may be constructed following various design models. Figure 5-12 Collapsed and Multi-tier Data Center Designs Multi-tier Data Center Core Distribution Database Tier Application Tier Cisco IPS Web Tier Collapsed Data Center Data Center Serverfarm Core Application Servers Cisco ASA with IPS Module Cisco ASA 227630 Independent from the design model adopted by the enterprise. port security. and high availability is achieved by using redundant processors and interfaces. Intrusion prevention—An IPS module on the Cisco ASA or a separate IPS appliance may be implemented for enhanced threat detection and mitigation. This includes restricting and controlling administrative access. Figure 5-12 illustrates a collapsed and multi-tier data center design. The firewall may also be leveraged to ensure the appropriate segregation between application layers or groups. storm control. the following are the primary security guidelines for the data center design: • Network Foundation Protection—All infrastructure equipment should be protected following the NFP best practices described earlier in this document. man-in-the-middle. the firewall’s deep packet inspection may be used to mitigate DoS attacks and enforce protocol compliance. Logical isolation may be achieved by separating applications and services in different VLANs and by assigning them into different firewall interfaces (physical or logical). DoS. Switch security—Private VLANs. • • • • Medium Enterprise Design Profile Reference Guide 5-27 . and securing the switching and routing planes. The IPS is responsible for identifying and blocking anomalous traffic and packets recognized as well-known attacks. the Cisco IPS is placed in the traffic path and is capable of stopping malicious traffic before it reaches the intended target. Isolation helps prevent data leakage and contain possible compromises from spreading across different server farm groups. and for the intended users. The Cisco IPS may be configured either in inline or promiscuous mode. Large enterprises may implement a more scalable multi-tier design data center with chassis redundancy. When deployed in inline mode. Service isolation—Services and applications serving different groups of users or under different security requirements should be properly isolated. and other network-based attacks directed to the data center applications and the switching infrastructure. protecting the management and control planes. In addition. Firewall—A stateful firewall may be deployed to limit access to only the necessary applications and services. The firewall should be configured to control and inspect both traffic entering and leaving the server farm segments. This is illustrated in Figure 5-13.

Web Application Firewall (WAF). Contractors and consultants regularly have access to secure areas. For a more detailed discussion of data center security.Chapter 5 Network Access Security and Control Medium Enterprise Design Profile (MEDP)—Network Security Design • Endpoint protection—Servers residing at the different layers should be protected with host-based IPS or other endpoint security software. and security policy compliance before granting access to the network. or patches. Service Isolation Figure 5-13 Data Center Serverfarms Group 3 Core Distribution Group 2 Group 1 Cisco ASA SSL termination and inspection. Network Access Security and Control One of the most vulnerable points of a network is at the access edge. Security policy compliance can consist of requiring anti-virus software. with the proliferation of wireless networks. privilege level. everyone has access to all resources on the network. When connected to the network. wired users Cisco Unified Wireless Network (CUWN) Integrated Security Features.html. In the past. and there is nothing preventing them from plugging into a wall jack in a cubicle or conference room to gain access to the enterprise network. and the increased use of laptops and smart mobile devices. Unauthorized or noncompliant devices can be placed in a quarantine area where remediation can occur before network access. Protection needs to be embedded into the network infrastructure. The access layer is where end users connect to the network.cisco. Unauthorized users were not allowed to enter secure buildings where they could plug into the network.com/en/US/docs/solutions/Enterprise/Security/SAFE_RG/chap4. and other solutions may be leveraged to complement the guidelines described above. leveraging the native security features available in switches and routers. the network infrastructure should also provide dynamic identity or role-based access controls for all devices attempting to gain access. Implementing role-based access controls for users and devices helps reduce the potential loss of sensitive information by enabling administrators to verify a user or device identity. wireless users Medium Enterprise Design Profile Reference Guide 5-28 227631 . network administrators have largely relied on physical security to protect this part of the network. enterprises cannot simply rely on physical controls to prevent these unauthorized devices from plugging into ports of the access switches. The Medium Enterprise Design Profile achieves access security and control by leveraging the following technologies: • • Cisco Catalyst Integrated Security Features (CISF). OS updates. Intranet Data Center” of the Cisco SAFE Reference Guide at the following URL: http://www.Today. Application Control Engine (ACE). In addition. see “Chapter 4.

lease time. and network IDS integration.html. binding type. wired and wireless users Cisco Catalyst Integrated Security Features Cisco CISF is a set of native security features available on Cisco Catalyst switches designed to protect the access layer infrastructure and users from spoofing. wireless intrusion detection system (IDS). man-in-the-middle (MITM).Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Network Access Security and Control • • Cisco Identity-Based Network Services (IBNS). management frame protection. only packets with a permitted source MAC address are allowed to pass through the port. The Cisco Unified Wireless Network solutions are discussed in the Wireless and Network Security Integration Solution Design Guide at the following URL: http://www. Medium Enterprise Design Profile Reference Guide 5-29 . rogue AP detection. IP address. it builds and maintains a DHCP snooping binding table that contains the MAC address. DoS. Some of these are the WLAN equivalent of CISF features such as Dynamic Host Configuration Protocol (DHCP) and Address Resolution Protocol (ARP) protection. • • • • Cisco Unified Wireless Network (CUWN) Integrated Security Features The Cisco Unified Wireless Network adds to the 802. VLAN number. When the suppression-level threshold is reached. Additionally. CISF includes the following features: • Port Security—Mitigates MAC flooding and other Layer 2 CAM overflow attacks by restricting the MAC addresses that are allowed to send traffic on a particular port. A permitted MAC address is referred to as a secure MAC address. DHCP Snooping—Inspects and filters DHCP messages on a port to ensure DHCP server messages come only from a trusted interface. multicast. After Port Security is enabled on a port. Storm Control—Prevents broadcast and multicast storms by monitoring packets passing from an interface to the switching bus and determines whether the packet is unicast. including Enhanced WLAN security options. Dynamic ARP inspection (DAI)—Validates that the source MAC and IP address in an ARP packet received on an untrusted interface matches the source MAC and IP address registered on that interface (using the DHCP snooping binding table) to prevent ARP spoofing and man-in-the-middle attacks. or broadcast. dynamic radio frequency management. peer-to-peer blocking. client exclusion. other more WLAN specific features are provided. the port blocks traffic until the traffic falls below the threshold level.cisco. wired and wireless users Cisco Network Admission Control (NAC) Appliance.com/en/US/solutions/ns340/ns414/ns742/ns820/landing_sec_wireless. The switch counts the number of packets of a specified type received within the 1-second time interval and compares the measurement with a predefined suppression-level threshold. IP Source Guard—Restricts IP traffic on a port based on DHCP or static IP address MAC bindings to prevent IP spoofing attacks. and other network-based attacks. CISF should be considered part of the security baseline of any network and should be deployed on all ports on the access switches within the enterprise network architecture.11 security standards by providing additional security features. and access control list and firewall features. This binding table is used by the other CISF features. Additionally. and interface information corresponding to the local untrusted interfaces of a switch. IP address bindings are validated using information in the DHCP Snooping binding table.

offering the capability to permit or deny network connectivity based on the identity of the end user or device. Medium Enterprise Design Profile Reference Guide 5-30 . The switch forwards the response to the policy database (authentication server).1X is first enabled on a port. 2. When 802. The high-level message exchange shown in Figure 5-14 illustrates how port-based access control works within an identity-based system.1X supplicant. connects to an IEEE 802. 7. When the start message is received.1X protocol to secure the physical ports where end users connect.1X authentication successfully completes. IEEE 802. After the user identity is confirmed. The authentication server authenticates the user. 802. Every port on the switch is individually enabled or disabled based on the identity of the user or device connecting to it.1X protocol allows Cisco Catalyst switches to offer network access control at the port level.1X is an IEEE standard for media-level (Layer 2) access control. 4.Chapter 5 Network Access Security and Control Medium Enterprise Design Profile (MEDP)—Network Security Design Cisco Identity-Based Network Services (IBNS) The Cisco IBNS solution is a set of Cisco IOS software services that provide secure user and host access to enterprise networks powered by Cisco Catalyst switches and wireless LANs. 3. 6. such as a laptop with an 802. Figure 5-14 Port-Based Access Control 7 Switch enables port 1 EAP0L Start 2 Login Request 3 Login Response Authenticator Authentication Server 4 Check with Policy DB 5 Policy DB 228543 6 Policy DB informs switch confirms ID and grants access The following steps describe the port-based access control flow shown in Figure 5-14: 1. 5. the LAN switch sends a login request to the client. the policy database authorizes network access for the user and informs the LAN switch. The client replies with a login response. After the 802. It provides standards-based network access control at the access layer by using the 802. A client.1X Protocol The IEEE 802.1X is a well-known way to secure wireless network access and is also capable of securing wired network access.1X-enabled network and sends a start message to the LAN switch (the authenticator). the switch automatically drops all traffic received on the port except the request to start 802. 802. the switch starts accepting other kinds of traffic on the port. The LAN switch then enables the port connected to the client.1X authentication.

1X encapsulation is sometimes referred to as EAP over LAN (EAPoL). legacy servers. Understanding and accommodating for this change in access behavior facilitates a smooth deployment of 802. The switch in turn relays the EAP information to the authentication server using the RADIUS protocol (EAP over RADIUS).1X timers to accommodate the various non-802. but the ones used more frequently for 802. and EAP-FAST. or externally using database sources such as Microsoft Active Directory. After 802.1X protocol defines an encapsulation for the transport of the Extensible Authentication Protocol (EAP) from the client to the switch. This is one of the key elements of the strong security and network access control provided by 802. There are many EAP methods. The 802. The default security posture says that 802. This is a fundamental change from the traditional model. Therefore. Instead. These features provide fallback mechanisms when there is no 802. Medium Enterprise Design Profile Reference Guide 5-31 .1X supplicant attempts to connect to a port that is enabled for 802.1X. However.1X supplicant.1X must be enabled on both the host device and on the switch to which it connects. These are MAC Authentication Bypass (MAB) and Guest VLAN. where traffic is allowed from the moment a port is enabled and a device is plugged into the port.1X authentication must succeed before access to the network is granted. the port can move to an open state if MAB succeeds or if a Guest VLAN is configured. by default. it is subjected to the default security posture. the default security posture is to drop all traffic except 802.1X deployment. the 802. EAP is defined by RFC 3748.1X network access control.1X wired authentication include EAP-TLS.1X-capable devices cannot get access to a 802. this change in the default network access model can have a profound impact on network devices and applications.1X is enabled on a port. non-802. The Cisco IBNS solution provides two features to accommodate non 802.1X devices. Although an increasing number of devices support 802. EAP is a framework and not a specific authentication method. Ports that were traditionally open are now closed by default.1X-Enabled Devices 802. badge readers.1X.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Network Access Security and Control The user or device credentials are processed by a AAA server. which simplifies overall deployment. If a device without an 802.1X does not dictate how this is achieved. and Preboot Execution Environment (PXE) boot machines. Novelle Directory.1X-capable devices on your network. Non-802. It provides a way for the client and the authentication server to negotiate an authentication method that they both support. Lightweight Directory Access Protocol (LDAP).1X on the Network When 802. Impacts of 802.1X and EAP When authenticating users for network access. This enables the IBNS solution to be integrated into existing user management structures and schemes. IEEE 802. 802.1X. the client must provide user and/or device identification using strong authentication technologies.1X EAPoL packets.1X times out on a port. Note Network-specific testing is required to determine the optimal values for the 802. Some provisions must be made for these devices. using the integrated user database. Examples of such devices include network printers. there will always be devices that require network connectivity but do not and/or cannot support 802.1X-protected network.1X. EAP-PEAP. The AAA server is able to reference user or device profile information either internally. Application of either or both of these features is required for a successful 802. or Oracle databases.

With Cisco NAC Appliance. Other locations in the enterprise network still need protection. Cisco NAC Appliance should be considered. or operating system. printer and legacy device support are typical applications Web auth—Allowing a user to authenticate by entering username and passwords in a web page. Evaluates whether machines are compliant with security policies. Security policies can include requiring specific anti-virus or anti-spyware software. this is still the case. isolating. This first step occurs at the point of authentication. because these locations are more likely to have managed PCs. wireless. there are four main 802. In addition. IP phones. or game consoles are compliant with your network security policies.cisco.1X may be a good choice.1X network access solution.1X protected ports may be a good choice for the network ports in the company’s headquarters or main site. device types. and remediate wired. For example.1X authentication process.1X controlled port with an 802. When deployed.1X or Cisco NAC Appliance to protect these ports. Cisco NAC Appliance supports policies that vary by user type. • • Medium Enterprise Design Profile Reference Guide 5-32 .1X deployment very challenging. network administrators can authenticate. there may be pockets of an enterprise network where 802.1X authentication options to consider: • • • • Basic 802. and their roles in the network. evaluate. before malicious code can cause damage. 802. their devices. where remediation occurs at the discretion of the administrator. OS updates.com/go/ibns. Non-compliant machines are redirected to a quarantine network. In many enterprise environments. authorize.1X authentication—An 802. but user network access may be better served by a NAC Appliance Solution (discussed in the next section).1X in Medium Enterprise Networks As mentioned in the previous sections. and repairing non-compliant machines. However. The NAC Appliance identifies whether networked devices such as laptops. or patches. Cisco NAC Appliance Cisco Network Admission Control (NAC) Appliance (formerly known as Cisco Clean Access) uses the network infrastructure to enforce security policy compliance on all devices seeking to access network computing resources. which makes a company-wide 802. and can repair any vulnerability before permitting access to the network. Cisco NAC Appliance provides the following benefits: • • Recognizes users.Chapter 5 Network Access Security and Control Medium Enterprise Design Profile (MEDP)—Network Security Design 802.1X client connected to the phone MAC auth bypass—Using the MAC address of the client to provide authentication and bypass the 802. and remote users and their machines before network access. see the following URL: http://www.1X controlled port with an 802.1X deployment. legacy device support and guest access are typical deployment applications For more information on the Cisco IBNS 802.1X client directly connected IP phone ports—An IP Phone and an 802. Enforces security policies by blocking.1X authentication requires a supplicant on the host device. network access ports in open areas such as lobbies and meeting rooms may use 802. 802. For networks requiring role-based access control using posture assessments to ensure security compliance. This typically has been a challenge in enterprise environments that have a wide range of devices and limited or no management of many of these devices. When considering an 802.

cisco. etc. and quarantines vulnerable or infected clients for remediation before clients access the network. as shown in Figure 5-15: • • • • Authenticates and authorizes Scans and evaluates Quarantines and enforces Updates and remediates Four Functions of the NAC Solution Figure 5-15 Authenticate and Authorize • Enforces authorization policies and privilges • Supports multiple user roles Scan and Evaluate • Agent scan for required versions of hotfixes. AV. enforces network requirements. Figure 5-16 shows Cisco NAC Appliance components. integrated solution administered from the Cisco Clean Access Manager (CAM) web console and enforced through the Cisco Clean Access Server (CAS) and (optionally) the Clean Access Agent (CAA) or NAC Web Agent. • Network scan for virus and worm infections and port vulnerbilities Quarantine and Enforce • Isolate non-compliant devices from rest of network • MAC and IP-based quarantine effective at a per-user level Update and Remediate • Network-based tools for vulnerbility and threat remediation • Help-desk integration 227497 For more details of the NAC Appliance Solution. NAC Appliance Components Cisco NAC Appliance is a network-centric. Medium Enterprise Design Profile Reference Guide 5-33 .com/go/nacappliance. distributes patches and anti-virus software. Cisco NAC Appliance checks client systems. see the following URL: http://www.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Network Access Security and Control The NAC solution provides the following four functions.

the CAS can be deployed in Layer 2 mode (users are Layer 2-adjacent to the CAS) or Layer 3 mode (users are multiple Layer 3 hops away from the CAS). authentication requirements. The CAS can be installed as either a standalone appliance (such as the Cisco NAC-3300 Series) or as a network module (Cisco NME-NAC-K9) in a Cisco ISR chassis. Cisco Clean Access Server (CAS) The Cisco CAS is the enforcement server between the untrusted network and the trusted network.Chapter 5 Network Access Security and Control Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-16 NAC Appliance Components Internet Switch L2 eth1 eth0 Router L3 Firewall LAN/Intranet Clean Access Server (CAS) PCs with Clean Access Agent (CAA) Clean Access Manager (CAM) Clean Access Manager Web admin console Authentication sources (LDAP. Additionally. In the Medium Enterprise Design Profile. RADIUS. the CAM is located in the data center at the main campus site. The CAS enforces the policies defined by the CAM web administration console. and system requirements. The CAS can be deployed in in-band (always inline with user traffic) or OOB (inline with user traffic only during authentication and posture assessment). The secure web console of the CAM is the single point of management for up to 20 Clean Access Servers in a deployment (or 40 CASs if using a SuperCAM). Medium Enterprise Design Profile Reference Guide 5-34 228544 Admin laptop . WindowsNT) DNS server Cisco Clean Access Manager The Cisco CAM is the administration server for NAC Appliance deployments. For OOB deployments. Policies can include network access privileges. bandwidth restrictions. For example. Multiple CASs of varying size/capacity can be deployed to fit the needs of various network segments. the web administration console controls the switches and VLAN assignment of user ports through the use of SNMP. Kerberos.

files. and remediation (see Figure 5-17). NAC Appliance Modes and Positioning The NAC Appliance can be deployed in multiple deployment options and placed at various locations in the network. Using a Web browser. anti-spyware (AS). the NAC Web Agent can be used for unmanaged clients such as guest users and contractors. and applications even if a personal firewall is installed and running. and deployed in Layer 2 OOB (for wireless clients) and Layer 3 OOB (for wired clients) modes for authentication and posture assessments. Cisco NAC Web Agent The Cisco NAC Web Agent provides temporal posture assessment for client machines. In the Medium Enterprise Design Profile. It checks applications. If NAC is implemented as part of the Medium Enterprise Design Profile. and other client software. When a user is authenticated and passes all policy checks. services. anti-virus (AV). The modes of operation can be generally defined as follows: • • • • Out-of-band (OOB) virtual gateway OOB real IP gateway In-band (IB) virtual gateway IB real IP gateway OOB Modes OOB deployments require user traffic to traverse through the NAC Appliance only during authentication. Built-in support is provided for 24 AV and 17 AS vendors. it is recommended that the CAA be used.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Network Access Security and Control Cisco NAC-3300 Series appliances can be installed in a main site core to handle thousands of users. Clean Access Policy Updates Regular updates of prepackaged policies/rules can be used to check the up-to-date status of operating systems. services. the Web Agent logs the user off the network and their user ID disappears from the online users list. In the Medium Enterprise Design Profile. The agent can check the client registry. Cisco Clean Access Agent (CAA) The Cisco CAA is an optional read-only agent that resides on Windows clients. Note There is no client firewall restriction with CAA posture assessment. and one or more Cisco NAC network modules can be simultaneously installed in ISR platforms to accommodate smaller groups of users in a satellite office. which installs the Web Agent files in a temporary directory on the client machine via ActiveX control or Java applet. or registry keys to ensure that clients meet the specified network and software requirements before gaining access to the network. their traffic is switched normally through the network and bypasses the NAC Appliance. the CAS would be located at the main site and the remote campus sites. When the user terminates the Web Agent session. users launch the Cisco Web Agent executable file. Medium Enterprise Design Profile Reference Guide 5-35 . posture assessment.

and Figure 5-19 shows a physical in-band topology example. passes through the NAC Appliance. Medium Enterprise Design Profile Reference Guide 5-36 . the client device must be directly connected to the network via a Cisco Catalyst switch port. the CAM instructs the switch to map the user port from an unauthenticated VLAN (which switches or routes user traffic to the CAS) to an authenticated (authorized) VLAN that offers full access privileges. Figure 5-18 shows a logical in-band topology example. as shown in Figure 5-17. The CAS may be positioned logically or physically between the end users and the networks being protected. For example. all user traffic. the client PC is connected through VLAN 110 to the NAC CAS for the authentication and posture assessment. In-Band Modes When the NAC Appliance is deployed in-band.1q Trunk VLANs 110 and 10 VLAN 10 VLAN 110 228545 Posture Assessment Authenticated Access To deploy the NAC Appliance in OOB mode. both unauthenticated and authenticated. After the user is authenticated and passes posture assessment.Chapter 5 Network Access Security and Control Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-17 Layer 2 OOB Topology Clean Access VLAN 10 Manager (CAM) VLAN 99 VLAN 10 VLAN 110 Clean Access Server (CAS) 802. and is moved to VLAN 10 after it successfully completes the authentication/authorization and scan/evaluation phases of the NAC Appliance solution.

Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Network Access Security and Control Figure 5-18 In-Band Virtual Gateway Topology Clean Access VLAN 10 Manager (CAM) VLAN 99 VLAN 10 Clean Access Server (CAS) VLAN 110 VLAN 110 VLAN 110 228546 228547 Posture Assessment Authenticated Access Figure 5-19 Physical In-Band Topology Clean Access Manager (CAM) VLAN 99 VLAN 10 VLAN 10 Clean Access Server (CAS) VLAN 110 Posture Assessment Authenticated Access In-Band Virtual Gateway When the NAC Appliance is configured as a virtual gateway. the NAC server bridges traffic from its untrusted interface to its trusted interface. and undergo Medium Enterprise Design Profile Reference Guide 5-37 . it acts as a bridge between the end users and the default gateway (router or switch) for the client subnet being managed. authenticate. The following two bridging options are supported by the NAC server: • Transparent—For a given client VLAN. The NAC server is aware of “upper layer” protocols and is able to permit those protocols that are necessary for a client to connect to the network.

as shown in Figure 5-19. the NAC server by default routes traffic from the untrusted networks to the trusted interface. static routes must be configured in the NAC server. After Enforcement is achieved through being inline with traffic. The process is reversed for packets returning to the client. VLAN 10 is configured between the trusted interface of the NAC server and the next-hop router interface (or SVI) for the client subnet. that. There is no routed interface or SVI associated with VLAN 110. Depending on the topology. posture assessment. By default. In-Band Versus Out-of-Band Table 5-1 summarizes various characteristics of the two deployment types. in this mode. Multiprotocol Label Switching (MPLS) VPN. In-Band Real IP Gateway When the NAC server is configured as a “real” IP gateway. static routes. user traffic does not go to the CAS. If one or more Layer 3 hops exist between the untrusted NAC interface and the end-client subnets. one or more client VLAN/subnets resides behind the untrusted interface. of authentication. and remediation). client VLAN 110 is defined for the untrusted interface of the NAC server. where it is then forwarded based on the routing topology of the network. such as DNS and DHCP. These static routes should reference the IP address of the NAC server trusted interface as its next hop. posture assessment. including ACLs. multiple options exist to facilitate routing clients to and from the NAC server. and those protocols explicitly permitted in the “unauthorized” role. After successful client authentication and posture assessment. Medium Enterprise Design Profile Reference Guide 5-38 . For example. BPDUs are not passed from the untrusted-side VLANs to their trusted-side counterparts. as shown in Figure 5-18. Enforcement is achieved through the use of SNMP to control switches and VLAN assignments to end-user ports. Also. static routes must be configured within the trusted side of the Layer 3 network for each client subnet terminating on or residing behind the untrusted interface. A mapping rule is made in the NAC server that forwards packets arriving on VLAN 110 and forwards them out VLAN 10 by swapping VLAN tag information. a single VLAN/subnet is defined on the trusted interface. it blocks all traffic except for Bridge Protocol Data Unit (BPDU) frames (spanning tree). Conversely. In this scenario. The NAC server acts as a default gateway for all clients residing on those networks. This option is viable when the NAC server is positioned physically in-band between the end users and the upstream network(s) being protected. The NAC server is not currently able to support dynamic routing protocols. which represents the path to the protected upstream network(s). and other segmentation techniques. The VLAN mapping option is typically used when the NAC server is positioned logically in-band between clients and the network(s) being protected. PBR. These options are discussed in later sections. and remediation.Chapter 5 Network Access Security and Control Medium Enterprise Design Profile (MEDP)—Network Security Design posture assessment and remediation. In addition. two separate VLANs are used. This is the bridging option that should be used if the NAC Appliance is deployed in virtual gateway mode. Table 5-1 In-Band versus Out-of-Band Characteristics In-Band Deployment Characteristics Out-of-Band Deployment Characteristics The CAS is always inline with user traffic (both before and The CAS is inline with the user traffic only during the process after authentication. • VLAN mapping—This is similar in behavior to the transparent option except that rather than bridging the same VLAN from the untrusted side to the trusted side of the NAC server. it behaves like a router and routes packets between its interfaces. VRF-Lite. a static default route is required within the downstream Layer 3 network (referencing the IP address of the untrusted NAC server interface) to facilitate default routing behavior from the client networks to the NAC server. Therefore.

Medium Enterprise Design Profile Reference Guide 5-39 . the NAC Solution must be deployed in in-band mode. Does not provide switch port level control. OOB NAC deployments for wireless require the NAC server to be deployed in Layer 2 OOB virtual gateway (bridge) mode. and for wired clients. and so on. If access switches are to be used that are not supported. and remediation process.1X in an OOB deployment. A CAS is deployed at each of the sites (main and remote sites) and is connected within the service block connecting to the core switches at each of the sites. 1. Provides port-level control by assigning ports to specific VLANs as necessary using SNMP. post remediation because traffic is out-of-band. bandwidth policies. NAC Deployment in the Medium Enterprise Design Profile Within the Medium Enterprise Design Profile. Layer 2 and Layer 3 Out-of-Band The proposed deployment option for the Medium Enterprise Design Profile is an OOB design.com/en/US/docs/security/nac/appliance/configuration_guide/47/cam/47cam-book. This provides the highest possible performance and scalability for traffic that has completed the authentication. and remote small site. The Medium Enterprise Design Profile accommodates host network connectivity using wired and wireless technologies. Out-of-Band Requirements OOB implementation of Cisco NAC Appliance requires the access switches and WLCs to be supported by the NAC Appliance software for the NAC Manager to make the necessary changes to the switch ports and WLCs during the authentication.cisco. posture assessment. the NAC Appliance solution must provide a solution for both connectivity options. and remediation phases but cannot do so protocol.1X. Cisco NAC in-Band deployment with supported Cisco switches is compatible with 802. remote medium site. Wireless OOB requires a specific network topology.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Network Access Security and Control Table 5-1 In-Band versus Out-of-Band Characteristics (continued) The CAS can be used to securely control authenticated and The CAS can control user traffic during the authentication. a Cisco NAC Appliance solution is deployed at each of the site types. a Layer 2 OOB or Layer 3 OOB solution can be deployed. unauthenticated user traffic policies (based on port. and remediation stages of NAC.ht ml. subnet). assessment. a Layer 2 OOB solution should be deployed and for wired users. posture assessment. and the NAC server must be placed Layer 2-adjacent to the wireless LAN controller (WLC). remote large site. see the latest version of the Cisco NAC Appliance-Clean Access Manager Installation and Administration Guide at the following URL: http://www.1 Cisco does not recommend using 802. To obtain the latest list of supported devices. For wireless clients. For wireless clients. OOB deployments support wired and wireless clients.1X in setting the VLAN on the switch interfaces/ports. depending on the topology of your network. a Layer 2 OOB or a Layer 3 OOB NAC solution may be deployed. a Layer 2 OOB NAC solution is deployed. because conflicts will likely exist between Cisco NAC Appliance OOB and 802. In-band deployment is supported for wired and wireless clients. main or headquarters site. As such. A centralized CAM is deployed at the main site and is deployed within the data center at that site.

In the Medium Enterprise Design Profile. When NAC authentication. which is trunked to the CAS untrusted interface. The NAC Manager is implemented in the data center block. as detailed in Chapter 4. When a wireless client associates to the WLC. as shown in Figure 5-20. See Figure 5-21. and remediation stages are complete and the user is certified.Chapter 5 Network Access Security and Control Medium Enterprise Design Profile (MEDP)—Network Security Design NAC Deployment for Wireless Clients To provide network access control for wireless clients within the Medium Enterprise Design Profile. posture assessment. On the switch. Figure 5-20 NAC OOB Deployment for Wireless Clients Access AP Distribution Service Block Clean Access Server (CAS) Core WLC Internet Edge Internet QFP Data Center Clean Access Manager (CAM) WAN Edge The WLC connects to the service block switch using a trunk port carrying the unauthenticated quarantine VLAN and authenticated access VLAN (VLAN 20 and 120). and the access VLAN is trunked directly to the Layer 3 switch interface. Traffic that reaches the quarantine VLAN on the CAS is mapped to the access VLAN based on a static mapping configuration within the CAS. Medium Enterprise Design Profile Reference Guide 5-40 228548 MetroE QFP HDLC . the NAC server must be placed Layer 2-adjacent to the WLC. the traffic then bypasses the NAC server and goes directly to the network. the recommended design is the virtual gateway (bridge mode) and central OOB deployment. In this design. the NAC Manager sends an SNMP set message to the WLC that updates the VLAN ID from the quarantine VLAN to the access VLAN. it initially maps the WLAN/SSID to the quarantine VLAN interface and the client traffic flows in the quarantine VLAN (VLAN 120). “Medium Enterprise Design Profile (MEDP)— Mobility Design.” Therefore. the NAC server must also be implemented in the service block. the quarantine VLAN is trunked to the untrusted interface on the NAC server (CAS). the WLCs are centrally deployed at each site and are implemented in the service block off the core switches. After this occurs.

1q Trunk VLANs 120 and 20 LWAPP LWAPP VLAN 20 VLAN 120 Posture Assessment Authenticated Access When implementing the NAC OOB wireless solution.sht ml. see the NAC Out-Of-Band (OOB) Wireless Configuration Example at the following URL: http://www. Medium Enterprise Design Profile Reference Guide 228549 5-41 . users are still automatically authenticated.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Network Access Security and Control Figure 5-21 Wireless NAC OOB Traffic Flow Clean Access Manager (CAM) VLAN 20 VLAN 20 VLAN 99 VLAN 120 Clean Access Server (CAS) 802. Note If VPN SSO authentication is enabled without the Clean Access Agent installed on the client PC. they are connected to their originally requested URL. However. the NAC server can be configured to forward the accounting packet to the RADIUS server. they are momentarily redirected (without a logon prompt) within the agentless phase. In the event that accounting records need to be forwarded to a RADIUS server upstream in the network. VPN SSO uses RADIUS accounting records to notify the NAC Appliance about authenticated remote access users that connect to the network. The most transparent method to facilitate wireless user authentication is to enable VPN SSO authentication on the NAC server and configure the WLCs to forward RADIUS accounting to the NAC server. they are not automatically connected through the NAC Appliance until their web browser is opened and a connection attempt is made. coupled with the Clean Access Agent software that runs on the client PC. For more information on deploying NAC OOB for wireless environments. when users open their web browser. This option makes use of the VPN SSO capability of the NAC solution.com/en/US/products/ps6128/products_configuration_example09186a0080a138cc. this feature can be used in conjunction with the WLAN controller to automatically inform the NAC server about authenticated wireless clients that connect to the network. which is an option that does not require user intervention and is relatively easy to implement. In this case. When the SSO process is complete. it is recommended to enable RADIUS single sign-on (SSO).cisco. In the same way.

ACLs should be applied on the SVIs for the dirty VLAN. The benefit to the second approach is that minimal configuration changes are required to your core infrastructure. For more information on this approach. the same NAC server can be leveraged for both wired and wireless clients. The ACLs on the Layer 3 edge access switches act as the enforcement point to ensure segregation between the “clean” and “dirty” networks. and remediation purposes: • Access control lists—Use ACLs on the edge access switches to allow traffic from the unauthenticated VLAN only to the NAC server untrusted interface and specific infrastructure resources needed to get on the network for authentication purposes such as DHCP. an L3 OOB NAC deployment is recommended. After users are certified by the NAC server. in which case all Layer 3 devices participate in the tag switching. Traffic policies configured on the NAC server (CAS) are used for enforcement on the dirty network. they are placed in the authenticated access VLAN. When clients first attach to the network. DHCP. and remediation servers. separate NAC servers must be deployed for wired and wireless users. see the following URL: http://www. the Medium Enterprise Design Profile also uses a central OOB NAC deployment with a NAC server implemented at each of the sites deployed in the service block off the core switch. DNS. VRFs/GRE/MPLS—Use VRFs to route unauthenticated traffic to the CAS. when a user connects to the access switch before being certified by the NAC server. • • The most common approach used for isolating the dirty VLAN traffic is to use ACLs. large. and Active Directory servers. For the main. Thus.shtml. This ACL should block all access from the dirty VLAN going to the internal networks and allow traffic only to the untrusted interface on the NAC server. the user is placed in the authentication VLAN (also called “dirty” VLAN). This approach has two sub-approaches. the needed remediation servers. Layer 3 Out-of-Band Deployment Layer 3 (L3) OOB is best suited for routed access designs and has rapidly become one of the most popular deployment methodologies for NAC. if the Layer 3 OOB solution is deployed.com/en/US/products/ps6128/products_configuration_example09186a0080a3a8a 7. Policy-based routing—Use PBR to redirect all traffic in the dirty VLAN to the NAC server. The user should not have access to any part of the network from the authentication VLAN except for the NAC server and the remediation servers in the quarantine segment.cisco. In the L3 OOB NAC solution. Medium Enterprise Design Profile Reference Guide 5-42 . All other traffic from the dirty VLAN must be blocked. a Layer 3 OOB or Layer 2 OOB solution can be deployed. In the first approach. The second approach uses VRF-Lite and GRE tunnels to tunnel the VRFs through the Layer 3 devices that do not understand tag switching. This deployment also allows NAC Appliances to be centrally located rather than distributed across the site or organization. VRFs are pervasive throughout the infrastructure. L3 OOB deployments are much more cost-effective. PBR needs to be configured on every Layer 3 hop between the dirty VLAN and the NAC server to ensure that traffic is appropriately redirected. The following are three widely deployed techniques for redirecting client traffic from the dirty VLAN to the NAC server for authentication. By deploying NAC in an L3 OOB methodology. given the 3-tier hierarchical design. However. they are placed in a quarantine or dirty VLAN on the access switches. a single NAC Appliance can scale to accommodate more users. posture assessment. If the Layer 2 OOB solution is used. and medium remote site locations. Depending on the type of network topology deployed. and a few infrastructure devices needed for network access such as the DNS. both from a capital and operational expense standpoint.Chapter 5 Network Access Security and Control Medium Enterprise Design Profile (MEDP)—Network Security Design NAC Deployment for Wired Clients For wired clients. where their traffic is switched normally through the network and bypasses the NAC server.

Methods for getting the dirty VLAN traffic to the untrusted interface vary. Option 2—Create a dummy DNS server for the unauthenticated user subnet. “Medium Enterprise Design Profile (MEDP)—LAN Design. The discovery host value in the NAC Agent points to the untrusted interface of the NAC server. the user is not automatically redirected to the login page when first opening the browser. the unauthenticated and authenticated VLANs on the access switch (VLANs 30 and 130) are extended to the core/distribution switch using a trunk connection. a Layer 2 Out-of-Band (L2 OOB) NAC deployment can be used. When guests open a browser.nac. When the NAC agent is used. collapsed core/distribution LAN design is recommended. In the L2 OOB NAC design for the small remote site. the NAC server untrusted interface is not directly in the path of the data traffic. the guest must open a browser and manually enter this URL. the NAC Agent can be used for managed PCs. In this case. the NAC Agent communicates with the NAC server untrusted interface to initiate the login process. as shown in Figure 5-22. The ACLs on the access switches act as the enforcement point for path isolation for the dirty VLAN traffic. When users are then moved to the respective Role/VLAN.local). The NAC Agent tries to discover the NAC server based on the known discovery host value. therefore. they get a new DNS address assignment when performing IP release/renew on a successful login. The following two options can enable the end host to get the login page: • • Option 1—Have a guest login URL known to the users (for example. This dummy DNS server resolves every URL to the untrusted interface of the NAC server. In the Medium Enterprise Design Profile. guest. as explained in Chapter 2. With the ACL isolation technique. regardless of which URL they are trying to reach. Web login may also be required for devices that are not managed.” In a collapsed core/distribution design. In this simple topology. which redirects them to the login page. they are redirected to the login page.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Network Access Security and Control The clients need to communicate with the NAC server untrusted interface for the certification process. the CAS should be deployed in the services block connected to the core/distribution switch. Figure 5-22 Layer 2 OOB Topology Clean Access VLAN 30 Manager (CAM) VLAN 99 VLAN 30 VLAN 130 Clean Access Server (CAS) Virtual GW 130<->30 802.1q Trunk VLANs 130 and 30 VLAN 30 VLAN 130 229407 Posture Assessment Authenticated Access Medium Enterprise Design Profile Reference Guide 5-43 . Layer 2 Out-of-Band Deployment For the small remote sites. depending on whether the NAC Client Agent is used. a two-tier.

However. Secure Mobility Today’s workers use laptops. Like the CAS. Although the client has changed Layer 2 VLANs. and if NAC is deployed in in-band mode. assets. To continue to foster innovation. the CAM has an HA solution that provides for a primary server and a hot standby secondary server. each CAS may be configured with a fallback option that defines how it manages client traffic in a situation where the CAM is unavailable. In addition. Medium Enterprise Design Profile Reference Guide 5-44 . even during a network outage. companies must adapt to the changing trends in mobility. In situations where availability of a CAS is critical. However. While embracing a mobile workforce clearly boosts productivity and makes the medium enterprise more competitive. and where to access both personal and professional information to be productive without being inconvenienced by security checks. In addition. and network remain secure. spyware. authorization. the access switch is instructed. A CAS outage for inline clients prevents access for all clients.com/en/US/docs/security/nac/appliance/configuration_guide/461/cas/461cas-book. when. After the client is authenticated and passes the posture assessment. to change the client VLAN to the authenticated VLAN (VLAN 30). Consideration must be given to the impact on clients if either a CAS or CAM fails or needs to be taken out of service for a period of time.cisco. A viable solution is one that enables access for mobile workers while ensuring that the corporate data. operating systems. allowing the client to obtain an IP address that belongs on VLAN 30. the impact of its availability needs to be considered in the network design as well. The CAM is also a critical part of the authentication. which connects the client directly to the untrusted interface of the CAS. it is inline even after authentication and certification. a number of challenges arise from the use of mobile technologies. and a secondary in hot standby. NAC Availability Considerations Both the CAS and CAM are highly involved in client network access. users want the flexibility of choosing how. The use of the CAM and CAS HA features depends on the requirements of the enterprise. The CAS maps VLAN 130 to the VLAN 30 trusted interface. The CAS is inline with client devices during the authentication. the great variety in hardware types. and posture assessment phases of NAC. a high availability (HA) CAS solution can be implemented where a pair of CAS servers are installed using a primary CAS. authorization.ht ml. if NAC is deployed in OOB mode. see the Cisco NAC Appliance . For more information. and other types of malware as mobile workers connect back to the corporate network. Although it does not pass client traffic. Workers often use the same devices to access both business and personal information. via SNMP from the CAM. where the traffic now bypasses the CAS to access the rest of the network.Chapter 5 Secure Mobility Medium Enterprise Design Profile (MEDP)—Network Security Design When a client device initially connects to the access switch before authentication. it is placed in the unauthenticated VLAN (VLAN 130). worms. Additionally. and applications represents a clear challenge to the enforcement of security controls and policies. Devices used outside the enterprise onsite controls may potentially introduce viruses. enable productivity. smartphones. CAS fallback should always be configured to ensure that critical network services are available. a CAS outage does not affect already connected clients but does prevent network access for new clients. and meet the needs of the mobile workforce.Clean Access Server Installation and Configuration Guide at the following URL: http://www. Confidential and proprietary information may also be lost or stolen while mobile users connect outside the company premises. and other smart mobile devices to access information and applications at anytime and from anywhere there is an Internet connection. and posture assessment phases of NAC. its Layer 3 network connections are unchanged.

Persistent security and policy enforcement—The Web Security appliance applies context-aware policies. The products that work together to provide AnyConnect Secure Mobility are as follows: • • • Cisco IronPort Web Security Appliance (WSA) Cisco ASA 5500 Series Adaptive Security Appliance (ASA) Cisco AnyConnect client Cisco AnyConnect Secure Mobility addresses the challenges of a mobile workforce by offering the following features: • Secure. it is also flexible enough to apply different policies based on location. when users must accept terms of agreement before accessing the Internet. persistent connectivity to all mobile employees independently from the type of mobile device used. • Figure 5-23 shows the relationship between the various elements of the Cisco AnyConnect Secure Mobility solution. no matter when. The connection is secure because both the user and device must be authenticated and validated before being provided access to the network. including enforcing acceptable use policies and protection from malware for all users. providing an automatic authentication step for the user to access web content. The Cisco AnyConnect Secure Mobility is a collection of features across multiple Cisco products that extends control and security into borderless networks. and how they connect to the network. allowing users access to the Internet in a “captive portal” situation. where. including mobile (remote) users. This solution delivers secure. The Cisco AnyConnect Secure Mobility solution also ensures a consistent enforcement of the network security policies to all users. Figure 5-23 Cisco AnyConnect Secure Mobility Solution Combined Solution End-to-End Seamless Security Information Sharing Between Cisco ASA and Cisco WSA News Email AnyConnect ASA www Cisco Web Security Appliance Social Networking Enterprise SaaS Cisco AD Medium Enterprise Design Profile Reference Guide 229290 5-45 .Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Secure Mobility The Medium Enterprise Design Profile provides persistent and secure mobile access by implementing the Cisco AnyConnect Secure Mobility solution. Although Cisco AnyConnect is always-on. persistent connectivity—Cisco AnyConnect (with the Cisco ASA at the headend) provides the remote access connectivity portion of AnyConnect Secure Mobility. The WSA also accepts user authentication information from the AnyConnect client. The connection is persistent because Cisco AnyConnect is typically configured to be always-on even when roaming between networks.

Table 5-2 summarizes how the security tools and measures used in the Medium Enterprise Design Profile help mitigate certain threats. Threats Mitigated The success of the security tools and measures in place ultimately depends on the degree they enhance visibility and control. and how they contribute to increasing visibility and control. the enterprise can more easily and quickly update security updates and acceptable use policies because the enterprise does not have to wait days. This improves overall performance by not burdening the mobile device. The WSA tracks the requests it receives and applies policies configured for remote users to traffic received from remote users. The Cisco ASA returns all traffic deemed safe and acceptable to the user.html. it is difficult to enforce any control. security can be defined as a function of visibility and control. and without any control it is hard to achieve an adequate level of security. some of which have limited processing power. or even months to push the updates to the client. Therefore. Note that the table is provided for illustration purposes and it is not intended to include all possible security tools and threats. Simply put. not the client on the mobile device.Chapter 5 Threats Mitigated Medium Enterprise Design Profile (MEDP)—Network Security Design Remote and mobile users use the Cisco AnyConnect Secure VPN client to establish VPN sessions with the Cisco ASA appliance.com/en/US/netsol/ns1049/index. by scanning Internet traffic on the network. Table 5-2 Security Measures of the Enterprise Design Profile for Small Enterprise Networks Service Disruption Network Foundation Protection Stateful Firewall IPS Security Mobility Web Security E-mail Security Access Security and Control Harmful Content Network Abuse Unauthorized Access Yes Data Loss Visibility Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Control Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Medium Enterprise Design Profile Reference Guide 5-46 . The WSA scans the traffic. enforces acceptable use policies.cisco. For complete details about the Cisco AnyConnect Secure Mobility solution. The Cisco ASA sends web traffic to the WSA appliance along with information identifying the user by IP address and user name. weeks. the security tools selected in the enterprise network design were carefully chosen not only to mitigate certain threats but also to increase the overall visibility and control. In addition. Without any visibility. All Internet traffic scanning is done by the WSA. see the documentation available at the following URL: http://www. and protects the user from security threats.

219. invalid source addresses.255 any Medium Enterprise Design Profile Reference Guide 5-47 . and that the upstream link is configured in the 64.219.219.0 0.16.0.0. RFC 1918 space.0. This includes restricting and controlling administrative access.0. The configuration assumes the enterprise is assigned the 198.255.133. and spoofs of the internal address space. access-list 110 deny ip 10.255 fragments • Deny special-use address sources.0 0.0.0 31.0.255.133.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Network Security Deployment Guidelines The previous sections of this document provide design guidelines and considerations for deploying security within a medium enterprise network environment. the Internet border router may be leveraged as the first layer of protection against outside threats. access-list 110 deny tcp any 198.255 any 224.0.) access-list access-list access-list access-list 110 110 110 110 deny deny deny deny ip ip ip ip host 0. Security features and devices covered include the following: • • • • • • Internet Border Router Edge ACL Deployment Internet Firewall Deployment IPS Global Correlation Deployment Web Security Deployment Catalyst Integrated Security Features Deployment NAC Deployment for Wired and Wireless Clients Internet Border Router Edge ACL Deployment Whether the Internet border router is managed by the enterprise or the ISP. • Deny fragments.104.255.255.0 any 127.0.255. In addition.0.255 fragments access-list 110 deny udp any 198. edge ACLs.219.0 0.168.255.0.10.0.0 0. Module 1—Implement Anti-spoofing Denies These ACEs deny fragments.0 0.0.255.0 0.0.0. The following configuration snippets illustrate the structure of an edge ACL applied to the upstream interface of the Internet border router.133.255 any • Filter RFC 1918 space.255 any access-list 110 deny ip 172.15. (See RFC 3330 for additional special-use addresses.0 0. and securing the dynamic exchange of routing information.0.255 any 192.0/24 subnet. it must be hardened following the best practices discussed in the “Network Foundation Protection” section on page 5-6. The sections that follow provide deployment and configuration examples and guidelines for deploying some of these features.255 fragments access-list 110 deny icmp any 198.0.0.0.255. To that end. uRPF and other filtering mechanisms may be implemented for anti-spoofing and to block invalid packets.0/24 address block for its public-facing services.0.0 0. The ACL is designed to block invalid packets and to protect the infrastructure IP addresses from the Internet.2. protecting the management and control planes.0.133.255 any access-list 110 deny ip 192.

10. The source of the traffic should be known and authorized.104. Inc. Internet Firewall Deployment The Internet firewall is responsible for protecting the enterprise's internal resources and data from external threats.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design • Deny packets spoofing the enterprise public addresses. • Permit external BGP to peer 64.255 Note The 64. and to control user's traffic to the Internet.0.10.219.0.0. access-list 110 deny ip 198.255 any Module 2—Implement Explicit Permits Permit only applications/protocols whose destination address is part of the infrastructure IP block.104.10.219.255 any Module 4—Implement Explicit Permit for Traffic to the Enterprise Public Subnet access-list 110 permit ip any 198.0.0 0. Medium Enterprise Design Profile Reference Guide 5-48 .113 eq bgp access-list 110 permit tcp host 64.10.104.104.0 0.0/24 address blocks used in the examples in this document are reserved for the exclusive use of Cisco Systems.133.113 Module 3—Implement Explicit Deny to Protect Infrastructure access-list 110 deny ip 64. The Medium Enterprise Design Profile uses a Cisco ASA appliance for the Internet Firewall.104.0 0.114 eq bgp host 64.114 host 64. securing the public services provided by the DMZ.0. see “Chapter 6.0/16 and 198.cisco.com/en/US/docs/solutions/Enterprise/Security/SAFE_RG/chap6.10.104. For more information and configuration examples on how to secure the Internet border router using the other Network Foundation Protection features.104.0.0.html.219. as illustrated in Figure 5-24. Enterprise Internet Edge” in the Cisco SAFE Reference Guide at the following URL: http://www.133.133.10.113 access-list 110 permit tcp host 64.

Demilitarized zone (DMZ)—The DMZ hosts the enterprise's public-facing services that are accessible over the Internet. The router may be managed either by the enterprise or a service provider. 100. and therefore should be given any security value between the ones defined for the inside and the outside interfaces. 0. its deployment should be carefully planned. Therefore. The inside interface connects to the internal trusted networks. Wireless guest access clients should have access only to the Internet and not to any internal resources. therefore. Guest access—The interface connecting to the LAN segment that wireless guest access in which clients will be placed by the anchor WLC in the DMZ. therefore it is given the highest security level. The DMZ serves a medium-level security segment. for example. The following are key aspects to be considered when implementing the firewall: • • • • • • Firewall hardening and monitoring Network Address Translation (NAT) Firewall access policies Firewall redundancy Routing Botnet Traffic Filter Medium Enterprise Design Profile Reference Guide 5-49 229408 . therefore. 10. for example. 50. it is given the lowest security level. The outside interface connects to the Internet. they should be given a value lower than the internal and DMZ interfaces.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Figure 5-24 Access Internet Edge Firewall Internet Edge Wireless Guest Users Distribution Core Catalyst 3750E Stack Cisco ASA 5540 Inside DMZ Catalyst Guest 3750E Access Stack Outside Internet Border Router Internet QFP Secure Mobility Cisco IPS SSM-20 Cisco Security Intelligence Operation Anchor WLC SensorBase WAN Edge www Web Security QFP MetroE HDLC Web Server Email Security Email Server The Cisco ASA is implemented with four interface groups with each group representing a distinct security domain: • Inside—The interface connecting to the distribution switch that faces the interior of the network where internal users and resources reside. • • • The Internet firewall acts as the primary gateway to the Internet. These services may include the company’s website and E-mail services. Outside—Interface connecting to the Internet border router.

254. The following Cisco ASA configuration fragment illustrates the configuration needed to generate a 768 RSA key pair and enable SSH and HTTPS access for devices located in the management subnet.255. Management access to the firewall should be restricted to SSH and HTTPS. Use a local fallback account in case the AAA server is unreachable. banner motd All activities performed on this device are logged and monitored. banner motd You must have explicit.170 255.26. Using a dedicated management interface keeps the management plane of the firewall isolated from threats originating from the data plane.136. Limit access to known IP addresses used for administrative access. Implement firewall access policies (explained in “Firewall Access Policies” section on page 5-52). Additionally. Use NTP to synchronize the time. ! Generate RSA key pair with a key modulus of 768 bits Medium Enterprise Design Profile Reference Guide 5-50 . the following is a summary of the measures to be taken: • • • • • • • • Implement dedicated management interfaces to the OOB management network. banner motd Unauthorized attempts and actions to access or use this system may result in civil and/or criminal penalties.0 management-only ! Note Any physical interface or logical sub-interface can be configured as a management-only interface using the management-only command.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design Firewall Hardening and Monitoring The Cisco ASA should be hardened in a similar fashion as the infrastructure routers and switches. authorized permission to access or configure this device. this access should only be permitted for users authorized to access the firewalls for management purposes. The notification banner should be written in consultation with your legal advisors. SSH is needed for CLI access and HTTPS is needed for the firewall GUI-based management tools such as CSM and ASDM. The Cisco ASA 5510 and higher appliance models come with a dedicated management interface that should be used whenever possible. if one is available. Use syslog or SNMP to keep track of system status. Use HTTPS and SSH for device access. Configure AAA for role-based access control and logging. Authenticate routing neighbors and log neighbor changes. Present legal notification for all access attempts. and device access information. The following example displays the banner after the user logs in: banner motd UNAUTHORIZED ACCESS TO THIS DEVICE IS PROHIBITED. traffic statistics. The management interface should connect to the OOB management network. It is recommended that a legal notification banner is presented on all interactive sessions to ensure that users are notified of the security policy being enforced and to which they are subject. According to the Cisco SAFE security best practices. The following is an example of the configuration of a dedicated management interface: interface Management0/0 nameif management security-level 100 ip address 172.

and log user access to the firewall: aaa-server tacacs-servers protocol tacacs+ reactivation-mode timed aaa-server tacacs-servers host <ACS-Server> key <secure-key> aaa authentication ssh console tacacs-servers LOCAL aaa authentication serial console tacacs-servers LOCAL aaa authentication enable console tacacs-servers LOCAL aaa authentication http console tacacs-servers LOCAL aaa authorization command tacacs-servers LOCAL aaa accounting ssh console tacacs-servers aaa accounting serial console tacacs-servers aaa accounting command tacacs-servers aaa accounting enable console tacacs-servers aaa authorization exec authentication-server ! define local username and password for local authentication fallback username admin password <secure-password> encrypted privilege 15 As with the other infrastructure devices in the network.255. NetFlow Security Event Logging (NSEL). authorize. authorized.32. may also be used for the monitoring and reporting of session activity.255 management ! restrict SSH access to the firewall to well-known administrative systems ssh <admin-host-IP-address-subnet> 255.255.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines crypto key generate rsa modulus 768 ! Save the RSA keys to persistent flash memory write memory ! enable HTTPS http server enable ! restrict HTTPS access to the firewall to permitted management stations http <CSM/ADSM-IP-address> 255. and access should be logged using AAA.240 Medium Enterprise Design Profile Reference Guide 5-51 .18 255.255.125. device access and session activity.255. The following Cisco ASA configuration fragment illustrates the use of EIGRP MD5 authentication to authenticate the peering session between the inside firewall interface and the Internet edge distribution switch: interface Redundant1 description connection to CR12-3750s-IE distribution switch nameif inside security-level 100 ip address 10. The following configuration fragment illustrates the NTP configuration needed on a Cisco ASA to enable NTP to an NTP server located in the management network: ntp ntp ntp ntp authentication-key 10 md5 * authenticate trusted-key 10 server <NTP-Server-address> source management Syslog and SNMP can be used to keep track of system status. logging trap informational logging host management <Syslog-Server-address> logging enable The routing protocol running between the Internet firewall and the distribution switch should be secured.0 management ! Configure a timeout value for SSH access to 5 minutes ssh timeout 5 Administrative users accessing the firewalls for management must be authenticated.255. it is important to synchronize the time on the firewall protecting the management module using NTP. now supported on all Cisco ASA models. The following configuration fragment illustrates the configuration of Syslog.255. The following Cisco ASA configuration fragment illustrates the AAA configurations needed to authenticate.

255 ! ! Dynamic Port Address Translation (PAT) for inside hosts and wireless guest access ! clients going to the Internet global (outside) 10 interface nat (inside) 10 10. In addition. and 0.255.255. The following illustrates the NAT configuration: ! Static translation for servers residing at DMZ static (dmz.133.255. At the same time.133.255.0.125. However.0. 10.0.219.0 10. ! The inside IP addresses are visible to the DMZ.0. respectively.219.240 ! ! Static translation for inside hosts going to the DMZ and vice-versa.125.outside) 198.32.125. and from the guestaccess to the outside is allowed freely.219.255.255 static (dmz.255.outside) 198.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design authentication key eigrp 100 <removed> key-id 1 authentication mode eigrp 100 md5 Network Address Translation (NAT) NAT is required because enterprises typically get a limited number of public IP addresses. and outside. the security administration is recommended to override the default rules with more stringent rules indicating exactly what ports and protocols are permitted.133.32. from inside to outside).125.0.255. In this configuration example.0.outside) 198.0. NAT helps shield the company's internal address space from reconnaissance and other malicious activity.41 10. the Cisco ASA appliance allows traffic from higher to lower security level interfaces (that is. it is always a good idea to reinforce the policies by enforcing granular ACLs. Medium Enterprise Design Profile Reference Guide 5-52 .219. static (inside. from the DMZ to the guestaccess and outside interface.133.255.255 static (dmz.35 netmask 255. DMZ.32.35 10.dmz) 10. By default.32. and from the DMZ to the guestaccess and inside interfaces is blocked. Although this may satisfy the basic access control requirements of the organization.40 netmask 255.255. by default any traffic originating from the inside to the DMZ.64 255.40 10.0 Firewall Access Policies The Internet firewall should be configured with access policies to do the following: • • • • Protect the enterprise’s internal resources and data from external threats by preventing incoming access from the Internet Protect public resources served by the DMZ by restricting incoming access to the public services and by limiting outbound access from DMZ resources out to the Internet Control user's Internet-bound traffic Preventing wireless guest access users from accessing internal resources Enforcing such policies requires configuration of the appropriate interface security levels and the deployment of ACLs to control what traffic is allowed or prevented from transiting between interfaces. guestaccess.255 static (dmz.0 255.36 netmask 255.0. 50.125.0 nat (guestaccess) 10 10.0. and outside interfaces were configured with the security levels of 100. depending on the sensitivity of an enterprise environment. guestaccess. guestaccess. any traffic originating from the outside to the DMZ.outside) 198. and inside. the inside.32.41 netmask 255.0 netmask 255. With this.36 10.0.255.

0 host 10.0.124.125.30.125.32.66 host 10.125. UDP 16667. Permit management traffic from the management segment to the Anchor WLC in the DMZ (SNMP. Depending on the policy of the enterprise.255.0.30.32. The following example allows only HTTP and HTTPS access to the Internet: access-list outbound extended permit tcp 10.3 host 10.0.34 eq snmp access-list outbound extended permit udp 10.125.125.31.34 eq 16666 access-list outbound extended permit udp host 10.0.255.0.125.32.125.125.0.125.255.0 host 10.3 host 10.0 255. Permit tunneled control and user traffic from internal WLCs to the Anchor WLC in the DMZ for wireless guest access (UDP 16666.2.0.3 host 10.0.0 host 10.34 eq 16666 access-list outbound extended permit udp host 10.40 eq smtp access-list outbound extended permit tcp 10.32.34 eq 16667 access-list outbound extended permit udp host 10. In the following sample configurations.2 host 10.125.30.0.255.125.0 255.0 host 10.32.32.0 host 10. and HTTPS).125. as the Cisco ASA inspects traffic.0.0 255.30.125. ! Allow DNS queries to DNS server located in DMZ access-list outbound extended permit udp 10.0.0.124.255. IP Protocol 97). the firewall ACLs should be constructed to match traffic in the direction in which it is being initiated. IMAP.2 host 10.0. and DNS protocols.0. SSH. The following are guidelines and configuration examples for the ACLs controlling access and traffic flows: • Ingress inside Allow users residing at all enterprise sites to access the Internet for the allowed ports and protocols. POP3 and IMAP access to DMZ mail server access-list outbound extended permit tcp 10.0 255.32. This can include HTTP.34 eq 16667 access-list outbound extended permit udp host 10.32.30. Therefore.34 eq 16667 access-list outbound extended permit 97 host 10.34 eq snmptrap access-list outbound extended permit tcp 10.0 255.35 eq domain ! Allow SMTP.32.125.125.0. or may be less restrictive to allow additional protocols and ports.34 access-list outbound extended permit 97 host 10.0.32.32.32.32. this may allow only HTTP and HTTPS access.0.0 255.125.0.2 host 10.2.125.124.125.125.32.0. POP.0.125.34 eq ssh ! ! Apply ACL to inside interface access-group outbound in interface inside Medium Enterprise Design Profile Reference Guide 5-53 .Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Note also that.0 any eq https Allow users access to DMZ services such as the company’s web portal.0 255.34 ! Allow management access to the Anchor WLC on the DMZ access-list outbound extended permit udp 10.34 access-list outbound extended permit 97 host 10.34 eq 16666 access-list outbound extended permit udp host 10. and domain name resolution.32. SMTP.40 eq pop3 access-list outbound extended permit tcp 10.125.30.0 255.66 host 10.0 any eq www access-list outbound extended permit tcp 10. Note that the previous entries in the ACL already permit HTTP and HTTPS traffic.66 host 10. it is able to recognize packets belonging to already established sessions. HTTPS.255.0.125.125. The stateful inspection engine of the firewall dynamically allows the returning traffic associated with those sessions.31.0 host 10.0.0. E-mail.40 eq imap4 ! Allow access to the Anchor WLC on the DMZ from the internal WLCs for wireless Guest access access-list outbound extended permit udp host 10.31. ACLs are applied in the ingress direction.0.125. Allow WSA access to the IronPort SensorBase network (HTTPS) for updates.125.32.2.0 255.0 host 10.

0.36 ! ! Allow HTTP/HTTPS access to the company’s public web portal access-list inbound extended permit tcp any host 198.32.35 access-list inbound extended permit tcp any host 198.125. and so on.125.41 ! ! Apply ACL to outside interface access-group inbound in interface outside eq domain eq domain eq smtp eq www eq https • Ingress guest access Wireless guest access users should be restricted to having access only to the Internet.41 access-list inbound extended permit tcp any host 198. Because the security level of the Guest Access interface is lower than the internal and DMZ interfaces.0 access-list guestaccess-acl extended deny ip any 172.240. Any connection attempts to internal resources and subnets from the Internet should be blocked.125.133. However.35 any ! ! Allow SMTP from Cisco IronPort ESA access-list dmz-acl extended permit tcp host 10. ! Allow DNS queries and zone transfer from DNS server access-list dmz-acl extended permit udp host 10.0 ! Permit all other access to the Internet access-list guestaccess-acl extended permit ip any any ! ! Apply ACL to guest-access interface access-group guestaccess-acl in interface guestaccess Medium Enterprise Design Profile Reference Guide 5-54 . This typically includes DNS queries and zone transfer from DNS server.0 255. In addition.0 255.35 ! ! Allow SMTP to Cisco IronPort ESA access-list inbound extended permit tcp any host 198. If the guest wireless clients need to access the DMZ servers.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design • Ingress DMZ Restrict connections initiated from DMZ only to the necessary protocols and sources. ! Allow DNS queries and zone transfer to DNS server access-list inbound extended permit udp any host 198.36 any ! ! Allow update and SensorBase access to Cisco IronPort ESA access-list dmz-acl extended permit tcp host 10.0. if desired to reinforce this policy.36 any access-list dmz-acl extended permit tcp host 10.133. HTTP/SSL access from the Cisco IronPort ESA for updates.0.0.36 any ! ! Apply ACL to DMZ interface access-group dmz-acl in interface dmz eq domain eq domain eq smtp eq www eq https • Ingress outside Inbound traffic from the Internet should be restricted to the public services provided at the DMZ such as SMTP.255. because the security level for the Guest Access interface is also higher than the outside interface. an ACL must be configured and applied to allow this access.0.125. Access to the internal enterprise network should not be allowed.219.0.0 255.0.16.32.0 access-list guestaccess-acl extended deny ip any 192.219. traffic is permitted to the Internet. SMTP from E-mail server. and DNS.168. traffic coming from the Guest Access interface going to the internal and DMZ segments is automatically blocked.125. SensorBase.32.0. web. granular ACLs may also be applied to the guestaccess interface.219.32.133.32.133.35 any access-list dmz-acl extended permit tcp host 10.219.133. ACLs should be constructed using the servers' global IP addresses.219. ! Deny access to internal networks access-list guestaccess-acl extended deny ip any 10.

18 5540 Outside Gi1/0/1 Gi0/0 Internet Gi0/1 Gi2/0/1 VLAN 101 10. routing protocols. Under normal operation. so its deployment should be carefully planned. security level are configured as part of the logical redundant interface. representing an affordable option for high availability. the active interface is the only one passing traffic.cisco. the standby interface becomes active and starts passing traffic. ! Configures IP and logical interface parameters. This section explains the use of redundant interfaces.17 The configuration of a redundant interface requires the configuration of the physical interface parameters and the logical redundant interface. For information on how to configure stateful failover using multiple platforms. In cases where chassis redundancy is desirable. called active and standby interfaces. and the MAC address of the first physical interface associated with the redundant interface. Medium Enterprise Design Profile Reference Guide 228865 Redundant Interface 5-55 . Physical parameters such as media type. and speed are still configured within the physical interface. duplex. the enterprise may consider deploying a pair of Cisco ASA appliances configured for stateful failover. it requires the deployment of two identical Cisco ASA appliances and the adjustment of the topologies around the firewalls.ht m A Cisco ASA redundant interface is a logical interface that pairs two physical interfaces. The active interface uses the IP address defined at the redundant interface.32. The same IP address and MAC address are maintained so that traffic is not disrupted. Figure 5-25 illustrates the concept of redundant interface. The use of redundant interfaces makes the design resilient to link-level failures. IP address. When the active interface fails.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Firewall Redundancy The Internet perimeter of the Medium Enterprise Design Profile uses a single Cisco ASA appliance configured with redundant interfaces.com/en/US/products/ps6120/products_installation_and_configuration_guides_list. While stateful failover protects against chassis failures.125. refer to the Cisco ASA 5500 Series Adaptive Security Appliances Configuration Guides at the following URL: http://www. The following configuration example corresponds to Figure 5-25. Figure 5-25 Cisco ASA Redundant Interface Catalyst 3750E Stack Cisco Inside ASA 10. interface name.125. Both active/active and active/standby failover modes are supported.32. ! Physical interface and Ethernet parameters interface GigabitEthernet0/0 description Connection to CR12-3750s-IE port Gig1/0/1 no nameif no security-level no ip address ! interface GigabitEthernet0/1 description backup connection to CR12-3750s-IE port Gig2/0/1 no nameif no security-level no ip address ! ! Define logical redundant interface and associate with physical interfaces.

and from there propagated into the rest of the internal network. The default route is redistributed into EIGRP. If available. Therefore. The Internet firewall may participate in routing by learning the internal routes within the enterprise network and by injecting a default route pointing to the Internet. EIGRP.45 96.248. an interior gateway protocol. the static default route can be configured with object tracking.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design interface Redundant1 description connected to CR12-3750s-IE member-interface GigabitEthernet0/0 member-interface GigabitEthernet0/1 nameif inside security-level 100 ip address 10.255. Without object tracking.240 authentication key eigrp 100 ***** key-id 1 authentication mode eigrp 100 md5 ! Routing Within the Medium Enterprise Design Profile. In the configuration example below. Pick one that can receive and respond to ICMP echo requests sent by the Cisco ASA.18 255. the Cisco ASA monitors the IP address of the next hop gateway. Object tracking is configured to dynamically remove the default route when the Internet connection becomes unavailable.125.45) is used as the monitoring target. is used for dynamic routing. but it does not help if the connection is lost upstream.32. It is better to use a persistent network object. The default route should be removed dynamically if the Internet connection becomes unavailable. as shown in Figure 5-26. In the following configuration snippet. Static route tracking can also be configured for default routes obtained through DHCP or PPPoE.32.248. there is a possibility that the default route may remain in the routing table even if the Internet border router becomes unavailable. Figure 5-26 Cisco ASA Static Route EIGRP 100 Catalyst 3750E Stack Cisco Internet Inside ASA Border 10. which helps identifying if the Internet gateway goes down. Within the Medium Enterprise Design Profile.17 Object Tracking Internet It is highly recommended to use object tracking so that the default route is removed when the Internet connection becomes unavailable. This is accomplished by associating the default route with a monitoring target.253.125. To avoid this problem. If an echo reply is not received within a specified time period.253. The monitoring target needs to be carefully selected. router eigrp 100 Medium Enterprise Design Profile Reference Guide 5-56 229409 . the Cisco ASA appliance is configured with a static default route pointing to the Internet gateway. you may want to monitor a persistent network object located somewhere in the ISP network. The Cisco ASA appliance monitors the target using ICMP echo requests.46 Gi0/1 Gi2/0/1 VLAN 101 default 10.125. the IP address of the next hop gateway (96.18 5540 Outside Router Gi1/0/1 Gi0/0 Gi0/3 . the default route is removed only if the outside interface of the appliance goes down.255.32. the object is considered down and the associated default route is removed from the routing table. The static default route is then redistributed into EIGRP.

253. Injecting a default route with OSPF requires the configuration of an OSPF process between the Cisco ASA and the Internet border router. Enable DNS snooping.0.32. or other proprietary data) when the malware starts a connection to a known bad IP address. Configuring the Botnet Traffic Filter requires the following steps: 1. Verify and monitor Botnet Traffic Filter operation The following sections provides configuration examples for each of these steps.0. 2. The default route is then redistributed into EIGRP. and then logs or blocks any suspicious activity.248. This scenario also requires the default route to be propagated over OSPF.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines network 10. and from there propagated into the rest of the internal network. 5.0 255. Enable traffic classification and actions for the Botnet Traffic Filter.45 interface outside sla monitor schedule 1 life forever start-time now ! track 10 rtr 1 reachability Note The frequency and timeout parameters of object tracking can be adjusted to detect topological changes faster.0. Another option for dynamically controlling the injection and removal of a default route in the enterprise routing table is to use OSPF. Configure DNS server. credit card numbers. key strokes.45 1 track 10 ! sla monitor 1 type echo protocol ipIcmpEcho 96. 4. If the Internet border router is managed by the ISP.0 passive-interface default no passive-interface dmz no passive-interface inside redistribute static metric 1000000 2000 255 1 1500 ! route outside 0.248.255. 3.125.255. where the Cisco ASA appliance learns the default route from the Internet border router using OSPF.253. Configure DNS Server The Botnet Traffic Filter requires a DNS server to access Cisco’s dynamic database update server and to resolve entries in the static database.0 0.0 96.0. The Botnet Traffic Filter checks incoming and outgoing connections against a dynamic database of known bad domain names and IP addresses (the blacklist). Botnet Traffic Filter The Medium Enterprise Design Profile uses the ASA Botnet Traffic Filter on the Internet firewall to detect malware that attempts network activity such as sending private data (passwords. the configuration requires coordination with the service provider. The following configuration illustrates this configuration: ! Enable DNS requests to a DNS Server out the outside interface dns domain-lookup outside Medium Enterprise Design Profile Reference Guide 5-57 . Enable use of the dynamic database. The actual default route may originate from the Internet border router itself or somewhere in the ISP network.

The following configuration example enables the Botnet Traffic Filter feature on all traffic and additionally enables dropping of connections going to IP addresses with a severity of moderate and higher. static database. creates unnecessary load on the ASA. and sends a syslog message and/or drops any matching traffic. For example. and DNS host cache. including that going to an internal DNS server. access-list btf-filter-acl extended permit ip any any ! enable Botnet Traffic Filter on the outside interface for traffic classified by the ! btf-filter-acl access list dynamic-filter enable interface outside classify-list btf-filter-acl Medium Enterprise Design Profile Reference Guide 5-58 . The following configuration example illustrates enabling DNS Snooping on the outside interface: ! create a class map to identify the traffic you want to inspect DNS class-map dynamic-filter-snoop-class match port udp eq domain ! create a policy map to enable DNS inspection with Botnet Traffic Filtering snooping ! for the class map policy-map dynamic-filter-snoop-policy class dynamic-filter-snoop-class inspect dns preset_dns_map dynamic-filter-snoop ! activate the policy map on the outside interface service-policy dynamic-filter-snoop-policy interface outside Enable Traffic Classification and Actions for the Botnet Traffic Filter The Botnet Traffic Filter compares the source and destination IP address in each initial connection packet to the IP addresses in the dynamic database.238. The following configuration enables database updates. This database lists thousands of known bad domain names and IP addresses.com Enable Use of the Dynamic Database The Botnet Traffic Filter can receive periodic updates for the dynamic database from the Cisco update server. the ASA sends a syslog message and can optionally be configured to drop the connection. It is recommended that DNS Snooping is enabled only on interfaces where external DNS requests are going. and also enables use of the downloaded dynamic database by the adaptive security appliance. Enabling DNS Snooping on all UDP DNS traffic. which compares the domain name with those in the dynamic or static databases and adds the name and IP address to the DNS reverse lookup cache.96. you should enable DNS inspection with snooping for all UDP DNS traffic on the outside interface.12 domain-name cisco.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design ! Specify the DNS Server Group and the DNS Servers dns server-group DefaultDNS name-server 68. This cache is then used by the Botnet Traffic Filter when connections are made to the suspicious address. ! identify the traffic that you want to monitor or drop.12 name-server 68. ! enable downloading of the dynamic database from the Cisco Update server dynamic-filter updater-client enable ! enable use of the dynamic database dynamic-filter use-database Enable DNS Snooping DNS Snooping enables inspection of DNS packets and enables Botnet Traffic Filter Snooping. if the DNS server is on the outside interface. You can enable Botnet Traffic Filter on a subset of traffic or for all traffic by enabling an access list to classify traffic.238. When an address matches. DNS reverse lookup cache.112.

including the server IP address." threat-level: low. 0 IPv4 addresses cr12-asa-1-ie# Medium Enterprise Design Profile Reference Guide 5-59 . size: 2097152 cr12-asa-1-ie# • show dynamic-filter data—Shows information about the updater server. Some of these are associated with rogue online vendors and distributors of dialers which deceptively call premium-rate phone numbers. greyware. They are either systems hosted on threat networks or systems that are part of the botnet itself. interstitials. adware. description: "These are sources that use various exploits to deliver adware. spyware and other malware to victim computers. description: "These are sources that distribute spyware.com Application name: threatcast. category: Ads. and the database version last installed.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines ! enable automatic dropping of traffic with threat level moderate or higher dynamic-filter drop blacklist interface outside action-classify-list btf-filter-acl threat-level range moderate very-high Botnet Traffic Filter Verification To monitor and verify the operation of the Botnet Traffic Filter feature. size: 2097152 Sample contents from downloaded database: win-antimalware2. spyware and adware. description: "These are rogue systems that control infected computers." threat-level: moderate. description: "These are advertising networks that deliver banner ads. 2565 IPv4 addresses Local data: 0 domain names . pop-ups.0 Encrypted UDI: 0bb93985f42d941e50dc8f022350d1a8a8c5097dc1d252b9cff62d26d4ec58e202883d704fc62b85bf8629 fa757fe36b Last update attempted at 15:14:11 UTC Apr 7 2010. and pop-unders for websites. cr12-asa-1-ie# show dynamic-filter updater-client Dynamic Filter updater client is enabled Updater server URL is https://update-manifests. and the database version last installed. 2565 IPv4 addresses Local data: 0 domain names ." threat-level: high. category: Bot and Threat Networks.com lookmbox.bg bisexual-photo. 0 IPv4 addresses Active rules in Dynamic Filter asp table: Dynamic data: 0 domain names .ironport. the following commands can be used: • show dynamic-filter updater-client—Shows information about the updater server. and other potentially unwanted advertising software. category: Malware. Some of these also run exploits to install such software. rich media ads.info zardoz.com firstlook.gymdb.wizardz. the next time the adaptive security appliance will connect with the server. cr12-asa-1-ie# show dynamic-filter data Dynamic Filter is using downloaded database version '1270651144' Fetched at 15:14:11 UTC Apr 7 2010. category: Spyware." Total entries in Dynamic Filter database: Dynamic data: 82119 domain names . with result: Downloaded file successfully Next update is in 00:52:14 Database file version is '1270651144' fetched at 15:14:11 UTC Apr 7 2010. the next time the adaptive security appliance will connect with the server.com Sample meta data from downloaded database: threat-level: very-high. version: 1. Some of these networks send ad-oriented HTML emails and email verification services.com mswindowsupdate.com red-devil-sport-club. including the server IP address.com exchange.

You might want to use ASDM to generate a PDF file instead of using the CLI. The max-connections keyword shows the 20 infected hosts with the most number of connections. dropped 0. 0. ingress ingress ingress ingress ingress 0. show dynamic-filter dns-snoop [detail]—Shows the Botnet Traffic Filter DNS Snooping summary. and malware ports. egress 19 Threat-level very-high: classified 9. visited malware sites. egress 0 Threat-level high: classified 0. 0. The top 10 malware sites report includes the number of connections dropped. dropped 0. dropped 0. 0. and greylist. dropped 0. egress 10 Threat-level very-low: classified 0. and how many of those connections match the whitelist. This report is a snapshot of the data. 0. egress 16 Threat-level very-low: classified 0. blacklist. egress 0 Total greylist classified 16. egress 0 Threat-level low: classified 10. dropped 0. ingress 0. • • Medium Enterprise Design Profile Reference Guide 5-60 . dropped 0. All inspected DNS data is included in this output. and the threat level and category of each site.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design • show dynamic-filter statistics detail—Shows how many connections were monitored and dropped with the Botnet Traffic Filter. dropped 0. The highest-threat keyword shows the 20 hosts that connected to the malware sites with the highest threat level. egress 9 Threat-level high: classified 0. cr12-asa-1-ie# show dynamic-filter statistics detail Enabled on interface outside using classify-list btf-filter-acl Total conns classified 35. egress 0 cr12-asa-1-ie# ingress ingress ingress ingress ingress 0.) The detail keyword shows how many packets at each threat level were classified or dropped. egress 16 Threat-level very-high: classified 0. The subnet keyword shows up to 20 hosts within the specified subnet. 0. Other commands that are useful for monitoring the Botnet Traffic Filter include the following: • show dynamic-filter reports top [malware-sites | malware-ports | infected-hosts]—Generates reports of the top 10 malware sites. enter the clear dynamic-filter statistics [interface name] command. dropped 0. dropped 0. and infected hosts monitored. This display might include thousands of entries. ingress 0. ingress 0. dropped 0. showing the correlation between infected hosts. and may not match the top 10 items since the statistics started to be collected. and not just matching names in the blacklist. These reports contain detailed history about infected hosts. 0. egress 0 Threat-level low: classified 16. (The greylist includes addresses that are associated with multiple domain names. 0. or with the detail keyword. show dynamic-filter reports infected-hosts {max-connections | latest-active | highest-threat | subnet ip_address netmask | all}—Generates reports about infected hosts. but not all of these domain names are on the blacklist. ports. The latest-active keyword shows the 20 hosts with the most recent activity. egress 0 Threat-level moderate: classified 0. egress 0 Threat-level moderate: classified 0. The all keyword shows all buffered infected-hosts information. ingress 0. dropped 0. Note To clear the statistics. the actual IP addresses and names. DNS data from static entries are not included. egress 0 Total blacklist classified 19. egress 35 Total whitelist classified 0. 0. dropped 0.

When configured to fail open. The following example illustrates how a Cisco ASA can be configured to divert all IP traffic to the AIP SSM in inline mode. and to block all IP traffic in the AIP SSM card fails for any reason: access-list IPS extended permit ip any any class-map ips_class match access-list IPS policy-map ips_policy class ips_class ips inline fail-close service-policy ips_policy global IPS Global Correlation Deployment Before configuring IPS Global Correlation. full-featured intrusion prevention services to stop malicious traffic including worms and network viruses before they can affect your network. page 5-13. the Cisco ASA sends a duplicate stream of traffic to the AIP SSM for inspection. Cisco IME. This section describes some of the best practices for integrating and configuring the IPS service module for maximum threat control and visibility as well as the deployment of the IPS Global Correlation feature. The AIP SSM may be deployed in inline or promiscuous mode as described in Intrusion Prevention. After you configure the DNS and proxy settings. Cisco IDS Device Manager (IDM). the Cisco ASA blocks all traffic in case of an AIP SSM failure.0 with the latest patch and signature updates and that Cisco IPS is configured for network connectivity in either IDS or IPS mode. Deploying IPS with the Cisco ASA The AIP SSM is supported in the Cisco ASA 5510 and higher platforms. The AIP SSM runs advanced IPS software that provides proactive. it is important to determine how traffic should be treated in case of module failure. When deploying the AIP SSM in inline mode.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines • show asp table dynamic-filter [hits]—Shows the Botnet Traffic Filter rules that are installed in the accelerated security path. Conversely. In inline mode. when configured to fail close. in promiscuous mode. leaving your network unprotected. or Cisco Security Manager. The AIP SSM may be configured to fail open or close when the module becomes unavailable. be sure that you are using Cisco IPS Version 7. This is more secure but impacts traffic during a failure. the Cisco ASA appliance allows all traffic through uninspected if the AIP SSM becomes unavailable. the AIP SSM is placed directly in the traffic flow. Medium Enterprise Design Profile Reference Guide 5-61 . The following screenshots from Cisco IME illustrate the basic steps in the configuration of the IPS Global Correlation. This step enables a connection to Cisco SensorBase and is illustrated in Figure 5-27. The configuration of Global Correlation can be performed using the command-line interface (CLI). The first step in configuring the IPS sensor (module or appliance) to use Global Correlation is to add either a DNS address and/or the proxy server setup. Intrusion Prevention Deployment The Medium Enterprise Design Profile implements Intrusion Prevention using and Advanced Inspection and Prevention Security Services Module (AIP SSM) on the Cisco ASA appliance deployed at the Internet perimeter. the Global Correlation settings goes into effect as soon as the sensor has downloaded the latest Global Correlation updates.

a sensor runs Global Correlation Inspection in Standard mode and enables the reputation filters. and then later change the configuration to Standard or Aggressive mode as desired. Medium Enterprise Design Profile Reference Guide 5-62 .Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-27 DNS and HTTP Proxy Within the Network Setting Configuration Screen By default. A good practice is to configure Global Correlation Inspection initially in permissive mode while monitoring the effects. as illustrated in Figure 5-28.

it is recommended to configure the IPS sensors with partial or full network participation. For this reason. network participation is disabled. which accelerates the identification and mitigation of threats propagating throughout the Internet. which means the sensor does not share any event data back to the Cisco SensorBase network. The event data provided by all devices participating in the Cisco SensorBase network is a key element that provides realtime and worldwide visibility into threat activity. Network participation configuration is illustrated in Figure 5-29.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Figure 5-28 Global Correlation Inspection Settings By default. Medium Enterprise Design Profile Reference Guide 5-63 .

Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-29 Network Participation Settings (Off by Default) Event Monitoring with Global Correlation Event monitoring with IPS Global Correlation is similar to event monitoring with signature-only IPS. Figure 5-30 shows Cisco IPS events with reputation scores in Cisco IME. Medium Enterprise Design Profile Reference Guide 5-64 . The primary difference is the potential addition of reputation scores representing the Global Correlation data.

Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Figure 5-30 Event Monitoring with Global Correlation in Cisco IME Figure 5-30 shows several TCP SYN Port Sweep and ICMP Network Sweep attacks that were seen by the sensor. This time the risk rating was high enough for the packets to be dropped.8. which still did not meet the thresholds to be dropped in Standard Mode. The next three events were identical except that the attacker had a negative reputation of -1. which elevated the risk ratings to 86 and 89. and the event’s risk ratings were 52 and 60. which did not meet the threshold for the packets to be dropped.3. Medium Enterprise Design Profile Reference Guide 5-65 . elevating the risk ratings to 70 and 75. The last events were also identical except this time the attacker has a negative reputation if -4. The first three events had no reputation. Figure 5-31 illustrates the detail view of the TCP SYN Port Sweep event coming from the attacker with a negative reputation of -4.3.

The WSA is located at the inside of the Cisco ASA acting as the Internet firewall. as illustrated in Figure 5-32. Deploying the WSA at the Internet edge distribution layer gives the WSA complete visibility on the traffic before getting out to the Internet through the firewall. Medium Enterprise Design Profile Reference Guide 5-66 .Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-31 Detailed View of a TCP SYN Port Sweep from an Attacker with a Negative Reputation Score Web Security Deployment The Medium Enterprise Design Profile implements a Cisco IronPort WSA at the Internet edge distribution layer at the main site.

The System Setup Wizard guides the user through the initial system configuration such as network and security settings. Use the System Setup Wizard only the first time you install the appliance. Interface and Network Configuration As part of the initial setup of the WSA. The following are some of the default settings when running the System Setup Wizard: • • Web Proxy is deployed in transparent mode. the following steps need to be completed: 1. but can be later modified using the WSA web-based GUI. or if you want to completely overwrite the existing configuration. Configuring network interfaces Adding routes Configuring DNS Setting time These settings are configured as part of an initial setup using the system setup wizard. Medium Enterprise Design Profile Reference Guide 5-67 . 4. The L4 Traffic Monitor is active and set to monitor traffic on all ports. 2. 3. Initial System Setup Wizard The WSA provides a browser-based system setup wizard that must be executed the first time the appliance is installed.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Figure 5-32 Access WSA Deployment Distribution Internet Edge Core Catalyst 3750E Stack Inside Cisco ASA 5540 Outside Catalyst 3750E Stack Internet Border Router Internet QFP Secure Mobility Cisco IPS SSM-20 WAN Edge SensorBase Cisco Security Intelligence Operation www Web Security MetroE QFP HDLC 229410 The following subsections provides guidelines for the WSA configuration and deployment. Note that running the initial System Setup Wizard completely reconfigures the WSA appliance and resets the administrator password.

Medium Enterprise Design Profile Reference Guide 5-68 227435 . However. refer to the WSA configuration guides. Use the “P” ports for the Web Proxy. Figure 5-33 WSA Interfaces Use the “T” ports for the L4 Traffic Monitor. Only the P1 interface is used in the Medium Enterprise Design Profile. In the Medium Enterprise Design Profile. Cisco IPS Global Correlation and the Cisco ASA Botnet Traffic Filter features were used instead. For more information on L4TM. P1 connects to the inside subnet of the firewall. These ports are used to capture traffic for inspection using either SPAN on a switch or a network tap. interface M1 connects to the out-of-band management network. • • Figure 5-34 illustrates the network topology for the WSA design in the validation lab. all Cisco IronPort WSA appliances are equipped with six Ethernet interfaces as shown in Figure 5-33. The WSA interfaces are grouped for the following functions: • Management—Interfaces M1 and M2 are out-of-band (OOB) management interfaces. Interface M1 can optionally be used to handle data traffic in case the enterprise does not have an out-band management network. Web Proxy—Interfaces P1 and P2 are Web Proxy interfaces used for data traffic. Use the M1 port for administering the appliance. only M1 is enabled.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design Configuring Network Interfaces Independent of the model. L4 Traffic Monitor (L4TM)—T1 and T2 are the L4TM interfaces. L4TM was not validated as part of the Medium Enterprise Design Profile.

These settings are illustrated in Figure 5-36. This allows the definition of a default route for management traffic separate from the default route used for data traffic. Figure 5-35 WSA Interface Configuration Adding Routes A default route is defined for management traffic pointing to the OOB management default gateway (172.18). the WSA is configured to maintain a separate routing instance for the M1 management interface.0.171 OOB Management VLAN 101 10.32.19 www Cisco Inside ASA 10.125.0/8 is defined pointing to the switch IP address (10.125.32.0. a route to 10.18 5540 Outside Gi1/0/1 Gi0/0 Internet Gi2/0/1 Gi0/1 M1 172.125. A separate default route is defined for the data traffic pointing to the inside IP address of the firewall (10.26.17 Figure 5-35 shows the IP address and hostname configurations for the interfaces used within the WSA web-based GUI. Medium Enterprise Design Profile Reference Guide 5-69 229411 Enterprise Network . In this case.26.125. an out-of-band management network is used where the M1 port is configured with an IP address in the management subnet.32.125. In addition.136.32.32. As all internal networks are reachable through the Internet edge distribution switch.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Figure 5-34 WSA Network Topology Cisco IronPort WSA S650 Catalyst 3750E Stack Gi2/0/2 P1 10.136.1).17) to allow the WSA to communicate with the clients directly.

Figure 5-37 WSA DNS Configuration Setting Time Time synchronization is critical for forensic analysis and troubleshooting. and defining the DNS servers. Figure 5-38 shows how the WSA is configured to synchronize its clock with an NTP server located on the OOB management network. Medium Enterprise Design Profile Reference Guide 5-70 . therefore enabling NTP is highly recommended. Figure 5-37 shows the DNS configuration.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-36 WSA Route Configuration Configuring DNS The initial setup requires the configuration of a host name for the WSA appliance.

Chapter 5

Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines

Figure 5-38

WSA NTP Configuration

Note

If Internet access is provided by an upstream proxy, the WSA must be configured to use the proxy for component updates and system upgrades. For information on configuring upstream proxies for upgrades, see the WSA configuration guides located at the following URL: http://www.cisco.com/en/US/docs/security/wsa/wsa6.3/user_guide/WSA_6.3.0_GA_UserGuid e.pdf.

WCCP Transparent Web Proxy
The configuration of the WCCP Transparent Web Proxy includes the following steps:
1. 2. 3. 4.

Defining WSA WCCP Service Group Enabling WSA Transparent Redirection Enabling WCCP redirection on the Cisco ASA Enabling WSA HTTPS scanning

Defining WSA WCCP Service Group
Web Proxy settings are configured as part of an initial setup using the System Setup Wizard and can be later modified with the WSA Web-based GUI. The Web Proxy settings include the following:
• • •

HTTP Ports to Proxy—Lists the ports to be proxied. Default is 80 and 3128. Caching—Defines whether or not the WSA should cache response and requests. Caching helps reduce latency and the load on the Internet links. Default is enabled. IP Spoofing—Defines whether or not the Web Proxy should spoof IP addresses when forwarding requests to upstream proxies and servers.

Figure 5-39 illustrates the Web Proxy settings.

Medium Enterprise Design Profile Reference Guide

5-71

Chapter 5 Medium Enterprise Network Security Deployment Guidelines

Medium Enterprise Design Profile (MEDP)—Network Security Design

Figure 5-39

WSA Proxy Settings

Enabling WSA Transparent Redirection
Configuring WCCP Transparent Redirection requires the definition of a WCCP service profile in the WSA. If redirecting HTTP and HTTPS, define a dynamic service ID to be used with the Cisco Catalyst Internet Edge Distribution Switch. Use MD5 authentication to protect the WCCP communication between the WSA and Cisco Catalyst Switch. Figure 5-40 shows an example.
Figure 5-40 WSA Transparent Proxy

Medium Enterprise Design Profile Reference Guide

5-72

Chapter 5

Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines

Enabling WCCP Redirection on Catalyst 3750E Distribution Switch
The configuration of WCCP on the Cisco Catalyst 3750 switch requires the following components:
• •

A group-list indicating the IP addresses of the WSA appliances that are members of the service group. In the example provided below the group-list is called wsa-farm. A redirect-list indicating the ports and subnets of traffic to be redirected. In the example, the ACL named proxylist is configured to redirect any HTTP and HTTPS traffic coming from the 10.0.0.0/8 subnet. WCCP service indicating the service ID. The service ID defined on the Catalyst switch must be the same as the service ID defined on the WSAs. Use a password for MD5 authentication. Enabling WCCP redirection on an interface. Apply the WCCP service on the Internet Edge distribution switch interface facing the Core switch.

• •

The following is a Cisco Catalyst switch configuration example:
! Group-list defining the IP addresses of all WSAs ip access-list standard wsa-farm permit 10.125.32.19 ! ! Redirect-list defining what ports and hosts/subnets should be redirected ip access-list extended proxylist permit tcp 10.0.0.0 0.255.255.255 any eq www permit tcp 10.0.0.0 0.255.255.255 any eq 443 ! ! Configure WCCP service ip wccp 10 redirect-list proxylist group-list wsa-farm password <MD5-password> ! ! Apply WCCP on an interface interface Port-channel1 ip wccp 10 redirect in !

The WCCP connection status and configuration can be monitored on the Cisco Catalyst 3750 switch with the show ip wccp command. An example is provided below:
cr12-3750s-ie# show ip wccp Global WCCP information: Router information: Router Identifier: Protocol Version: Service Identifier: 10 Number of Service Group Clients: Number of Service Group Routers: Total Packets s/w Redirected: Process: CEF: Redirect access-list: Total Packets Denied Redirect: Total Packets Unassigned: Group access-list: Total Messages Denied to Group: Total Authentication failures: Total Bypassed Packets Received: cr12-3750s-ie#

10.125.200.23 2.0

1 1 0 0 0 proxylist 0 5 wsa-farm 0 0 0

Medium Enterprise Design Profile Reference Guide

5-73

Chapter 5 Medium Enterprise Network Security Deployment Guidelines

Medium Enterprise Design Profile (MEDP)—Network Security Design

Note

Cisco Catalyst 3750 switches support switching in hardware only at Layer 2; therefore, no counters increment when the show ip wccp command is issued on the switch.

Enabling WSA HTTPS Scanning
To monitor and decrypt HTTPS traffic, you must enable HTTPS scanning on the WSA. The HTTPS Proxy configuration is illustrated in Figure 5-41.
Figure 5-41 WSA HTTPS Proxy

Note

In cases where Internet access is handled by upstream proxies, you must configure the WSA to route through the upstream proxies. For information regarding the configuration of upstream proxies, see the Cisco IronPort WSA configuration guide located at the following URL: http://www.cisco.com/en/US/docs/security/wsa/wsa6.3/user_guide/WSA_6.3.0_GA_UserGuide.pdf

Web Access Policies
The access policies define how the Web Proxy handles HTTP requests and decrypted HTTPS connections for network users. By configuring access policies, the enterprise can control what Internet applications (instant messaging clients, peer-to-peer file-sharing, web browsers, Internet phone services, and so on) and URL categories users can access. In addition, access policies can be used to block file downloads based on file characteristics, such as file size and file type. The WSA comes with a default global policy that applies to all users. However, multiple policies can be defined when different policies need to be applied to different group of users. Figure 5-42 shows the global policy.

Medium Enterprise Design Profile Reference Guide

5-74

Chapter 5

Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines

Figure 5-42

Global Access Policy

URL categories corresponding to non-business related content should be blocked in compliance with the company's Internet access policies. Figure 5-43 provides an example on how the Adult/Sexually Explicit and Chat categories are blocked.
Figure 5-43 URL Categories

Catalyst Integrated Security Features Deployment
Within the Medium Enterprise Design Profile, the Cisco Catalyst Integrated Security Features (CISF) were implemented in the access layer switches. CISF is a set of native security features available on the Cisco Catalyst switches that protect the infrastructure and users from spoofing, man-in-the-middle (MITM), DoS, and other access layer attacks. The following configuration illustrates an example of the CISF configurations used on a Cisco 3750E switch in the Medium Enterprise Design Profile in the access layer.
! configure dhcp snooping on the access VLANs in global configuration mode ip dhcp snooping vlan 101-113 no ip dhcp snooping information option ip dhcp snooping ! ! configure arp inspection on the access VLANs in global configuration mode ip arp inspection vlan 101-113 ip arp inspection validate src-mac dst-mac ip allow zeros !

Medium Enterprise Design Profile Reference Guide

5-75

Chapter 5 Medium Enterprise Network Security Deployment Guidelines

Medium Enterprise Design Profile (MEDP)—Network Security Design

! configure the port recovery parameters for ports being disabled by dhcp snooping, arp-inspection, or storm control errdisable recovery cause dhcp-rate-limit errdisable recovery cause storm-control errdisable recovery cause arp-inspection errdisable recovery interval 120 ! ! configure port specific parameters on access ports interface GigabitEthernet1/0/1 ! configure port security parameters switchport port-security switchport port-security aging time 5 switchport port-security violation restrict switchport port-security aging type inactivity ! configure arp inspection rate limiting ip arp inspection limit rate 100 ! configure storm control parameters storm-control broadcast level pps 1k storm-control multicast level pps 2k storm-control action trap ! configure IP Source Guard parameters ip verify source

Note

When deploying Cisco Catalyst 3000 switches in the access layer in a routed Layer 3 deployment, configuring IP Source Guard causes edge router ACLs and VLAN ACLs to be ineffective for blocking traffic. When IP Source Guard is enabled, it creates a port-based ACL to permit traffic only from IP addresses that were assigned via the DHCP server. On Cisco Catalyst 3000 switches, port-based ACLs overrides router and VLAN ACLs resulting in all traffic being permitted to all destinations.

NAC Appliance Deployment
In the Medium Enterprise Design Profile, a NAC Appliance solution is deployed at all locations; the main site and each of the remote offices. A centralized NAC Manager is deployed at the main site and is deployed within the data center at that site. A NAC server is deployed at the main site and each of the remote site, and is connected within the service block connecting to the core switches at each of the sites. The Medium Enterprise Design Profile provides host network connectivity using wired and wireless technologies. As such, the NAC Appliance solution must provide a solution for both connectivity options. For wireless clients, a Layer 2 OOB NAC solution is deployed; and for wired clients, a Layer-2 OOB or a Layer-3 OOB NAC solution may be deployed. The following subsections provide configuration steps for configuring a Layer-3 OOB NAC solution for wired clients and a Layer-2 OOB NAC solution for wireless clients.

NAC Deployment for Wired Clients
Within the Medium Enterprise Design Profile, a NAC Layer-3 OOB deployment using ACLs was used for the wired clients. Figure 5-44 shows the L3 OOB logical network diagram that was used to validate NAC for wired clients in the Medium Enterprise Design Profile.

Medium Enterprise Design Profile Reference Guide

5-76

Chapter 5

Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines

Figure 5-44

NAC L3 OOB Logical Topology Diagram
Access

VLAN 111 – Un-auth VLAN – 10.125.108.128/28 VLAN 102 – Faculty VLAN – 10.125.96.64/28

Active Directory

DNS DHCP Server

Distribution

.5 NAC Server Trusted .146 .130 Untrusted

.2 VLAN 101 10.125.31.0/28 Core

VLAN 120 10.125.30.144/28 VLAN 119 10.125.30.128/28

Internet
Service Block Datacenter Switch VLAN 102 10.125.31.16/28 WAN Edge

.18

MetroE NAC Manager

QFP

HDLC
229412

The following subsections illustrate the needed steps to configure a L3 Real-IP OOB NAC Deployment using ACLs.

Configuring the Edge Access Switch for Enforcement
VLANs and edge ACLs are used on the access switches to restrict access to the network based on the NAC assigned user roles. The following configuration snippets provide sample configurations for two VLANs (Unauthenticated and Employee) and the associated edge ACLs. Edge ACLs and VLANs should be configured on all access switches that users are connecting to.

Unauthenticated role—VLAN 111 and ACL Name: nac-unauth-acl
! create NAC unauthenticated VLAN vlan 111 name nac-unauth-vlan ! create SVI for unauthenticated VLAN interface Vlan111 ip address 10.125.108.129 255.255.255.192 ip helper-address 10.125.31.2 ! ! configure ACL for the unauthenticated role ip access-list extended nac-unauth-acl ! allow Discovery packets from the NAC Agent to the NAC Server permit udp any host 10.125.30.130.eq 8906 ! allow Discovery packets from the NAC Agent to the NAC Server for ADSSO permit udp any host 10.125.30.130 eq 8910 ! allow web traffic from the PC to the NAC Server permit tcp any host 10.125.30.130 eq www ! allow SSL traffic from the PC to the NAC Server permit tcp any host 10.125.30.130 eq 443 ! allow DHCP traffic to the DHCP server permit udp any host 255.255.255.255 eq bootps permit udp any host 10.125.31.2 eq bootps ! allow DNS traffic to the DNS Server

Medium Enterprise Design Profile Reference Guide

5-77

the rest of the configuration of the NAC Manager and Server is performed using the NAC Manager GUI. it still attempts to discover the NAC Server.2 eq domain ! allow traffic to the remediation servers permit tcp any host 12. The below configuration snippet illustrates the ACL entry needed to drop these discovery packets on the authenticated employee VLAN.2 ! configure ACL for the employee role to prevent NAC Discovery packets from ! reaching NAC Server ip access-list extended employee-acl deny udp any host 10.30. even though the client is already granted access.120.243 eq www permit tcp any host 12. the Agent pops up trying to perform the login process again.96.243 eq www permit tcp any host 12.78.31.65 255.120.125.125. See the following link to perform initial setup: http://www.com/en/US/docs/security/nac/appliance/installation_guide/hardware/47/hi_instal.120.10.cisco.206 eq www permit tcp any host 12. The first step is to upload the NAC Manager and Server licenses that came with the appliances.120.208 eq www permit tcp any host 216.com/en/US/docs/security/nac/appliance/installation_guide/hardware/47/hi_instal.31.255.125.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design permit udp any host 10.177.125.130 eq 8906 permit ip any any ! ! apply ACL to the employee VLAN interface Vlan102 ip access-group employee-acl in NAC Manager and NAC Servers Initial Setup The initial installation and configuration of the NAC Manager and NAC Server is performed via console access. If the Agent is able to reach the NAC Server.cisco.79. ! create NAC employee VLAN vlan 102 name employee-vlan ! create SVI for employee VLAN interface Vlan102 ip address 10.81 eq ftp ! ! apply ACL to the Unauthenticated VLAN interface Vlan111 ip access-group nac-unauth-acl in • Employee role—VLAN 102 and ACL name: employee-acl After the client is moved to this VLAN.255.htm l#wp1113597 Medium Enterprise Design Profile Reference Guide 5-78 . To prevent this.31.htm l Apply License to the NAC Manager After performing the initial setup through the console. an ACL entry needs to be added to the ACL on the employee VLAN to prevent UDP 8906 Discovery packets originating from the Agent are dropped once the client is authenticated. if the native NAC Agent is used. and the install utility guides you through the initial configuration for both NAC Manager and NAC Server.2 eq domain permit tcp any host 10.151.11. See the following URL for more detail on uploading the licenses: http://www.125. This NAC Agent behavior is by design.192 ip helper-address 10.

This list is updated regularly for the AV/AS products and versions supported in each Agent release and include new products for new Agent versions. Add the IP address of the NAC Server’s Trusted interface. Medium Enterprise Design Profile Reference Guide 5-79 . The list provides version information only.html# wp1078189 For more information on installing certificates on the NAC Server from a third-party CA. For more information on installing certificates on the NAC Manager from a third-party CA. the initial configuration utility script for both the NAC Manager and NAC Server requires you to generate a temporary SSL certificate. See the following URL for details on setting this up: http://www. which requires you to upload each other’s certificates as a Trusted Certificate Authority under SSL > Trusted Certificate Authorities.cisco. it is downloading the information about what the latest versions are for AV/AS products.html#w p1040111 Note If you are using the self-signed certificates in the lab environment.com/en/US/docs/security/nac/appliance/configuration_guide/47/cam/m_agntd.com/en/US/docs/security/nac/appliance/configuration_guide/47/cas/s_admin.cisco.com on the NAC Manager The NAC Manager needs to be configured to retrieve periodic updates from the central update server located at Cisco.cisco. When the CAM downloads the Supported AV/AS Product List. and click Add Clean Access Server. from within the NAC Manager GUI. see the following URL: http://www.html# wp1351880 Installing Certificates from Third-Party Certificate Authority (CA) During installation. the self-signed CERTs are not recommended for a production network. select Out-of-Band Real-IP-Gateway from the Server Type dropdown list. Adding the NAC Server to the NAC Manager Step 1 Step 2 To add the NAC Server to the NAC Manager. See Figure 5-45. it is not downloading actual patch files or virus definition files.com/en/US/docs/security/nac/appliance/configuration_guide/47/cam/m_admin. However. you may continue to use the self-signed CERTs. The Cisco NAC Appliance Supported AV/AS Product List is a versioned XML file distributed from a centralized update server that provides the most current matrix of supported anti-virus (AV) and antispyware (AS) vendors and product versions used to configure AV or AS Rules and AV or AS Definition Update requirements for posture assessment/remediation. Based on this information. For a lab environment. see the following URL: http://www. click CCA Servers > New Server. the agent can then trigger the native AV/AS application to perform updates. the NAC Manager and NAC Server need to trust the certificate of each other.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Update Policies from Cisco.

check (enable) the options for the following: • • Enable L3 Support Enable L3 strict mode to block NAT devices with Clean Access Agent Step 6 Click Update and reboot the NAC Server as instructed. click the Network tab. Figure 5-47.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-45 Adding the NAC Server to the NAC Manager Once added. Configure the NAC Server Step 3 Click the Manage icon for the NAC Server to continue the configuration. See Figure 5-46. Layer 3 Support Step 5 To enable Layer 3 support for L3 OOB. Note The NAC Manager and NAC Server have to trust each other’s certificate authority (CA) for NAC Manager to successfully add the NAC server. the NAC Server appears in the list. Figure 5-46 NAC Server Managed by NAC Manager Step 4 After clicking the Manage icon. Medium Enterprise Design Profile Reference Guide 5-80 .

See Figure 5-48.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Figure 5-47 NAC Server Network Details Note Always generate the certificate for the NAC Server with the IP address of its untrusted interface. Fill in the appropriate subnets for the unauthenticated VLANs and click Add Route. For name-based certificate. the login process will not function correctly. the NAC Server will redirect the user to the certificate hostname or IP. Static Routes Once the NAC Server reboots. the name should resolve to the untrusted interface IP address. Step 1 Go to Advanced > Static Routes to add routes to the unauthenticated VLAN. Be sure to select untrusted interface [eth1] for these routes. The NAC Server will need to communicate with endpoints on the unauthenticated VLAN with the untrusted interface. If the certificate points to the trusted interface. When the endpoint communicates with the untrusted interface of the NAC Server to begin the NAC process. Medium Enterprise Design Profile Reference Guide 5-81 . return to managing the NAC Server and continue the configuration.

In the example shown in Figure 5-49. Figure 5-49 SNMP Profile Used to Manage a Cisco Catalyst 4507 Switch Switch Configuration for SNMP Step 3 The edge access switches should be configured for SNMP read/write community strings which are the same as those configured on the NAC Manager. a Cisco Catalyst 4507 switch is added. Add a profile for each type of edge switch the NAC Manager will manage by going to Profiles and clicking on the Device tab.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-48 Adding Static Route to Reach the Unauthenticated User Subnet Setup Profiles for Managed Switches in the NAC Manager Step 2 Each switch will be associated with a profile. snmp-server community enterprise RW snmp-server community cisco123 RO Medium Enterprise Design Profile Reference Guide 5-82 .

Step 6 For the access VLAN.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Configuring Port Profiles Step 4 Step 5 For individual port control. then uncheck the option for bouncing the port. In the access VLAN section. The next step is to define the port profile to control the port’s VLAN based upon User Roles and VLANs implemented. See Figure 5-51. which will likely reboot the IP Phone when the port is bounced. the Auth VLAN is the unauthenticated VLAN to which unauthenticated devices are initially assigned. specify the User Role VLAN. Figure 5-50 Port Profile to Manage the Switch Port Note You can also define VLAN names instead of IDs. but the same VLAN name attached to a particular Role. which is defined under the User Role. select User Role VLAN to map users to the VLAN configured in the user’s role. The default access VLAN is the employee VLAN. Medium Enterprise Design Profile Reference Guide 5-83 . If the user is behind an IP phone. Additional options are available under the port profile for IP release/renew options. The NAC Manager changes the unauthenticated VLAN to the access VLAN based on the VLAN defined in the role where the user belongs. The Access VLAN can override the default VLAN to a user role VLAN. This offers the flexibility of having different VLAN IDs on different switches across the site. configure a port profile under OOB Management > Profiles> Ports that includes the default unauthenticated VLAN and default access VLAN. This is used if the authenticated user does not have a role-based VLAN defined. In the example shown in Figure 5-50.

When the NAC Server sends the MAC/IP address information of a particular end point to the NAC Manager. the Manager is able to build a mapping table internally for MAC/IP and switch port. See Figure 5-52. Figure 5-52 NAC Manager SNMP Receiver Setting to Collect SNMP Traps/Informs Medium Enterprise Design Profile Reference Guide 5-84 .Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-51 Various Options Available under Port Profile SNMP Receiver Setting In addition to setting up the SNMP community string for Read/Write. These traps are sent when the user connects and disconnects from the port. you also need to configure the NAC Manager to receive SNMP traps from the switch.

Adding Switches as Devices in the NAC Manager The switch profile created in the previous section will be used to add the managed switches. ! global applicable SNMP configurations snmp-server trap-source Loopback0 snmp-server enable traps mac-notification change move threshold snmp-server host 10. See Figure 5-53. use the profile you created.125. In addition. Step 1 Under the Device Profile. Having a source trap command ensures a consistent source address will be used to send out the traps. See Figure 5-54.31.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines The switch needs to be configured to enable SNMP traps to be sent to the NAC Manager. it is recommended to increase the default switch CAM table entry flush timer to 1 hour per Cisco best practice recommendations for NAC OOB.18 version 2c NacTraps ! interface specific configurations mac-address-table aging-time 3600 You can optionally configure Linkup/Linkdown traps to send to the NAC Manager. but do not change the default port profile value when adding the switch. This reduces the frequency of MAC notifications that are sent out from already connected devices to the NAC Manager. you can select the ports that you want to manage. Medium Enterprise Design Profile Reference Guide 5-85 . Figure 5-53 Adding Edge Switch in the NAC Manager to Control via SNMP Configuring Switch Ports for the Devices to be Managed by NAC Step 2 Once the switch is added to the NAC Manager. They are only used in a deployment scenario where the end hosts are not connected behind an IP phone.

The VLANs were already created in the edge access switches that correspond to each role. Additional roles and VLAN can be created for more granular access control if desired.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-54 Port Control Selection available for a Managed Switch Configuring User Roles Step 3 The next step is to configure the user roles and map the appropriate VLANs to these roles. The screenshots in Figure 5-55 show the creation of the employee role for the employee clients. Medium Enterprise Design Profile Reference Guide 5-86 .

Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Figure 5-55 Creating Employee Role and Mapping it to VLAN 102 Adding Users and Assigning to Appropriate User Role For user authentication. For a NAC L3 OOB solution. LDAP. and so on. it is important to download the ActiveX or Java component to the end client. Medium Enterprise Design Profile Reference Guide 5-87 . is typically preferred.cisco.html Customizing User Login Page for Web Login A default login page is already created in the NAC Manager.com/en/US/docs/security/nac/appliance/configuration_guide/47/cam/m_auth. This is done to perform the following: • • Fetch the MAC address of the client machine Perform IP address release/renew To do this. Kerberos. However. For information on configuring external authentication servers with NAC. integrating NAC with external authentication servers using RADIUS. Go to Administration > User Pages. Edit the page to make sure these options are enabled as shown in Figure 5-56. a local user database can be defined on the NAC Manager. users are mapped to a particular role via RADIUS or LDAP attributes. However. When using external authentication servers. see the following URL: http://www. the login page can be customized to change the appearance of the web portal. in environments where there is a large user base or pre-existing authentication servers.

Figure 5-57 Agent Login Required for Employee Role Medium Enterprise Design Profile Reference Guide 5-88 . the NAC Web Agent is made mandatory for the employee role. The agent should be made mandatory for any role that you want to perform posture assessment prior to granting them access to the network.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-56 User Page Settings for Web Login Customizing the Agent for the User Roles The NAC Manager can be configured to make the Agent mandatory for any user role. In the example in Figure 5-57.

Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines NAC Deployment for Wireless Clients Within the Medium Enterprise Design Profile. if yes. Traffic that reaches the quarantine VLAN on the NAC appliance is mapped to access the VLAN based on static mapping configuration. Similar steps would be taken to enable NAC for additional clients/roles as needed.0/28 VLAN 113 – Employee VLAN – 10.32/28 LWAPP NAC Manager As illustrated in Figure 5-58.30.0/28 VLAN 113. 313 Service Block Datacenter Switch VLAN 102 10. Figure 5-58 shows the specifics for the employee wireless clients. the quarantine VLAN traffic is trunked to the NAC appliance.31. Figure 5-58 Layer-2 OOB NAC Deployment Topology for Employee Wireless Clients Active Directory DNS DHCP Server . the NAC server (CAS) sends an SNMP set message that updates the access VLAN ID to the controller.16/28 . the WLC is connected to a trunk port that carries the quarantine VLAN and access VLAN for the employee clients (VLANs 113 and 313). The following subsections illustrate the configurations needed for deploying L2 OOB NAC for the Employee clients.30. the data is sent on the quarantine interface.125. The client traffic that flows in the quarantine VLAN is trunked to the NAC appliance. and the access VLAN traffic is trunked directly to the Layer 3 switch. 30. Figure 5-58 shows the L2 OOB logical network diagram that was used to validate the NAC L2 OOB deployment in the Medium Enterprise Design Profile. and the data traffic starts to switch from the WLC directly to the network without going through the NAC server.31.5 NAC Server Trusted Untrusted VLAN 101 10.125.32/28 VLAN 313 – Un-auth VLAN – 10. When client associates and complete the L2 Auth. 113.18 VLAN 111 – WLC Mgmt VLAN – 10.125. 118 VLAN 313 . a NAC Layer-2 OOB deployment was used for wireless clients. After posture validation is done. On the switch.2 Trunk Port VLANs 111.118 switchport mode trunk Medium Enterprise Design Profile Reference Guide 5-89 229420 Employee Wireless Clients .125.Ethernet 0 switchport trunk encapsulation dot1q switchport trunk native vlan 802 switchport trunk allowed vlan 113.125. Catalyst Switch Configuration The following Cisco Catalyst 3750E configuration example illustrates the configurations used on the service block switch in the Medium Enterprise Design Profile for the NAC wireless deployment: interface GigabitEthernet2/0/9 description Connected to cr25-nac-mgr-1 switchport access vlan 102 switchport mode access spanning-tree portfast ! interface GigabitEthernet2/0/19 description NAC Server trusted interface . it checks whether the quarantine interface is associated.

240 ! interface Vlan113 description Employee Client Subnet Access VLAN ip address 10.33 255.255.113.255.1 255. See Figure 5-59. Click OOB Management Profile > Device > New from within the NAC Manager GUI.240 ! NAC OOB Configuration Steps on the WLC and NAC Manager Perform the following steps to configure the WLC and the NAC Manager for a NAC L2 OOB deployment.255.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design ! interface GigabitEthernet2/0/20 description NAC Server untrusted interface .30.313 switchport mode trunk switchport nonegotiate ! interface Vlan111 description WLC Management VLAN ip address 10. Figure 5-59 Enabling SNMPv2 Step 2 Create a profile for WLC on the NAC Manager. Medium Enterprise Design Profile Reference Guide 5-90 .125.30. Step 1 Enable SNMPv2 mode on the controller.125.255. See Figure 5-60.ethernet 1 switchport trunk encapsulation dot1q switchport trunk native vlan 803 switchport trunk allowed vlan 313 switchport mode trunk ! interface Port-channel11 description Connection to WLC cr23-5508-1 switchport trunk encapsulation dot1q switchport trunk native vlan 801 switchport trunk allowed vlan 111.

Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Figure 5-60 Creating Profile for WLC Step 3 After the profile is created in the NAC Manager. add the WLC in the profile. Use the exact name of the trap receiver in the NAC Manager as the SNMP receiver. Medium Enterprise Design Profile Reference Guide 5-91 . go to OOB Management > Devices > New and enter the management IP address of WLC. See Figure 5-62. Figure 5-61 Adding WLC in Profile Step 4 Add the NAC Manager as the SNMP trap receiver in the WLC. See Figure 5-61.

click OOB Management > Profiles > SNMP Receiver. See Figure 5-64. Figure 5-63 Configure the SNMP Trap Receiver in the NAC Manager At this stage. the WLC and the NAC Manager can talk to each other for client posture validation and access/quarantine state updates. create a dynamic interface with access and quarantine VLAN mapped to it. Medium Enterprise Design Profile Reference Guide 5-92 . Step 6 In the controller.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-62 Adding MAC Manager as the SNMP Trap Receiver Step 5 Configure the SNMP trap receiver in the NAC Manager with the same name that was specified in the WLC controller.

See Figure 5-66. Figure 5-65 Creating the WLAN Step 8 Enable NAC in the WLAN on the WLC Controller.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Figure 5-64 Creating Dynamic Interface in the Controller Step 7 Create the WLAN and associate it with the dynamic interface. See Figure 5-65. Medium Enterprise Design Profile Reference Guide 5-93 .

See Figure 5-68. Medium Enterprise Design Profile Reference Guide 5-94 . Figure 5-67 Adding the Client Subnet in the CAS Server Step 10 Create VLAN mappings on the CAS. Click CAS server > Select your CAS server > Manage > Advanced > VLAN Mapping.See Figure 5-67. Add the access VLAN as trusted and the quarantine VLAN as untrusted. Add an unused IP address from the client subnet and put the quarantine VLAN (untrusted VLAN) for the managed subnet.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-66 Enabling NAC in the WLAN on the WLC Controller Step 9 Add the client subnet in the CAS server as the managed subnet by clicking CAS server > Select your CAS server > Manage >Advanced > Managed Subnets.

1x/EAP WLAN that is a managed subnet in the NAC.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Figure 5-68 Creating VLAN Mappings Configuring Single SignOn (SSO) with the OOB Wireless Solution The following is required to enable VPN SSO for a wireless NAC OOB deployment: • • Enabling VPN authentication on the NAC server with the WLC defined as the VPN concentrator in the NAC appliance. Enabling RADIUS accounting on the WLC controller. Medium Enterprise Design Profile Reference Guide 5-95 . click CAS server > Select your CAS server > Manage > Authentication > VPN Auth. The following steps outline the needed configuration on the NAC Manager to enable SSO. See Figure 5-69. Step 1 From the NAC Manager GUI. The WLC that is defined in the NAC appliance must be configured to send RADIUS accounting records to the NAC appliance for each 802.

Medium Enterprise Design Profile Reference Guide 5-96 . add the new authentication server with type vpn sso under User Management > Auth Servers. Populate the entry fields for the WLC Management IP address and shared secret you want to use between the WLC and NAC server. See Figure 5-71.Chapter 5 Medium Enterprise Network Security Deployment Guidelines Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-69 NAC Manager Configuration—Enabling SSO Step 2 Select the VPN Concentrators tab to add a new entry for the WLC. See Figure 5-70. Figure 5-70 Adding New Entry for WLC Step 3 For role mapping.

the attribute value is employee. RADIUS accounting needs to be enabled and sent to the NAC Server. In this example.Chapter 5 Medium Enterprise Design Profile (MEDP)—Network Security Design Medium Enterprise Network Security Deployment Guidelines Figure 5-71 Adding New Authentication Server for Role Mapping Step 4 Click the Mapping icon and then add Mapping Rule. and it is placed in the Wireless_Employee role. The mapping varies depending on the class attribute 25 value that WLC sends in the accounting packet. See Figure 5-73. See Figure 5-72. Medium Enterprise Design Profile Reference Guide 5-97 . This attribute value is configured in the RADIUS server and varies based on the user authorization. Figure 5-72 Mapping Class Attribute from WLC to User Roles Step 5 To configure VPN SSO on the Wireless LAN Controller.

Chapter 5 Additional Information Medium Enterprise Design Profile (MEDP)—Network Security Design Figure 5-73 Enabling RADIUS Accounting for VPN SSO Note When deploying a wireless NAC solution that requires single sign-on for some WLANs and non-single sign-on for other WLANs. devices. Additional Information The configuration guidelines and examples in the previous sections were based on the features. refer to Appendix A.” Medium Enterprise Design Profile Reference Guide 5-98 . RADIUS accounting must be disabled for the WLANs not requiring SSO. “Reference Documents. Otherwise. and designs that were used for validating the Medium Enterprise Design Profile. NAC mistakenly authenticates the non-single sign-on clients without prompting them. For more information on all of these features.

cisco.com/en/US/prod/collateral/wireless/ps5679/ps8368/product_data_sh Lightweight Outdoor Access Point eet0900aecd8066a157.cisco.html http://www.html http://www.html Ordering Guide Cisco NAC Guest Server Overview http://www.html http://www. Release 6.1 Design Guide Cisco Aironet 1520. 1240 Series Wireless Mesh Access Points.cisco.html http://www. Release 6.0/configuration/guide/WCS60cg. Release 6.com/en/US/docs/solutions/Enterprise/Security/SAFE_RG/SAFE_rg.com/en/US/prod/collateral/wireless/ps5755/ps6301/ps6305/product_ data_sheet0900aecd802570d0. Design and Deployment Guide.com/en/US/prod/collateral/wireless/ps6302/ps8322/ps10315/data_sh eet_c78-521631.com/en/US/prod/collateral/vpndevc/ps5707/ps8418/ps6128/product _data_sheet0900aecd806e98c9.org/rfc/rfc5415. 1130.A P P E N D I X A Reference Documents Document Title CCVE SRA Solution Overview Cisco SAFE Reference Guide Enterprise Mobility Design Guide 4.11n Design and Deployment Guidelines Cisco 5500 Series Wireless Controllers Data Sheet RFC 5415 Control And Provisioning of Wireless Access Points (CAPWAP) Protocol Specification Voice over Wireless LAN 4.html http://www.com/en/US/docs/wireless/technology/meshhttps://www.scribd.com/design/guide/MeshAP_6 0.html http://www.ietf.com/en/US/docs/wireless/controller/6.html http://www.cisco.com/en/US/solutions/collateral/ns340/ns394/ns348/ns767/white_pap er_80211n_design_and_deployment_guidelines.cisco.com/en/US/docs/wireless/wcs/6.0 Cisco 802. html http://www.html Cisco Wireless Control System (WCS) Overview Cisco Wireless Control System Configuration Guide.com/en/US/docs/solutions/Enterprise/Mobility/emob41dg/emob41d g-wrapper.0 URL http://www.cisco.0/configuration/guide/Control ler60CG.cisco.cisco.cisco.com/en/US/docs/solutions/Verticals/Education/srajrcollegesovervie w.0 http://www.1 Cisco Wireless LAN Controller Configuration Guide.com/en/US/docs/solutions/Enterprise/Mobility/vowlan/41dg/vowlan 41dg-book.cisco.cisco.html Cisco Aironet 1520 Series http://www.cisco.ht ml Medium Enterprise Design Profile Reference Guide A-1 .txt http://www.

com/en/US/partner/prod/collateral/switches/ps5718/ps708/prod_whi te_paper0900aecd801c5cd7.cisco.cisco.com/en/US/docs/security/nac/appliance/configuration_guide/47/cam /47cam-book.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND _40/QoSCampus_40.ironport.0 Service Ready Architecture for Schools Design Guide http://www.com/en/US/products/ps6638/products_ios_protocol_group_home.cisco.com/en/US/docs/solutions/Enterprise/Campus/HA_campus_DG/hac ampusdg.0/configuration/guide/cli/cli_collabo ration.com/en/US/docs/switches/lan/catalyst3750e_3560e/software/release /12.html http://www.cisco.html http://www.2_46_se/configuration/guide/swwccp.cisco.ht ml http://www.cisco.cisco.cisco.html Clean Access Server Configuration http://www.html http://www.Appendix A Reference Documents Document Title Deploying Cisco 440X Series Wireless LAN Controllers Cisco ASA Botnet Traffic Filter Configuring Global Correlation Cisco IronPort Support WCCP Configuration Guide Identity Based Networking Services NAC Appliance Support Clean Access Manager Configuration Guide URL http://www.com/en/US/prod/vpndevc/ps6032/ps6094/ps6120/botnet_index.shtml http://www.html http://www.html http://www.html Medium Enterprise Design Profile Reference Guide A-2 .cisco.com/en/US/docs/solutions/Enterprise/Education/SchoolsSRA_DG/S choolsSRA-DG.cisco.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND _40/QoSCampus_40.com/go/nacappliance http://www.html High Availability Campus Network http://www.html Cisco Catalyst 4500 E-Series High http://www.com/en/US/docs/security/ips/7.com/en/US/docs/solutions/Enterprise/Campus/routed-ex.cisco.html http://www.html Design-Routed Access Layer using EIGRP or OSPF High Availability Campus Recovery Analysis Design Guide Campus Virtual Switching System Design Guide Nonstop Forwarding with Stateful Switchover on the Cisco Catalyst 6500 http://www.com/en/US/docs/solutions/Enterprise/Campus/campover.com/en/US/products/ps6128/products_configuration_example09186 a0080a138cc.cisco.cisco.com/en/US/docs/wireless/technology/controller/deployment/guide/d ep.cisco.html NAC Out-Of-Band Wireless Configuration Example Overall Campus Design Campus Network for High Availability Design Guide http://www.com/en/US/partner/prod/collateral/switches/ps5718/ps5023/prod_w Paper hite_paper09186a00801b096a.cisco.com/en/US/docs/solutions/Enterprise/Campus/VSS30dg/campusVS S_DG.html Cisco StackWise Technology White http://www.html http://www.cisco.com/support/ http://www.cisco.cisco.cisco.com/en/US/partner/prod/collateral/switches/ps5718/ps4324/prod_w Availability hite_paper0900aecd806f0663.com/en/US/docs/security/nac/appliance/configuration_guide/461/cas Guide /461cas-book.html Campus QoS Design 4.html http://www.