Computer Networking first-step By Wendell Odom Publisher: Cisco Press Pub Date: April 21, 2004 Print ISBN: 1-58720-101-1 Pages: 552 Table of Contents | Index Your first step into the world of computer networking No experience required Includes clear and easily understood explanations Makes learning easy The best-selling introductory networking author Your first step to computer networking begins here! Learn basic networking terminology Understand how information is routed from place to place Explore Internet connectivity secrets Protect your computer from intrusion Build local-area networks (LANs) Welcome to the world of networking! Networking and the Internet touch our lives in untold ways every day From connecting our computers together at home and surfing the net at high speeds to editing and sharing digital music and video, computer networking has become both ubiquitous and indispensable No experience needed! Computer Networking First-Step explains the basics of computer networking in easy-to-grasp language that all of us can understand This book takes you on a guided tour of the core technologies that make up network and Internet traffic Whether you are looking to take your first step into a career in networking or are interested in just gaining a conversational knowledge of the technology, this book is for you! Computer Networking first-step By Wendell Odom Publisher: Cisco Press Pub Date: April 21, 2004 Print ISBN: 1-58720-101-1 Pages: 552 Table of Contents | Index Copyright About the Author About the Technical Reviewers Acknowledgments Introduction Who Ought to Read This Book Stuff You'll Find in This Book For More Information… Part I Networking Basics Chapter 1 What Is a Network? No, Really, What Is a Network? Different Types of Traditional Computer Networks Chapter Summary Chapter Review Questions Chapter 2 A Network's Reason for Existence Using the Network by Accident Using the Network on Purpose Chapter Summary Chapter Review Questions Chapter 3 Building a Network: It All Starts with a Plan Conforming to the Rules The Book(s) of Rules How to Eat an Elephant, TCP/IP Style How to Eat a T-Rex, OSI Style Chapter Summary Chapter Review Questions Part II Running the Local Department of (Network) Transportation Chapter 4 How to Build a Local (Network) Roadway Driving Bits Across the Network Roadway Sharing the Local Roadway: Ethernet Hubs Dirt Roads Versus the DOT Chapter Summary Chapter Review Questions Chapter 5 Rules of the Road: How to Use the Local (Network) Roadway Preparing for a Trip: How to Make Your Car (Data) "Street Legal" Stopping at the Destination: What Happens When Someone Comes to See You Two Standards for Ethernet Chapter Summary Chapter Review Questions Chapter 6 Reducing Congestion and Driving Faster on the Local (Network) Roadway Reducing Congestion by Opening Up More Lanes on Each LAN Switches: The Rest of the Story I Feel the Need, the Need for Speed Chapter Summary Chapter Review Questions Chapter 7 Adding Local (Network) Roadways for No Extra Money The Physical Reality Precedes the Virtual Reality Virtual (LAN) Reality: One Switch, but Multiple LANs Packing Your VLAN's Frames in a Trunk When Leaving the Switch Chapter Summary Chapter Review Questions Part III Shipping and Logistics: Commerce Using the (Network) Roadways Chapter 8 Shipping Goods over a (Network) Roadway Neither Rain, Nor Sleet, Nor Dark of Night: E-Mail Building a Centralized Warehouse: File Transfer Browsing Around the Internet Shopping Mall: The World Wide Web Chapter Summary Chapter Review Questions Chapter 9 Choosing Shipping Options When Transporting the Goods over the (Network) Roadway "Hello, I'm at Your Service" Chapter Summary Chapter Review Questions Part IV Navigating the Roadways to Find the Right Street Address Chapter 10 Delivering the Goods to the Right Street (IP) Address Navigation Basics: Driving to the Right Destination How to Run a (Network) Postal Service Subdividing a Network into Subnets Chapter Summary Chapter Review Questions Chapter 11 Knowing Where to Turn at Each Intersection (Router) A Short Trip from Your House (PC) to the Local Store (Server) Other Rules of the Road Chapter Summary Chapter Review Questions Chapter 12 Painting the Road Signs on Your Interstate (Internetwork) Routing to Nearby Places Painting Road Signs and Other Long-Lasting Directions Dynamically Learning and Changing Routing Tables Picking the Best Road (Route) Introducing the Long List of Routing Protocols Chapter Summary Chapter Review Questions Chapter 13 People Like Names, but Computers Like Numbers Looking Up the Name and Number in the Phone Book (Host Table) Asking Someone Else to Look Up the Phone Number (IP Address) for You Chapter Summary Chapter Review Questions Part V Building an Interstate (Inter-LAN) Highway System Chapter 14 Leasing a (Network) Roadway Between Two Points Leasing the Cable When You Can't Run the Cable Routers and WANs: A Match Made in Heaven Chapter Summary Chapter Review Questions Chapter 15 Leasing a (Network) Roadway Between Lots of Places Making the Telco Look Like One Big Whopping Switch Faster, Cheaper, BetterYou Can't Go Wrong with Frame Relay Routers and WANs: Still a Match Made in Heaven Chapter Summary Chapter Review Questions Chapter 16 Driving from Home onto the Globally Interconnected (Internet) Roadway Once on the Interstate (Internet), You Can Go Anywhere Using a Phone Line for Data Calling the Internet! Calling the Internet! Using the Phone Line for Datathe DSL Way Sending Data from Home Without Using a Phone Line Chapter Summary Chapter Review Questions Part VI Securing the Network Chapter 17 Accepting the Right People and Rejecting the Wrong People Safe Driving by Using AAA Making Sure (Internet) Drivers Have Valid Drivers' Licenses You're Wearing Your Credit Card Number on Your T-Shirt Chapter Summary Chapter Review Questions Chapter 18 Keeping a Watchful Eye Over Who Drives into Your (Network) Neighborhood Setting the Ground Rules Enforcing the Ground Rules Using the Police to Watch for Bad Guys Chapter Summary Chapter Review Questions Part VII Appendixes Appendix A Answers to Chapter Review Questions Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Chapter 12 Chapter 13 Chapter 14 Chapter 15 Chapter 16 Chapter 17 Chapter 18 Appendix B Converting IP Addresses Between Decimal and Binary Decimal and Binary Numbering Systems Converting Between Binary and Decimal Numbers Converting IP Addresses Chapter Summary Glossary Index Copyright Copyright© 2004 Cisco Systems, Inc Published by: Cisco Press 800 East 96th Street 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 April 2004 Library of Congress Cataloging-in-Publication Number: 2003108109 Warning and Disclaimer This book is designed to provide information about computer networking 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, 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 Credits Publisher John Wait Editor-in-Chief John Kane Executive Editor Brett Bartow Cisco Representative Anthony Wolfenden Cisco Press Program Manager Nannette M Noble Production Manager Patrick Kanouse Development Editor Dayna Isley Project Editor San Dee Phillips Copy Editor Karen A Gill Technical Editors Blair Buchanan, Ron Kovac, Scott Van de Houten, Paul Negron Team Coordinator Tammi Barnett Book and Cover Designer Louisa Adair Compositor Mark Shirar Indexer Tim Wright 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 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feedback@ciscopress.com Please make sure to include the book title and ISBN in your message We greatly appreciate your assistance Corporate Headquarters Cisco Systems, Inc 170 West Tasman Drive San Jose, CA 95134-1706 USA www.cisco.com Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 526-4100 European Headquarters Cisco Systems International BV Haarlerbergpark Haarlerbergweg 13-19 1101 CH Amsterdam The Netherlands Index [SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [R] [S] [T] [U] [V] [W] RADIUS reducing congestion with LAN switches 2nd 3rd buffers 2nd 3rd full-duplex transmission resolving DNS names to IP addresses 2nd 3rd 4th 5th 6th resolving IP addresses RFCs 2nd RJ-45 connectors pinout options root DNS servers routers configuring 2nd dynamic routes configuring forwarding to WAN links IP forwarding packets over WAN links 2nd next-hop static routes configuring routing 2nd 3rd assigning IP addresses to interfaces 2nd directly connected subnets end-to-end routing process 2nd 3rd 4th ARP decapsulation default gateways DHCP 2nd encapsulation 2nd 3rd Ethernet framing 2nd finding web server MAC address routing table lookups 2nd 3rd with subnets 2nd 3rd IP addresses 2nd 3rd 4th 5th canonical format conventions 2nd destination IP address field hosts network classes 2nd 3rd 4th 5th 6th network number 2nd NICs octets source IP address field 2nd subnetting 2nd 3rd 4th 5th static IP 2nd routing protocols metrics 2nd routing table lookups 2nd 3rd routing tables 2nd routing updates 2nd 3rd Index [SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [R] [S] [T] [U] [V] [W] security accounting 2nd anti-virus software 2nd authentication 2nd 3rd CHAP 2nd PAP 2nd 3rd with username and password 2nd 3rd authorization 2nd firewalls 2nd 3rd 4th DMZs 2nd traffic filtering logic 2nd 3rd identifying allowable traffic on enterprise network Internet connection 2nd 3rd 4th IDSs network-based signatures VPNs 2nd 3rd segmentation TCP segments mss TCP versus packets sending email sequence number field TCP header sequence numbers serial interfaces CSU/DSU serial links 2nd addressing 2nd 3rd SEs (sales engineers) signatures single broadcast domains single site networks SMTP 2nd and POP3 snail mail Sneakernet sniffers 2nd software email client source address field Ethernet header 2nd 3rd source IP address field 2nd standards 2nd encoding Ethernet networking models proprietary 2nd public 2nd 3rd 4th 5th OSI reference model 2nd standards (networking) data transmission 2nd electrical interference error recovery standards bodies IEEE ITU static IP routes 2nd static routes STP (shielded twisted pair) straight-through cables structured wiring plans 2nd 3rd subnets directly connected 2nd end-to-end routing process 2nd 3rd subnetting 2nd 3rd 4th 5th 6th switch ports 2nd switches autonegotiation 2nd creating multiple physical LANs devices:switches:creating multiple physical LANs 2nd flooding 2nd forwarding decisions Frame Relay MAC address table MAC addresses learning 2nd reducing congestion 2nd 3rd buffers 2nd 3rd full-duplex transmission supporting multiple speeds trunking 2nd 3rd trunks VLANs creating 2nd 3rd forwarding decisions frame forwarding 2nd reasons for implementing 2nd SYN flag bit SYN flag bit (TCP) Index [SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [R] [S] [T] [U] [V] [W] T1 lines TCP 2nd 3rd connection establishment 2nd error recovery 2nd 3rd forward acknowledgement headers 2nd port numbers 2nd segmentation segments SYN flag bit 2nd TCP (Transmission Control Protocol) TCP connections TCP destination port field (TCP header) 2nd TCP/IP 2nd 3rd DNS 2nd name format name resolution 2nd 3rd 4th 5th 6th root DNS servers email standards IP 2nd IP addressing subnets local host file 2nd TCP TCP/IP model layers TCP/IP networking model versus OSI model TCP/IP networking models layers 2nd telcos COs Frame Relay service leased lines 2nd 3rd 4th 5th SEs telephone switches three-site Frame Relay networks traffic filtering with firewalls 2nd 3rd monitoring with PIX Firewall 2nd 3rd trailers Ethernet FCS field 2nd transferring files 2nd 3rd 4th 5th transferring files with FTP 2nd 3rd 4th transmission speed of DSL transmission speeds CIR 2nd of WAN links transmission speeds of modems transport layer protocols 2nd 3rd 4th TCP connection establishment 2nd error recovery 2nd 3rd headers 2nd port numbers 2nd segmentation segments trunking 2nd 3rd 802.1Q ISL trunks twisted pair cabling STP UTP two-part email addresses types of WANs Index [SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [R] [S] [T] [U] [V] [W] unicast MAC addresses uploading files URLs (uniform resource locators) URLs (Universal Resource Locators) usernames authentication passwords:authentication 2nd 3rd clear-text UTP (unshielded twisted pair) Index [SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [R] [S] [T] [U] [V] [W] VCs PVCs CIR VCs (virtual circuits) vendor consortiums vendor-proprietary networking models 2nd viruses 2nd 3rd VLAN trunking VLANs creating 2nd 3rd frame forwarding 2nd reasons for implementing 2nd switch logic trunking 2nd 3rd 802.1Q ISL voice circuits voltage VPNs client software concentrators VPNs (virtual private networks) 2nd Index [SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [R] [S] [T] [U] [V] [W] wall plates WANs 2nd 3rd data link framing 2nd Ethernet-based Frame Relay 2nd access links CIR 2nd DLCIs 2nd FCS field full mesh Inverse ARP messages 2nd PVCs routing 2nd three-site networks VCs 2nd verus leased lines 2nd 3rd leased lines 2nd 3rd 4th 5th 6th analog transmission 2nd digital transmission voice traffic links 2nd addressing 2nd 3rd full duplex transmission installing 2nd transmission speeds serial interfaces CSU/DSU types versus LANs waveform web addresses web browsers 2nd 3rd 4th web clients web pages loading from browsers 2nd web servers 2nd websites 2nd well-known ports 2nd wiring closets wall plates wiring panels 2nd word processing applications WWW ... below, and his buddy shouts out, "Watch out for that first step It's a doozy!" Computer Networking First- Step is an easy first step toward learning about networking, instead of taking a doozy of a step off the networking ledge With Computer Networking First- Step, ... is a First- Step book on computer security!" Well, if you really thought that, the book Network Security FirstStep is meant for you Cisco Press introduced the First- Step Series in the spring of 2004. . .Computer Networking first- step By Wendell Odom Publisher: Cisco Press Pub Date: April 21, 2004 Print ISBN: 1-58720-101-1 Pages: 552 Table of Contents