Routing TCPIP

Volume I

Cisco Ststehs.

Cisco Ststehs.

Crür.o PRfSi dicäprHMoni

Crür.o PRfSi dicäprHMoni

CCIE Professional Development: Routing TCP/IP, Volume I

Copyright Information

Copyright© 1998 by Macmillan Technical Publishing Cisco Press logo is a trademark of Cisco Systems, Inc.

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 2 3 4 5 6 7 8 9 0

Library of Congress Cataloging-in-Publication Number 98-84220

Warning and Disclaimer

This book is designed to provide information about TCP/IP. 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 author, Macmillan Technical Publishing, 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.


This book would not have been possible without the concerted efforts of many dedicated people. I would like to thank the following people for their contributions:

First, thanks to Laurie McGuire, development editor, who not only improved the book but improved me as a writer.

Thanks to Jenny DeHaven Carroll and Mike Tibodeau for their careful technical editing. I would also like to thank the following people, who provided technical advice or reviews on selected sections of the book: Howard Berkowitz, Dave Katz, Burjiz Pithawala, Mikel Ravizza, Russ White, and Man-Kit Yueng.

I would like to thank the following people at Macmillan Technical Publishing: Tracy Hughes and Lynette Quinn, who managed the project, and Julie Fairweather, the Executive Editor. In addition to being highly competent, they are three of the nicest people anyone could hope to work with. Also, thanks to Jim LeValley, Associate Publisher, who first approached me about writing this book.

Thanks to Wandel & Golterman, and to Gary Archuleta, W&G's Regional Sales Manager in Denver, for arranging the use of one of their excellent protocol analyzers for the length of the project.

Finally, I want to thank my wife, Sara, and my children: Anna, Carol, James, and Katherine. Their patience, encouragement, and support were critical to the completion of this book.

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 regarding how we could improve the quality of this book, or otherwise alter it to better suit your needs, you can contact us at [email protected]. Please make sure to include the book title and ISBN in your message.

We greatly appreciate your assistance. Trademark Acknowledgments

All terms mentioned in this book that are known to be trademarks or service marks have been appropriately capitalized. Macmillan Technical Publishing 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.

About the Reviewers

Jennifer DeHaven Carroll is a principal consultant for International Network Services. She is CCIE number 1402. Jennifer has planned, designed and implemented many IP networks over the past 10 years, utilizing RIP version 2, IGRP, E-IGRP, OSPF and BGP. She has also developed and taught theory and Cisco implementation classes on all IP routing protocols.

Michael Tibodeau is a Systems Engineer for Cisco Systems. Over the past two years, Michael has specialized in security technologies for both his own customers and Networkers audiences. He also focuses on the Electronic Commerce and Quality of Service arenas. Michael holds a Bachelor's degree in Systems Engineering from the University of Virginia and holds a Master's degree in Systems Engineering and Management, concentrating on telecommunications.

I ntroduction

Routing is an essential element of all but the smallest data communications networks. At one level, routing and the configuration of routers are quite simple. But as internetworks grow in size and complexity, routing issues can become at once both large and subtle. Perversely, perhaps, I am grateful for the difficult problems large-scale routing can present—as a network systems consultant, these problems are my bread and butter. Without them, the phrase "You want fries with that?" could be an unfortunate part of my daily vocabulary.

Cisco Certified Internetwork Experts are widely recognized for their ability to design, troubleshoot, and manage large internetworks. This recognition comes from the fact that you cannot become a CCIE by attending a few classes and then regurgitating some memorized facts onto a written test. A CCIE has proven his or her expertise in an intense, famously difficult hands-on lab exam.


This book is the first in a series designed to aid you in becoming a Cisco Certified Internetwork Expert and the first of two volumes that focuses on TCP/IP routing issues. Early in the project, Kim Lew, Cisco Systems program manager, said, "Our objective is to make CCIEs, not to make people who can pass the CCIE lab." I entirely agree with that statement and have used it as a guiding principle throughout the writing of this book. Although the book includes many case studies and exercises to help you prepare for the CCIE lab, my primary objective is to increase your understanding of IP routing—both on a generic level and it is implemented on Cisco routers.


The audience for this book is any network designer, administrator, or engineer who needs a full understanding of the interior routing protocols of TCP/IP. Although the practical aspects of the book focus on Cisco's IOS, the information is applicable to any routing platform.

The book is not only for readers who plan to become Cisco Certified Internetwork Experts, but for anyone who wishes to advance his or her knowledge of TCP/IP routing. These readers will fall into one of three categories:

• The "beginner" who has some basic networking knowledge and wishes to begin a deep study of internetworking

• The intermediate-level networking professional who has experience with routers, Cisco or otherwise, and plans to advance that experience to the expert level

• The highly experienced networking expert. This individual has extensive hands-on expertise with Cisco routers and is ready to take the CCIE lab; however, he or she wants a structured review and series of exercises for verification and validation.

CCIE Professional Development: Routing TCP/IP, Volume I focuses primarily on the intermediate-level networking professional while offering to the beginner a structured outline of fundamental information and to the expert the required challenges to hone his or her skills.


The fourteen chapters of the book are divided into three parts.

Part I examines the basics of networks and routing. Although more advanced readers may wish to skip the first two chapters, I recommend that they at least skim Chapter 3, "Static Routing," and Chapter 4, "Dynamic Routing Protocols."

Part II covers the TCP/IP Interior Gateway Protocols. Each protocol-specific chapter begins with a discussion of the mechanics and parameters of the protocol. This general overview is followed by case studies on configuring and troubleshooting the protocol on Cisco routers in various network topologies.

The Exterior Gateway Protocols, as well as such topics as multicast routing, Quality of Service routing, router security and management, and routing IPv6 will be covered in Volume II.

Part III examines the tools available for creating and managing interoperability with multiple IP routing protocols, as well as such tools as default routes and route filtering. These chapters, like the ones in Part II, begin with concepts and conclude with case studies.

Conventions and Features

Most chapters conclude with a set of review questions, configuration exercises, and troubleshooting exercises. The review questions focus on the theoretical aspects of the chapter topic, whereas the configuration and troubleshooting exercises address Cisco-specific aspects of the chapter topic.

Also at the end of each chapter is a table with a brief description of all important Cisco IOS commands used in that chapter. The conventions used to present these commands are the same conventions used in the IOS Command Reference. The Command Reference describes these conventions as follows:

• Vertical bars (|) separate alternative, mutually exclusive, elements.

• Square brackets [] indicate optional elements.

• Braces {} indicate a required choice.

• Braces within square brackets [{}] indicate a required choice within an optional element.

• Boldface indicates commands and keywords that are entered literally as shown.

• Italics indicate arguments for which you supply values.

Important concepts are called out in margin notes for quick reference.

Figure I.1 shows the conventions used in the illustrations throughout the book.

Figure I.1. Illustration conventions used in this book.


Ethernet Token Ring

Serial Circuit

Virtual Circuit FDDI

All protocol analyzer displays shown in the book are taken from a Wandel & Goltermann DA-320 DominoLAN Internetwork Analyzer.


In today's world of networking, mission-critical networks are being designed for data, voice, and video. Due to different traffic patterns and the quality of service required by each type of information, solid hands-on experience is imperative for managing, designing, and troubleshooting these networks.

Attaining a strong degree of hands-on experience translates into in-depth understanding of the concepts, scalability, and deployment issues of today's networks. Such experience also builds the expertise to analyze traffic patterns and the knowledge of when, where, and how to apply protocol and bandwidth features to enhance performance.

To help further your hands-on experience, Cisco Press is publishing the CCIE Professional Development series of books. Books in this series will significantly help your understanding of protocol concepts, and they provide real-world examples and case studies to strengthen the theoretical concepts examined. I highly recommend that you use these books as a hands-on learning tool by duplicating the examples and case studies using Cisco products. You can even take this further by tweaking the configuration parameters to see which changes each network goes through by using the extensive debugging features provided in each Cisco product.

In the first book of the CCIE Professional Development series, CCIE Professional Development: Routing TCP/IP, Volume I, Jeff Doyle does a fantastic job of building the TCP/IP concepts, from IP address classes to analyzing protocol metrics. Each chapter contains examples, network topologies with IP addresses, packet analysis, and Cisco debugging outputs. In my opinion, the best parts are the case studies, in which Jeff compares different features of the protocol by using more or less the similar topology. This generates a strong understanding of the protocol concepts and features.

I recommend CCIE Professional Development: Routing TCP/IP, Volume I for any networking certification, and I believe that it also makes an excellent university networking course book.

Imran Qureshi

CCIE Program Manager

0 0

Post a comment