CCNP BCMSN exam certification guide

Cisco Press

800 East 96th Street, 3rd Floor

Indianapolis, IN 46240 USA

Cisco Press

CCNP Self-Study

CCNP BCMSN Exam

Certification Guide

David Hucaby, CCIE No. 4594

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CCNP BCMSN Exam Certification Guide

David Hucaby

Copyright © 2004 Cisco Systems, Inc.

Published by:

Cisco Press

800 East 96th Street, 3rd Floor

Indianapolis, IN 46240 USA

All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical,

including photocopying, recording, or by any information storage and retrieval system, without written permission from the publisher,

except for the inclusion of brief quotations in a review.

Printed in the United States of America 1 2 3 4 5 6 7 8 9 0

First Printing September 2003

Library of Congress Cataloging-in-Publication Number: 2002115604

ISBN: 1-58720-077-5

Warning and Disclaimer

This book is designed to provide information about selected topics for the Building Cisco Multilayer Switched Networks (BCMSN)

exam for the CCNP certification. Every effort has been made to make this book as complete and as accurate as possible, but no

warranty 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.

Feedback Information

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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.

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Publisher: John Wait

Editor-In-Chief: John Kane

Executive Editor: Brett Bartow

Cisco Representative: Anthony Wolfenden

Cisco Press Program Manager: Sonia Torres Chavez

Manager, Marketing Communications,

Cisco Systems: Scott Miller

Cisco Marketing Program Manager: Edie Quiroz

Production Manager: Patrick Kanouse

Development Editor: Christopher Cleveland

Project Editor: San Dee Phillips

Copy Editor: Marcia Ellett

Technical Editors: Stephen Daleo, Steve McQuerry, Geoff Tagg

Team Coordinator: Tammi Ross

Book Designer: Gina Rexrode

Cover Designer: Louisa Adair

Indexer: Tim Wright

Composition: Octal Publishing, Inc.

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About the Author

David Hucaby, CCIE No. 4594, is a lead network engineer for a large medical environment, using

Cisco multilayer switching and security products. He is also an independent networking consultant,

focusing on Cisco-based solutions for healthcare and banking clients. David lives in Kentucky with

his wife, Marci, and two daughters.

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About the Technical Reviewers

Stephen Daleo, president of Golden Networking Consultants, Inc. is a network consultant whose

clients include the University of South Florida – St. Petersburg, FL and North Broward Hospital

District (Fort Lauderdale, FL). Steve was one of the course developers for Cisco Internet Learning

Solutions Group – BCMSN 2.0 class. Steve is a frequent contributor to the technical content of

Cisco Press books and is an active certified Cisco Systems instructor (97025) teaching the BCMSN,

BCRAN, CIPT, CIT, BSCI, and ICND Cisco courses.

Steve McQuerry, CCIE No. 6108, is an instructor, technical writer, and internetworking consultant

with over 10 years of networking industry experience. He is a certified Cisco Systems instructor

teaching routing and switching concepts to internetworking professionals throughout the world.

Steve is also a founding partner in Intrellix, an internetworking consulting company specializing in

post-sales consulting services.

Geoff Tagg runs a networking consultancy in the UK, where he has over 20 years experience in

working with companies ranging from small local businesses to large multinationals. Prior to that,

he was a systems programmer for a number of years. Geoff’s main specialty is IP network design

and implementation. Geoff lives in Oxford, England with his wife, Christine, and family, and is a

visiting professor at nearby Oxford Brookes University.

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Dedications

As always, this book is dedicated to the most important people in my life—my wife, Marci, and my

two little daughters, Lauren and Kara. Their love, encouragement, and support carry me along. I’m

so grateful to God, who gives endurance and encouragement (Romans 15:5) and has allowed me to

work on projects like this.

I would also like to dedicate this book to the memory of two teachers who have made an impact

on me:

Mabel “Stoney” Stonecipher, my college technical writing teacher and family friend, who made

writing about technical things fun and educational.

Ron Sabel, my high school biology and physics teacher, who taught me an important lesson: “The

‘A’ student doesn’t have all the answers—the ‘A’ student knows where to find all the answers!”

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Acknowledgments

It has been my great pleasure to work on another Cisco Press project. I enjoy the networking field

very much, and technical writing even more. And more than that, I’m thankful for the joy and inner

peace that Jesus Christ gives, making everything more abundant.

Technical writing may be hard work, but I’m finding that it’s also quite fun because I’m working

with very good friends. I can’t say enough good things about Chris Cleveland. Somehow, Chris is

able to handle many book projects all at once, while giving each one an incredible amount of

attention and improvement. Brett Bartow is a constant source of organization, project management,

and encouragement. I’m glad he agreed to have me back for another project!

Now a few words about another group of good friends—the technical reviewers that made this a

much, much better book. I am very grateful for the insight, suggestions, and helpful comments that

Steve Daleo, Steve McQuerry, and Geoff Tagg contributed. Each one offered a different perspective,

which helped make this a more well-rounded book and me a more educated author. Christopher

Paggen also provided some early help with new Catalyst features and development.

Lastly, for the very first time, I am able to announce that no laptop computers were harmed in the

writing of this book.

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Contents at a Glance

Foreword xxiii

Introduction: Overview of Certification and How to Succeed xxiv

PART I Overview and Design of a Campus Network 2

Chapter 1 Campus Network Overview 5

Chapter 2 Modular Network Design 33

PART II Building a Campus Network 54

Chapter 3 Switch Operation 57

Chapter 4 Switch Configuration 83

Chapter 5 Switch Port Configuration 107

Chapter 6 VLANs and Trunks 137

Chapter 7 VLAN Trunking Protocol (VTP) 167

Chapter 8 Aggregating Switch Links 189

Chapter 9 Traditional Spanning Tree Protocol 209

Chapter 10 Spannning Tree Configuration 239

Chapter 11 Protecting the Spanning Tree Protocol Topology 263

Chapter 12 Advanced Spanning Tree Protocol 279

PART III Layer 3 Switching 302

Chapter 13 Multilayer Switching 305

Chapter 14 Router Redundancy and Load Balancing 327

Chapter 15 Multicast 353

PART IV Campus Network Services 374

Chapter 16 Quality of Service Overview 377

Chapter 17 DiffServ QoS Configuration 401

Chapter 18 IP Telephony 431

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Chapter 19 Securing Switch Access 451

Chapter 20 Securing with VLANs 469

PART V Scenarios for Final Preparation 494

Chapter 21 Scenarios for Final Preparation 497

PART VI Appendix 514

Appendix A Answers to Chapter “Do I Know This Already?” Quizzes and Q&A

Sections 517

Index 582

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Contents

Foreword xxiii

Introduction: Overview of Certification and How to Succeed xxiv

Part I Overview and Design of a Campus Network 2

Chapter 1 Campus Network Overview 5

“Do I Know This Already?” Quiz 5

Foundation Topics 9

Switching Functionality 9

Layer 2 Switching 10

Layer 3 Routing 10

Layer 3 Switching 11

Layer 4 Switching 12

Multilayer Switching (MLS) 12

Campus Network Models 12

Shared Network Model 13

LAN Segmentation Model 14

Network Traffic Models 17

Predictable Network Model 19

Hierarchical Network Design 19

Access Layer 20

Distribution Layer 21

Core Layer 21

Cisco Products in the Hierarchical Design 21

Access Layer Switches 22

Distribution Layer Switches 23

Core Layer Switches 24

Product Summary 25

Foundation Summary 27

Q&A 30

Chapter 2 Modular Network Design 33

“Do I Know This Already?” Quiz 33

Foundation Topics 37

Modular Network Design 37

The Switch Block 38

Sizing a Switch Block 39

The Core Block 41

Collapsed Core 42

Dual Core 43

Core Size in a Campus Network 45

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Other Building Blocks 45

Server Farm Block 46

Network Management Block 46

Enterprise Edge Block 47

Service Provider Edge Block 47

Can I Use Layer 2 Distribution Switches? 48

Foundation Summary 50

Q&A 52

Part II Building a Campus Network 54

Chapter 3 Switch Operation 57

“Do I Know This Already?” Quiz 57

Foundation Topics 61

Layer 2 Switch Operation 61

Transparent Bridging 61

Follow That Frame! 63

Multilayer Switch Operation 66

Types of Multilayer Switching 66

Follow That Packet! 67

Multilayer Switching Exceptions 69

Tables Used in Switching 69

Content Addressable Memory (CAM) 70

Ternary Content Addressable Memory (TCAM) 71

TCAM Structure 71

TCAM Example 72

Port Operations in TCAM 74

Troubleshooting Switching Tables 75

CAM Table Operation 75

TCAM Operation 76

Foundation Summary 77

Q&A 79

Chapter 4 Switch Configuration 83

”Do I Know This Already?” Quiz 83

Foundation Topics 87

Switch Management 87

Operating Systems 87

Identifying the Switch 88

Passwords and User Access 89

Password Recovery 90

Remote Access 90

Inter-Switch Communication—Cisco Discovery Protocol 91

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Switch File Management 91

OS Image Files 92

Filename Conventions 93

Configuration Files 93

Other Catalyst Switch Files 94

Moving Catalyst Switch Files Around 94

Troubleshooting from the Operating System 96

Show Configuration and File Contents 96

Debugging Output 97

View CDP Information 98

Foundation Summary 100

Q&A 103

Chapter 5 Switch Port Configuration 107

”Do I Know This Already?” Quiz 107

Foundation Topics 112

Ethernet Concepts 112

Ethernet (10 Mbps) 112

Long Reach Ethernet (LRE) 113

Fast Ethernet 114

Full-Duplex Fast Ethernet 115

Gigabit Ethernet 117

10Gigabit Ethernet 118

Metro Ethernet 119

Connecting Switch Block Devices 120

Console Port Cables/Connectors 120

Ethernet Port Cables and Connectors 121

Gigabit Ethernet Port Cables and Connectors 121

Switch Port Configuration 123

Selecting Ports to Configure 123

Identifying Ports 124

Port Speed 124

Port Mode 125

Managing Error Conditions on a Switch Port 125

Detecting Error Conditions 125

Automatically Recover from Error Conditions 126

Enable and Use the Switch Port 126

Troubleshooting Port Connectivity 126

Looking for the Port State 127

Looking for Speed and/or Duplex Mismatches 127

Foundation Summary 129

Q&A 133

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Chapter 6 VLANs and Trunks 137

”Do I Know This Already?” Quiz 137

Foundation Topics 141

Virtual LANs 141

VLAN Membership 142

Static VLANs 142

Configuring Static VLANs 143

Dynamic VLANs 144

Deploying VLANs 144

End-to-End VLANs 145

Local VLANs 145

VLAN Trunks 146

VLAN Frame Identification 146

Inter-Switch Link Protocol 148

IEEE 802.1Q Protocol 148

Dynamic Trunking Protocol 150

VLAN Trunk Configuration 150

VLAN Trunk Configuration 150

Service Provider Tunneling 153

IEEE 802.1Q Tunnels 153

Configuring a 802.1Q Tunnel 155

Layer 2 Protocol Tunnels 155

Configuring Layer 2 Protocol Tunneling 156

Ethernet over MPLS Tunneling 157

Troubleshooting VLANs and Trunks 159

Foundation Summary 162

Q&A 164

Chapter 7 VLAN Trunking Protocol (VTP) 167

“Do I Know This Already?” Quiz 167

Foundation Topics 171

VLAN Trunking Protocol 171

VTP Domains 171

VTP Modes 171

VTP Advertisements 172

VTP Configuration 175

Configuring a VTP Management Domain 175

Configuring the VTP Mode 176

Configuring the VTP Version 177

VTP Status 178

VTP Pruning 179

Enabling VTP Pruning 181

Troubleshooting VTP 182

Foundation Summary 184

Q&A 186

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Chapter 8 Aggregating Switch Links 189

“Do I Know This Already?” Quiz 189

Foundation Topics 193

Switch Port Aggregation with EtherChannel 193

Bundling Ports with EtherChannel 194

Distributing Traffic in EtherChannel 194

Configuring EtherChannel Load Balancing 195

EtherChannel Negotiation Protocols 197

Port Aggregation Protocol (PAgP) 197

Link Aggregation Control Protocol (LACP) 198

EtherChannel Configuration 198

Configuring a PAgP EtherChannel 199

Configuring a LACP EtherChannel 199

Troubleshooting an EtherChannel 200

Foundation Summary 204

Q&A 206

Chapter 9 Traditional Spanning Tree Protocol 209

“Do I Know This Already?” Quiz 209

Foundation Topics 213

IEEE 802.1D Overview 213

Bridging Loops 213

Preventing Loops with Spanning Tree Protocol 217

Spanning Tree Communication: Bridge Protocol Data Units 217

Electing a Root Bridge 218

Electing Root Ports 220

Electing Designated Ports 223

STP States 225

STP Timers 227

Topology Changes 228

Types of STP 229

Common Spanning Tree (CST) 229

Per-VLAN Spanning Tree (PVST) 229

Per-VLAN Spanning Tree Plus (PVST+) 230

Foundation Summary 231

Q&A 234

Chapter 10 Spannning Tree Configuration 239

“Do I Know This Already?” Quiz 239

Foundation Topics 243

STP Root Bridge 243

Root Bridge Placement 243

Root Bridge Configuration 246

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