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CCNA Routing and Switching
Practice and Study Guide:
Exercises, Activities, and Scenarios to Prepare
for the ICND2 (200-101) Certification Exam

Allan Johnson

Cisco Press
800 East 96th Street
Indianapolis, Indiana 46240 USA

ii CCNA Routing and Switching Practice and Study Guide

Publisher
CCNA Routing and Switching Practice and Paul Boger
Study Guide: Associate Publisher
Exercises, Activities, and Scenarios to Prepare Dave Dusthimer

for the ICND2 (200-101) Certification Exam Business Operation Manager,
Cisco Press
Student Edition Jan Cornelssen

Allan Johnson Executive Editor
Mary Beth Ray
Copyright© 2014 Cisco Systems, Inc.
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8

iv CCNA Routing and Switching Practice and Study Guide

About the Author
Allan Johnson entered the academic world in 1999 after 10 years as a business owner/opera-
tor to dedicate his efforts to his passion for teaching. He holds both an MBA and an M.Ed in
Occupational Training and Development. He is an information technology instructor at Del
Mar College in Corpus Christi, Texas. In 2003, Allan began to commit much of his time and
energy to the CCNA Instructional Support Team, providing services to Networking Academy
instructors worldwide and creating training materials. He now works full time for Cisco
Networking Academy as a Learning Systems Developer.

having earned CCNA Security and CCNP level certifications. . v About the Technical Reviewer Steve Stiles is a Cisco Network Academy Instructor for Rhodes State College and a Cisco Certified Instructor Trainer. He was the recipient of the 2012 Outstanding Teacher of the Year by the Ohio Association of Two-Year Colleges and co-recipient for the Outstanding Faculty of the Year at Rhodes State College.

Without the sacrifices you made during the project. Becky.vi CCNA Routing and Switching Practice and Study Guide Dedication For my wife. Thank you providing me the comfort and resting place only you can give. this work would not have come to fruition. —Allan Johnson .

Mary Beth Rey. when Mary Beth Ray contacted him. but for more advanced college-level technology courses and degrees. The Cisco Network Academy authors for the online curriculum and series of Companion Guides take the reader deeper. and Bob Vachon—for their excellent treatment of the material. His dedication to perfection pays dividends in countless. Thank you especially to Amy Gerrie and her team of authors— Rick Graziani. Steve Stiles immediately came to mind. and his excel- lent work building activities for the new Cisco Networking Academy curriculum. he was willing and able to do the arduous review work necessary to make sure that you get a book that is both technically accurate and unambiguous. as well. With his instructor and industry background. This is my seventh project with Christopher Cleveland as development editor. I can always count on you to make the tough deci- sions. it is reflected throughout this book. Wayne Lewis. Thankfully. with the ultimate goal of not only preparing the student for CCENT certification. Chris. he was an obvious choice. you amaze me with your ability to juggle multiple projects at once. unseen ways. Executive Editor. vii Acknowledgments When I began to think of whom I would like to have as a technical editor for this work. This book could not be a reality without your persis- tence. . steering each from beginning to end. Thank you again. past the CCENT exam topics. for providing me with much-needed guidance and support.

viii CCNA Routing and Switching Practice and Study Guide Contents at a Glance Introduction xvi Part I: Scaling Networks Chapter 1 Introduction to Scaling Networks 1 Chapter 2 LAN Redundancy 11 Chapter 3 Link Aggregation 27 Chapter 4 Wireless LANs 37 Chapter 5 Adjust and Troubleshoot Single-Area OSPF 51 Chapter 6 Multiarea OSPF 71 Chapter 7 EIGRP 81 Chapter 8 EIGRP Advanced Configurations and Troubleshooting 101 Chapter 9 IOS Images and Licensing 119 Part II: Connecting Networks Chapter 10 Hierarchical Network Design 127 Chapter 11 Connecting to the WAN 135 Chapter 12 Point-to-Point Connections 143 Chapter 13 Frame Relay 157 Chapter 14 Network Address Translation for IPv4 167 Chapter 15 Broadband Solutions 177 Chapter 16 Securing Site-to-Site Connectivity 187 Chapter 17 Monitoring the Network 197 Chapter 18 Troubleshooting the Network 207 .

ix Contents Introduction xvi Part I: Scaling Networks Chapter 1 Introduction to Scaling Networks 1 Implementing a Network Design 2 Hierarchical Network Design 2 Identify Scalability Terminology 4 Selecting Network Devices 5 Selecting Switch Hardware 5 Selecting Router Hardware 6 Managing Devices 6 Basic Router Configuration Review 7 Basic Router Verification Review 8 Basic Switch Configuration Review 8 Basic Switch Verification Review 9 Chapter 2 LAN Redundancy 11 Spanning-Tree Concepts 12 Draw a Redundant Topology 12 Purpose of Spanning Tree 12 Spanning-Tree Operation 13 Identify the 802.1D Port Roles 15 Varieties of Spanning Tree Protocols 16 Comparing the STP Varieties 16 PVST+ Operation 18 Rapid PVST+ Operation 19 Spanning-Tree Configuration 20 PVST+ and Rapid PVST+ Configuration 20 First Hop Redundancy Protocols 22 Identify FHRP Terminology 23 Identify the Type of FHRP 24 HSRP and GLBP Configuration and Verification 24 Chapter 3 Link Aggregation 27 Link Aggregation Concepts 28 EtherChannel Advantages 28 EtherChannel Operation 28 .

x CCNA Routing and Switching Practice and Study Guide Link Aggregation Configuration 29 Configuring EtherChannel 30 EtherChannel Configuration Scenario 1 30 EtherChannel Configuration Scenario 1 30 EtherChannel Configuration Scenario 1 31 Verifying and Troubleshooting EtherChannel 31 Chapter 4 Wireless LANs 37 Wireless LAN Concepts 38 Identify Wireless Technologies 38 WLANs Components and Topologies 40 Wireless LAN Operations 41 Label the 802.11 Frame 41 Wireless Media Contention 44 Associating with an AP 45 Channel Management Concepts 47 Wireless LAN Security 48 WLAN Security Terminology 48 Identify the WLAN Security Characteristics 49 Wireless LAN Configuration 49 Configuring WLAN Routers and Clients 49 Troubleshooting WLAN Issues 50 Chapter 5 Adjust and Troubleshoot Single-Area OSPF 51 Advanced Single-Area OSPF Configurations 52 Single-Area OSPF Configuration Review 52 Configuring Single-Area OSPFv2 52 Verifying Single-Area OSPFv2 53 Configuring Single-Area OSPFv3 53 Verifying Single-Area OSPFv3 55 Identify Network Types 56 OSPF and Multi-Access Networks 57 OSPF and Multi-Access Networks Completion Exercise 57 DR/BDR Election Exercise 59 Redistributing an OSPF Default Route Exercise 61 OSPFv2 Default Route Redistribution 61 OSPFv3 Default Route Redistribution 62 Fine-Tuning OSPF Interfaces 63 Securing OSPFv2 with MD5 Authentication 63 Troubleshooting Single-Area OSPF Implementations 65 OSPF Adjacency Issues 65 Identify OSPFv2 Troubleshooting Commands 65 Identify OSPFv3 Troubleshooting Commands 68 .

xi Chapter 6 Multiarea OSPF 71 Multiarea OSPF Operation 72 Multiarea OSPF Terminology and Concepts 72 Multiarea OSPF LSA Operation 73 OSPF Routing Table and Types of Routes 73 Configuring Multiarea OSPF 74 Configuring Multiarea OSPF 74 Configuring Route Summarization for Multiarea OSPFv2 77 Verifying Multiarea OSPF 79 Chapter 7 EIGRP 81 Characteristics of EIGRP 82 Describe Basic EIGRP Features 82 Identify and Describe EIGRP Packet Types 82 Identify Elements of the EIGRP Message Formats 83 Configuring EIGRP for IPv4 86 Configuring EIGRP with IPv4 86 Verifying EIGRP with IPv4 89 Operation of EIGRP 92 EIGRP Metric Concepts 92 DUAL Concepts Exercise 93 DUAL FSM Completion Exercise 95 Configuring EIGRP for IPv6 96 Comparing EIGRP for IPv4 and EIGRP for IPv6 96 Configuring and Verifying EIGRP for IPv6 97 Chapter 8 EIGRP Advanced Configurations and Troubleshooting 101 Advanced EIGRP Configurations 102 Automatic Summarization 102 Manual Summarization 104 IPv4 Manual Summarization 105 IPv6 Manual Summarization 107 Default Route Propagation 108 Fine-Tuning EIGRP Interfaces 110 Securing EIGRP Routing Updates 112 Troubleshoot EIGRP 113 Commands for Troubleshooting EIGRP 113 Troubleshoot EIGRP Connectivity Issues 114 Connectivity Issue #1 114 Connectivity Issue #2 115 Connectivity Issue #3 115 .

Trains. and Naming Conventions 120 Backing Up Cisco IOS Images 122 IOS Licensing 123 Software Licensing 124 License Verification and Management 124 Part II: Connecting Networks Chapter 10 Hierarchical Network Design 127 Hierarchical Network Design Overview 128 Enterprise Network Campus Design 128 Hierarchical Network Design 128 Cisco Enterprise Architecture 129 Modular Network Design 129 Cisco Enterprise Architecture Model 130 Evolving Network Architectures 133 Cisco Enterprise Architectures 133 Emerging Network Architectures 133 Chapter 11 Connecting to the WAN 135 WAN Technologies Overview 136 Network Types and Their Evolving WAN Needs 136 WAN Operations and Terminology 137 Selecting a WAN Technology 139 Varieties of WAN Link Connections 139 Private and Public WAN Access Options 139 Chapter 12 Point-to-Point Connections 143 Serial Point-to-Point Overview 144 Serial Communications 144 WAN Protocols 146 HDLC Encapsulation 146 HDLC Configuration and Troubleshooting 147 Troubleshooting Serial Interfaces 147 PPP Operation 148 PPP Components 148 PPP Sessions 150 Configure PPP 152 Basic PPP Configuration with Options 152 PPP Authentication 154 PAP Configuration 155 CHAP Configuration 156 Troubleshoot WAN Connectivity 156 .xii CCNA Routing and Switching Practice and Study Guide Chapter 9 IOS Images and Licensing 119 Managing IOS System Files 120 IOS Families.

xiii Chapter 13 Frame Relay 157 Introduction to Frame Relay 158 Frame Relay Concepts and Terminology 158 Frame Relay Operation 159 Configure Frame Relay 161 Configure Basic Frame Relay 162 Configure Subinterfaces 163 Troubleshoot Connectivity 164 Chapter 14 Network Address Translation for IPv4 167 NAT Operation 167 NAT Characteristics 167 Configuring NAT 169 Configuring Static NAT 169 Configuring Dynamic NAT 170 Configuring Port Address Translation 171 A Word About Port Forwarding 173 Configuring NAT and IPv6 174 Troubleshooting NAT 175 Chapter 15 Broadband Solutions 177 Teleworking 178 Benefits of Teleworking 178 Costs of Teleworking 178 Business Requirements for Teleworker Services 178 Comparing Broadband Solutions 179 Cable 179 DSL 181 Broadband Wireless 182 Selecting Broadband Solutions 183 Configuring xDSL Connectivity 183 PPPoE Overview 183 Configuring PPPoE 184 Chapter 16 Securing Site-to-Site Connectivity 187 VPNs 188 Fundamentals of VPNs 188 Types of VPNs 188 Site-to-Site GRE Tunnels 189 Fundamentals of Generic Routing Encapsulation 189 Configuring GRE Tunnels 190 .

xiv CCNA Routing and Switching Practice and Study Guide Introducing IPsec 192 Internet Protocol Security 192 IPsec Framework 192 Remote Access 194 Remote-Access VPN Solutions 194 IPsec Remote-Access VPNs 195 Chapter 17 Monitoring the Network 197 Syslog 198 Syslog Operation 198 Configuring Syslog 199 SNMP 199 SNMP Operation 199 Configuring SNMP 201 NetFlow 203 NetFlow Operation 203 Configuring NetFlow 204 Chapter 18 Troubleshooting the Network 207 Troubleshooting with a Systematic Approach 208 Network Documentation 208 Troubleshooting Process and Methodologies 211 Network Troubleshooting 213 Troubleshooting Tools 214 Network Troubleshooting and IP Connectivity 215 .

In actual configuration examples and output (not general command syntax). The Command Reference describes these conventions as follows: ■ Boldface indicates commands and keywords that are entered literally as shown. ■ Italics indicate arguments for which you supply actual values. ■ Braces within brackets [{ }] indicate a required choice within an optional element. ■ Braces { } indicate a required choice. ■ Square brackets [ ] indicate optional elements. . mutually exclusive elements. ■ Vertical bars (|) separate alternative. boldface indicates commands that are manually input by the user (such as a show command). xv Icons Used in This Book DSU/CSU Router Bridge Hub DSU/CSU Catalyst Multilayer ATM ISDN/Frame Relay Switch Switch Switch Switch Communication Gateway Access Server Server Command Syntax Conventions The conventions used to present command syntax in this book are the same conventions used in the IOS Command Reference.

components. visit http://www. and VTP in both IPv4 and IPv6 networks. They are divided into five broad categories: ■ LAN Switching Technologies ■ IP Routing Technologies ■ IP Services ■ Troubleshooting ■ WAN Technologies . taking the student deeper into the architecture. you can buy any or all of CCNA Routing and Switching Companion Guides (CG) and Lab Manuals (LM) of the Academy’s popular online curriculum. the reader will have completed the first two courses: Introduction to Networks (ITN) and Routing and Switching Essentials (RSE). if you are not an Academy student but would like to benefit from the extensive authoring done for these courses.netacad. However. operate. which is associated with the Cisco Certified Network Associate (CCNA) certification.com. This book maps to the third and fourth Cisco Networking Academy courses in the CCNA Routing and Switching curricula: Scaling Networks (SN) and Connecting Networks (CN). To learn more about CCNA Routing and Switching courses and to find an Academy near you.xvi CCNA Routing and Switching Practice and Study Guide Introduction The purpose of this book is to provide you with an extra resource for studying the exam top- ics of the Interconnecting Cisco Networking Devices Part 2 (ICND2) exam that leads to Cisco Certified Networking Associate (CCNA) certification. Successfully completing this course means that you should be able to configure and troubleshoot routers and switches and resolve common issues with OSPF. Although you will not have access to the Packet Tracer network simulator software. CN pulls everything from the first three courses together as the student learns the WAN technologies and network services required by converged applications in a complex network. The titles and ISBNs for the first two courses of the CCNA Routing and Switching CGs and LMs are as follows: ■ Scaling Networks Companion Guide (ISBN: 9781587133282) ■ Scaling Networks Lab Manual (ISBN: 9781587133251) ■ Connecting Networks Companion Guide (ISBN: 9781587133329) ■ Connecting Networks Lab Manual (ISBN: 9781587133312) Goals and Methods The most important goal of this book is to help you pass the 200-101 Interconnecting Cisco Networking Devices Part 2 (ICND2) exam. Successfully completing this course means that you should be able to configure and trouble- shoot network devices and resolve common WAN issues and implement IPsec and virtual pri- vate network (VPN) operations in a complex network. Passing the CCNA exam means that you have the knowledge and skills required to successfully install. Ideally. and operations of routers and switches in a large and complex network. and troubleshoot a small branch office network. You can view the detailed exam topics any time at http://learningnetwork. you will have access to the tireless work of an outstanding team of Cisco Academy instructors dedi- cated to providing students with comprehensive and engaging CCNA Routing and Switching preparation course material.cisco. SN continues where RSE left off.com. EIGRP. STP.

Video Demonstration . complete those activities. and troubleshoot- ing skills crucial to your success as a CCNA exam candidate. However. This book has 18 chapters. the Labs are available in the Lab Manuals previously cited. progressing from Chapter 1 to Chapter 18. These refer- ences are provided so that you can. xvii This book offers exercises that help you learn the concepts. This book can also be used for college. The Packet Tracer activities are accessible only if you have access to the online curriculum. operations. and outputs.and university-level networking courses. whereas other Academies recommend the Practice Study Guide as an additional resource to prepare for class exams and the CCNA certification. Most of the configuration chapters use a single topology where appropriate. at that point. you should work through this Practice and Study Guide in order beginning with Chapter 1. The online cur- riculum starts over at Chapter 1 in the Connecting Networks course. Many Academies use this Practice Study Guide as a required tool in the course. How This Book Is Organized Because the content of the Scaling Networks Companion Guide. Packet Tracer Activity Note: Throughout the book. The book covers the major topic headings in the same sequence as the online curriculum. the num- bering is sequential in this book. The secondary audiences for this book include people taking CCNA-related classes from pro- fessional training organizations. A different topology affords you the opportunity to practice your knowl- edge and skills without just simply recording the information you find in the text. This allows for better continuity and easier understanding of routing and switching commands. However. configurations. the Connecting Networks Companion Guide. the topology differs from the one used in the online curriculum and the Companion Guide. their names the same as the online course chapters. and the online curriculum is sequential. and by anyone wanting to gain a detailed understanding of INCD2 routing and switching concepts. you will find references to Packet Tracer and Lab activities. Each chapter differs slightly and includes some or all of the following types of practice: ■ Vocabulary-matching exercises ■ Concept question exercises ■ Skill-building activities and scenarios ■ Configuration scenarios ■ Troubleshooting scenarios Audience for This Book This book’s main audience is anyone taking the CCNA Routing and Switching courses of the Cisco Networking Academy curriculum. However.

So. EIGRP for IPv4 and IPv6. it is still a viable option in depending on your location. configuration. Exercises in this chapter focus on the serial interface and then the con- cepts. ■ Chapter 2. configuration. ■ Chapter 4. opera- tions. The exercises focus on differentiating between all these WAN options. verification. ■ Chapter 8. and verification of all the current varieties of STP. Part II: Connecting Networks ■ Chapter 10. and troubleshooting. verifica- tion. configuration. “Connecting to the WAN”: This chapter is a survey of all the various WAN access options and technologies that are available for connecting today’s networks. and still viable. “EIGRP”: The exercises in this chapter are devoted to the basic concepts and configuration of Cisco’s routing protocol. “IOS Images and Licensing”: This chapter is devoted to the crucial knowl- edge and skills you need to manage IOS images. and troubleshooting. “Hierarchical Network Design”: Part II. you will complete activities focused on WLAN compo- nents. starts off network design. and troubleshooting of Frame Relay. “Link Aggregation”: This chapter’s exercises are devoted to the concepts. “Frame Relay”: Although some may consider Frame Relay obsolete. and troubleshooting of PPP with PAP and CHAP authentication. verification. Exercises focus on the various types of network design models and architec- tures. ■ Chapter 12. configuration.xviii CCNA Routing and Switching Practice and Study Guide Part I: Scaling Networks ■ Chapter 1. much like Part I. configuration. “LAN Redundancy”: The exercises in this chapter cover the concepts. You will complete exercises that focus on various types of wireless and the stan- dards for 802. “Point-to-Point Connections”: One of the older. ■ Chapter 5. “Introduction to Scaling Networks”: This chapter provides vocabulary and concept exercises to reinforce your understanding of hierarchical network design and selecting hardware. ■ Chapter 11. configuration. and troubleshooting. Exercises focus on basic IOS image con- cepts and management tasks. ■ Chapter 7.11. and security. . topologies. verification. “EIGRP Advanced Configurations and Troubleshooting”: This chapter focuses on advanced EIGRP concepts. This chapter includes exercises cover- ing the concepts. ■ Chapter 6. “Wireless LANs”: This chapter is all about wireless connectivity technolo- gies. verification. “Adjust and Troubleshoot Single-Area OSPF”: This chapter focuses on advanced OSPF concepts. In addition. verification. ■ Chapter 3. “Multiarea OSPF”: The CCNA exam now includes multiarea OSPF. You will also practice basic router and switch configuration and veri- fication. ■ Chapter 9. ■ Chapter 13. this chapter includes exercises covering multiarea OSPF concepts and configuration. and troubleshooting of EtherChannel. WAN options is PPP.

This exercises in this chapter help you distinguish between the various broadband offerings on the market. a link to the supplemental content will be listed on your My Registered Books page. About the Cisco Press Website for This Book Cisco Press provides additional content that can be accessed by registering your individual book at the ciscopress.com to continue registration. “Troubleshooting the Network”: Throughout your CCNA studies.ciscopress. “Network Address Translation for IPv4”: NAT was created to provide a temporary solution to the limited address space in IPv4. and PAT. This chapter reviews troubleshooting methodologies and the tools and commands you use to troubleshoot a network.asp and enter the book’s ISBN located on the back cover of this book. go to http://www. and NetFlow.com/bookstore/register. ■ Chapter 15. xix ■ Chapter 14. You’ll then be prompted to log in or join ciscopress. you are more likely to be managing a network using a variety of tools rather than designing and building them. Becoming a member and registering is free. “Broadband Solutions”: Working from home or away from a central office has largely been made possible by the advent of broadband technologies and VPNs. . dynamic NAT. The exercises in this chapter are devoted to the concepts of the various VPN solutions. This chapter focuses on exercises to reinforce your understanding of NAT operation and characteristics. SNMP. you have practice troubleshooting skills in relation to specific technologies. “Monitoring the Network”: As a network administrator. verifying. The exercises in this chapter cover three popular network monitoring tools: syslog. Troubleshooting is a key skill to fine-tune now that you are close to taking your CCNA exam. and trou- bleshooting static NAT. After you register the book. including IPsec and GRE configuration. and you then gain access to exclusive deals on other resources from Cisco Press. “Securing Site-to-Site Connectivity”: VPNs allow teleworkers and branch sites connect to the corporate network regardless of the underlying WAN access option. Practice activities include configuring.com website. ■ Chapter 17. ■ Chapter 18. ■ Chapter 16. Just about every router con- nected to the network uses NAT or forwards traffic to a NAT-enabled device for address translation. To register this book.

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A network that scales well is not only one that can handle growing traffic demands. and appropriate device selections that you can use to systematically design a highly functional network. . a network must be designed to scale. CHAPTER 1 Introduction to Scaling Networks As a business grows. This short chapter sets the stage for the rest of the course. so does its networking requirements. This chapter covers the hierarchical network design model. To keep pace with a business’s expansion and new emerging technologies. the Cisco Enterprise Architecture modules. but also one designed with the inevitable need to expand.

Why should a network be organized so that traffic stays local and is not propagated unneces- sarily on to other portions of the network? Designing a network using the three-layer hierarchical design model helps optimize the net- work. label the three layers of the hierarchical design model. IP telephony. Figure 1-1 Hierarchical Design Model Hierarchical Design Model Internet Internet . In Figure 1-1. Describe what failover capability means for enterprise class equipment.2 CCNA Routing and Switching Practice and Study Guide Implementing a Network Design An enterprise network must be designed to support the exchange of various types of network traffic. To provide this kind of reliability. Hierarchical Network Design Users expect enterprise networks to be up percent of the time. enterprise class equipment uses power supplies and has failover capabilities. and video applications for multiple business units. email. including data files.

. A well-designed network not only controls traffic but also limits the size of failure domains. Service Provider Edge.. MAN. The primary Cisco Enterprise Architecture modules include Enterprise Campus. and Remote. The Cisco Enterprise Architecture divides the network into functional components while still maintaining the core. Briefly describe a failure domain. and access layers. . Network Management . Chapter 1: Introduction to Scaling Networks 3 Briefly describe each layer of the hierarchical design model. distribution. Enterprise Edge. ATM. Modules 1 Campus Core 2 Remote Access & VPN 3 Building Distribution 4 Internet Connectivity 5 Building Access 6 Server Farm & Data Center 7 WAN Site-to-Site VPN 8 E-Commerce Figure 1-2 Cisco Enterprise Architecture Enterprise Campus Enterprise Edge Service Remote Provider Edge Enterprise Branch Campus Infrastructure Module ISP A ISP B Enterprise Teleworker PSTN Enterprise Data Center Frame Relay. Use the list of modules to label the parts of the Cisco Enterprise Architecture in Figure 1-2.

Redundancy switching loops f. EtherChannel failure Supports new features and devices without requiring major equipment upgrades Link-state routing protocol with a two-layer hierarchical design Increases flexibility. Wireless LANs Allows for redundant paths by eliminating e. Modular equipment size of routing tables b. EIGRP protocol d. This is a one-to-one matching exercise.4 CCNA Routing and Switching Practice and Study Guide Identify Scalability Terminology Match the definition on the left with the term on the right. Definition Terms Isolates routing updates and minimizes the a. and pro- vides mobility to users . OSPF Cisco proprietary distance vector routing c. Spanning Tree Protocol Technique for aggregating multiple links between equipment to increase bandwidth g. Scalable Routing Protocol Minimizes the possibility of a single point of h. reduces costs.

Fixed configuration How fast the interfaces will process network data h. Power throughput d. Frame buffers appropriate number of devices on the network f. Port density other areas of the network Provides electrical current to other device and support redundant power supplies Switches with preset features or options Depends on the number and speed of the interfaces. and expansion capability Switches with insertable switching line/port cards . Reliability network b. Port speed there may be congested ports to servers or j. supported features. Business Consideration Switch Feature Should provide continuous access to the a. Within an enterprise network. Stackable Refers to a switch’s ability to support the e. Modular Daisy-chain switches with high-bandwidth c. Scalability Important consideration in a network where i. Chapter 1: Introduction to Scaling Networks 5 Selecting Network Devices When designing a network. it is important to select the proper hardware to meet current network requirements and to allow for network growth. This is a one-to-one matching exercise. both switches and routers play a critical role in network communication. Cost Ability to adjust to growth of network users g. Selecting Switch Hardware Match the business consideration on the left with the switch feature on the right.

A router configuration also includes basic routing.Comparing 2960 and 3560 Switches (SN 1.255.1 255.255.1 255.1. In addition to configuration commands.7/SwN 1.252 N/A S0/0/1 192. and assignment of IP addresses to interfaces for connectivity.252 N/A S1 VLAN 1 192.16. data center.255. Use the address scheme in Table 1-2 in the following exercises that review the most common router and switch configuration and verification commands. passwords for security.255.5) Activity Selecting Router Hardware In Table 1-1.0 N/A S0/0/0 172.1.168.0 192.6 CCNA Routing and Switching Practice and Study Guide Packet Tracer Packet Tracer . Table 1-1 Identify Router Category Features Router Description Branch Network Service Routers Edge Provider Routers Routers Fast performance with high security for data centers. and branch networks Simple network configuration and management for LANs and WANs Optimizes services on a single platform End-to-end delivery of subscriber services Deliver next-generation Internet experiences across all devices and locations High capacity and scalability with hierarchical quality of service Maximizes local services and ensures 24/7/365 uptime Unites campus.168. Table 1-2 Router and Switch Addressing Table Device Interface IPv4 Address Subnet Mask Default Gateway R1 G0/0 172.255.1.1.1 .255. select the router category that applies to each description. router and switch verification commands are used to verify the operational status of the router or switch and related network functionality.16.5 255. campus.168.255.2.3.10.2.5 255.1.255. and branch networks Managing Devices A basic router or switch configuration includes the hostname for identification.

■ Console and Telnet line’s password is cisco. ■ OSPF routing. Router(config)# . including the router prompt. Chapter 1: Introduction to Scaling Networks 7 Basic Router Configuration Review Using Table 1-2 and the following requirements. record the commands. including an appropriate router ID. ■ Interface addressing. ■ Save the configuration. ■ Privileged EXEC password is class. to implement a basic router configuration: ■ Hostname is R1. ■ Banner message-of-the-day.

including admin- istrative distance. and duplex type Basic Switch Configuration Review Using Table 1-2 and the following requirements. Table 1-3 Router Verification Commands Command Command Output Displays the routing table for known networks.8 CCNA Routing and Switching Practice and Study Guide Basic Router Verification Review In Table 1-3. IP address. record the verification command that will generate the described output. including router ID. and neighbors Displays information about directly connected Cisco devices Displays all interfaces in an abbreviated format. Switch(config)# . ■ Console and Telnet line’s password is cisco. and outbound interface Displays information about routing protocols. ■ VLAN 1 interface addressing. ■ Privileged EXEC password is class. router ID. including the switch prompt. to implement a basic switch configuration: ■ Hostname is S1. including status. state. record the commands. metric. bandwidth. ■ Save the configuration. including process ID. including IP address and status Displays information about neighbors. ■ Banner message-of-the-day. and local interface that learned of neighbor Displays one or all interfaces.

and action to be taken Packet Tracer Packet Tracer .Skills Integration Challenge (SN 1. and duplex type Displays information about maximum MAC addresses allowed.2) Challenge . including status. current counts. bandwidth.1. Chapter 1: Introduction to Scaling Networks 9 Basic Switch Verification Review In Table 1-4. security violation count. record the verification command that will generate the described output.3. including the port number and VLAN assigned to the port Displays one or all interfaces. Table 1-4 Router Verification Commands Command Command Output Displays information about directly connected Cisco devices Displays all secure MAC addresses Displays a table of learned MAC addresses.

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In addition. Consequently. CHAPTER 2 LAN Redundancy Computer networks are inextricably linked to productivity in today’s small and medium-sized business- es. another link needs to quickly take its place without introducing any traffic loops. . IT administrators have to implement redundancy in their hierarchical networks. the chapter briefly explores how Layer 3 redundancy is implemented through First Hop Redundancy Protocols (FHRPs). This chapter investigates how Spanning Tree Protocol (STP) logically blocks physical loops in the network and how STP has evolved into a robust protocol that rapidly calculates which ports should be blocked in a VLAN-based network. When a switch connection is lost.

Each distribution layer switch should have two links to the core layer with each link connecting to a different core layer switch.12 CCNA Routing and Switching Practice and Study Guide Spanning-Tree Concepts Redundancy increases the availability of a network topology by protecting the network from a single point of failure. Describe each of the following issues: ■ MAC database instability: ■ Broadcast storms: ■ Multiple frame transmission: . Figure 2-1 Redundant Topology C1 C2 Core Distribution D1 D2 D3 D4 Access S1 S2 S3 S4 S5 S6 PC1 PC2 PC3 PC4 PC5 PC6 Purpose of Spanning Tree STP prevents specific types of issues in a redundant topology like the one in Figure 2-1. Draw a Redundant Topology In Figure 2-1. distribution. Each access switch should have two links to the distribution layer with each link connecting to a different distribution layer switch. and core switches. Specifically. three potential issues would occur if STP was not implemented. such as a failed network cable or switch. STP was developed to address the issue of loops in a redundant Layer 2 design. draw redundant links between the access.

STP uses the (STA) to determine which switch ports on a network need to be to prevent from occurring.1. A (BPDU) is a frame containing STP information exchanged by switches running STP. STA chooses the path with the lowest . each switch identifies itself as the bridge after boot. all references to STP assume RSTP unless otherwise indicated.1.5/SwN 4. How would a switch determine that another switch is now the root bridge? How does the STA determine path cost? . it configures the switch ports into distinct port roles. The STA designates a single switch as the bridge and uses it as the reference point for all subsequent calculations. When the STA has determined the “best” paths emanating from the root bridge. Each BPDU contains a BID that identifies the switch that sent the BPDU. This switch automatically becomes the bridge. Switches participating in STP determine which switch has the lowest (BID) on the network. Packet Tracer . which is documented in IEEE -2004. supersedes the original STP documented in IEEE -1998. The port roles describe their relation in the network to the root bridge and whether they are allowed to forward traffic: ■ ports: Switch ports closest to the root bridge ■ ports: Nonroot ports that are still permitted to forward traffic on the network ■ ports: Ports in a blocking state to prevent loops ■ port: Ports that are administratively shut down After a switch boots. STP ensures that there is only one logical path between all destinations on the network by intentionally blocking redundant paths that could cause a . After the root bridge has been determined.5) Packet Tracer Activity Spanning-Tree Operation Because (RSTP). the STA calculates the shortest path to the root bridge. If there is more than one path to choose from.1.Examining a Redundant Design (SN 2. A switch port is considered when network traffic is prevented from entering or leaving that port. Chapter 2: LAN Redundancy 13 You should be prepared to use a topology like Figure 2-1 to explain exactly how these three issues would occur if STP was not implemented. The BID value determines which switch is root. it sends BPDU frames containing the switch BID and the root ID every seconds.1. Initially.

enter the privileged EXEC mode command. Table 2-1 Port Costs Link Speed Cost (Revised IEEE Cost (Previous IEEE Specification) Specification) 10 Gbps 1 Gbps 100 Mbps 10 Mbps Although switch ports have a default port cost associated with them. the port cost is configu- rable.2 P2p Fa0/3 Desg LIS 19 128. To configure the port cost of an interface.a980 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 15 sec Interface Role Sts Cost Prio.--. enter the command in interface configuration mode.5cd7.--------.14 CCNA Routing and Switching Practice and Study Guide Record the default port costs for various link speeds in Table 2-1.bcc4. Record the commands.6 P2p<output omitted> . The range value can be between and .Nbr Type ------------------.1 P2p Fa0/2 Altn BLK 19 128. as shown here: S2# VLAN0001 Spanning tree enabled protocol ieee Root ID Priority 32769 Address c025. to configure the port cost for F0/1 as 15: To verify the port and path cost to the root bridge.3 P2p Fa0/4 Desg LIS 19 128.-------.ef00 Cost 15 Port 1 (FastEthernet0/1) Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Bridge ID Priority 32769 (priority 32768 sys-id-ext 1) Address c07b. including the switch prompt.-------------------------------- Fa0/1 Root FWD 15 128.4 P2p Fa0/6 Desg FWD 19 128.---.

the is a customizable value that you can use to influence which switch becomes the root bridge.Scenario 1 G1/1 G1/1 S1 S2 F0/1 F0/1 G1/2 G1/2 F0/1 F0/1 S3 S4 Device Priority MAC Address S1 32769 000a:0001:1111 S2 24577 000a:0002:2222 S3 32769 000a:0003:3333 S4 32769 000a:0004:4444 . use the priority values and MAC addresses to determine the root bridge. Identify the 802. Then label the ports with one of the following: ■ RP: Root Port ■ DP: Designated Port ■ AP: Alternate Port Figure 2-2 802. the switch with the lowest has the lower BID. they provide good exercise topologies for you to practice determining the STP port roles. When two switches are configured with the same priority and have the same extended system ID. Chapter 2: LAN Redundancy 15 The BID field of a BPDU frame contains three separate fields: . Of these three fields. The default value for this field is . Because using the extended system ID changes the number of bits available for the bridge pri- ority. . which contains the ID of the with which the BPDU is associated.1D Port Roles The topologies in the next three figures do not necessarily represent an appropriate network design. Cisco enhanced its implementation of STP to include support for the extended system ID field.1D Port Roles . the customizable values can only be multiples of . However. and . In Figures 2-2 through 2-4.

■ : This is an evolution of STP that provides faster conver- gence than STP. Comparing the STP Varieties Identify each of the STP varieties described in the following list: ■ : This is an IEEE that maps multiple VLANs into the same spanning tree instance.2.2.Scenario 2 G1/1 G1/1 S1 S2 F0/1 F0/1 G1/2 G1/2 F0/1 F0/1 S3 S4 Device Priority MAC Address S1 24577 000a:0001:1111 S2 32769 000a:0002:2222 S3 32769 000a:0003:3333 S4 32769 000a:0004:4444 Figure 2-4 802.10/SwN 4. .1.1D Port Roles .1D speci- fication.16 CCNA Routing and Switching Practice and Study Guide Figure 2-3 802. A network administrator should know which type to implement based on the equip- ment and topology needs.10) Varieties of Spanning Tree Protocols STP has been improved multiple times since its introduction in the original IEEE 802.1D Port Roles .1.Scenario 3 G1/1 G1/1 S1 S2 F0/1 F0/1 G1/2 G1/2 F0/1 F0/1 S3 S4 Device Priority MAC Address S1 32769 000a:0001:1111 S2 32769 000a:0002:2222 S3 24577 000a:0003:3333 S4 32769 000a:0004:4444 Lab – Building a Switched Network with Redundant Links (SN 2.

Cisco proprietary versions of STP. Cisco Medium or high In Table 2-3. Table 2-2 STP Characteristics .1D-1998 and earlier) that provides a loop-free topology in a network with redundant links.1s that provides up to 16 instances of RSTP. BPDU filter. Has the highest CPU and memory requirements. ■ : This is a Cisco enhancement that provides a separate instance of 802. ■ : This is the original IEEE 802. Table 2-3 STP Characteristics .1w Rapid PVST+ 802. Chapter 2: LAN Redundancy 17 ■ : This is an updated version of the STP standard. Some characteristics apply to more than one STP variety. . incorpo- rating IEEE 802.1s. regardless of the number of VLANs.1D spanning-tree instance for each VLAN. Complete the cells in Table 2-2 to identify each the characteristics of each STP variety. Uses 1 IEEE 802. BPDU guard. and loop guard. An evolution of STP that provides faster STP convergence. There is only 1 root bridge and 1 tree. Can lead to suboptimal traffic flows.Exercise 1 Protocol Standard Resources Needed Convergence Tree Calculation STP Low Cisco 802.1w per VLAN. The default STP mode for Cisco Catalyst switches.Exercise 2 Characteristic STP PVST+ RSTP Rapid MSTP MST PVST+ A Cisco implementation of 802.1D spanning tree instance for each VLAN configured in the network. ■ : This is a Cisco enhancement of STP that provides a sepa- rate 802. Cisco enhancement of RSTP.1D spanning-tree instance for the entire bridged network. Provides a separate 802.1w. indicate which varieties of STP are best described by the characteristic. Supports PortFast. Cisco enhancement of STP.1D version (802. root guard.

18 CCNA Routing and Switching Practice and Study Guide Characteristic STP PVST+ RSTP Rapid MSTP MST PVST+ Maps multiple VLANs that have the same traffic flow requirements into the same spanning-tree instance. every active port in the switched network is either in the state or the state. PVST+ Operation After a switch boots. First version of STP to address conver- gence issues. List and briefly describe the four steps PVST+ performs for each VLAN to provide a loop-free logical topology. but still provided only one STP instance. . the spanning tree is immediately determined as ports transition through five possible states and three BPDU timers on the way to convergence. Briefly describe each state: ■ Blocking: ■ Listening: ■ Learning: ■ Forwarding: ■ Disabled: Once stable.

indicate whether the characteristic describes PVST+. alternate. Ports can transition to forwarding state without relying on a timer. backup. Chapter 2: LAN Redundancy 19 In Table 2-4. designated. Runs a separate IEEE 802. Table 2-5 Comparing PVST+ and Rapid PVST+ Characteristic PVST+ Rapid PVST+ Both Cisco proprietary protocol. Rapid PVST+. . Rapid PVST+ is the Cisco implementation of RSTP on a per-VLAN basis. Sends a BPDU “hello message” every 2 seconds. What command implements Cisco’s version of an edge port? In Table 2-5. or both. Table 2-4 Operations Allowed at Each Port State Operation Allowed Port State Blocking Listening Learning Forwarding Disabled Can receive and process BPDUs Can forward data frames received on interface Can forward data frames switched from another interface Can learn MAC addresses Rapid PVST+ Operation RSTP (IEEE ) is an evolution of the original standard and is incorporated into the IEEE -2004 standard. The root bridge is determined by the lowest BID + VLAN ID + MAC. edge. Possible to have load sharing with some VLANS forwarding on each trunk. Port roles: root.1D STP instance for each VLAN. CPU processing and trunk bandwidth usage is greater than with STP. answer the “Operation Allowed” question with “yes” or “no” for each port state. What is the primary difference between Rapid PVST+ and RSTP? Briefly describe the RSTP concept that corresponds to the PVST+ PortFast feature.

Table 2-6 Default Switch Configuration Feature Default Setting Enable state Enabled on VLAN 1 Spanning-tree mode Switch priority Spanning-tree port priority (configurable on a per-interface basis) Spanning-tree port cost 1000 Mbps: (configurable on a per-interface basis) 100 Mbps: 10 Mbps: Spanning-tree VLAN port priority (configurable on a per-VLAN basis) Spanning-tree VLAN port cost 1000 Mbps: (configurable on a per-VLAN basis) 100 Mbps: 10 Mbps: Spanning-tree timers Hello time: seconds Forward-delay time: seconds Maximum-aging time: seconds Transmit hold count: BPDUs Document the two different configuration commands that you can use to configure the bridge priority value so that the switch is root for VLAN 1.3333 This bridge is the root Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec .0033.20 CCNA Routing and Switching Practice and Study Guide Spanning-Tree Configuration It is crucial to understand the impact of a default switch configuration on STP convergence and what configurations can be applied to adjust the default behavior. Use the value 4096 when necessary: Record the command to verify that the local switch is now root: S1# VLAN0001 Spanning tree enabled protocol ieee Root ID Priority 24577 Address 000A. PVST+ and Rapid PVST+ Configuration Complete Table 2-6 to show the default spanning-tree configuration for a Cisco Catalyst 2960 series switch.

Chapter 2: LAN Redundancy 21 Bridge ID Priority 24577 (priority 24576 sys-id-ext 1) Address 0019.Nbr Type ---------------.2 Shr Explain the purpose of the BPDU guard feature on Cisco switches.b000 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 300 Interface Role Sts Cost Prio. For this example. Figure 2-5 represents a small section of Figure 2-1. D2 should be the primary root for VLAN 25 and the secondary root for VLAN 15. By default.--------. So.--. and PC2 is assigned to VLAN 25. showing only two distribution layer switch- es and one access layer switch. the least- favored redundant link is not used.1 Shr Fa0/2 Desg FWD 4 128.-------.aa9e. PC1 is assigned to VLAN 15.-------------------------------- Fa0/1 Desg FWD 4 128.---. you must manually configure PVST+ to use the link. D1 should be the primary root for VLAN 1 and VLAN 15 and the secondary root for VLAN 25. Figure 2-5 PVST+ Configuration Topology Root for VLAN 15 Root for VLAN 25 D1 D2 S1 PC1 PC2 VLAN 15 VLAN 25 . What command interface configuration command enables BPDU guard? What global configuration command will configure all nontrunking ports as edge ports? What global configuration command will configure BPDU guard on all PortFast-enabled ports? The power of PVST+ is that it can load balance across redundant links. we have attached PC2 to S1.

In addition to Layer 1 and Layer 2 redundancy.Configuring Rapid PVST+ (SN 2.3.3.3. . a high-availability network might also implement Layer 3 redundancy by sharing the default gateway responsibility across multiple devices.22 CCNA Routing and Switching Practice and Study Guide Based on these requirements. Through the use of a virtual IP address.3.3.3) Packet Tracer .Configuring PVST+ (SN 2.5/SwN 4.2.1.Configuring Rapid PVST+.2) Packet Tracer Activity First Hop Redundancy Protocols Up to this point.1.5) Packet Tracer Activity Packet Tracer . The section reviews First Hop Redundancy Protocols (FHRPs) that provide Layer 3 redundancy.2/SwN 4. PortFast.2.2. document the commands to modify the default PVST+ operation on D1 and D2. two Layer 3 devices can share the default gateway responsibility. we’ve been reviewing STP and how to manipulate the election of root bridges and load balance across redundant links.3/SwN 4.3. What command is required? Lab . Now. assume that you want to run rapid PVST+ on all three switches.2. and BPDU Guard (SN 2. D1 commands D2 commands Document the commands to configure all nontrunking ports on S1 as edge ports with BPDU guard enabled.

Virtual MAC address router should take the active role in forwarding h. Default gateway failure of a device acting as the default gate. Virtual IP address Provides the mechanism for determining which g. Virtual router traffic A device that routes traffic destined to net- work segments beyond the source network segment A device that is part of a virtual router group assigned the role of alternate default gateway A Layer 3 address assigned to a protocol that shares the single address among multiple devices The Layer 2 address returned by ARP for an FHRP gateway . Standby router A device that is part of a virtual router group assigned to the role of default gateway f. Chapter 2: LAN Redundancy 23 Identify FHRP Terminology Match the definition on the left with the terms on the right. Definitions Terms The ability to dynamically recover from the a. b. This is a one-to-one matching exercise. First-hop redundancy way c. Redundancy rrotocol IP address e. Forwarding router Two or more routers sharing a single MAC and d.

1. indicate whether the characteristic describes HSRP.168.168.168.20 192.20. Cisco-proprietary FHRP protocol designed to allow for transparent failover of a first-hop IPv4 devices.168. One router is elected as the virtual router master. or GLBP. A nonproprietary election protocol that allows several routers on a multi-access link to use the same virtual IPv4 address.1.1 standby 20 priority 120 <output omitted> .1. and virtual IP address 192. HSRP and GLBP Configuration and Verification Refer to the topology in Figure 2-6.1.1.1.1.0 standby 20 ip 192. Table 2-7 FHRP Characteristics FHRP Characteristic HSRP VRRP GLBP Used in a group of routers for selecting an active device and a stand- by device.1.20 255.1 192. Cisco-proprietary FHRP protocol that protects data traffic from a failed router or circuit while also allowing load sharing between a group of redundant routers. with the other rout- ers acting as backups in case the virtual router master fails. R2 has been configured for HSRP group 20.255.168.24 CCNA Routing and Switching Practice and Study Guide Identify the Type of FHRP In Table 2-7. IP address 192.10 Example 2-1 shows the HSRP configuration for R2. priority 120. VRRP.168.168. Example 2-1 R2 HSRP Configuration R2# show run interface g0/1 <output omitted> interface GigabitEthernet0/1 ip address 192.255. Figure 2-6 HSRP and GLBP Configuration Topology Core R2 Virtual IP R1 192.

1. and virtual IP address 192.1 glbp 20 priority 120 <output omitted> Using the information in Example 2-2.168.20 192.20.168.1.0 glbp 20 ip 192.1. Example 2-2 shows the GLBP configuration for R2.1.1 Now assume that all HSRP configurations have been removed.20 255.1 .1. R2 has been configured for GLBP group 20.168.168.255. Chapter 2: LAN Redundancy 25 Using the information in Example 2-1. last state change 00:03:05 Virtual IP address is 192. document the commands to configure R1 to be in GLBP group 20 using a priority of 210.Group 20 State is Active 1 state change.1.168. IP address 192.1. document the commands to configure R1 as the HSRP active router in group 20 using a priority of 210.168. priority 120. What command would generate the following output to verify the HSRP configuration? R1# P indicates configured to preempt.1. | Interface Grp Pri P State Active Standby Virtual IP Gi0/1 20 210 Active local 192.255. What command would generate the following output to verify the GLBP configuration? R1# GigabitEthernet0/0 .168. Example 2-2 R2 GLBP Configuration R2# show run interface g0/1 <output omitted> interface GigabitEthernet0/1 ip address 192.

312 sec) Lab .4/SwN 4.1.eb38 Redirection enabled.20) There are 2 forwarders (1 active) Forwarder 1 State is Active 1 state change.db58 Redirection enabled Preemption enabled.26 CCNA Routing and Switching Practice and Study Guide Hello time 3 sec. last state change 00:02:53 MAC address is 0007. 599.040 sec remaining (maximum 600 sec) Time to live: 14399.f671.0a01 (default) Owner ID is 0006. upper 100 Load balancing: round-robin Group members: 0006.3.20 (primary).1.f671.f671.b400.1. min delay 30 sec Active is 192. forwarder timeout 14400 sec Preemption disabled Active is local Standby is 192.b400.20. min delay 30 sec Active is local.db58 (192.168.eb38 (192.040 sec (maximum 14400 sec) Preemption enabled.024 sec) Priority 210 (configured) Weighting 100 (default 100).792 secs Redirect time 600 sec.168.4) .Configuring HSRP and GLBP (SN 2. hold time 10 sec Next hello sent in 1.168.168.1.0a02 (learnt) Owner ID is 0006. priority 120 (expires in 9. weighting 100 Forwarder 2 State is Listen MAC address is 0007. weighting 100 (expires in 9. thresholds: lower 1.3.4.4.10) local 0006.f671.

CHAPTER 3 Link Aggregation Link aggregation is the ability to create one logical link using multiple physical links between two devices. This allows load sharing among the physical links. . rather than having a STP block one or more of the links.

. there are also two proto- cols that can be used to configure the negotiation process: Port Aggregation Protocol (PAgP— Cisco proprietary) and Link Aggregation Control Protocol (LACP—IEEE 802. EtherChannel Advantages EtherChannel technology was originally developed by Cisco as a technique of grouping several Fast Ethernet or Gigabit Ethernet switch ports into one logical channel. The modes for each differ slightly.28 CCNA Routing and Switching Practice and Study Guide Link Aggregation Concepts One of the best ways to reduce the time it takes for STP convergence is to simply avoid STP.3ad). List at least three advantages to using EtherChannel: ■ ■ ■ ■ ■ EtherChannel Operation You can configure EtherChannel as static or unconditional. For PAgP. These two protocols ensure that both sides of the link have compatible configurations—same speed. indicate the mode that is described. and VLAN information. However. EtherChannel is a form of link aggregation used in switched networks. duplex setting. briefly describe each of the following modes: ■ On: ■ Desirable: ■ Auto: For LACP. briefly describe each of the following modes: ■ On: ■ Active: ■ Passive: In Table 3-1.

Actively initiates PAgP negotiations with other interfaces. Table 3-2 EtherChannel Negotiation Using PAgP Switch 1 Mode Switch 2 Mode EtherChannel Established? Auto Auto Auto Desirable On Desirable On Off Desirable Desirable In Table 3-3. Indicate with “yes” or “no” whether EtherChannel is established. Places an interface in a passive. . responding state. Does not initiate LACP negotiations. The mode that is configured on each side of the EtherChannel link determines whether EtherChannel will be operational. In Table 3-2. Does not initiate PAgP negotiations. responding state. Places an interface in a passive. two switches are using PAgP. Indicate with “yes” or “no” whether EtherChannel is established. Forces EtherChannel state without PAgP or LACP initiated negotiations. two switches are using LACP. Chapter 3: Link Aggregation 29 Table 3-1 PAgP and LACP Modes Mode PAgP and/or LACP Mode Description Initiates LACP negotiations with other interfaces. Table 3-3 EtherChannel Negotiation Using LACP Switch 1 Mode Switch 2 Mode EtherChannel Established? Passive On Passive Active On On Passive Passive On Active Link Aggregation Configuration EtherChannel configuration is rather straightforward once you decide on which protocol you will use. In fact. the easiest method is to just force both sides to be on.

complete the following steps: Step 1. Then force the channel to trunking using native VLAN 99. The key- words and enable LACP. to configure the S1 Fa0/1 and Fa0/2 into an EtherChannel using PAgP. participate in the EtherChannel group using the interface range interface command. native VLANs. The channel-group command automatically creates a port channel interface using the identifier as the number. Create the port channel interface with the channel-group identifier mode {on | auto | desirable | active | passive} command in interface range configuration mode. to configure the S1 Fa0/1 and Fa0/2 into an EtherChannel without negotiations. What are the requirements for each interface before they can form an EtherChannel? Step 2. consider Figure 3-1 in each of the following configuration scenarios. the way you specify whether to use PAgP. 10. Specify the interfaces that. The keywords and enable PAgP. or allowed VLANs. So. The channel should trunk.30 CCNA Routing and Switching Practice and Study Guide Configuring EtherChannel To configure EtherChannel. S1 should initiate the negotiations. allowing only VLANs 1. or no negotiations is by configuring one keyword in the channel-group command. S1(config)# EtherChannel Configuration Scenario 1 Record the commands. including the switch prompt. and 20. Figure 3-1 EtherChannel Topology Fa0/1 S1 S2 Fa0/2 EtherChannel Configuration Scenario 1 Record the commands. Use the interface port-channel identifier command to configure channel-wide settings like trunking. As you can see from the configuration steps. including the switch prompt. with those steps in mind. Step 3. S1(config)# . LACP. The keyword forces the port to channel without PAgP or LACP.

line protocol is up (connected) Hardware is EtherChannel. The channel should trunk.default port Number of channel-groups in use: 1 Number of aggregators: 1 . Chapter 3: Link Aggregation 31 EtherChannel Configuration Scenario 1 Record the commands.96e8.1. rxload 1/255 <output omitted> S1# Flags: D . BW 200000 Kbit/sec.2. DLY 100 usec.in use f . allowing all VLANs.4) Packet Tracer .2. including the switch prompt.1.8a01) MTU 1500 bytes.1.4/SwN 5.2.waiting to be aggregated d . S1 should not initiate the negotiations.suspended H .8a01 (bia 0cd9. to configure the S1 Fa0/1 and Fa0/2 into an EtherChannel using LACP.Configuring EtherChannel (SN 3. S1(config)# Lab .unsuitable for bundling w .96e8.not in use.stand-alone s .Layer3 S .3/SwN 5.1.3) Packet Tracer Activity Verifying and Troubleshooting EtherChannel Record the commands used to display the output in Example 3-1. reliability 255/255. minimum links not met u .down P . address is 0cd9.Configuring EtherChannel (SN 3.failed to allocate aggregator M .bundled in port-channel I .2.Hot-standby (LACP only) R .Layer2 U . txload 1/255. Example 3-1 EtherChannel Verification Commands S1# Port-channel1 is up.

P . Pseudo port-channel = Po1 Port index = 0 Load = 0x00 Protocol = LACP Flags: S .Device is sending fast LACPDUs.Device is in active mode. A .Device is sending Slow LACPDUs F .Device is in passive mode. .32 CCNA Routing and Switching Practice and Study Guide Group Port-channel Protocol Ports ------+-------------+-----------+----------------------------------------------- 1 Po1(SU) LACP Fa0/1(P) Fa0/2(P) S1# Channel-group listing: ---------------------- Group: 1 ---------- Port-channels in the group: --------------------------- Port-channel: Po1 (Primary Aggregator) ------------ Age of the Port-channel = 0d:00h:25m:17s Logical slot/port = 2/1 Number of ports = 2 HotStandBy port = null Port state = Port-channel Ag-Inuse Protocol = LACP Port security = Disabled Ports in the Port-channel: Index Load Port EC state No of bits ------+------+------+------------------+----------- 0 00 Fa0/1 Active 0 0 00 Fa0/2 Active 0 Time since last port bundled: 0d:00h:05m:41s Fa0/2 Time since last port Un-bundled: 0d:00h:05m:48s Fa0/2 S1# Port state = Up Mstr Assoc In-Bndl Channel group = 1 Mode = Active Gcchange = - Port-channel = Po1 GC = .

suspended H .not in use.stand-alone s .down P .default port Number of channel-groups in use: 1 Number of aggregators: 1 Group Port-channel Protocol Ports ------+-------------+-----------+----------------------------------------------- 1 Po1(SD) .Layer2 U . minimum links not met u .Hot-standby (LACP only) R . List at least four restrictions.96d2. Example 3-2 Troubleshooting an EtherChannel Issue S1# Flags: D .Layer3 S . Fa0/1(D) Fa0/2(D) S1# show run | begin interface Port-channel .4000 4s 0x0 0x1 0x102 0x3D Age of the port in the current state: 0d:00h:24m:59s S1# When troubleshooting an EtherChannel issue.unsuitable for bundling w .failed to allocate aggregator M .bundled in port-channel I . Chapter 3: Link Aggregation 33 Local information: LACP port Admin Oper Port Port Port Flags State Priority Key Key Number State Fa0/1 SA bndl 32768 0x1 0x1 0x102 0x3D Partner's information: LACP port Admin Oper Port Port Port Flags Priority Dev ID Age key Key Number State Fa0/1 SA 32768 0cd9. Record the command that generated the output.waiting to be aggregated d . ■ ■ ■ ■ ■ Refer to the output for S1 and S2 in Example 3-2.in use f . keep in mind the configuration restrictions for interfaces that participate in the channel.

For this reason. To correct this issue.34 CCNA Routing and Switching Practice and Study Guide interface Port-channel1 switchport mode trunk ! interface FastEthernet0/1 switchport mode trunk channel-group 1 mode auto ! interface FastEthernet0/2 switchport mode trunk channel-group 1 mode auto ! <output omitted> S 1# S2# show run | begin interface Port-channel interface Port-channel1 switchport mode trunk ! interface FastEthernet0/1 switchport mode trunk channel-group 1 mode auto ! interface FastEthernet0/2 switchport mode trunk channel-group 1 mode auto ! <output omitted> S2# Explain why the EtherChannel between S1 and S2 is down. EtherChannel and spanning tree must interoperate. the order in which EtherChannel-related commands are entered is important. spanning-tree errors cause the associated ports to go into blocking or errdisabled state. what would you suggest to correct the issue shown in Example 3-2 if the requirement is to use PAgP? What commands would be required? . With that in mind. you must first remove the port channel. Otherwise.

3.2.3.2.Troubleshooting EtherChannel (SN 3.4/SwN 5.1.Troubleshooting EtherChannel (SN 3.2.Skills Integration Challenge (SN 3.2.2.2) .2.2.4) Packet Tracer Packet Tracer .3/SwN 5.3) Activity Packet Tracer .2/SwN 5.2.1. Chapter 3: Link Aggregation 35 Lab .