Que upgrading and repairing networks 5th edition may 2006 ISBN 078973530x

This updated edition includes the latest on network planning and design, and building a network using wired, wireless, or both technologies.. Although he has taught classes virtually non

By Terry W Ogletree, Mark Edward Soper

Publisher: Que Pub Date: May 11, 2006 Print ISBN-10: 0-7897-3530-X Print ISBN-13: 978-0-7897-3530-0 Pages: 1200

Table of Contents | Index

Upgrading and Repairing Networks, Fifth Edition

is the definitive guide for anyone with a network, from home networking enthusiasts to professional network administrators The book explains network architectures and

protocols using plain English and real-world examples, and gives valuable insight for fixing network problems This updated edition includes the latest on network planning and design, and building a network using wired, wireless, or both technologies It covers the latest updates in Windows XP Service Pack 2, as well as Gigabit Ethernet, virtual LANs, Bluetooth, WAP, security, firewalls, and VPN use.

By Terry W Ogletree, Mark Edward Soper

Publisher: Que Pub Date: May 11, 2006 Print ISBN-10: 0-7897-3530-X Print ISBN-13: 978-0-7897-3530-0 Pages: 1200

Upgrading and Repairing Networks, Fifth Edition

Copyright © 2006 by Que Publishing

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 informationcontained herein Although every precaution has been taken inthe preparation of this book, the publisher and author assume

no responsibility for errors or omissions Nor is any liabilityassumed for damages resulting from the use of the informationcontained herein

Warning and Disclaimer

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 provided is on an "as is" basis The author andthe publisher shall have neither liability nor responsibility to anyperson or entity with respect to any loss or damages arisingfrom the information contained in this book

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Scott Mueller is president of Mueller Technical Research (MTR),

an international research and corporate training firm Since

1982, MTR has produced the industry's most in-depth, accurate,and effective seminars, books, articles, videos, and FAQs

covering PC hardware and data recovery MTR maintains a clientlist that includes Fortune 500 companies, the U.S and foreigngovernments, major software and hardware corporations, aswell as PC enthusiasts and entrepreneurs His seminars havebeen presented to several thousands of PC support

professionals throughout the world

Scott personally teaches seminars nationwide covering all

aspects of PC hardware (including troubleshooting,

maintenance, repair, and upgrade), A+ Certification, and datarecovery/forensics He has a knack for making technical topicsnot only understandable but entertaining as well; his classesare never boring! If you have 10 or more people to train, Scottcan design and present a custom seminar for your organization

Although he has taught classes virtually nonstop since 1982,Scott is best known as the author of the longest running, mostpopular, and most comprehensive PC hardware book in the

Repairing Windows; Upgrading and Repairing PCs: A+

Certification Study Guide, 1st and 2nd editions; Upgrading and Repairing PCs Technician's Portable Reference, 1st and 2nd

editions; Upgrading and Repairing PCs Field Guide; Upgrading

and Repairing PCs Quick Reference; Upgrading and Repairing PCs, Linux Edition; Killer PC Utilities; The IBM PS/2 Handbook;

and Que's Guide to Data Recovery.

Scott has produced several video training packages covering PChardware, including a six-hour, CD-based seminar titled

Upgrading and Repairing PCs Training Course: A Digital Seminar from Scott Mueller Scott has also produced other videos over

Scott has been featured in Forbes magazine and has written several articles for Maximum PC magazine, several newsletters, and the Upgrading and Repairing PCs website.

www.upgradingandrepairingpcs.com and click the Ask Scott

button

When he is not working on PC-related books or on the road

teaching seminars, Scott can usually be found in the garageworking on several vehicular projects

Certification, and Tech TV's Upgrading Your PC, Second Edition.

Mark is also the lead author of the forthcoming Upgrading and

Repairing Servers Mark's books have been translated into

several languages, including Chinese, Russian, Czech, Urdu,Spanish, Italian, and French

Mark has also contributed content to many other book series,

including Upgrading and Repairing PCs (11th to current 17th edition) and Special Edition Using Windows (Me and XP).

In addition to a successful career as a technology book author,Mark is also the author of about 150 articles for computer and

technology magazines, most recently for Maximum PC's October

2005 issue Mark has also contributed chapters to two

Maximum PC books: Maximum PC Guide to Building a Dream PC and Maximum PC Ultimate Performance Guide.

Community College of Indiana, including digital photography,image scanning and archiving, eBay, A+ Certification, and

spyware/virus protection

Mark currently provides online tutorials for Skywire Software, aleading source for corporate technology help desk services, andhas also provided technology screening questions for

ReviewNet, a leading source for technology employment

screening services

When he's not working, Mark enjoys photography, researchingthe history of transportation, church activities, and his

grandchildren

Terry William Ogletree is a consultant currently working in

New Jersey He has worked with networked computer systemssince 1980, starting out on Digital Equipment PDP computersand OpenVMS-based VAX systems He has worked with Unixand TCP/IP since 1985 and has been involved with Windows NTand Windows 2000 since they first appeared, as well as thenewest additions to the family, Windows XP and the WindowsServer 2003 family of servers Besides being the lead author ofthe third and fourth editions of this book, he is the author of

Windows XP Unleashed 1st Edition, Practical Firewalls, and The Complete Idiot's Guide to Creating Your Own CDs 1st and 2nd Editions He has also contributed chapters to many other books

published by Que, including Microsoft Windows 2000 Security

Handbook and Special Edition Using Unix, Third Edition He is

also the author of Fundamentals of Storage Area Networking.

When between jobs and not writing for Que, he can often befound on street corners holding a sign that reads "Will work forhundreds of thousands of dollars."

This book is the 16th book with my name on the cover, but I amfar from alone in the process of creating it Above all, I want tothank Almighty God for the opportunity to live, learn, and writeduring a period of amazing technological changes All glory toHim

I also want to thank my wife Cheryl for putting up with anotherround of long days and nights during the creation of this

edition Her encouragement and support make my career as atechnology writer possible I also want to thank my ever-

growing family for helping me remember that one of the

greatest benefits of networking is the ability to, at the click of amouse, stay in touch with those you care about

Many thanks to Scott Mueller, whose Upgrading and Repairing

PCs has been my most-referred-to reference book since its first

edition, and to Terry William Ogletree, who has helped bringScott's vision of encyclopedic thoroughness and accuracy tonetwork topics in previous editions of this book I am humbled

to have the opportunity to work with these individuals

I also want to thank the staff at Que Publishing for the

continued opportunity to write about technology subjects Inparticular:

As the reader of this book, you are our most important critic

and commentator We value your opinion and want to know

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completely embraced TCP/IP as a replacement for IPX/SPX, andMicrosoft no longer provides NetBEUI for any use other thannetwork troubleshooting The incorporation of wizards for bothwired and wireless networking into Windows XP, starting withService Pack 2, makes client configuration easier than ever

firewall types and products, not to mention the threats theyguard against, are more numerous than ever before Anotherfactor complicating network design is the increasing use of

Linux servers as well as clients in previously all-Microsoft

network environments

Upgrading and Repairing Networks, Fifth Edition is designed to

help you navigate through the changing world of networking toreach the destination of a powerful, properly operating network,regardless of size

If you are an experienced network administrator, you can usethis book as an encyclopedia of recent and current network

technologies and best practices It can help you understandproducts and services you might not have previously

encountered, and it can provide you with the details you need

to understand which network choices are best in a particularsituation

What Will You Find Inside?

This edition contains 57 chapters and 5 appendixes To help youlocate the information you need, the chapters are organizedinto 11 parts, each of which is detailed in this section

Part I, "Up Front: Network Planning and Design Concepts," is agreat place to start reading if you are new to networks, networkdesign, or network planning The first chapter provides a shorthistory of computer networking Later chapters show you how

to select the right network topology, how to prepare to

implement a network, how to manage the network upgradeprocess, and how to protect a network and its data

Part II, "Physical Networking Components," covers the physicalcomponents that make up your network, from the network

cables and network adapter cards to the devices that are used

to connect these components, such as switches and routers

Part III, "Low-Level Network Protocols," is where you'll find

information about many types of technologies you can use totransmit data across your network This section starts with areview of the IEEE 802 network standards, followed by an in-depth look at the major LAN wire protocol: Ethernet, which

continues to be on the cutting edge of network performance

Part IV, "Dedicated Connections and WAN Protocols," is

designed to help you select the right network connection,

whether you're a network administrator who needs to connectLANs across large distances or an individual user who needs alocal dedicated connection to another LAN or the Internet Fromdial-up and dedicated to cable and DSL, this section discussesthe major WAN protocols available

Part V, "Wireless Networking Protocols," covers all flavors of the802.11 family of wireless Ethernet (Wi-Fi), including the manyproprietary extensions now on the market and Bluetooth-basedand PDA devices To help you protect your wireless network,this section also discusses wireless encryption methods andbest practices

Part VI, "LAN and WAN Network, Service, and Application

Protocols," provides coverage of the TCP/IP protocol suite used

in virtually all networks and WAN connections today, along withTCP/IP services, applications, and troubleshooting tools Emailprotocols, IP address configuration methods, network nameresolution, Active Directory, routing protocols, SSL, and theIPv6 protocol are also covered in this section

Part VII, "Network User and Resource Management," deals withmanaging users and controlling access to network resources,including folders, printers, and domains, on Windows NT,

Windows Server, and Linux/Unix

selecting and using firewall appliances and software, configuringand using VPNs, and using encryption, the tools and techniquesyou need to keep your network safe are discussed in this

section

Part IX, "Troubleshooting Networks," provides strategies, tools,and techniques for troubleshooting enterprise, corporate, andsmall office/home office (SOHO) wired and wireless networks

Part X, "Upgrading Network Hardware," is a valuable reference

if you want to move to the latest Ethernet hardware standardswhile trying to protect your investment in existing equipmentwhere possible One chapter discusses the issues involved inadding wireless networking to your existing wired network

Part XI, "Migration and Integration," covers the other side of thecoin, upgrading from one operating system to another, as well

as using multiple operating systems on the same network Thissection discusses the many things that are common to mostoperating systems, as well as tools that can help you integrate

a diverse collection of systems into a single heterogeneous

network Whether you are migrating from NetWare to WindowsServer, upgrading older Windows networks to Windows Server

2003, or integrating Linux with your Windows or NetWare

network, you'll find the information you need in this section

The appendixes provide focused coverage of specialized

information that applies to many chapters, including the OSInetwork reference model, a glossary of network terms, onlineresources for network administrators and builders, a discussion

of Lightweight Directory Access Protocol (LDAP) products andconfiguration, and an introduction to setting up a SOHO

network

Upgrading and Repairing Networks, Fifth Edition features many

updates, reflecting changes and enhancements in network

hardware, software, services, and best practices since the lastedition was published Chapters covering wireless networkinghave been extensively revised, including the latest information

on Wi-Fi security; a closer look at the technical details of

2.4GHz Wi-Fi (802.11g/b) networking; differences betweenstandard 802.11g and various proprietary extensions; dual-mode and dual-band Wi-Fi hardware; the features of the

Windows XP Service Pack 2 wireless setup wizard; and the

differences between various classes of wireless devices such asPDA, Smartphones, and others

Other major updates include coverage of the latest firewalldevices and software, redundant power supplies, and backupdevices; 10 Gigabit Ethernet and UTP cabling standards;

methods for testing firewall products; configuring a VPN client;selecting a router with appropriate levels of VPN support; andmethods for SOHO network troubleshooting Appendixes BEhave been extensively revised to provide the latest terms,

information resources, and methods

Chapter 1 A Short History of Computer Networking

Today, computer networks are taken for granted much as thetelephone network is The telephone network was, until the

explosive growth of the Internet, the largest network in the

world It just wasn't a computer network You could use

modems to connect computers to each other on a one-by-onebasis, but this wasn't networking in the sense we think of it

today And those early modems300 bps or lessdidn't make thetransfer of data an inexpensive matter, especially when long-distance calls were required In a funny twist of fate, voice

communications are becoming very popular in the networkingworld Both corporate and home network users can now useVoice over IP (VoIP) to make telephone calls via the Internet,making the telephone network itself less important No wonderthat many telephone companies have expanded into the datanetworking field so that they can offer data, voice, video, andother services Many have also developed cellular or other

alternatives to the traditional telephone network

Computer networking has been evolving since the late 1960s.Early work on the ARPANET began in the 1960s, and in 1969 afour-node network using primitive packet switching was

created The growth of this predecessor of today's Internet

wasn't quite the phenomenon you see today

As discussed in Chapter 13, "Ethernet: The Universal Standard,"the ALOHAnet was created to establish connections betweenseveral computers in Hawaii Robert Metcalf was later to use thebasic principles from ALOHAnet to create what eventually

became the Ethernet local area networking protocol still usedtoday Ethernet was simply a means to get a signal from oneplace to anotherit was another thing to decide what kind of

signaling to use On the ARPANET, TCP was being created, and

Layer Networking Reference Model"), you can see that Ethernetworks at a low level in the model, and is used to transmit

Reference Model (see Appendix A, "Overview of the OSI Seven-packets of information from higher-level protocols TCP was thefirst major higher-level protocol created One of the first

refinements of TCP was to break it into several parts (or layers),which is why the protocol "suite" is known today as TCP/IP

TCP (the Transmission Control Protocol) and IP (the InternetProtocol) are the basis of the Internet Another break-out fromTCP was the User Datagram Protocol (UDP) Both TCP and UDPprovide different types of service, yet both use IP as the

workhorse protocol that is used to route packets (or datagrams)

on the Internet, as well as any intranet And what does IP use

to send data across the wire (or the air, in case of a wirelessnetwork)? Ethernet in most cases Learn more about how

wireless networks work with Ethernet in Part V of this book,

"Wireless Networking Protocols."

level protocols simply provide the means to frame datacreatediscrete units of data for transmissionand then use a specifiedmethod to send data across the network media For example,simply varying the voltage on a wire can be used to send datafrom one point to another An early transmission method, callednon-return to zero (NRZ) encoding, used just this method Ahigh value was used to specify the bit value of one, and a lowvalue was used for zero A drawback to this encoding scheme isthat a long stream of either ones or zeros can be difficult to

It is important to keep in mind that Ethernet and other wire-decipher at the receiving end The term "clock" is used to meanthat each end of the transmission understands where a bit

starts and where it ends during the transmission Because itwould be very expensive to have a physical clock at each endthat could precisely time each bit transmission, this encodingmethod does not scale well

Early Ethernet networks used a technique called Manchester

is built into the coding scheme itself Instead of using a high- orlow-voltage state to indicate a specific bit, Manchester encodinguses the change from one state to another, during a specificinterval

While TCP/IP continued its development on the ARPANET,

computer vendors began to recognize the importance of

networking, and many proprietary protocols were developed.Digital Equipment Corporation (DEC) created DECnet (and

numerous other protocols), which was used to connect its PDPcomputers and, later, VAX and AlphaServer computers TodayDECnet is still used, although TCP/IP has pretty much replaced

it for most installations For a short time in the 1980s, however,DEC operated the largest computer network in the world, short

of the Internet What protocol was used? DECnet, of course.During that same period, the OSI model was created, and

Digital incorporated the concepts of that model, as well as theprotocols that were developed by ISO based on the OSI model,into DECnet Because the VMS (Virtual Memory System)

operating system used on DEC's VAX computers was adoptingthese open standards, the name of the operating system waschanged to OpenVMS However, few other vendors chose to

protocols) As networking began to become an important part ofthe computing world, other vendors, such as Xerox (XNS), alsocame up with their own protocols

The result was that if you wanted to create a network of

computers for your business, you had to stick with a single

vendor Proprietary protocols, then, were not a good solution to

During the early days of PCs, the same sort of situation

occurred Although PCs were basically the same when it came

to the operating system (DOS at the start), you could buy anetwork setup from many different vendors One that comes tomind is NetWare (which is still around today, although in recentyears TCP/IP has replaced the proprietary IPX/SPX NetWareprotocols) LAN Manager was Microsoft's entry into the field,with a legacy of NetBEUI and NetBIOS still lurking around onmany Windows computers prior to Windows 2000 When DECstarted to build its own PCs, it licensed LAN Manager technologyand created Pathworks You might still find Pathworks in somenetworks, although, like LAN Manager, it is considered historytoday

Other pioneering networking packages included Banyan Vinesand Artisoft LANtastic, neither of which is still on the market.However, Banyan Vines helped establish the idea of a

nameservice, StreetTalk, which helped pioneer the idea of adistributed database for tracking network resources LANtasticwas an early advocate of peer-to-peer networking, which hasled to the current popularity of SOHO wired and wireless

networks

The Internet changed the entire landscape As TCP/IP continued

to mature into the stable protocol suite that it is today, the PClandscape, as well as mainframe and minicomputers, began toadopt TCP/IP Although the ISO first attempted to define openprotocols so that computers from different vendors could

interact to exchange data, it turns out that TCP/IP is the winner

in the end And when IPv6 (IP version 6) finally reaches fromthe inner core of the Internet to the edge, you will find that

TCP/IP continues to add new features, enhance security, andprovide more robust features

Other protocols, such as ATM and Frame Relay, are used forlong-distance transfer of data, and can encapsulate other

The old standard Ethernet has itself continued to be enhanced

to keep up with the need for speed Early versions operated at25Mbps, and most desktops today use 100BASE-T, or 100MbpsEthernet Gigabit and 10Gigabit Ethernet are now on the

market, although these newer versions do not use the samesignaling techniques as earlier versions The capability to

provide backward compatibility with earlier versions, however,

is another important factor for the continued use of Ethernet

Today you will find that most desktop computers in a company'sLAN use TCP/IP Although other protocols may encapsulate

TCP/IP for transmission over a long distance, the TCP/IP

protocol is still the de facto standard for computer-to-computercommunications TCP/IP is also supported by networked

printers and wireless communications

Because of this standardization, prices for equipment that

support Ethernet and TCP/IP are dramatically less than a

decade ago Network adapters themselves may become historybecause many computer motherboard manufacturers are

focused and productive Because network uptime is relateddirectly to productivity, a solid grasp of network concepts is anecessity when you're facing a troubled LAN

In this chapter, you will review the topologies in use today andlearn the strengths and weaknesses of each

Several unique network technologies have been developed overthe past three decades Different types of networks have

different design criteria and, thus, various topologies have comeinto use One important distinction needs to be made before weenter into a serious discussion on topology: physical topology

The basic topologies you will find in most LANs today includethe following:

computing system Taps can be physical cores cut into the coax(sometimes called a "vampire tap") or BNC-style "T-connectors"that join several individual pieces of coax together to form thecommon bus (see Figure 2.1 and Figure 2.2 for a comparison ofthe two methods)

Figure 2.1 Computers can connect to coaxial cables on a bus by tapping directly through the core of the cable The vampire taps pierce the

thicknet cable but not the BNC.

[View full size image]

Figure 2.2 BNC-style T-connectors make

attaching computers to a bus a simpler operation.

networks are created using coaxial cables and the bus topology in

Chapter 13 , "Ethernet: The Universal Standard."

A bus is also a logical topology From a device's viewpoint, allother systems communicate through the same, shared path.Because it is a shared media technology, mechanisms must beput into place to arbitrate network traffic over the cable

Typically, collision detection (CD) or collision avoidance (CA)algorithms are used in bus topologies to arbitrate network

access along with concepts such as "broadcasts" to reach everydevice on the cable This subject is covered in detail in Chapter13

The bus topology is very simple and inexpensive to implementdue to its low cost requirements for cable installation (there'sonly one main trunk) But some serious deficiencies make bustopology LANs unattractive to deploy:

Bus topologies require proper terminations on both ends ofthe bus to effectively dampen the network signal and toavoid a "reflection" or reoccurrence of a previous

cumbersome and disruptive process

Due to these limitations, the bus topology is typically found only

in the smallest or most austere of installations Some

proprietary manufacturing process control systems use a bustopology, but these aren't covered in this book

For the most part, the bus topology is a historical relic

However, it is something you should be cognizant of in order tounderstand why other topologies are the norm today Early

networks were composed of only a few computers and therewas no need to provide for today's high-bandwidth networksthat use switches and other devices to connect a diverse

collection of computers and other networked devices

Star Topology

The concept behind the star topology is simple Every node onthe LAN has a dedicated cable that is pulled back to a

centralized point, typically a wiring closet All cables are

terminated in a network component within the closet, such as ahub or, more typically today, a switch, which handles the

repeating or switching of traffic out to the other nodes on the