CCNA Command Quick Reference - Webs

1 ccna Command Quick Reference Scott Empson 800 East 96th StreetIndianapolis, IN 46240 USA Cisco Press ii ccna Command Quick Reference Scott Empson Copyright 2005 Cisco Systems, Press logo is a trademark of Cisco Systems, by:Cisco Press800 East 96th Street Indianapolis, IN 46240 USAAll 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 in the United States of America 1 2 3 4 5 6 7 8 9 0 First Printing March 2005 Library of Congress Cataloging-in-Publication Number: 2004116146 ISBN: 1-58713-159-5 Warning and Disclaimer This book is designed to provide information about the Certified Cisco Networking Associate ( ccna ) exam and the commands needed at this level of Network Administration.

2 Every effort has been made to make this book as complete and as accurate as possible, but no warranty or fitness is 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 opinions expressed in this book belong to the author and are not necessarily those of Cisco Systems, Inc. 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 feedback is a natural continuation of this process.

3 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 through e-mail at Please make sure to include the book title and ISBN in your greatly appreciate your assistance. iii Corporate and Government Sales Cisco Press offers excellent discounts on this book when ordered in quantity for bulk purchases or special more information please contact: Corporate and Government Sales 1-800-382-3419 sales outside the please contact: International Sales Trademark Acknowledgments All terms mentioned in this book that are known to be trademarks or service marks have been appropriately capitalized.

4 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. Publisher John Wait Editor-in-Chief John Kane Cisco Representative Anthony Wolfenden Cisco Press Program Manager Jeff Brady Executive Editor Mary Beth Ray Production Manager Patrick Kanouse Senior Development Editor Christopher Cleveland Copy Editor Keith Cline Technical Editors Gerlinde Brady, David Kotfila Team Coordinator Tammi Barnett Book and Cover Designer Louisa Adair Composition Mark Shirar iv About the Author Scott Empson is currently an instructor in the Department of Telecommunications at the Northern Alberta Institute of Technology in Edmonton, Alberta, Canada, where he is tasked to teach Cisco routing, switching.

5 And network design courses in a variety of different programs certificate, diploma, and applied degree at the post-secondary level. Scott is also the Program Coordinator of the Cisco Networking Academy Program at NAIT, a Regional Academy covering Central and Northern Alberta. He has earned three under-graduate degrees: a bachelor of arts, with a major in English; a bachelor of education, again with a major in English/language arts; and a bachelor of applied information systems technology, with a major in network management. He currently holds several industry certifications, including CCNP, CCDA, CCAI, and Network+. Prior to instructing at NAIT, he was a junior/senior high school English/language arts/computer science teacher at different schools throughout Northern Alberta.

6 Upon completion of this project he plans to complete a master s degree. Scott lives in Edmonton, Alberta, with his wife and two children. v About the Technical Reviewers Gerlinde Brady , , CCNP has been a Cisco Certified Academy Instructor (CCAI) since 2000. She holds an degree in education from the University of Hanover, Germany. Besides A+ certification courses and general IT courses, she has been teaching Cisco ccna and CCNP courses at Cabrillo College since 1999. Her industry experience includes LAN design, network administration, and technical support. David Kotfila is the director of the Cisco Networking Academy Program at Rensselaer Polytechnic Institute (RPI) in Troy, New York.

7 He is also on the National Advisory Council for the Networking Academy. In the past three years, more than 260 students have received their ccna , and 80 students their CCNP at RPI. Previously, David was the senior manager in charge of training at PSINet, a Tier 1, global, Internet service provider. David enjoys spending time with his family, hiking in the mountains, and kayaking. vi Dedications To my wife, Trina, and my kids, Zachariah and Shaelyn. You are my meaning and purpose, and I love you all. vii Acknowledgments Wow, where do I begin? This book was not just me; it took a lot of people a lot of hours to put this all together in the form you see it now.

8 So I guess a big thanks goes out to everyone at Cisco Press for making this all happen Mary Beth Ray, Raina Han, and Chris Cleveland. Thanks to my technical reviewers Gerlinde Brady and David Kotfila who corrected me when I was wrong or heading down the wrong path. Your dedication to your students and to the Cisco Networking Academy Program is obvious; your students are very fortunate to have you both as to some former students of mine, both Academy and not Wing, Lars, Brian, Mike, and Kyle who reviewed some (very) rough drafts of this book and told me what worked and what didn t from a student s perspective. Good luck with the rest of your thanks go out to Terry Short, Chad Klymchuk, Colin Polanski, and Hans Roth for all of their advice and suggestions.

9 Your students are also very fortunate to have you as instructors Finally, a big note of thanks to William McBride and Randy Hirose for pushing me to do this. viii Contents at a Glance Introduction xviii Part I ccna 1 1 Part II ccna 2 3 Chapter 1 WANs and Routers 5 Chapter 2 Introduction to Routers 11 Chapter 3 Configuring a Router 17 Chapter 4 Learning About Other Devices 27 Chapter 5 Managing Cisco IOS Software 33 Chapter 6 Routing and Routing Protocols 43 Chapter 7 Distance Vector Routing Protocols 47 Chapter 8 TCP/IP Suite Error and Control Messages 55 Chapter 9 Basic Router Troubleshooting 57 Chapter 10 Intermediate TCP/IP 61 Chapter 11 Access Control Lists (ACLs)

10 63 Part III ccna 3 81 Chapter 1 Introduction to Classless Routing 83 Chapter 2 Single-Area OSPF 87 Chapter 3 EIGRP 97 Chapter 4 Switching Concepts 103 Chapter 5 Switches 105 Chapter 6 Switch Configuration 107 Chapter 7 Spanning Tree Protocol 123 Chapter 8 Virtual LANs 125 Chapter 9 VLAN Trunking Protocol 135 ix Part IV ccna 4 153 Chapter 1 Scaling IP Technologies 155 Chapter 2 WAN Technologies 165 Chapter 3 PPP 167 Chapter 4 ISDN and DDR 173 Chapter 5 Frame Relay 185 Chapter 6 Introduction to Network Administration 195 Part V Appendixes 197 Appendix A Subnetting 199 Appendix B VLSM 211 x Contents Introduction xviii Part I ccna 1 1 Part II ccna 2 3 Chapter 1 WANs and Routers 5 Connecting a Rollover Cable to Your Router or Switch 5 Terminal Settings 5 LAN Connections 6 Serial Cable Types 7 Which Cable to Use?