BaseTech / Network+® Guide to Managing & Troubleshooting Networks / Meyers / 225560-9 …books.mhprofessional.com/downloads/products/0072255609/... · 2005-11-17 · Mike Meyers’

CONTENTS

Acknowledgments . . . . . . . . . . . . . . iiiPreface . . . . . . . . . . . . . . . . . . . . . . . . xiii

Chapter 1■ Introduction 1

Who Needs Net+?I Just Want to Learn About Networks! . . . 1

What Is Network+ Certification? . . . . . . . . . 1What Is CompTIA? . . . . . . . . . . . . . . 2The Current Network+

Certification Exam Release . . . . . . . . 2How Do I Become Network+ Certified? . . . . 3

What Are the Tests Like? . . . . . . . . . . . . . 3How Do I Take the Tests? . . . . . . . . . . . 4How Much Does the Test Cost? . . . . . . . . 4

How to Pass the Network+ Exam . . . . . . . . 4Obligate Yourself . . . . . . . . . . . . . . . 5Set Aside the Right Amount of Study Time . . 5Studying for the Test . . . . . . . . . . . . . 5

Chapter 2■ Defining Networking 8The Birth of Networking . . . . . . . . . . . . . . 10

Pre-Networking Issues . . . . . . . . . . . . . 12ARPANET . . . . . . . . . . . . . . . . . . . 14

The Goal of Networking . . . . . . . . . . . . . . 15What to Share? . . . . . . . . . . . . . . . . 15How Do We Share? . . . . . . . . . . . . . . 16

Servers and Clients . . . . . . . . . . . . . . . . . 16Making Shared Resources Usable . . . . . . . . 19

Sharing a Resource . . . . . . . . . . . . . . 19Accessing a Shared Resource . . . . . . . . . 20The Goal of Networking Redux . . . . . . . . 21

Chapter 2 Review . . . . . . . . . . . . . . . . . . 22

Chapter 3■ Building a Network with OSI 26Welcome to MHTechEd! . . . . . . . . . . . . . . 27Let’s Get Physical . . . . . . . . . . . . . . . . . . 28

The NIC . . . . . . . . . . . . . . . . . . . . 30The Two Aspects of Hardware . . . . . . . . . 34

Beyond the Single Wire—Network Software . . 36There’s Frames in Them Thar Frames! . . . . 38Assembly and Disassembly . . . . . . . . . . 40Talking on a Network . . . . . . . . . . . . . 40Standardized Formats . . . . . . . . . . . . . . 41Network Applications . . . . . . . . . . . . . 42How Dana Gets Her Document . . . . . . . . 43

The OSI Seven-Layer Model . . . . . . . . . . . 47Biography of a Model . . . . . . . . . . . . . 47The Seven Layers . . . . . . . . . . . . . . . 47

Chapter 3 Review . . . . . . . . . . . . . . . . . . 51

Chapter 4■ Hardware Concepts 56Topology . . . . . . . . . . . . . . . . . . . . . . 57Hybrid Topologies . . . . . . . . . . . . . . . . . 58Cabling . . . . . . . . . . . . . . . . . . . . . . . 60

Coax . . . . . . . . . . . . . . . . . . . . . . 60Twisted Pair . . . . . . . . . . . . . . . . . . 62Fiber-Optic . . . . . . . . . . . . . . . . . . . 64

Networking Industry Standards—IEEE . . . . . 65Chapter 4 Review . . . . . . . . . . . . . . . . . . 67

Chapter 5■ Ethernet Basics 72Information in a Teeming Sea of Proto-Geeks . . 73How Ethernet Works . . . . . . . . . . . . . . . . 73

Physical Bus . . . . . . . . . . . . . . . . . . 74Organizing the Data: Ethernet Frames . . . . 74

CSMA/CD . . . . . . . . . . . . . . . . . . . . . 76Termination . . . . . . . . . . . . . . . . . . 79Cable Breaks . . . . . . . . . . . . . . . . . . 80

Ethernet Cabling Systems . . . . . . . . . . . . . 8110Base5 . . . . . . . . . . . . . . . . . . . . 8110Base2 . . . . . . . . . . . . . . . . . . . . 84

Extending the Network:Repeaters and Bridges . . . . . . . . . . . . . 87

Repeaters . . . . . . . . . . . . . . . . . . . . 87Bridges . . . . . . . . . . . . . . . . . . . . . 90

Chapter 5 Review . . . . . . . . . . . . . . . . . . 94

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Chapter 6■ Modern Ethernet 9810BaseT . . . . . . . . . . . . . . . . . . . . . . . 99

10BaseT Topology . . . . . . . . . . . . . . . 100UTP . . . . . . . . . . . . . . . . . . . . . . 10210BaseT Limits and Specifications . . . . . . 10410BaseFL . . . . . . . . . . . . . . . . . . . . 104

Connecting Ethernet Segments . . . . . . . . . . 105How Big Can an Ethernet Network Be?

The 5-4-3 Rule . . . . . . . . . . . . . . . 107A Useful Approximation . . . . . . . . . . . 107

High-Speed Ethernet . . . . . . . . . . . . . . . . 109100Base Ethernet . . . . . . . . . . . . . . . 109Gigabit Ethernet . . . . . . . . . . . . . . . . 111Switched Ethernet . . . . . . . . . . . . . . . 111Full-Duplex Ethernet . . . . . . . . . . . . . 113

Chapter 6 Review . . . . . . . . . . . . . . . . . . 115

Chapter 7■ Non-Ethernet Networks 120Token Ring . . . . . . . . . . . . . . . . . . . . . 121Logical Ring Topology . . . . . . . . . . . . . . . 121

Physical Star . . . . . . . . . . . . . . . . . . 123Token Ring vs. Ethernet . . . . . . . . . . . . 126

Gone But Not Forgotten—ARCnet and LocalTalk . . . . . . . . . . . . . 127

ARCnet . . . . . . . . . . . . . . . . . . . . 127LocalTalk . . . . . . . . . . . . . . . . . . . . 128

LAN to WAN—FDDI and ATM . . . . . . . . . 128FDDI . . . . . . . . . . . . . . . . . . . . . . 128ATM . . . . . . . . . . . . . . . . . . . . . . 129Don’t Be an Ethernet Snob! . . . . . . . . . . 129

Chapter 7 Review . . . . . . . . . . . . . . . . . . 130

Chapter 8■ Installing a Physical Network 134Structured Cabling . . . . . . . . . . . . . . . . . 135

Cable Basics—A Star Is Born . . . . . . . . . 136The Basic Star . . . . . . . . . . . . . . . . . 137Structured Cable Network Components . . . . 137Planning the Installation . . . . . . . . . . . 144Installing the Cable . . . . . . . . . . . . . . 148Making Connections . . . . . . . . . . . . . . 150Labeling the Cable . . . . . . . . . . . . . . . 151Testing the Cable Runs . . . . . . . . . . . . 152Getting Physical . . . . . . . . . . . . . . . . 154

Beyond the Basic Star . . . . . . . . . . . . . . . 154Switched Networks . . . . . . . . . . . . . . 155Multispeed Networks . . . . . . . . . . . . . 156

Multiple Floors, Multiple Buildings . . . . . . 157Backbones and Building Entrances . . . . . . 158Complexity Is Cool! . . . . . . . . . . . . . . 158

NICs . . . . . . . . . . . . . . . . . . . . . . . . . 159Ethernet NICs . . . . . . . . . . . . . . . . . 159Token Ring NICs . . . . . . . . . . . . . . . 160Installing NICs . . . . . . . . . . . . . . . . 162Lights . . . . . . . . . . . . . . . . . . . . . 164Direct Cable Connections . . . . . . . . . . . 165

Diagnostics and Repair of Physical Cabling . . . 165Diagnosing Physical Problems . . . . . . . . 165Check Your Lights . . . . . . . . . . . . . . . 166Check the NIC . . . . . . . . . . . . . . . . . 167Cable Testing . . . . . . . . . . . . . . . . . 167Toners . . . . . . . . . . . . . . . . . . . . . 167

Chapter 8 Review . . . . . . . . . . . . . . . . . . 169

Chapter 9■ Wireless Networking 174Wireless Networking Basics . . . . . . . . . . . . 175

Wireless Networking Hardware . . . . . . . . 176Wireless Networking Software . . . . . . . . 177Wireless Network Modes . . . . . . . . . . . 178Wireless Networking Security . . . . . . . . . 179Wireless Networking Speed . . . . . . . . . . 182Wireless Networking Range . . . . . . . . . . 182Wireless Network Broadcasting Frequencies . 183Wireless Networking Media Access Methods . 183

Wireless Networking Standards . . . . . . . . . 184IEEE 802.11-Based Wireless Networking . . . 184Bluetooth . . . . . . . . . . . . . . . . . . . . 187

Configuring Wireless Networking . . . . . . . . 191Wi-Fi and HomeRF . . . . . . . . . . . . . . 191Bluetooth . . . . . . . . . . . . . . . . . . . . 194

Troubleshooting Wireless Networks . . . . . . . 195Troubleshooting Wi-Fi and

HomeRF Wireless Networks . . . . . . . . 196Troubleshooting Bluetooth . . . . . . . . . . . 198

Chapter 9 Review . . . . . . . . . . . . . . . . . . 201

Chapter 10■ Protocols 206Network Protocols . . . . . . . . . . . . . . . . . 207

Protocol Stacks . . . . . . . . . . . . . . . . . 207Protocols by Layer . . . . . . . . . . . . . . . 207

Implementing Protocols . . . . . . . . . . . . . . 214Multiple Protocols . . . . . . . . . . . . . . . 215Binding . . . . . . . . . . . . . . . . . . . . 216Installation . . . . . . . . . . . . . . . . . . . 216Protocol Concepts . . . . . . . . . . . . . . . 218

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NetBIOS/NetBEUI . . . . . . . . . . . . . . . . . 218In the Early Days . . . . . . . . . . . . . . . 218NetBIOS at Session . . . . . . . . . . . . . . 219NetBEUI at Transport . . . . . . . . . . . . . 222NetBIOS/NetBEUI Naming Weaknesses . . . 222Installing NetBIOS/NetBEUI . . . . . . . . . 223NetBIOS/NetBEUI—Fading Away . . . . . . 225

IPX/SPX . . . . . . . . . . . . . . . . . . . . . . . 225NCP/SAP at Session . . . . . . . . . . . . . . 226IPX/SPX at Transport and Network . . . . . 226Installing IPX/SPX . . . . . . . . . . . . . . 227Splitting Protocols I: NetBIOS

over IPX/SPX . . . . . . . . . . . . . . . . 228TCP/IP . . . . . . . . . . . . . . . . . . . . . . . 229

Applications . . . . . . . . . . . . . . . . . . 230TCP at Session . . . . . . . . . . . . . . . . . 230TCP as Transport . . . . . . . . . . . . . . . 231IP at Network . . . . . . . . . . . . . . . . . 231Installing TCP/IP . . . . . . . . . . . . . . . 231Splitting Protocols II: NetBIOS

over TCP/IP . . . . . . . . . . . . . . . . 232Also-Ran Protocols . . . . . . . . . . . . . . . . . 232

AppleTalk . . . . . . . . . . . . . . . . . . . 233DLC . . . . . . . . . . . . . . . . . . . . . . 233

Chapter 10 Review . . . . . . . . . . . . . . . . . 234

Chapter 11■ TCP/IP 238IP Address Basics . . . . . . . . . . . . . . . . . . 239

IP Address Format . . . . . . . . . . . . . . . 239Converting IP Addresses . . . . . . . . . . . 240

Local vs. Remote . . . . . . . . . . . . . . . . . . 243ARP . . . . . . . . . . . . . . . . . . . . . . 245Gateways . . . . . . . . . . . . . . . . . . . . 246

Subnet Masks and Subnetting . . . . . . . . . . . 248Network IDs . . . . . . . . . . . . . . . . . . 248Subnet Mask . . . . . . . . . . . . . . . . . . 249Class Licenses . . . . . . . . . . . . . . . . . 251Classless Subnetting . . . . . . . . . . . . . . 253Special IP Addresses . . . . . . . . . . . . . . 257

Other Critical TCP/IP Settings . . . . . . . . . . 258DNS . . . . . . . . . . . . . . . . . . . . . . 258DHCP . . . . . . . . . . . . . . . . . . . . . 261WINS . . . . . . . . . . . . . . . . . . . . . 261

TCP/UDP/ICMP Ports . . . . . . . . . . . . . . 263TCP . . . . . . . . . . . . . . . . . . . . . . 263UDP . . . . . . . . . . . . . . . . . . . . . . 263ICMP . . . . . . . . . . . . . . . . . . . . . 264

IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . 266Chapter 11 Review . . . . . . . . . . . . . . . . . 267

Chapter 12■ Network Operating Systems 272Categorizing Operating Systems . . . . . . . . . 273

Client/Server vs. Peer-to-Peer . . . . . . . . . 275Security . . . . . . . . . . . . . . . . . . . . 278Security Models . . . . . . . . . . . . . . . . 279

The Major Network Operating Systems . . . . . 284Microsoft Windows . . . . . . . . . . . . . . 284Windows 9x . . . . . . . . . . . . . . . . . . 285Windows NT . . . . . . . . . . . . . . . . . . 288Windows 2000 . . . . . . . . . . . . . . . . . 292Windows XP . . . . . . . . . . . . . . . . . . 298Windows Server 2003 . . . . . . . . . . . . . 299User Profiles . . . . . . . . . . . . . . . . . . 299Novell NetWare . . . . . . . . . . . . . . . . 300UNIX and Linux . . . . . . . . . . . . . . . 301Mac OS . . . . . . . . . . . . . . . . . . . . 303

Creating Servers and Clients . . . . . . . . . . . 304Network Interface . . . . . . . . . . . . . . . 304Protocol . . . . . . . . . . . . . . . . . . . . 305Naming . . . . . . . . . . . . . . . . . . . . 305Server or Client . . . . . . . . . . . . . . . . 306Super User Accounts . . . . . . . . . . . . . 306Groups . . . . . . . . . . . . . . . . . . . . . 306Passwords . . . . . . . . . . . . . . . . . . . 306

Chapter 12 Review . . . . . . . . . . . . . . . . . 309

Chapter 13■ Sharing Resources 314Resource Naming . . . . . . . . . . . . . . . . . 315UNC . . . . . . . . . . . . . . . . . . . . . . . . . 316

URL . . . . . . . . . . . . . . . . . . . . . . 318Permissions . . . . . . . . . . . . . . . . . . . . . 318

Dueling Security Models . . . . . . . . . . . 319Windows 9x Permissions . . . . . . . . . . . 320Windows NT Permissions . . . . . . . . . . . 320Windows 2000/2003 Permissions . . . . . . . 323Windows XP Permissions . . . . . . . . . . . 324NetWare 3.x Rights . . . . . . . . . . . . . . 325NetWare 4.x/5.x/6.x . . . . . . . . . . . . . . 325UNIX/Linux . . . . . . . . . . . . . . . . . . 326Sharing Is Sharing . . . . . . . . . . . . . . . 326

Sharing Resources . . . . . . . . . . . . . . . . . 327Sharing Folders . . . . . . . . . . . . . . . . 327Sharing Printers . . . . . . . . . . . . . . . . 336

Accessing Shared Resources . . . . . . . . . . . 338Accessing Files in Windows . . . . . . . . . . 338Accessing Shared Printers in Windows . . . . 339Troubleshooting Shared Resources . . . . . . 339Access Errors . . . . . . . . . . . . . . . . . 341

Chapter 13 Review . . . . . . . . . . . . . . . . . 342

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Chapter 14■ Going Large with TCP/IP 346DNS . . . . . . . . . . . . . . . . . . . . . . . . . 347

DNS in Detail . . . . . . . . . . . . . . . . . 347The DNS Cache . . . . . . . . . . . . . . . . 355DNS Servers . . . . . . . . . . . . . . . . . . 355Troubleshooting DNS . . . . . . . . . . . . . 357

DHCP . . . . . . . . . . . . . . . . . . . . . . . . 359DHCP in Detail . . . . . . . . . . . . . . . . 360DHCP Servers . . . . . . . . . . . . . . . . . 360Troubleshooting DHCP . . . . . . . . . . . . 362Release or Renew? . . . . . . . . . . . . . . . 362

WINS . . . . . . . . . . . . . . . . . . . . . . . . 363WINS in Detail . . . . . . . . . . . . . . . . 363Configuring WINS Clients . . . . . . . . . . 366Troubleshooting WINS . . . . . . . . . . . . 366

Diagnosing TCP/IP Networks . . . . . . . . . . 366Chapter 14 Review . . . . . . . . . . . . . . . . . 369

Chapter 15■ TCP/IP and the Internet 374Real-World Routers . . . . . . . . . . . . . . . . 375

Static Routes . . . . . . . . . . . . . . . . . . 376SNMP . . . . . . . . . . . . . . . . . . . . . 380Dynamic Routing . . . . . . . . . . . . . . . 381

Connecting to the Internet . . . . . . . . . . . . . 382NAT . . . . . . . . . . . . . . . . . . . . . . 383Proxy Server . . . . . . . . . . . . . . . . . . 384So What’s the Big Difference

Between NAT and a Proxy, Anyway? . . . 385TCP/IP Applications . . . . . . . . . . . . . . . . 385

The Web . . . . . . . . . . . . . . . . . . . . 385E-mail . . . . . . . . . . . . . . . . . . . . . 391FTP . . . . . . . . . . . . . . . . . . . . . . 394Telnet . . . . . . . . . . . . . . . . . . . . . 397

Chapter 15 Review . . . . . . . . . . . . . . . . . 399

Chapter 16■ Remote Connectivity 404SOHO LAN Connections . . . . . . . . . . . . . 405

Telephone Options . . . . . . . . . . . . . . . 405Public Switched Telephone Network . . . . . 405ISDN . . . . . . . . . . . . . . . . . . . . . . 409DSL . . . . . . . . . . . . . . . . . . . . . . 411Cable Modems . . . . . . . . . . . . . . . . . 414Satellite . . . . . . . . . . . . . . . . . . . . 414Which Connection? . . . . . . . . . . . . . . 415

WAN Connections . . . . . . . . . . . . . . . . . 415Copper Carriers: T1 and T3 . . . . . . . . . . 416Fiber Carriers: SONET/SDH and OC . . . . 419Packet Switching . . . . . . . . . . . . . . . . 420

Using Remote Access . . . . . . . . . . . . . . . 421Dial-Up to the Internet . . . . . . . . . . . . 422Private Dial-Up . . . . . . . . . . . . . . . . 429VPNs . . . . . . . . . . . . . . . . . . . . . 431Dedicated Connection . . . . . . . . . . . . . 432Internet Connection Sharing . . . . . . . . . 434

Troubleshooting Remote Access . . . . . . . . . 436Is the Physical Remote

Connection Running? . . . . . . . . . . . 436Is Your Hardware Running? . . . . . . . . . 437Are You Configured? . . . . . . . . . . . . . 437Is the Server Awake? . . . . . . . . . . . . . 437

Chapter 16 Review . . . . . . . . . . . . . . . . . 439

Chapter 17■ Protecting Your Network 444Defining Network Threats . . . . . . . . . . . . . 445

Internal Threats . . . . . . . . . . . . . . . . 445External Threats . . . . . . . . . . . . . . . . 446

Protecting from Internal Threats . . . . . . . . . 450Passwords . . . . . . . . . . . . . . . . . . . 450User Account Control . . . . . . . . . . . . . 451Careful Use of Permissions . . . . . . . . . . 455Policies . . . . . . . . . . . . . . . . . . . . . 455

Protecting a Network from External Threats . . 458Physical Protection . . . . . . . . . . . . . . 459Firewalls . . . . . . . . . . . . . . . . . . . . 459Encryption . . . . . . . . . . . . . . . . . . . 463Public Keys and Certificates . . . . . . . . . . 466VLAN . . . . . . . . . . . . . . . . . . . . . 467

Implementing External Network Security . . . . 469Personal Connections . . . . . . . . . . . . . 469SOHO Connections . . . . . . . . . . . . . . 471Large Network Connections . . . . . . . . . . 471

Chapter 17 Review . . . . . . . . . . . . . . . . . 473

Chapter 18■ Interconnecting Network

Operating Systems 478Connecting to Windows . . . . . . . . . . . . . . 480

Connecting Macintosh to Windows 9xShared Resources . . . . . . . . . . . . . . 481

Connecting UNIX/Linux Systems toWindows 9x Systems . . . . . . . . . . . . 481

Connecting to Windows Workstations(NT 2000 XP) . . . . . . . . . . . . . . . 483

Connecting to Windows Server Systems . . . 484Connecting to NetWare . . . . . . . . . . . . . . 487

Connecting Windows Systems to NetWare . . 487Connecting Macintosh to NetWare . . . . . . 489Native File Access . . . . . . . . . . . . . . . 490

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Connecting to Macintosh . . . . . . . . . . . . . 490Connecting Windows Systems to

Macintosh Serving Systems . . . . . . . . 491Connecting UNIX/Linux Systems

to Macintosh Sharing Systems . . . . . . . 491Connecting to UNIX/Linux . . . . . . . . . . . . 491

Connecting Windows Systems toUNIX/Linux Sharing Systems . . . . . . . 492

Connecting Macintosh Systems toUNIX/Linux Sharing Systems . . . . . . . 492

When All Else Fails, Terminal Emulate! . . . 493Chapter 18 Review . . . . . . . . . . . . . . . . . 495

Chapter 19■ The Perfect Server 500Protection of Data—Fault Tolerance . . . . . . . . 502

RAID . . . . . . . . . . . . . . . . . . . . . 504NAS . . . . . . . . . . . . . . . . . . . . . . 511SAN . . . . . . . . . . . . . . . . . . . . . . 512Tape Backup . . . . . . . . . . . . . . . . . . 512Data Redundancy Is the Key . . . . . . . . . 513

Speed . . . . . . . . . . . . . . . . . . . . . . . . 514Fast NICs . . . . . . . . . . . . . . . . . . . 514Make the Drives Faster . . . . . . . . . . . . 515It’s Not Just Hardware . . . . . . . . . . . . 515

Reliability . . . . . . . . . . . . . . . . . . . . . . 516Good Power . . . . . . . . . . . . . . . . . . 516The Computer Virus . . . . . . . . . . . . . . 517Environment . . . . . . . . . . . . . . . . . . 520Putting Them All Together . . . . . . . . . . 521Nothing’s Perfect . . . . . . . . . . . . . . . 522

Chapter 19 Review . . . . . . . . . . . . . . . . . 523

Chapter 20■ Zen and the

Art of Network Support 528Troubleshooting Tools . . . . . . . . . . . . . . . 529

“Touchy” Tools . . . . . . . . . . . . . . . . 529Hardware Tools . . . . . . . . . . . . . . . . 530Software Tools . . . . . . . . . . . . . . . . . 531Your Toolbox . . . . . . . . . . . . . . . . . . 532

The Troubleshooting Process . . . . . . . . . . . 532Backups . . . . . . . . . . . . . . . . . . . . 533Baselines . . . . . . . . . . . . . . . . . . . . 536Troubleshooting Model . . . . . . . . . . . . 540Troubleshooting as Art—

Mike’s Four-Layer Model . . . . . . . . . . 543Using the Four-Layer Model . . . . . . . . . 545

Troubleshooting Scenarios . . . . . . . . . . . . 546“I Can’t Log In!” . . . . . . . . . . . . . . . 546“I Can’t Get to This Web Site!” . . . . . . . . 547“Our Web Server Is Sluggish!” . . . . . . . . 547“I Can’t See Anything

in Network Neighborhood!” . . . . . . . . 548Troubleshooting Is Fun! . . . . . . . . . . . . 548

Chapter 20 Review . . . . . . . . . . . . . . . . . 549

■ Glossary 555

■ Index 599

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Documents

BaseTech / Network+® Guide to Managing & Troubleshooting Networks / Meyers / 225560-9 …books.mhprofessional.com/downloads/products/0072255609/... · 2005-11-17 · Mike Meyers’