Networking AIO desk reference for dummies 2nd ed

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Networking
ALL-IN-ONE DESK REFERENCE

FOR

DUMmIES

‰

2ND

by Doug Lowe

EDITION



Networking
ALL-IN-ONE DESK REFERENCE

FOR

DUMmIES

‰

2ND

by Doug Lowe

EDITION


Networking All-in-One Desk Reference For Dummies®, 2nd Edition
Published by
Wiley Publishing, Inc.
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Copyright © 2005 by Wiley Publishing, Inc., Indianapolis, Indiana
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About the Author
Doug Lowe has written a whole bunch of computer books, including more
than 35 For Dummies books, among them Networking For Dummies, 7th
Edition, Java All-in-One Desk Reference For Dummies, PowerPoint 2003 For
Dummies, and Word 2003 All-in-One Desk Reference For Dummies. He lives in
sunny Fresno, California, where the motto is “No, we aren’t really the Armpit
of California,” with his wife, the youngest of his three daughters, and a goofylooking six-month-old Shar-Pei/Black Lab mix named Lucy. He’s one of those
obsessive-compulsive decorating nuts who puts up tens of thousands of

lights at Christmas and creates computer-controlled Halloween decorations
that rival Disney’s Haunted Mansion. Last year he actually built a pirate ship
in his backyard.



Dedication
To Debbie, Rebecca, Sarah, and Bethany.

Author’s Acknowledgments
I’d like to start by thanking everyone who was involved with the second edition of this book, especially project editor Christopher Morris, who heeded
the Hitchhiker’s Guide creed (“Don’t panic!”) when I was occasionally late with
submissions and who did a great job following through on all the little editorial details needed to put a book of this scope together on time. Thanks also
to Dan DiNicolo, who gave the manuscript a thorough review and offered
many excellent suggestions for improvements, and to copy editors Jean
Rogers and Andy Hollandbeck, who whipped my prose into shape, crossing
all the i’s and dotting all the t’s, or something like that. And, as always, thanks
to all the behind-the-scenes people who chipped in with help I’m not even
aware of.


Publisher’s Acknowledgments
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Publishing and Editorial for Technology Dummies
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Composition Services
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Debbie Stailey, Director of Composition Services


Contents at a Glance
Introduction ................................................................1
Book I: Networking Basics ...........................................7
Chapter 1: Understanding Networks ...............................................................................9
Chapter 2: Understanding Network Protocols and Standards ..................................19
Chapter 3: Understanding Network Hardware ............................................................41
Chapter 4: Understanding Network Operating Systems ............................................59

Book II: Building a Network .......................................75
Chapter 1: Planning a Network ......................................................................................77
Chapter 2: Installing Network Hardware ......................................................................95
Chapter 3: Setting Up a Network Server .....................................................................111
Chapter 4: Configuring Client Computers ..................................................................127
Chapter 5: Configuring Other Network Features .......................................................139
Chapter 6: Verifying Your Network Installation .........................................................151

Book III: Network Administration and Security ..........157
Chapter 1: Help Wanted: Job Description for a Network Administrator ................159
Chapter 2: Security 101 .................................................................................................173
Chapter 3: Managing User Accounts ...........................................................................183
Chapter 4: Firewalls and Virus Protection .................................................................191

Book IV: Network Troubleshooting

and Disaster Planning ..............................................203
Chapter 1: Solving Network Problems ........................................................................205
Chapter 2: Network Performance Anxiety .................................................................219
Chapter 3: Protecting Your Network ...........................................................................229
Chapter 4: Disaster Recovery and Business Continuity Planning ..........................239
Chapter 5: Dealing with Dysfunctional E-Mail ............................................................247

Book V: TCP/IP and the Internet ...............................255
Chapter 1: Introduction to TCP/IP and the Internet .................................................257
Chapter 2: Understanding IP Addresses .....................................................................265
Chapter 3: Using DHCP .................................................................................................283
Chapter 4: Using DNS ....................................................................................................297
Chapter 5: Using FTP .....................................................................................................321
Chapter 6: TCP/IP Tools and Commands ...................................................................343


Book VI: Home Networking .......................................371
Chapter 1: Networking Your Home .............................................................................373
Chapter 2: Connecting to the Internet ........................................................................383
Chapter 3: Home Networking with Windows XP .......................................................397
Chapter 4: Other Ways to Network Your Home .........................................................421
Chapter 5: Using VoIP to Make the Internet Your Phone ..........................................427

Book VII: Wireless Networking .................................431
Chapter 1: Setting Up a Wireless Network .................................................................433
Chapter 2: Securing a Wireless Network ....................................................................453
Chapter 3: Hotspotting .................................................................................................465
Chapter 4: Troubleshooting a Wireless Network ......................................................471
Chapter 5: Wireless Networking with Bluetooth .......................................................477

Book VIII: Windows Server 2003 Reference ...............483
Chapter 1: Installing and Configuring Windows Server 2003 ...................................485
Chapter 2: Managing Windows Server 2003 ...............................................................499
Chapter 3: Dealing with Active Directory ...................................................................515
Chapter 4: Managing Windows User Accounts ..........................................................525
Chapter 5: Managing a File Server ...............................................................................545
Chapter 6: Managing Security ......................................................................................561
Chapter 7: Managing Exchange Server 2003 ..............................................................575
Chapter 8: Troubleshooting .........................................................................................585
Chapter 9: Windows Commands .................................................................................597

Book IX: Linux Networking Reference ........................625
Chapter 1: Installing a Linux Server ............................................................................627
Chapter 2: Getting Used to Linux ................................................................................653
Chapter 3: Basic Linux Network Configuration .........................................................663
Chapter 4: Running DHCP and DNS .............................................................................675
Chapter 5: Doing the Samba Dance .............................................................................691
Chapter 6: Running Apache .........................................................................................705
Chapter 7: Running Sendmail .......................................................................................717
Chapter 8: Linux Commands ........................................................................................727

Book X: Appendixes .................................................755
Appendix A: Directory of Useful Web Sites ................................................................757
Appendix B: Glossary ...................................................................................................765


Table of Contents
Introduction .................................................................1
About This Book ..............................................................................................2
How to Use This Book ....................................................................................3

How This Book Is Organized ..........................................................................3
Book I: Networking Basics ....................................................................3
Book II: Building a Network ..................................................................4
Book III: Network Administration and Security .................................4
Book IV: Network Troubleshooting and Disaster Planning ..............4
Book V: TCP/IP and the Internet ..........................................................4
Book VI: Home Networking ..................................................................5
Book VII: Wireless Networking .............................................................5
Book VIII: Windows Server 2003 Reference .......................................5
Book IX: Linux Networking Reference ................................................5
Icons Used in This Book .................................................................................6
Where to Go from Here ...................................................................................6

Book I: Networking Basics ............................................7
Chapter 1: Understanding Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
What Is a Network? .........................................................................................9
Network building blocks .....................................................................10
Why bother? .........................................................................................11
Of Clients and Servers ..................................................................................12
Dedicated Servers and Peers .......................................................................13
Networks Big and Small ................................................................................14
Network Topology .........................................................................................15
Bus topology ........................................................................................15
Star topology ........................................................................................16
Expanding stars ...................................................................................17
Ring topology .......................................................................................17
Mesh topology .....................................................................................18

Chapter 2: Understanding Network Protocols and Standards . . . . . .19
Understanding Protocols .............................................................................19

Understanding Standards ............................................................................21
The Seven Layers of the OSI Reference Model ..........................................22
The Physical Layer ........................................................................................23
The Data Link Layer ......................................................................................24
How CSMA/CD works ..........................................................................25


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Networking All-in-One Desk Reference For Dummies, 2nd Edition

The Network Layer .......................................................................................26
Logical addressing ...............................................................................26
Routing ..................................................................................................27
The Transport Layer .....................................................................................28
The Session Layer .........................................................................................29
The Presentation Layer ................................................................................30
The Application Layer ..................................................................................30
Following a Packet through the Layers ......................................................31
The Ethernet Protocol ..................................................................................32
Standard Ethernet ...............................................................................32
Fast Ethernet ........................................................................................34
Gigabit Ethernet ...................................................................................35
The TCP/IP Protocol Suite ...........................................................................35
IP ............................................................................................................36
TCP ........................................................................................................37
UDP ........................................................................................................37
The IPX/SPX Protocol Suite .........................................................................38
Other Protocols Worth Knowing About .....................................................39

Chapter 3: Understanding Network Hardware . . . . . . . . . . . . . . . . . . .41
Servers ............................................................................................................41
What’s important in a server .............................................................41
Components of a server computer ...................................................42
Server form factors .............................................................................44
Network Interface Cards ..............................................................................46
Network Cable ...............................................................................................47
Coaxial cable ........................................................................................47
Twisted-pair cable ...............................................................................48
Hubs and Switches ........................................................................................50
Repeaters .......................................................................................................52
Bridges ............................................................................................................54
Routers ...........................................................................................................55
Network Attached Storage ...........................................................................57
Network Printers ...........................................................................................58

Chapter 4: Understanding Network Operating Systems . . . . . . . . . . .59
Network Operating System Features ..........................................................59
Network support .................................................................................59
File sharing services ...........................................................................60
Multitasking ..........................................................................................60
Directory services ...............................................................................62
Security services .................................................................................62
Microsoft’s Server Operating Systems .......................................................63
Windows NT Server 4 ..........................................................................63
Windows 2000 Server ..........................................................................65
Windows Server 2003 ..........................................................................66


Table of Contents

xi

Novell NetWare ..............................................................................................68
NetWare versions ................................................................................68
NetWare 6.5 ..........................................................................................68
Other Server Operating Systems ................................................................69
Linux ......................................................................................................69
Apple Mac OS/X Server .......................................................................70
Peer-to-Peer Networking with Windows ....................................................70
Advantages of peer-to-peer networks ...............................................70
Drawbacks of peer-to-peer networks ................................................71
Windows XP .........................................................................................72
Older Windows versions ....................................................................73

Book II: Building a Network ........................................75
Chapter 1: Planning a Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77
Making a Network Plan .................................................................................77
Being Purposeful ...........................................................................................78
Taking Stock ...................................................................................................79
What you need to know ......................................................................79
Programs that gather information for you .......................................82
To Dedicate or Not to Dedicate: That Is the Question .............................83
Types of Servers ............................................................................................83
File servers ...........................................................................................83
Print servers ........................................................................................84
Web servers ..........................................................................................84
Mail servers ..........................................................................................84
Database servers .................................................................................85
Choosing a Server Operating System .........................................................85

Planning the Infrastructure ..........................................................................85
Drawing Diagrams .........................................................................................86
Sample Network Plans ..................................................................................87
Building a small network: California Sport Surface, Inc. ................87
Connecting two networks: Creative Course Development, Inc. ....89
Improving network performance: DCH Accounting ........................91

Chapter 2: Installing Network Hardware . . . . . . . . . . . . . . . . . . . . . . . .95
Installing a Network Interface Card ............................................................95
Installing Twisted-Pair Cable .......................................................................97
Cable categories ..................................................................................97
What’s with the pairs? ........................................................................98
To shield or not to shield ...................................................................98
When to use plenum cable .................................................................99
Sometimes solid, sometimes stranded .............................................99
Installation guidelines .......................................................................100
Getting the tools that you need .......................................................101
Pinouts for twisted-pair cables ........................................................102
Attaching RJ-45 connectors .............................................................103


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Networking All-in-One Desk Reference For Dummies, 2nd Edition

Crossover cables ...............................................................................105
Wall jacks and patch panels .............................................................105
Installing Coaxial Cable ..............................................................................107
Attaching a BNC connector to coaxial cable .................................107
Installing Hubs and Switches .....................................................................109

Daisy-chaining hubs or switches .....................................................109

Chapter 3: Setting Up a Network Server . . . . . . . . . . . . . . . . . . . . . . .111
The Many Ways to Install a Network Operating System ........................111
Full install versus upgrade ...............................................................111
Installing over the network ..............................................................113
Automated and remote installations ..............................................113
Gathering Your Stuff ....................................................................................113
A capable server computer ..............................................................114
The server operating system ...........................................................114
Other software ...................................................................................115
A working Internet connection ........................................................115
A good book .......................................................................................115
Making Informed Decisions .......................................................................116
Final Preparations .......................................................................................117
Installing a Network Operating System ....................................................117
Phase 1: Collecting Information .......................................................118
Phase 2: Dynamic Update .................................................................118
Phase 3: Preparing Installation ........................................................119
Phase 4: Installing Windows .............................................................119
Phase 5: Finalizing Installation ........................................................120
Life after Setup ............................................................................................120
Logging on ..........................................................................................120
Activating Windows ..........................................................................120
Service packs .....................................................................................123
Testing the installation .....................................................................123
Configuring Server Roles ............................................................................124

Chapter 4: Configuring Client Computers . . . . . . . . . . . . . . . . . . . . . . .127
Configuring Network Connections ............................................................127

Windows XP and Windows 2000 ......................................................128
Windows 9x ........................................................................................132
Configuring Client Computer Identification .............................................132
Windows XP and Windows 2000 ......................................................133
Windows 9x ........................................................................................134
Configuring Network Domain Logon ........................................................135
Windows XP and Windows 2000 ......................................................135
Windows 9x ........................................................................................136


Table of Contents

xiii

Chapter 5: Configuring Other Network Features . . . . . . . . . . . . . . . .139
Configuring Network Printers ....................................................................139
Adding a network printer .................................................................139
Accessing a network printer using a Web interface ......................141
Configuring Internet Access ......................................................................143
Configuring clients for DHCP ...........................................................143
Disabling dialup connections ..........................................................146
Using Internet Connection Sharing .................................................147
Mapping Network Drives ............................................................................147

Chapter 6: Verifying Your Network Installation . . . . . . . . . . . . . . . . .151
Is the Computer Connected to the Network? ..........................................151
Is the Network Configuration Working? ...................................................152
Can the Computers Ping Each Other? ......................................................154
Can You Log On? .........................................................................................154
Are Network Drives Mapped Correctly? ..................................................155

Do Network Printers Work? .......................................................................155

Book III: Network Administration and Security ...........157
Chapter 1: Help Wanted: Job Description
for a Network Administrator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159
Figuring Out What Network Administrators Do ......................................159
Choosing the Part-Time Administrator ....................................................161
Completing Routine Chores .......................................................................162
Managing Network Users ...........................................................................163
Patching Things Up .....................................................................................164
Discovering Software Tools for Network Administrators ......................164
Building a Library .......................................................................................166
Certification .................................................................................................167
CompTIA .............................................................................................168
Microsoft ............................................................................................168
Novell ..................................................................................................169
Cisco ....................................................................................................169
Gurus Need Gurus, Too ..............................................................................170
Helpful Bluffs and Excuses .........................................................................170

Chapter 2: Security 101 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .173
Do You Need Security? ...............................................................................174
Two Approaches to Security .....................................................................175
Physical Security: Locking Your Doors ....................................................175
Securing User Accounts .............................................................................177


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Networking All-in-One Desk Reference For Dummies, 2nd Edition

Obfuscating your usernames ...........................................................177
Using passwords wisely ....................................................................178
A Password Generator For Dummies ..............................................179
Securing the Administrator account ...............................................180
Hardening Your Network ............................................................................180
Using a firewall ...................................................................................180
Disabling unnecessary services ......................................................180
Patching your servers .......................................................................181
Securing Your Users ....................................................................................181

Chapter 3: Managing User Accounts . . . . . . . . . . . . . . . . . . . . . . . . . .183
User Accounts .............................................................................................183
Built-In Accounts .........................................................................................184
The Administrator account ..............................................................184
The Guest account ............................................................................185
Service accounts ...............................................................................185
User Rights ...................................................................................................186
Permissions (Who Gets What) ..................................................................187
Group Therapy ............................................................................................188
User Profiles .................................................................................................189
Logon Scripts ...............................................................................................190

Chapter 4: Firewalls and Virus Protection . . . . . . . . . . . . . . . . . . . . . .191
Firewalls .......................................................................................................191
The Many Types of Firewalls .....................................................................193
Packet filtering ...................................................................................193
Stateful packet inspection (SPI) ......................................................195
Circuit-level gateway .........................................................................195
Application gateway ..........................................................................195

The Built-In Firewall in Windows XP .........................................................196
Virus Protection ..........................................................................................197
What is a virus? .................................................................................198
Antivirus programs ...........................................................................199
Safe computing ..................................................................................200
Using the Windows XP Security Center ....................................................200

Book IV: Network Troubleshooting
and Disaster Planning ..............................................203
Chapter 1: Solving Network Problems . . . . . . . . . . . . . . . . . . . . . . . . .205
When Bad Things Happen to Good Computers ......................................206
How to Fix Dead Computers ......................................................................207
Ways to Check a Network Connection .....................................................208


Table of Contents

xv

A Bunch of Error Messages Just Flew By! ................................................209
Double-Checking Your Network Settings .................................................210
Using the Windows Networking Troubleshooter ....................................210
Time to Experiment ....................................................................................211
Who’s on First ..............................................................................................212
How to Restart a Client Computer ............................................................213
Restarting Network Services .....................................................................214
How to Restart a Network Server .............................................................216
Looking at Event Logs ................................................................................217
Documenting Your Trials and Tribulations .............................................218

Chapter 2: Network Performance Anxiety . . . . . . . . . . . . . . . . . . . . . .219
Why Administrators Hate Performance Problems ................................219
What Exactly Is a Bottleneck? ....................................................................220
The Five Most Common Network Bottlenecks ........................................222
The hardware inside your servers ..................................................222
The server’s configuration options .................................................222
Servers that do too much .................................................................223
The network infrastructure ..............................................................223
Malfunctioning components ............................................................224
Tuning Your Network the Compulsive Way .............................................224
Monitoring Network Performance ............................................................225
More Performance Tips ..............................................................................227

Chapter 3: Protecting Your Network . . . . . . . . . . . . . . . . . . . . . . . . . . .229
Backing Up Your Data .................................................................................229
All About Tapes and Tape Drives ..............................................................230
Backup Software ..........................................................................................230
Types of Backups ........................................................................................231
Normal backups .................................................................................232
Copy backups ....................................................................................232
Daily backups .....................................................................................233
Incremental backups .........................................................................233
Differential backups ..........................................................................234
Local versus Network Backups .................................................................234
How Many Sets of Backups Should You Keep? ........................................235
A Word About Tape Reliability ..................................................................236
About Cleaning the Heads ..........................................................................237
Backup Security ...........................................................................................238

Chapter 4: Disaster Recovery and Business Continuity

Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .239
Assessing Different Types of Disasters ....................................................240
Environmental disasters ...................................................................240
Deliberate disasters ..........................................................................241
Disruption of services .......................................................................241


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Networking All-in-One Desk Reference For Dummies, 2nd Edition

Equipment failure ..............................................................................242
Other disasters ..................................................................................242
Analyzing the Impact of a Disaster ...........................................................242
Developing a Business Continuity Plan ....................................................243
Holding a Fire Drill ......................................................................................244

Chapter 5: Dealing with Dysfunctional E-Mail . . . . . . . . . . . . . . . . . .247
Coping with the Dreaded Nondelivery Report ........................................247
Viewing the Mail Server’s Error Logs .......................................................249
Checking Out a Remote Mail System ........................................................249
Discovering the mail server for a domain ......................................249
Verifying a mail server ......................................................................251
Viewing Message Headers ..........................................................................252
Help! I’ve Been Blacklisted! ........................................................................253

Book V: TCP/IP and the Internet ................................255
Chapter 1: Introduction to TCP/IP and the Internet . . . . . . . . . . . . . . .257
What Is the Internet? ..................................................................................257
A Little Internet History .............................................................................259

TCP/IP Standards and RFCs .......................................................................260
The TCP/IP Protocol Framework ..............................................................262
Network Interface layer ....................................................................262
Network layer ....................................................................................263
Transport layer ..................................................................................263
Application layer ...............................................................................263

Chapter 2: Understanding IP Addresses . . . . . . . . . . . . . . . . . . . . . . . .265
Understanding Binary ................................................................................265
Counting by ones ...............................................................................265
Doing the logic thing .........................................................................267
Working with the binary Windows Calculator ...............................268
Introducing IP Addresses ...........................................................................270
Networks and hosts ..........................................................................270
The dotted-decimal dance ...............................................................271
Classifying IP Addresses ............................................................................272
Class A addresses ..............................................................................273
Class B addresses ..............................................................................274
Class C addresses ..............................................................................275
Subnetting ....................................................................................................275
Subnets ...............................................................................................276
Subnet masks .....................................................................................277
Network prefix notation ....................................................................278


Table of Contents

xvii

Default subnets ..................................................................................278

The great subnet roundup ...............................................................279
IP block parties ..................................................................................279
Private and public addresses ..........................................................280
Network Address Translation ....................................................................281

Chapter 3: Using DHCP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .283
Understanding DHCP ..................................................................................283
Configuration information provided by DHCP ..............................284
DHCP servers .....................................................................................284
How DHCP actually works ................................................................285
Understanding Scopes ................................................................................286
Feeling excluded? ..............................................................................286
Reservations suggested ....................................................................287
How long to lease? .............................................................................288
Working with a DHCP Server .....................................................................289
Installing and configuring a DHCP server ......................................289
Managing a DHCP server ..................................................................293
How to Configure a Windows DHCP Client ..............................................295
Automatic Private IP Addressing ....................................................295
Renewing and releasing leases ........................................................295

Chapter 4: Using DNS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .297
Understanding DNS Names ........................................................................297
Domains and domain names ............................................................298
Fully qualified domain names ..........................................................300
Top-Level Domains ......................................................................................300
Generic domains ................................................................................300
Geographic domains .........................................................................301
The Hosts File ..............................................................................................303
Understanding DNS Servers and Zones ...................................................305

Zones ...................................................................................................306
Primary and secondary servers ......................................................307
Root servers .......................................................................................308
Caching ...............................................................................................310
Understanding DNS Queries ......................................................................311
A real-life example .............................................................................311
Zone Files and Resource Records .............................................................312
SOA records .......................................................................................314
NS records ..........................................................................................315
A records ............................................................................................315
CNAME records ..................................................................................316
PTR records ........................................................................................316
MX records .........................................................................................316


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Reverse Lookup Zones ...............................................................................317
Working with the Windows DNS Server ...................................................318
How to Configure a Windows DNS Client .................................................320

Chapter 5: Using FTP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .321
Introducing FTP ...........................................................................................321
Configuring an FTP Server .........................................................................322
Installing FTP .....................................................................................322
Changing the FTP site properties ....................................................323
Adding content to your FTP site .....................................................325
Adding an additional FTP site ..........................................................326

Accessing an FTP Site with a Browser ......................................................326
Using an FTP Command-Line Client ..........................................................327
FTP Command and Subcommand Reference ..........................................330
The FTP command ............................................................................330
! (Escape) ............................................................................................331
? (Help) ...............................................................................................331
Append ................................................................................................331
ASCII ....................................................................................................332
Bell .......................................................................................................332
Binary ..................................................................................................332
Bye .......................................................................................................332
Cd ........................................................................................................332
Close ....................................................................................................333
Debug ..................................................................................................333
Delete ..................................................................................................333
Dir ........................................................................................................334
Disconnect ..........................................................................................334
Get .......................................................................................................334
Glob .....................................................................................................335
Hash ....................................................................................................335
Help .....................................................................................................335
Lcd .......................................................................................................335
Literal ..................................................................................................336
Ls .........................................................................................................336
Mdelete ...............................................................................................336
Mdir .....................................................................................................336
Mget .....................................................................................................337
Mkdir ...................................................................................................337
Mls .......................................................................................................337
Mput ....................................................................................................338

Open ....................................................................................................338
Prompt ................................................................................................338
Put .......................................................................................................338


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Pwd ......................................................................................................339
Quit ......................................................................................................339
Quote ...................................................................................................339
Recv .....................................................................................................340
Remotehelp ........................................................................................340
Rename ...............................................................................................340
Rmdir ..................................................................................................340
Send .....................................................................................................341
Status ..................................................................................................341
Trace ...................................................................................................341
Type ....................................................................................................342
User .....................................................................................................342
Verbose ...............................................................................................342

Chapter 6: TCP/IP Tools and Commands . . . . . . . . . . . . . . . . . . . . . . . .343
Arp ................................................................................................................343
Hostname .....................................................................................................344
IPConfig ........................................................................................................344
Displaying basic IP configuration ....................................................345
Displaying detailed configuration information ..............................345
Renewing an IP lease .........................................................................346

Releasing an IP lease .........................................................................347
Flushing the local DNS cache ...........................................................347
Nbtstat ..........................................................................................................348
Netdiag .........................................................................................................349
Netstat ..........................................................................................................351
Displaying connections ....................................................................351
Displaying interface statistics ..........................................................352
Nslookup ......................................................................................................354
Looking up an IP address .................................................................354
Using Nslookup subcommands .......................................................355
Displaying DNS records ....................................................................356
Locating the mail server for an e-mail address .............................357
Taking a ride through DNS-Land ......................................................358
PathPing .......................................................................................................361
Ping ...............................................................................................................362
Route .............................................................................................................363
Displaying the routing table .............................................................364
Modifying the routing table ..............................................................365
Tracert ..........................................................................................................366
Winipcfg ........................................................................................................368


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Networking All-in-One Desk Reference For Dummies, 2nd Edition

Book VI: Home Networking .......................................371
Chapter 1: Networking Your Home . . . . . . . . . . . . . . . . . . . . . . . . . . . .373
Deciding Why You Need a Network ..........................................................373
Choosing How to Network Your Home .....................................................375

Phone line networks .........................................................................375
Power line networks .........................................................................375
USB networks .....................................................................................376
Wireless networks .............................................................................376
Cabled Ethernet .................................................................................378
Strange Things to Add to Your Network ..................................................379
A Home Network Example .........................................................................380

Chapter 2: Connecting to the Internet . . . . . . . . . . . . . . . . . . . . . . . . . .383
Some General Tips ......................................................................................383
Deciding How to Connect ...........................................................................384
Choosing dialup .................................................................................384
Choosing cable ..................................................................................386
Choosing DSL .....................................................................................388
Choosing a Provider ...................................................................................390
Online services ..................................................................................392
Basic Internet service providers .....................................................392
Getting Internet Explorer ...........................................................................393
Setting Up Your Internet Connection ........................................................395

Chapter 3: Home Networking with Windows XP . . . . . . . . . . . . . . . .397
Using the Windows XP Network Setup Wizard ........................................397
Deciding on computer names ..........................................................398
Running the wizard ...........................................................................398
Setting Up a Network without the Wizard ................................................401
Configuring the network connection ..............................................401
Identifying your computer ...............................................................404
Sharing Hard Drive Files .............................................................................405
Understanding hard drive sharing ..................................................405
Four good uses for a shared folder .................................................406

Designating a shared drive or folder ..............................................406
Oh, the Network Places You’ll Go .............................................................408
Mapping Network Drives ............................................................................410
Sharing a Printer .........................................................................................412
Designating a shared printer ...........................................................412
Adding a network printer .................................................................414
Using a network printer ....................................................................415


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Sharing an Internet Connection ................................................................415
Setting up a firewall ...........................................................................416
Using a broadband router ................................................................418
Managing Your Home Network ..................................................................419

Chapter 4: Other Ways to Network Your Home . . . . . . . . . . . . . . . . . .421
Networking Over Your Phone Lines ..........................................................421
Networking Over Power Lines ...................................................................423
Automating Your Home ..............................................................................424

Chapter 5: Using VoIP to Make the Internet Your Phone . . . . . . . . . .427
Understanding VoIP ....................................................................................427
Advantages of VoIP .....................................................................................428
Disadvantages of VoIP ................................................................................429
Popular VoIP Providers ..............................................................................430

Book VII: Wireless Networking ..................................431

Chapter 1: Setting Up a Wireless Network . . . . . . . . . . . . . . . . . . . . .433
Diving into Wireless Networking ...............................................................434
A Little High School Electronics ................................................................434
Waves and frequencies .....................................................................435
Wavelength and antennas ................................................................436
Spectrums and the FCC ....................................................................436
Eight-Oh-Two-Dot-Eleventy Something? (Or, Understanding
Wireless Standards) ................................................................................438
Home on the Range .....................................................................................439
Wireless Network Adapters .......................................................................440
Wireless Access Points ...............................................................................442
Infrastructure mode .........................................................................442
Multifunction WAPs ...........................................................................443
Roaming ........................................................................................................444
Wireless bridging ...............................................................................445
Ad-hoc networks ................................................................................445
Configuring a Wireless Access Point ........................................................445
Basic configuration options .............................................................446
DHCP configuration ...........................................................................448
Configuring Windows XP for Wireless Networking .................................449
Using a Wireless Network with Windows XP ...........................................450

Chapter 2: Securing a Wireless Network . . . . . . . . . . . . . . . . . . . . . .453
Understanding Wireless Security Threats ...............................................453
Intruders .............................................................................................454
Freeloaders .........................................................................................455


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Eavesdroppers ...................................................................................455
Spoilers ...............................................................................................456
Rogue access points .........................................................................456
What About Wardrivers and Warchalkers? ..............................................457
Wardriving ..........................................................................................457
Warchalking ........................................................................................458
Securing Your Wireless Network ...............................................................459
Changing the password ....................................................................459
Securing the SSID ...............................................................................460
Enabling WEP .....................................................................................461
Using WPA ..........................................................................................462
Using MAC address filtering .............................................................463
Placing your access points outside the firewall ............................464

Chapter 3: Hotspotting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .465
What Is a Hotspot? ......................................................................................465
What’s So Great about Hotspots? .............................................................466
Safe Hotspotting ..........................................................................................466
Free Hotspots ..............................................................................................467
Fee-Based Hotspots ....................................................................................467
T-Mobile ..............................................................................................468
Boingo .................................................................................................468
Wayport ..............................................................................................469
SBC FreedomLink ..............................................................................469
Setting Up Your Own Hotspot ....................................................................470

Chapter 4: Troubleshooting a Wireless Network . . . . . . . . . . . . . . . .471
Checking for Obvious Problems ................................................................471

Pinpointing the Problem ............................................................................472
Changing Channels .....................................................................................472
Fiddle with the Antennas ...........................................................................473
Adding Another Access Point ....................................................................474
Help! I Forgot My Router’s Password! .......................................................475

Chapter 5: Wireless Networking with Bluetooth . . . . . . . . . . . . . . . .477
Understanding Bluetooth ...........................................................................477
Bluetooth Technical Stuff ...........................................................................478
How to Add Bluetooth to Your Computer ................................................479
Using Bluetooth in Windows XP ................................................................480
Installing a USB Bluetooth Adapter ..........................................................480
Enabling Discovery .....................................................................................480
Installing a Bluetooth Mouse or Keyboard ..............................................481