Copyright

Faraz Shamim, Zaheer Aziz, Johnson Liu, Abe Martey

Copyright ‚ 2002 Cisco Systems, Inc.

Published by:

Cisco Press

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Indianapolis, IN 46290 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 May 2002

Library of Congress Cataloging-in-Publication Number: 2001086619

Warning and Disclaimer

This book is designed to provide information about troubleshooting IP routing protocols, including RIP, IGRP, EIGRP, OSPF, IS-IS, PIM, and BGP. 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.

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Credits

Publisher

John Wait

Editor-in-Chief

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Cisco Systems Management

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Patrick Kanouse

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Brett Bartow

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Louisa Klucznik

Composition

Publication Services, Inc.

Indexer

Tim Wright

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Copyright ‚ 2000, Cisco Systems, Inc. All rights reserved. Access Registrar, AccessPath, Are You Ready, ATM Director, Browse with Me, CCDA, CCDE, CCDP, CCIE, CCNA, CCNP, CCSI, CD-PAC, CiscoLink, the Cisco Net Works logo, the Cisco Powered Network logo, Cisco Systems Networking Academy, Fast Step, FireRunner, Follow Me Browsing, FormShare, GigaStack, IGX, Intelligence in the Optical Core , Internet Quotient, IP/VC, iQ Breakthrough, iQ Expertise, iQ FastTrack, iQuick Study, iQ Readiness Scorecard, The iQ Logo, Kernel Proxy, MGX, Natural Network Viewer, Network Registrar, the Networkers logo, Packet, PIX, Point and Click Internetworking, Policy Builder, RateMUX, ReyMaster, ReyView, ScriptShare, Secure Script, Shop with Me, SlideCast, SMARTnet, SVX, TrafficDirector, TransPath, VlanDirector, Voice LAN, Wavelength Router, Workgroup Director, and Workgroup Stack are trademarks of Cisco Systems, Inc.; Changing the Way We Work, Live, Play, and Learn, Empowering the Internet Generation, are service marks of Cisco Systems, Inc.; and Aironet, ASIST, BPX, Catalyst, Cisco, the Cisco Certified Internetwork Expert Logo, Cisco IOS, the Cisco IOS logo, Cisco Press, Cisco Systems, Cisco Systems Capital, the Cisco Systems logo, Collision Free, Enterprise/Solver, EtherChannel, EtherSwitch, FastHub, FastLink, FastPAD, IOS, IP/TV, IPX, LightStream, LightSwitch, MICA, NetRanger, Post-Routing, Pre-Routing, Registrar, StrataView Plus, Stratm, SwitchProbe, TeleRouter, are registered trademarks of Cisco Systems, Inc. or its affiliates in the U.S. and certain other countries.

All other brands, names , or trademarks mentioned in this document or Web site are the property of their respective owners . The use of the word partner does not imply a partnership relationship between Cisco and any other company. (0010R)

Dedications

Zaheer Aziz:

I would like to dedicate this book to my late father (may God bless his soul) for his struggling life for betterment of our life, to a person whose self-made, hardworking, and not-so-easy life history became a catalyst for the relatively little hard work I have put in my life. Undoubtedly, he would have tremendously enjoyed seeing this book, but he is not here. Truly, his Air Force blood would have rushed fast seeing this book, but he is not here. Verily, he would have immensely applauded me in seeing this book, but he is not here. Therefore, I want my mother, who has put in equal hard work in our life, to enjoy this accomplishment and success. She deserves equal credit in the success of our family, and I wish her a very long and happy life.

Johnson Liu:

I dedicate this book with my deepest love and affection to my wife, Cisco Liu, who has given me the inspiration and support to write this book.

Abe Martey:

I'd like to dedicate this book to all previous and current engineers of the Cisco Worldwide TAC for their remarkable enthusiasm , dedication, and excellence in providing technical and troubleshooting assistance to network operators in every corner of our planet and in space.

Faraz Shamim:

I would like to dedicate this book to my parents, whose favors I can never return and whose prayers I will always need. To my wife, who encouraged me when I felt too lazy to write, and to my sons, Ayaan and Ameel, who waited patiently for my attention on many occasions.