ARISTA 1010
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`1
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`ARISTA 1010
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`Ptaetiea fiisso Rosters
`
`Copyright © 1999 by Que Corporation
`
`All rights reserved. No part of this book shall be reproduced, stored in
`a retrieval system, or transmitted by any means, electronic, mechanical,
`photocopying, recording, or otherwise, without written permission
`from the publisher. No patent liability is assumed with respect to the
`use of the information contained herein. Although every precaution has
`been taken in the preparation of this book, the publisher and author
`assume no responsibility for errors or omissions. Neither is any liability
`assumed for damages resulting from the use of the information con-
`tained herein.
`
`Iuternational Standard Book Number: 0-7897-2103-1
`
`Library of Congress Catalog Card Number: 99-63284
`Printed in the United States of America
`
`First Printing: September 1999
`
`01
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`00
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`99
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`4
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`3
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`2
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`1
`
`Trademarks
`
`All terms mentioned in this book that are known to be trademarks or
`service marks have been appropriately capitalised. Que Corporation
`cannot attest to the accuracy of this informafion. Use of a term in this
`book should not be regarded as affecting the validity of any trademark
`or service mark.
`
`Warning and Disclaimer
`Every effort has been made to make this book as complete and as accu-
`rate as possible, but no warranty or fitness is implied. The information
`provided is on an “as is” basis. The author and the publisher 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.
`
`3
`
`

`
`Eonienis
`
`Introduction
`
`1
`
`About This Book
`
`1
`
`How This Book Is Organized
`
`2
`
`Wire Should Use This Book
`
`3
`
`Conventions Used In This Book
`
`3
`
`I Networking Overview
`
`1 LAN Review 7
`
`2 The OSI Model and Network Protocols
`
`33
`
`OSI—'1‘he Theoretical Networking Protocol
`Stack 34
`
`3 8
`38
`
`35
`The 031 Layers
`'1 he Application Layer
`The Presentation Layer
`The Sesrion La_yer
`3 8’
`The Yrzznspzm Lzgier
`40
`The Nerwarle Layer 40
`The Data—Linla Layer
`The Physical Layer
`
`41
`
`43
`
`The Advent of the PC 8
`
`The Data-Link Sublayers
`
`43
`
`8
`Networking PCs
`Peer-to-Peer Netzuarle: 9
`Ser:/er—Based Netwarlex
`10
`
`Making the Connection. 12
`Network Interface Cards
`13
`Dealing with IRQJ and I/O Port:
`Network Cabling
`17
`Hubs, Repeaterr, and A/I/1Ur
`
`19
`
`14
`
`Understanding Network Topologies
`em Nmmk 21
`StarNerwarle
`22
`
`20
`
`Ring Tbpolagy
`Merl; Wipolngy
`
`23
`25
`
`Understanding Network Architectures
`Ethernet 26
`
`25
`
`IBM '17)/zen, Ring
`FDDI 29
`
`28
`
`Applmzlk
`
`30
`
`Real-World Network Protocols
`NetBEUI 45
`TCP/IP 45
`11’)?/SPX 48
`
`44
`
`Appzemk
`
`49
`
`Wide Area Networking 53
`
`Understanding Wide Area Connectivity 54
`
`54
`Getting Connected
`Dial—Up Comlections 55
`Leased Liner
`5'6
`
`Switched Network Overview 5'9
`
`Circuit Switching
`Packet Switching
`
`60
`61
`
`WAN Packet Switching Protocols
`X.25
`62
`
`62
`
`64
`Frame Relay
`Asyrzc/Jronom '1ran.9‘erM0de (AYYM)
`
`64
`
`Other WAN Protocols
`
`65'
`
`4
`
`

`
`PRACTICAL Ciscn Routers
`
`4 internetwnrking Basics
`
`67
`
`VVhat Is Internetworking?
`
`68
`
`68
`
`Internetworking Devices
`Repeoterx
`70
`Bridge:
`71
`Switches
`'73
`Router:
`73
`
`Gzltewoyx
`
`74
`
`1 08
`Logical Interfaces
`Laopback Inteifmcs
`108
`NullInte1face.v
`109
`Yiimzel Inteifizcer
`1 09
`
`Setting Up a New Router
`
`111
`
`Becoming Familiar with Your Router
`
`112
`
`Cisco Router Design
`Router CPU:
`113
`
`113
`
`Building a Campus Network
`
`75
`
`Router Memory Component:
`
`113
`
`5 How a Router Works
`
`77
`
`Connecting the Console
`
`115
`
`78
`Routing Basics
`Pat}: Detemtin/ztiorz
`
`78
`
`Logical and Htmlwtzrc Addresses
`Pocket Switching
`81
`Routing Yitblex
`82
`
`80
`
`Routoble Protocols
`
`85'
`
`Routing Protocols
`
`85'
`
`Routing Protocol Basics
`Routing Algoritlm1.r
`Routing Metric:
`89
`
`87
`
`87
`
`91
`Types of Routing Protocols
`93
`Interior Gateway Protocol:
`Exterior Gateway Protocolr 95
`
`II Router Design and Basic
`Configuration
`
`6 Understanding Router Interfaces
`
`99
`
`Router Interfaces
`
`100
`
`LAN Interfaces
`
`102
`
`Serial Interfaces
`
`104
`
`Configuring the Router Console
`
`117
`
`Working with the Terminal Emulation
`Software
`1 18
`
`Connecting the Router to the Network 119
`LAN Comzectiom 119
`Serial C0127l€Cti071S
`121
`
`A Final Word on Physical Router
`Connections
`122
`
`Basic Router Configuration
`
`123
`
`Configuring a Router
`
`124
`
`Router Boot Sequence 126
`
`Working with the System Configuration
`Dialog Box
`128
`Starting the Setup Dixrlog B09:
`Configlmng Rented Protocolr
`Configuring Router Intevfacer
`
`129 A
`131
`1 32
`
`Using the Different Router Modes
`User (Urzprivileged) Mode
`135'
`Privileged Made
`136
`Configimltion Mode
`13 7
`Getting Around Lott Pr1.m1)ord.>‘
`
`134
`
`139
`
`5
`
`

`
`9 Working with the Gisco IDS
`
`141
`
`Introducing the Intemetworldiig Operating
`System 142
`
`Command Structure
`Exec Comm//nnlr
`
`144
`144
`
`Configzmltion. Mode
`
`145
`
`The IOS Help System 147
`
`Router Examination Commands
`
`149
`
`Using the Privileged Mode
`
`153
`
`Checking Router Memory
`
`154
`
`Checking Out the Internetwork
`Neighborhood
`I57
`"
`VVE7‘/eiizg with CDP
`
`157
`
`Viewing CDP Neighbors
`Using Ping
`1 60
`
`159
`
`Creating a Router Banner
`
`161
`
`Routing LAN Protocols
`
`TCP/lP Primer
`
`167
`
`The TCP/IP Protocol Suaclc 168
`
`TCP/IP and the OSI Model
`
`168
`
`1 70
`1 71
`
`Applimtion. Layer
`H0_Yt-t0~HOJt Layer
`Intemet Layer
`171
`Network Amy; L/(yer
`
`I 72
`
`Workiiig with IP Addresses
`IP C/line:
`175
`
`174
`
`Bimlry Eqztivaleim and First Octet:
`Basic 8111))! at Mark:
`1 78
`
`177
`
`180
`Subnetting IP Addresses
`Bimnjy zmd Dccimzil Corzversioizs
`Crcrztirzg Snlmcfs on (I Class A
`Network
`I 82
`
`181
`
`CONTENTS
`
`184
`
`188
`
`188
`
`Crerlting the Network Sulmet Marie
`Cr//cl!///ting IP Sulmet Range:
`1 86
`Cr!/cu/nting Available Norle Addrem:
`
`Creating Class B and Class C Subnets
`Cl/In B Sulzrletting
`188
`CI/I5: C Sflbizetting
`190
`U72dem‘rmdi7ig Submit 0
`
`192
`
`A Final \Vord on Subnetting
`
`194
`
`Configuring IP Routing
`
`195
`
`Configuring Router Interfaces
`.LANInte1]‘}1ce:
`198
`I/WIN I72te2fz1ce.r 200
`
`Configuring 2 Routing Protocol
`CD1lfig‘Il7‘171g RIP 202
`Corzfigmivzg IGRP
`204
`
`196
`
`201
`
`Dynamic Routing Versus Static Roudng
`
`207
`
`_ Using Telnet 209
`
`Routing Novell IPX 211
`
`Introducing IPX/SPX 212
`Routing-Re/ntea'. IPX/SPX Protocol:
`
`213
`
`Understanding IPX Addressing
`U71der.tm71di7zg SAP 21 6
`
`214
`
`Configuring IPX Routing
`
`21 7
`
`Configuring Router Interfaces with IPX 219
`LAN Ivztew;/hues 220
`PWIN Inteifzrces 222
`
`Monitoring IPX Routing 223
`
`Routing AppleTa|k 227
`
`228
`Understanding AppleTalk
`AppleC1?rl/z Addressing
`229
`Appleflrlk Zone: 232
`
`6
`
`

`
`PRACTICAL Cisco Routers
`
`232
`Configuring AppleTall< Routing
`Ca71figIm'71.g LAN Intcifrzazy 235
`Co71figm'i1z.g I/WIN I7ztc1f/my
`236
`
`Monitoring App1eTa1k Routing
`
`23 7
`
`IV Advanced Configuration and
`
`~ Configuration Tools
`'54 Filtering Router Traffic with Access
`List
`243
`
`Understanding Access Lists
`How Amos Lim Work
`244
`
`244
`
`Building rm Access List 246
`
`VVo1‘king with LP Access Lists
`IP H/i/dt117‘r17M/rxlex
`249
`
`247
`
`C1'er1ti12g the Access List 252
`Graz/ping the Acme Lirt to 1m
`Inteifzrce
`253
`
`16 Configuring the Router with Cisco
`Coniighflaker
`271
`
`VVhat Is Cisco ConfigMaker?
`
`2 72
`
`Downloading ConfigMal<er Z72
`
`Installing ConfigMaker
`
`273
`
`Designing Your Internetv.rork with
`ConfigMake1‘
`274
`2 76
`/ldri'z'ng Devizex
`Cozmert/'21g I./lNr to Router:
`Cnrtmzctivzg Routers to R011-tB7'.f
`
`278
`281
`
`Delivering the Configuration to a Router
`
`284
`
`Using a TFl'P Server for Router Configuration
`Storage
`289
`
`290
`Wlxat Is 3 TFTP Server?
`Obminirlg TFTP Sqfitvnre
`291
`
`Installing the Cisco TFTP Server Software
`
`292
`
`Creating IPX Standard Access Lists
`
`254
`
`Creating AppleTalk Standard Access
`Lists
`25'6
`
`Copying to the TFTP Server
`
`294
`
`Copying from the TFTP Server
`
`295
`
`Configuring WAN Protocols
`
`259
`
`Understanding Serial and WAN
`Interfaces
`260
`
`Configuring I-Iigh—Level Data Link
`Control (HDLC)
`261
`
`Configuring PP]?
`
`262
`
`Configuring X25
`
`263
`
`Configuring Frame Relay 265
`
`Configuring TSDN 268
`
`Loading 9 New IOS from the TFTP Server
`
`297
`
`Basic Router Troubleshooting 301
`
`Troubleshooting Hardware Problems
`Rontc~rP7'oZzlc7m 302
`Otlzer Hrzrduwe Prolzlems 305
`
`3 06
`Cabling Pro};/ems
`A Final I/V5712’. o71Ha1vlw/(re
`
`307
`
`302
`
`307
`Troubleshooting LAN Interfaces
`Trorrlzlesliaothzg Et/Jemet with Show 307
`Tnmblcslzootiwzg '1?1l:e7I Ring with Show 309
`
`Troubleshooting WAN Interfaces
`
`31}
`
`7
`
`

`
` A
`
`CONTENTS
`
`Troubleshooting TCP/IP 313
`3
`Using ping 314
`Ufing “me 315
`
`Troubleshuot1'ngIPX 316
`
`Troubleshooting AppleTalk 317
`
`A Final Word on Troubleshooting 318
`
`V Appendixes
`
`B Selected (Disco Router Specifications 337
`_
`Router Selection
`
`338
`
`C1560 7500 Routers
`
`Cisco 4500 Routers
`
`Cisco 2500 Routers
`Cisco 1000 Routers
`
`338
`
`339
`
`340
`341
`
`AFinal Note
`
`342
`
`A Basic Rouier Command Summary 323
`
`Gmssary 343
`
`Cisco IOS Command Summary 324
`Router Examination Conmzzzmir
`324
`
`‘
`
`Index 359
`
`325'
`Router Mammy Commands
`Password and Router Name Configzmztion
`Commands 326
`
`Interfilce Configmwtimz Cmnrrzanzis 327
`IP—RelateclComm1mdr 328
`IPX~Reb1ted Crmmtamir
`330
`
`331
`Apple'1?zlk—Relm.‘ed Comm/md:
`W‘1N—RelrztedCo7Im1/zm1'.v 332
`
`'1'i‘auI7le.v1Joati71g Commtnldr 334
`Mi:cel1zzneou.rCom1mzndr
`334
`
`8
`
`

`
`About the Author
`
`Joe Habraken is an information technology consultant and best-
`selling author whose publications include The Complete Idiot} Guide to
`Microsofi Access 2000, Microrofi Oflice 2000 8—i12-1, Ezzry Publisher 2000,
`and Sam; 72:15/9 YoursegfMicrosoft Outlook 2000 in I 0 Mi1Z1At6J.}Oe has
`a Masters degree from the American University in Washington, DC.
`and over 12 years of experience as an educator, author, and consul~
`rant in the information technology field. Joe is a Microsoft Certified
`Professional and currently provides consulting services in the NT
`Server and internetworking arenas to companies and organizations.
`He also currently serves as the lead instructor for the Networking
`Technologies program at Globe College in St. Paul, Aiinnesota.
`
`9
`
`

`
`edieatimn
`
`To all the NSS students at Globe College.
`
`Good luck with your careers, and thanks for staying awake in my
`Cisco class (even when I babbled excitedly about internetworking
`and routing technology).
`
`Aeimowedgmetats
`
`Creating a book like this takes a real team effort, and this particular
`book was created by 2 team of incredibly dedicated professionals. I
`would like to thankjenny Watson, our acquisitions editor, who
`worked very hard to assemble the team that made this book a reality
`and always made sure the right pieces ended up in the right places.
`
`I would also like to thank Rick Kughen, who served as the develop-
`ment editor for this book and who came up with many great ideas
`for improving its content. He always asked the right questions and
`wasn’t afraid to burn the midnight oil to get the job done.
`
`Also a tip of the hat and a thanks to Ariel Silverstone, who as the
`technical editor for the project did a fantastic job making sure that
`everything was correct and suggested several additions that made the
`book even more technically sound. Finally, a great big thanks to our
`production editor, Tonya Simpson, who ran the last leg of the race
`and made sure the book made it to press on time—what a great team
`of professionals.
`
`10
`
`

`
`fie What You iliriiii
`
`As the reader of this book, you are our most important critic and
`commentator. We value your opinion and want to know what we’re
`doing right, what we could do better, what areas you’d like to see us
`publish in, and any other words of wisdom you’re willing to pass our
`way.
`
`As an Associate Publisher for Que Corporation, I welcome your
`comments. You can Fax, email, or write me directly to let me know
`what you did or didn’t like about this b0ok~——as well as what we can
`do to make our books stronger.
`
`Please note that I cannot help you with teclmical prolzlemx related to tbe
`topit of this Izaak, and that due to the big}: vnlume ofmail I rereive, 1 might
`not be able to reply to every message.
`
`When you write, please be sure to include this book’s title and
`author as well as your name and phone or fax number. I will carefully
`review your comments and share them with the author and editors
`who worked on the book.
`
`Fax:
`
`317-581-4666
`
`Email:
`
`hardwarelélmcp . com
`
`Mail:
`
`Jim Minatel
`Associate Publisher
`
`Que Corporation
`201 West 103rd Street
`
`Indianapolis, IN 46290 USA
`
`11
`
`

`
`find it amazing how rapidly computer technology has changed
`over the last 10 years. Technology once considered too costly or too
`complex for small or medium—sized companies is now being embraced
`at breakneck speed. Internetworking devices, and routers in particu-
`lar, are some of the former “big—company" technologies now being
`used by even the smallest companies.
`
`Inexpensive, low-end routers provide the connection to service
`providers and the public switched telephone network for small com-
`panies (and even individuals) who are looking for more bandwidth as
`they increasingly use the Internet as a communication and marketing
`tool. And as companies grow, they also look for strategies to conserve
`the bandwidth on their company—owned LANs; LAN segmentation
`with routers has become a viable and cost-effective solution.
`
`VV1th this explosion of internetworking technology hitting the busi-
`ness world, there has been :1 growing need for professionals to config~
`ure, manage, and troubleshoot routers and other internetworking
`devices. And although several excellent books and training‘ materials
`that relate to internetworking and Cisco products are available, most
`of these materials have been written for IT professionals with many
`years of experience or training already under their belts. A basic
`primer and entry—level book on the subject really hasn’t been avail-
`able—until now.
`
`About flats ask
`
`When I sat down to write this book, T wanted to do two things: share
`my excitement about internetworking and Cisco router configuration
`and provide a book that someone new to this technology could use to
`explore the incredible possibilities this technology offers. I also
`wanted to create a solid learning tool and make the book useful as a
`reference for someone with little internetworking background, who
`suddenly found working with Cisco routers part of their job descrip-
`tion. And although that sounds like somewhat of a tall order, I knew
`that I would have help.
`
`12
`
`

`
`PRACTICAL Cisco Routers
`
`Skilled designers and editors at Macmillan Publishing have worked
`very hard to create a book design that embraces fresh ideas and
`approaches that will provide an environment in which you can get
`the inforrnation you need quickly and efficiently. You will find that
`this book embraces a streamlined, conversational approach to the
`subject matter that will help you learn the concepts and become
`familiar with the hardware and software facts that you need to get
`the job done.
`
`now this aoit is Qrgauizea
`
`I Part I, “Networking Overview”—~«This section of the book helps
`you get up to speed or review several networking technologies.
`Information is provided on LANS, WANS, and internetworking.
`A chapter also provides information on the Open System
`Interconnection reference model and how it relates to real—world
`
`network protocols. The basics on how routers Work is also
`included in this section.
`
`a Part II, “Router Design and Basic Conf1guration”—«This section
`walks you through the hardware components of a typical Cisco
`router. You are also introduced to the basic configuration of
`routers and learn an overview of the Cisco Internetworlc
`
`Operating System.
`
`- Part III, “Routing LAN Protocols”—This section provides
`information about popular LAN protocols, such as TCP/IP,
`IPX/SPX, and AppleTalk. You learn conceptual information on
`each of these protocol stacks. You also walk through the steps of
`configuring a Cisco router for each of these protocols.
`a Part TV, “Advanced Configuration and Configuration Tools”-
`This section helps you become familiar with several WAN tech-
`nologies available and how they are configured on a Cisco
`router. Restricting access to your routers and troubleshooting
`routers are also covered to give you a complete picture of work-
`ing with internetworkin g devices. Information on using Cisco’s
`ConfigMalcer router configuration software is also included in
`this section. It provides someone who must get a router con-
`
`13
`
`

`
`INTRODUCTION
`
`nectcd and configured in a hurry, a step—by—step look at how to
`use the ConfigMaker software.
`
`who steals Use This oak
`
`This book is for anyone who needs a primer on internetworking and
`the configuration of Cisco routers. And Whether you work for a big
`company, small company, or are just beginning your education to
`become a network professional, this book is an excellent first step as
`you build your knowledge base.
`
`Conventions Used in This Book
`
`Commands, directions, and explanations in this book are presented
`in the clearest format possible. The following items are some of the
`features that will make this book easier for you to use:
`
`n Commands that you must enter—Router commands that you’ll
`need to type are easily identified by a monospace font. For
`example, if I direct you to get the encapsulation (the VVAN pro-
`tocol set) for a serial interface, 1’ll display the command like this:
`show interface serial 0. This tells you that you’ll need to enter
`this command exactly as it is shown.
`
`Combination and shortcut keystrokes—'T‘ext that directs you to
`hold down several keys simultaneously is connected with a plus
`sign (+), such as Ctrl+P.
`
`Cross refe1‘ences—Iftheres a related topic that is prerequisite to
`the section or steps you are reading, or a topic: that builds fur-
`ther on what you are reading, you’ll find the cross reference to it
`at the end of the section, like this:
`SEE ALSO
`
`Tb ICE bow to create newxpnperco/1171/zirpveepnge xx.
`
`n Glossary terms——For all the terms that appear in the glossary,
`you’ll find the first appearance of that term in the text in italic
`along with its definition.
`
`14
`
`

`
`PRACTICAL Cisco Routers
`
`1: Sidenotes—Information related to the task at hand, or “inside”
`information from the author, is offset in sidebars that don’t
`interfere with the task at hand. This valuable information is also
`
`easier to find. Each of these sidebars has a short title to help you
`quickly identify the information y0u’ll find there. You’ll find the
`same kind of information in these that you might find in notes,
`tips, or warnings in other books but here, the titles should be
`more informative.
`
`15
`
`

`
`16
`
`

`
`17
`
`

`
`PART! Networking Overview
`CHAPTER1 LAN Review
`
`The Advent of the FC
`
`How and where people use computer technology has changed dra-
`matically over tl1e past 30 years. In the 19605, computing revolved
`around large mainframe computers. In the early days, users typically
`interfaced with this highly centralized computer through an interme-
`diary: an IS administrator or programmer. As computer technology
`evolved further, mainframe users were able to directly communicate
`with the computer using a dumb terminal (basically, a monitor and a
`keyboard hard—wired to the mainframe). In the 19705, the ininifratne
`gained dominance in the computing world, making computer tech-
`nology accessible to a larger number of companies and organizations
`(even though these companies paid a premium for their ability to
`compute). All storage and computing power was still centralized,
`however, much the same as in the mainframe environment.
`
`In the 19805 the personal computer (particularly the IBM Personal
`Computer) revolutionized the way you compute. Computing power
`was brought to the individual desktop. Not only was this new type of
`computer relatively easy to use (when compared to mainframes and
`miniframes) but also it was very affordable. The only flaw in this
`computing renaissance was the inability of users to collaborate and
`share resources. The individuality of the PC isolated its users.
`
`Neitfilmitttg Me
`
`To overcome this decentralized computing model offered by the PC,
`software and hardware were developed in the 1980s and [9905 to
`connect PCs into networks that could share resources (such as print-
`ers and files). Networked PCS made it easy to design a collaborative
`computing environment for any business situation. Networked com-
`puters can share :1‘ variety of resources, including hardware (printers,
`modems), software (application software), and user-created files.
`
`Different networking models arose to fit different types of network-
`ing needs. In situations where a few computers needed to share a
`particular hardware device, such as a printer, but did not require cen—
`tralized file storage, the peer—to—peer network evolved. The only time
`individual users interfaced with this type of network was when they
`
`18
`
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`
` V
`
`PART I
`
`Networking PCs CHAPTER1
`
`printed. The alternative to the peer—to—peer network was a network
`with more centralized control of resources and better security. This
`type of netw0rk#a .te7've7'—l1(1red 7ze22*u107'/e——uses 2: server computer (the
`central controller of the network) to authenticate users on the net-
`work and provide central file storage (as well as access to a number
`of different hardware and software resources). How these two net—
`working models differ deserves some additional discussion.
`
`Peer-to-Peer Networks
`
`Peer—Lo-peer networks provide an easy way to share resources, such
`as files and printers, without the need for an actual server computer.
`Peer computers act as both clients (the users of resources) and server;
`(the providers of resources). The only real requirements for building
`a peer—to—pcer network are installing an operating system on the PCs
`that supports peer-to—peer networking and physically connecting the
`PCS.
`
`Several operating systems, such as Microsoft Windows 3.11,
`Microsoft Windows 95/98, and Microsoft Windows NT
`Workstation, have peer—to—peer networking capabilities built in.
`‘Local drives, folders, and printers can be shared with others on the
`peer—to—peer network (see Figure 1.1).
`
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`open for use bv iani/on p
`physically anacned tom .2
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`PART! Networking Overview
`CHAPTER1 LAN Review
`
`Each resource that is shared (such as a drive or printer) potentially
`will have a different share password. This is one of the downsides of
`peer—to—peer networl<ing——every resource is capable of having a sepa-
`rate password. If many resources are shared across the network, you
`will have to remember the password for each resource. This type of
`security is referred to as r/J/I1‘c—lc1/cl sec-zm't_y.
`
`Peer—toApeer networks also don’t require a great deal of additional
`administration because each user can manage resources on his own
`peer computer. Peer networks, however, do have their downsides:
`
`I Increased performance hit on computers because of resource
`sharing
`No centralized location of shared files makes it difficult to back
`
`up data
`
`Security must be handled on a resource—hy—resource level
`Decentralization of resources makes it difficult for users to
`
`locate particular resources
`
`a Users might have to keep track of numerous passwords
`
`Although peer—to—peer networking may seem like a fast and cheap
`way to connect a group of computers, the biggest drawback in using
`this type of networlcing is that only a small number of users can be
`accommodated. Peer networking isn’t scalable (meaning expandable,
`because most peer networks are limited to 10 peer computers) and so
`is certainly not the appropriate choice for a growing company.
`
`It is pretty much a consensus among IS managers that peer—to—peer
`networking works ideally with five or fewer peer machines.
`SEE ALSO
`
`Far more infer)/Ititioli on the plzyrical roizuecriw/.v, we page 12.
`
`Setvehfiased Networks
`
`Servcr—bascd networks provide greater centralized control of
`resources and expandability if required. A server computer is basi-
`cally a special—purpose machine that logs in users and “serves” up
`resources to them. Because the server verifies users, this type of net-
`work makes it easier to manage your resources by providing different
`
`.~...r.._...v4..a..nu.u.,_.;—::.w:~_—.~:...i.-cm.\V
`
`
`
`._.._______._..__.Jv:«::-nvzueaueaaz-:2:nmr-2-3:-m-m_......._......n
`
`20
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`

`
`PART I
`
`Networking PCisiiCiHiAiP;fER1
`
`access levels to the Various users in your user pool, A username and
`one password puts users onto the network and gives them access to
`any resource for which they have the appropriate permissions.
`
`A server-based network typically employs a more powerful (in terms
`of processor speed, RAM, and hard~drive capacity) computer to act
`as the server. In addition to hardware that can handle a large number
`of user requests for services, the server computer must run special
`software—a network operating system (NOS). Two cominonly used
`network operating systems are Nlicrosoft Windows NT Server and
`Novell NetWare.
`
`Server—based networks, as mentioned before, are scalable. This
`means that the network can grow along with your company. Servers
`can be added to your network that take on specialized duties. For
`example, one server may handle user login and verification (a pri-
`mary domain controller on a Windows NT network would be an
`example), while another server on the network may handle the email
`system (a communications server). Table 1.] lists some of the special-
`ized sewers you might use on a local area network.
`
`Sen/er Type
`
`File server
`
`Communication server
`
`Application server
`
`Print server
`
`Use
`
`Stores shared user files and provides home directory
`space for users (such as a Novell NetVVare server)
`
`Provides communication services such as email (such as
`an NT Server running Microsoft Exchange Server)
`
`Provides access to a database or other application (such
`as an SQL server database)
`
`Provides the print queue and other services related to a
`network printer
`
`A server—based network of computers that is limited to a fairly small
`geographical area such as a particular building is described as a local
`area network (LAN). LANs are found in small, medium, and large
`companies. When several LANs are connected, you are dealing with
`an intemetwor/e, which is a network of networks (this type of network
`can also be referred to as a czmzpm). VVhen you start connected carn-
`puses and create networks that span large geographical areas, you are
`working in the realm of the Vl/Tide Area Network
`
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`
`PART! Networking Overview
`CHAPTER1 LAN Review
`
`Se1ver—based networks are really the standard for even small local
`area networks; these types of networks do have their downside, how-
`ever. Much of the downside, at least for the small company wanting
`to set up a PC network, is cost——the cost of at least one server PC ‘
`and the cost of the network operating system. Server—based networks
`also typically require the hiring of a full—time administrator to main—
`tain and manage the network (and whereas management sees this as
`an additional cost, the network administrator sees it as money well
`spent).
`
`Other negatives associated with the server—based network revolve
`around sewer failures, brorzdmst rtomzs (tons of broadcast traffic from
`devices on the network), and other hardware— and software—related
`disasters that are too numerous to mention in this book. Networks
`
`are by nature challenging, and that is why a good network adminis-
`trator is worth his or her weight in gold.
`SEE ALSO
`
`Fr Fo7‘7)m’e i/1f07wmt1‘o72 on i1IteI7Iem/01'/zr'11g,seepage 67.
`SEE ALSO
`
`is For more iI.'fi)f7)Iflll072 on wide area nerworlcing see page 53.
`
`Efiakaig the Qemieetion
`
`To create a computer network, you must use some type of connective
`medium that allows the transfer of your data. This medium can
`range from copper cable to microwave transmissions to a beam of
`infrared light (our discussion of network media will be restricted to
`copper and fiber~optic cables, with the understanding that there are a
`lot of possibilities for moving data from one point to another).
`
`After you choose a connective medium, such as copper cable, you
`also need a device that can prepare the data on the computer so that
`it can travel along your network cabling. This data restructuring is
`handled by a network interface card (NIC). A NIC is typically placed
`in one of the computer’s bus expansion slots and then the network
`cable is attached to a port on the NIC. Understanding how the NIC
`works, and your options as far as copper and fiber—optic cabling, will
`go a long way when you have to sit down and design even the small-
`est networks.
`
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`

`
`PARTI
`
`Making the Connection CHAPTER1
`
`Network interface Cards
`
`The network interface card (NIC) provides the connection between
`the PC and the networks physical medium (such as copper or fiber-
`optic cable). Data travels in parallel on the PC’s bus system; the net-
`work medium demands a serial transmission. The transceiver (a
`transmitter and receiver) on the NIC card is able to move data from
`parallel to serial and vice versa.
`
`Network interface cards each have a unique address that is burned
`onto a ROM chip on each NIC. This addressing system is used to
`move data from one physical connection to another (and you will
`find that resolving logical addresses such as IP addresses to NIC
`hardware addresses is really what networking is all about).
`
`NICS are available for a number of bus types (Figure 1.2 shows a
`PCI Ethernet NIC), so make it a point to open up the PC or PCS
`that you are going to network and check to see what type of bus slots
`are available. Newer PCs will typically have PCI slots available.
`Older computers mean that you will have to deal with ISA and possi-
`bility EISA slots. Obviously, purchasing the appropriate card is
`extremely important in making the computer netwoi-k—ready. The
`remainder of the battle is installing the network card and the appro-
`priate software drivers for the NIC and getting the computer to rec-
`ognize both.
`
`23
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`

`
`PART! Networking Overview
`
`CllAPTER1 LAN Review
`
`Make sure you have the CD or disk set for the operating system run—
`ning on the computer (such as Vi/"indows 98) and that you have any
`disks or CD5 that came with the network card. Implement the fol-
`lowing steps to get the PC up and running on the network:
`
`Setting up the PC on the network
`
`1. Open the case on the computer and install the NIC in an open
`expansion slot.
`. Close the case and attach the network medium (typically
`twisted—pair cabling).
`'
`. Boot up the computer. Ifyou purchased a plug—and~play network
`card and are using Windows 95/98, the card will be detected and
`the appropriate software drivers installed. You may be prompted
`to provide the drivers during this process (these drivers are on a
`disk or CD that came with the network card).
`
`. If you are using an operating system that doesn’t detect new
`hardware devices, you will have to manually install the NIC, If
`the card came with installation software, use that software to
`install the necessary drivers.
`l
`
`. Some operating systems will require that you select an IRQ and
`I/O port for the new NIC (this is the case with Windows NT
`4—both the server and workstation OS; select an open IRQ and
`I/O port and then complete the installation of the card as
`required by your operating system.
`
`After you physically install the card and add the appropriate driver to
`your software operating system, you should be up and running on
`the network (you might have to reboot the machine after installing
`any drivers for the NIC). Problems associated with NICs usually
`revolve around improper installation (press the card firmly into the
`expansion slot) and IRQ conflicts. The latter is discussed in the next
`section.
`V
`
`eating with mas and !/O Ports
`
`One of the most common pitfalls when installing any new device
`into one of the expansion slots on a PC is an TRQ conflict. IRQ
`
`24
`
`

`
`PART I
`
`Ii/laking the Connection CHAPTER’!
`
`stands for Irztermpt ReQuest. Each device in your computer, such as
`the mouse, keyboard, and NIC, are assigned an Interrupt Request
`line that the device uses to alert the microprocessor (CPU) that the
`device needs data processed. Each device must be assigned a unique
`IRQ or you have (yes, you guessed it) an IRQ conflict. Neither
`device will probably operate correctly if two devices are vying for tl1e
`same IRQ. Knowing which IRQS are already spoken for on your sys-
`tem will make it easier for you to assign an IRQ to a new device such
`as an NIC.
`‘
`
`Finding the available IRQS isn’t that difficult, and each operating’
`system (both PC operating systems and network operating systems)
`provides you with a tool to View both the used and available IRQS on
`a system.
`
`For DOS clients, you can use the executable file MSD.EXF,, which
`runs the Microsoft System Diagnostics program. This program is
`also available for Virmdows 3.11 clients.
`'
`
`For V‘/"mdows 95 and 98, open the Control Panel (doubleecliclc My
`Computer and then double«cliek the Control Panel icon).'In the
`Control Panel, double—click the System icon. On the System
`Properties dialog box, click the Computer icon, and then click
`Properties. A list of the IRQS on the system will appear (see
`Figure 1.3).
`
`5lar\da1d1D1I'1D2Ke9 in Mi{:vo{o(l