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.
Managing Editor
Cisco Press logo is a trademark of Cisco Systems, Inc. Sandra Schroeder

Published by: Senior Development Editor
Cisco Press Christopher Cleveland
800 East 96th Street
Project Editor
Indianapolis, IN 46240 USA
Mandie Frank
All rights reserved. No part of this book may be reproduced or transmitted in any
Copy Editor
form or by any means, electronic or mechanical, including photocopying, record- Keith Cline
ing, or by any information storage and retrieval system, without written permis-
sion from the publisher, except for the inclusion of brief quotations in a review. Technical Editor
Steve Stiles
Printed in the United States of America
Editorial Assistant
First Printing April 2014 Vanessa Evans
ISBN-13: 978-1-58713-344-2 Designer
Mark Shirar
ISBN-10: 1-58713-344-X
Library of Congress Control Number: 2014933142 Composition
Tricia Bronkella

Proofreader
Warning and Disclaimer Sarah Kearns

This book is designed to provide information about networking. Every effort has
been made to make this book as complete and as accurate as possible, but no war-
ranty or fitness is implied.
The information is provided on an “as is” basis. The authors, Cisco Press, and
Cisco Systems, Inc. shall have neither liability nor responsibility to any person or
entity with respect to any loss or damages arising from the information contained
in this book or from the use of the discs or programs that may accompany it.
The opinions expressed in this book belong to the author and are not necessarily
those of Cisco Systems, Inc.

iii

Trademark Acknowledgments
All terms mentioned in this book that are known to be trademarks or service marks have been
appropriately capitalized. Cisco Press or Cisco Systems, Inc. cannot attest to the accuracy of
this information. Use of a term in this book should not be regarded as affecting the validity of
any trademark or service mark.

Special Sales
For information about buying this title in bulk quantities, or for special sales opportunities
(which may include electronic versions; custom cover designs; and content particular to your
business, training goals, marketing focus, or branding interests), please contact our corporate
sales department at corpsales@pearsoned.com or (800) 382-3419.
For government sales inquiries, please contact governmentsales@pearsoned.com.
For questions about sales outside the U.S., please contact international@pearsoned.com.

Feedback Information
At Cisco Press, our goal is to create in-depth technical books of the highest quality and value.
Each book is crafted with care and precision, undergoing rigorous development that involves
the unique expertise of members from the professional technical community.
Readers’ feedback is a natural continuation of this process. If you have any comments regard-
ing how we could improve the quality of this book, or otherwise alter it to better suit your
needs, you can contact us through email at feedback@ciscopress.com. Please make sure to
include the book title and ISBN in your message.
We greatly appreciate your assistance.

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.

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

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

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 .

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 .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.

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 .

xii CCNA Routing and Switching Practice and Study Guide Chapter 9 IOS Images and Licensing 119 Managing IOS System Files 120 IOS Families. 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 .

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). ■ Braces { } indicate a required choice. ■ Square brackets [ ] indicate optional elements. The Command Reference describes these conventions as follows: ■ Boldface indicates commands and keywords that are entered literally as shown. 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. ■ Italics indicate arguments for which you supply actual values. ■ Vertical bars (|) separate alternative. . mutually exclusive elements. ■ Braces within brackets [{ }] indicate a required choice within an optional element. boldface indicates commands that are manually input by the user (such as a show command).

netacad. Ideally. visit http://www. the reader will have completed the first two courses: Introduction to Networks (ITN) and Routing and Switching Essentials (RSE).cisco. Successfully completing this course means that you should be able to configure and troubleshoot routers and switches and resolve common issues with OSPF. which is associated with the Cisco Certified Network Associate (CCNA) certification. and operations of routers and switches in a large and complex network.com. components. 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. operate. 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). 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. You can view the detailed exam topics any time at http://learningnetwork. if you are not an Academy student but would like to benefit from the extensive authoring done for these courses. and troubleshoot a small branch office network. 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. Passing the CCNA exam means that you have the knowledge and skills required to successfully install. Although you will not have access to the Packet Tracer network simulator software. and VTP in both IPv4 and IPv6 networks. 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. They are divided into five broad categories: ■ LAN Switching Technologies ■ IP Routing Technologies ■ IP Services ■ Troubleshooting ■ WAN Technologies . STP.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. 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. SN continues where RSE left off. To learn more about CCNA Routing and Switching courses and to find an Academy near you. taking the student deeper into the architecture.com. However. EIGRP.

Many Academies use this Practice Study Guide as a required tool in the course. and the online curriculum is sequential. The online cur- riculum starts over at Chapter 1 in the Connecting Networks course. you will find references to Packet Tracer and Lab activities. operations. the num- bering is sequential in this book. However. These refer- ences are provided so that you can. Most of the configuration chapters use a single topology where appropriate.and university-level networking courses. Video Demonstration . However. The Packet Tracer activities are accessible only if you have access to the online curriculum. and outputs. The secondary audiences for this book include people taking CCNA-related classes from pro- fessional training organizations. How This Book Is Organized Because the content of the Scaling Networks Companion Guide. Packet Tracer Activity Note: Throughout the book. This book has 18 chapters. and troubleshoot- ing skills crucial to your success as a CCNA exam candidate. you should work through this Practice and Study Guide in order beginning with Chapter 1. whereas other Academies recommend the Practice Study Guide as an additional resource to prepare for class exams and the CCNA certification. and by anyone wanting to gain a detailed understanding of INCD2 routing and switching concepts. This allows for better continuity and easier understanding of routing and switching commands. at that point. the Labs are available in the Lab Manuals previously cited. progressing from Chapter 1 to Chapter 18. the Connecting Networks Companion Guide. xvii This book offers exercises that help you learn the concepts. complete those activities. The book covers the major topic headings in the same sequence as the online curriculum. the topology differs from the one used in the online curriculum and the Companion Guide. This book can also be used for college. configurations. 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. their names the same as the online course chapters. 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.

verification. much like Part I. ■ Chapter 6. You will complete exercises that focus on various types of wireless and the stan- dards for 802. and verification of all the current varieties of STP. Exercises focus on basic IOS image con- cepts and management tasks. Part II: Connecting Networks ■ Chapter 10. “EIGRP Advanced Configurations and Troubleshooting”: This chapter focuses on advanced EIGRP concepts. ■ Chapter 2. verification. “EIGRP”: The exercises in this chapter are devoted to the basic concepts and configuration of Cisco’s routing protocol. this chapter includes exercises covering multiarea OSPF concepts and configuration. configuration. “Frame Relay”: Although some may consider Frame Relay obsolete. ■ Chapter 9. EIGRP for IPv4 and IPv6. verifica- tion. ■ Chapter 13. In addition. configuration. and troubleshooting. “Adjust and Troubleshoot Single-Area OSPF”: This chapter focuses on advanced OSPF concepts. and troubleshooting of EtherChannel. “LAN Redundancy”: The exercises in this chapter cover the concepts. and troubleshooting. WAN options is PPP. starts off network design. ■ Chapter 12.xviii CCNA Routing and Switching Practice and Study Guide Part I: Scaling Networks ■ Chapter 1. “Link Aggregation”: This chapter’s exercises are devoted to the concepts. and troubleshooting of Frame Relay. topologies. “IOS Images and Licensing”: This chapter is devoted to the crucial knowl- edge and skills you need to manage IOS images. and still viable. verification. and security. ■ Chapter 7. ■ Chapter 4. and troubleshooting. and troubleshooting of PPP with PAP and CHAP authentication. “Point-to-Point Connections”: One of the older. configuration. “Multiarea OSPF”: The CCNA exam now includes multiarea OSPF. “Wireless LANs”: This chapter is all about wireless connectivity technolo- gies. ■ Chapter 8. configuration. ■ Chapter 11. You will also practice basic router and switch configuration and veri- fication. ■ Chapter 5. configuration. Exercises in this chapter focus on the serial interface and then the con- cepts. opera- tions. So. ■ Chapter 3. it is still a viable option in depending on your location. configuration. verification. “Hierarchical Network Design”: Part II. The exercises focus on differentiating between all these WAN options. Exercises focus on the various types of network design models and architec- tures. verification.11. “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. “Introduction to Scaling Networks”: This chapter provides vocabulary and concept exercises to reinforce your understanding of hierarchical network design and selecting hardware. This chapter includes exercises cover- ing the concepts. you will complete activities focused on WLAN compo- nents. .

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

This page intentionally left blank .

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

To provide this kind of reliability. label the three layers of the hierarchical design model. email. and video applications for multiple business units. Describe what failover capability means for enterprise class equipment. IP telephony. including data files. Figure 1-1 Hierarchical Design Model Hierarchical Design Model Internet Internet . In Figure 1-1. 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. Hierarchical Network Design Users expect enterprise networks to be up percent of the time. enterprise class equipment uses power supplies and has failover capabilities.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.

A well-designed network not only controls traffic but also limits the size of failure domains. The primary Cisco Enterprise Architecture modules include Enterprise Campus. Use the list of modules to label the parts of the Cisco Enterprise Architecture in Figure 1-2. Service Provider Edge.. Enterprise Edge. distribution. MAN. . Briefly describe a failure domain. and access layers.. Chapter 1: Introduction to Scaling Networks 3 Briefly describe each layer of the hierarchical design model. and Remote. ATM. Network Management . 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. The Cisco Enterprise Architecture divides the network into functional components while still maintaining the core.

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

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

1 .Comparing 2960 and 3560 Switches (SN 1. Table 1-2 Router and Switch Addressing Table Device Interface IPv4 Address Subnet Mask Default Gateway R1 G0/0 172.16. and branch networks Managing Devices A basic router or switch configuration includes the hostname for identification.0 N/A S0/0/0 172. campus.255.1 255. router and switch verification commands are used to verify the operational status of the router or switch and related network functionality.6 CCNA Routing and Switching Practice and Study Guide Packet Tracer Packet Tracer . select the router category that applies to each description.10.5 255.252 N/A S0/0/1 192.1.7/SwN 1.255. In addition to configuration commands. data center.1.168.3.5) Activity Selecting Router Hardware In Table 1-1.1.1.1. A router configuration also includes basic routing. and assignment of IP addresses to interfaces for connectivity.255.16.5 255.255.255.252 N/A S1 VLAN 1 192.255.2.168. 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. Use the address scheme in Table 1-2 in the following exercises that review the most common router and switch configuration and verification commands.168.255.255. passwords for security.1 255.2.0 192. 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.

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

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

Skills Integration Challenge (SN 1. current counts.1. and action to be taken Packet Tracer Packet Tracer . record the verification command that will generate the described output. security violation count.3.2) Challenge . bandwidth. 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. including the port number and VLAN assigned to the port Displays one or all interfaces. Chapter 1: Introduction to Scaling Networks 9 Basic Switch Verification Review In Table 1-4. and duplex type Displays information about maximum MAC addresses allowed. including status.

This page intentionally left blank .

another link needs to quickly take its place without introducing any traffic loops. When a switch connection is lost. IT administrators have to implement redundancy in their hierarchical networks. In addition. . CHAPTER 2 LAN Redundancy Computer networks are inextricably linked to productivity in today’s small and medium-sized business- es. the chapter briefly explores how Layer 3 redundancy is implemented through First Hop Redundancy Protocols (FHRPs). Consequently. 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.

Describe each of the following issues: ■ MAC database instability: ■ Broadcast storms: ■ Multiple frame transmission: . and core switches. Draw a Redundant Topology In Figure 2-1. 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 redundant links between the access. Specifically. STP was developed to address the issue of loops in a redundant Layer 2 design. distribution.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. Each distribution layer switch should have two links to the core layer with each link connecting to a different core layer switch. such as a failed network cable or switch. three potential issues would occur if STP was not implemented. Each access switch should have two links to the distribution layer with each link connecting to a different distribution layer switch.

it sends BPDU frames containing the switch BID and the root ID every seconds. 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. Switches participating in STP determine which switch has the lowest (BID) on the network. it configures the switch ports into distinct port roles. the STA calculates the shortest path to the root bridge.5/SwN 4. STA chooses the path with the lowest . STP uses the (STA) to determine which switch ports on a network need to be to prevent from occurring. STP ensures that there is only one logical path between all destinations on the network by intentionally blocking redundant paths that could cause a . each switch identifies itself as the bridge after boot. all references to STP assume RSTP unless otherwise indicated.5) Packet Tracer Activity Spanning-Tree Operation Because (RSTP). This switch automatically becomes the bridge. The BID value determines which switch is root. which is documented in IEEE -2004. After the root bridge has been determined. A switch port is considered when network traffic is prevented from entering or leaving that port.1. 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 STA designates a single switch as the bridge and uses it as the reference point for all subsequent calculations. If there is more than one path to choose from. Initially.Examining a Redundant Design (SN 2. supersedes the original STP documented in IEEE -1998. When the STA has determined the “best” paths emanating from the root bridge. How would a switch determine that another switch is now the root bridge? How does the STA determine path cost? . Packet Tracer .1.1. A (BPDU) is a frame containing STP information exchanged by switches running STP. Each BPDU contains a BID that identifies the switch that sent the BPDU.1.

5cd7.---.bcc4.--.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.Nbr Type ------------------.2 P2p Fa0/3 Desg LIS 19 128. including the switch prompt. as shown here: S2# VLAN0001 Spanning tree enabled protocol ieee Root ID Priority 32769 Address c025. enter the command in interface configuration mode.1 P2p Fa0/2 Altn BLK 19 128.14 CCNA Routing and Switching Practice and Study Guide Record the default port costs for various link speeds in Table 2-1.a980 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 15 sec Interface Role Sts Cost Prio.6 P2p<output omitted> .-------.-------------------------------- Fa0/1 Root FWD 15 128. 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 range value can be between and .4 P2p Fa0/6 Desg FWD 19 128. To configure the port cost of an interface.3 P2p Fa0/4 Desg LIS 19 128.--------. Record the commands. the port cost is configu- rable. to configure the port cost for F0/1 as 15: To verify the port and path cost to the root bridge. enter the privileged EXEC mode command.

Cisco enhanced its implementation of STP to include support for the extended system ID field. the is a customizable value that you can use to influence which switch becomes the root bridge. . Then label the ports with one of the following: ■ RP: Root Port ■ DP: Designated Port ■ AP: Alternate Port Figure 2-2 802. Identify the 802. The default value for this field is .1D Port Roles . and . Of these three fields.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 . the switch with the lowest has the lower BID. In Figures 2-2 through 2-4. the customizable values can only be multiples of . use the priority values and MAC addresses to determine the root bridge. 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: . However. Because using the extended system ID changes the number of bits available for the bridge pri- ority. they provide good exercise topologies for you to practice determining the STP port roles.1D Port Roles The topologies in the next three figures do not necessarily represent an appropriate network design. which contains the ID of the with which the BPDU is associated.

16 CCNA Routing and Switching Practice and Study Guide Figure 2-3 802. ■ : This is an evolution of STP that provides faster conver- gence than STP.1.1D Port Roles . 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.10) Varieties of Spanning Tree Protocols STP has been improved multiple times since its introduction in the original IEEE 802. A network administrator should know which type to implement based on the equip- ment and topology needs.1D speci- fication.2.10/SwN 4. .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 2-4 802.1.1D Port Roles .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 2.2.

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

First version of STP to address conver- gence issues. Briefly describe each state: ■ Blocking: ■ Listening: ■ Learning: ■ Forwarding: ■ Disabled: Once stable.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. the spanning tree is immediately determined as ports transition through five possible states and three BPDU timers on the way to convergence. but still provided only one STP instance. . PVST+ Operation After a switch boots. List and briefly describe the four steps PVST+ performs for each VLAN to provide a loop-free logical topology. every active port in the switched network is either in the state or the state.

Sends a BPDU “hello message” every 2 seconds. edge. Port roles: root. Possible to have load sharing with some VLANS forwarding on each trunk. backup. .1D STP instance for each VLAN. Rapid PVST+. 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. answer the “Operation Allowed” question with “yes” or “no” for each port state. alternate. What command implements Cisco’s version of an edge port? In Table 2-5. indicate whether the characteristic describes PVST+. Rapid PVST+ is the Cisco implementation of RSTP on a per-VLAN basis. Runs a separate IEEE 802. designated. Ports can transition to forwarding state without relying on a timer. The root bridge is determined by the lowest BID + VLAN ID + MAC. Table 2-5 Comparing PVST+ and Rapid PVST+ Characteristic PVST+ Rapid PVST+ Both Cisco proprietary protocol. CPU processing and trunk bandwidth usage is greater than with STP. What is the primary difference between Rapid PVST+ and RSTP? Briefly describe the RSTP concept that corresponds to the PVST+ PortFast feature. Chapter 2: LAN Redundancy 19 In Table 2-4. or both.

0033. 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 .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.

--.--------. Figure 2-5 represents a small section of Figure 2-1. For this example.Nbr Type ---------------.b000 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 300 Interface Role Sts Cost Prio.-------.-------------------------------- Fa0/1 Desg FWD 4 128.1 Shr Fa0/2 Desg FWD 4 128.2 Shr Explain the purpose of the BPDU guard feature on Cisco switches. Figure 2-5 PVST+ Configuration Topology Root for VLAN 15 Root for VLAN 25 D1 D2 S1 PC1 PC2 VLAN 15 VLAN 25 . showing only two distribution layer switch- es and one access layer switch. you must manually configure PVST+ to use the link. we have attached PC2 to S1. Chapter 2: LAN Redundancy 21 Bridge ID Priority 24577 (priority 24576 sys-id-ext 1) Address 0019.aa9e.---. D1 should be the primary root for VLAN 1 and VLAN 15 and the secondary root for VLAN 25. PC1 is assigned to VLAN 15. D2 should be the primary root for VLAN 25 and the secondary root for VLAN 15. the least- favored redundant link is not used. 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. By default. and PC2 is assigned to VLAN 25. So.

1.1.3.3.22 CCNA Routing and Switching Practice and Study Guide Based on these requirements.3) Packet Tracer .5/SwN 4. two Layer 3 devices can share the default gateway responsibility. D1 commands D2 commands Document the commands to configure all nontrunking ports on S1 as edge ports with BPDU guard enabled.3.3.2. PortFast.3.2) Packet Tracer Activity First Hop Redundancy Protocols Up to this point.2/SwN 4.2. What command is required? Lab . document the commands to modify the default PVST+ operation on D1 and D2. we’ve been reviewing STP and how to manipulate the election of root bridges and load balance across redundant links. a high-availability network might also implement Layer 3 redundancy by sharing the default gateway responsibility across multiple devices.Configuring PVST+ (SN 2. . In addition to Layer 1 and Layer 2 redundancy. The section reviews First Hop Redundancy Protocols (FHRPs) that provide Layer 3 redundancy.3/SwN 4. Now.Configuring Rapid PVST+.Configuring Rapid PVST+ (SN 2.5) Packet Tracer Activity Packet Tracer .3. assume that you want to run rapid PVST+ on all three switches. and BPDU Guard (SN 2.2. Through the use of a virtual IP address.2.

Virtual IP address Provides the mechanism for determining which g. Default gateway failure of a device acting as the default gate. 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 . Redundancy rrotocol IP address e. b. 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. Standby router A device that is part of a virtual router group assigned to the role of default gateway f. Forwarding router Two or more routers sharing a single MAC and d. Virtual MAC address router should take the active role in forwarding h. First-hop redundancy way c. This is a one-to-one matching exercise.

10 Example 2-1 shows the HSRP configuration for R2.1. A nonproprietary election protocol that allows several routers on a multi-access link to use the same virtual IPv4 address. One router is elected as the virtual router master.168. Figure 2-6 HSRP and GLBP Configuration Topology Core R2 Virtual IP R1 192.1.1.20 192. 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.1 192.255.24 CCNA Routing and Switching Practice and Study Guide Identify the Type of FHRP In Table 2-7. or GLBP.1. with the other rout- ers acting as backups in case the virtual router master fails.255. and virtual IP address 192. R2 has been configured for HSRP group 20. indicate whether the characteristic describes HSRP.168.20.168. priority 120.168.1. VRRP. 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.168.20 255. HSRP and GLBP Configuration and Verification Refer to the topology in Figure 2-6.1. Cisco-proprietary FHRP protocol designed to allow for transparent failover of a first-hop IPv4 devices. IP address 192.1 standby 20 priority 120 <output omitted> . Example 2-1 R2 HSRP Configuration R2# show run interface g0/1 <output omitted> interface GigabitEthernet0/1 ip address 192.0 standby 20 ip 192.168.1.168.1.

168. Example 2-2 shows the GLBP configuration for R2.20 255.168. Example 2-2 R2 GLBP Configuration R2# show run interface g0/1 <output omitted> interface GigabitEthernet0/1 ip address 192.20. last state change 00:03:05 Virtual IP address is 192.255. Chapter 2: LAN Redundancy 25 Using the information in Example 2-1. IP address 192. R2 has been configured for GLBP group 20.1.1 . What command would generate the following output to verify the GLBP configuration? R1# GigabitEthernet0/0 . What command would generate the following output to verify the HSRP configuration? R1# P indicates configured to preempt. | Interface Grp Pri P State Active Standby Virtual IP Gi0/1 20 210 Active local 192.1.1 glbp 20 priority 120 <output omitted> Using the information in Example 2-2.1.168.168.1. and virtual IP address 192.20 192.1 Now assume that all HSRP configurations have been removed. document the commands to configure R1 as the HSRP active router in group 20 using a priority of 210.1. document the commands to configure R1 to be in GLBP group 20 using a priority of 210.1.1.168.168. priority 120.168.Group 20 State is Active 1 state change.0 glbp 20 ip 192.255.1.

024 sec) Priority 210 (configured) Weighting 100 (default 100).4.1. min delay 30 sec Active is local.040 sec remaining (maximum 600 sec) Time to live: 14399.eb38 Redirection enabled. hold time 10 sec Next hello sent in 1.792 secs Redirect time 600 sec.db58 Redirection enabled Preemption enabled.1.0a02 (learnt) Owner ID is 0006.20) There are 2 forwarders (1 active) Forwarder 1 State is Active 1 state change.26 CCNA Routing and Switching Practice and Study Guide Hello time 3 sec.20. weighting 100 Forwarder 2 State is Listen MAC address is 0007.20 (primary).eb38 (192.040 sec (maximum 14400 sec) Preemption enabled.db58 (192.10) local 0006. upper 100 Load balancing: round-robin Group members: 0006. 599.f671. min delay 30 sec Active is 192. forwarder timeout 14400 sec Preemption disabled Active is local Standby is 192. weighting 100 (expires in 9.3.f671.312 sec) Lab .4) .f671. last state change 00:02:53 MAC address is 0007.168.168.4.b400.f671. thresholds: lower 1.168.0a01 (default) Owner ID is 0006.1. priority 120 (expires in 9.1.168.b400.3.4/SwN 4.Configuring HSRP and GLBP (SN 2.

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

duplex setting. 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. These two protocols ensure that both sides of the link have compatible configurations—same speed. indicate the mode that is described. EtherChannel is a form of link aggregation used in switched networks. 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. and VLAN information. .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. 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. List at least three advantages to using EtherChannel: ■ ■ ■ ■ ■ EtherChannel Operation You can configure EtherChannel as static or unconditional. The modes for each differ slightly.3ad). For PAgP. However.

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 LACP negotiations. 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. . Indicate with “yes” or “no” whether EtherChannel is established. two switches are using LACP. responding state. Does not initiate PAgP negotiations. Forces EtherChannel state without PAgP or LACP initiated negotiations. Actively initiates PAgP negotiations with other interfaces. responding state. Places an interface in a passive. Places an interface in a passive. Indicate with “yes” or “no” whether EtherChannel is established. 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. the easiest method is to just force both sides to be on. two switches are using PAgP. In fact. 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.

LACP. What are the requirements for each interface before they can form an EtherChannel? Step 2. The channel should trunk. to configure the S1 Fa0/1 and Fa0/2 into an EtherChannel without negotiations. Use the interface port-channel identifier command to configure channel-wide settings like trunking. native VLANs. Create the port channel interface with the channel-group identifier mode {on | auto | desirable | active | passive} command in interface range configuration mode. with those steps in mind. The keyword forces the port to channel without PAgP or LACP. to configure the S1 Fa0/1 and Fa0/2 into an EtherChannel using PAgP. Step 3. and 20. S1(config)# EtherChannel Configuration Scenario 1 Record the commands. or no negotiations is by configuring one keyword in the channel-group command. participate in the EtherChannel group using the interface range interface command. allowing only VLANs 1.30 CCNA Routing and Switching Practice and Study Guide Configuring EtherChannel To configure EtherChannel. complete the following steps: Step 1. including the switch prompt. the way you specify whether to use PAgP. S1 should initiate the negotiations. consider Figure 3-1 in each of the following configuration scenarios. As you can see from the configuration steps. Then force the channel to trunking using native VLAN 99. So. Figure 3-1 EtherChannel Topology Fa0/1 S1 S2 Fa0/2 EtherChannel Configuration Scenario 1 Record the commands. 10. Specify the interfaces that. The key- words and enable LACP. or allowed VLANs. S1(config)# . The channel-group command automatically creates a port channel interface using the identifier as the number. including the switch prompt. The keywords and enable PAgP.

2. rxload 1/255 <output omitted> S1# Flags: D .Configuring EtherChannel (SN 3. to configure the S1 Fa0/1 and Fa0/2 into an EtherChannel using LACP.1. S1(config)# Lab .8a01 (bia 0cd9.not in use.8a01) MTU 1500 bytes.1.2.4/SwN 5.stand-alone s .1.2. line protocol is up (connected) Hardware is EtherChannel. BW 200000 Kbit/sec. minimum links not met u .Layer3 S .3) Packet Tracer Activity Verifying and Troubleshooting EtherChannel Record the commands used to display the output in Example 3-1.96e8. S1 should not initiate the negotiations.failed to allocate aggregator M . including the switch prompt. allowing all VLANs.default port Number of channel-groups in use: 1 Number of aggregators: 1 . Example 3-1 EtherChannel Verification Commands S1# Port-channel1 is up.Hot-standby (LACP only) R .suspended H . DLY 100 usec.down P . address is 0cd9. reliability 255/255.in use f .bundled in port-channel I . The channel should trunk.96e8.2. txload 1/255.4) Packet Tracer .1.3/SwN 5. Chapter 3: Link Aggregation 31 EtherChannel Configuration Scenario 1 Record the commands.Configuring EtherChannel (SN 3.unsuitable for bundling w .waiting to be aggregated d .Layer2 U .

Pseudo port-channel = Po1 Port index = 0 Load = 0x00 Protocol = LACP Flags: S . P .Device is sending Slow LACPDUs F .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 = .Device is in active mode. A . .Device is sending fast LACPDUs.Device is in passive mode.

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

spanning-tree errors cause the associated ports to go into blocking or errdisabled state. For this reason. Otherwise. the order in which EtherChannel-related commands are entered is important. you must first remove the port channel. 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? . To correct this issue. EtherChannel and spanning tree must interoperate. With that in mind.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.

1.3.2.1.2.Skills Integration Challenge (SN 3.2) . Chapter 3: Link Aggregation 35 Lab .4/SwN 5.2.2.2.4) Packet Tracer Packet Tracer .3.Troubleshooting EtherChannel (SN 3.Troubleshooting EtherChannel (SN 3.3/SwN 5.3) Activity Packet Tracer .2.2/SwN 5.2.2.