Introduction xxix

Assessment Test li

Chapter 1 Introduction to Networks 1

First Things First: What’s a Network? 2

The Local Area Network (LAN) 3

Common Network Components 5

Wide Area Network (WAN) 7

Network Architecture: Peer-to-Peer or Client-Server? 9

Physical Network Topologies 12

Bus Topology 12

Star Topology 13

Ring Topology 14

Mesh Topology 15

Point-to-Point Topology 16

Point-to-Multipoint Topology 17

Hybrid Topology 18

Topology Selection, Backbones, and Segments 18

Selecting the Right Topology 19

The Network Backbone 20

Network Segments 21

Summary 21

Exam Essentials 21

Written Labs 22

Review Questions 23

Chapter 2 The Open Systems Interconnection Specifications 27

Internetworking Models 28

The Layered Approach 28

Advantages of Reference Models 29

The OSI Reference Model 30

The Application Layer 31

The Presentation Layer 33

The Session Layer 33

The Transport Layer 33

The Network Layer 39

The Data Link Layer 42

The Physical Layer 44

Introduction to Encapsulation 45

Summary 46

Exam Essentials 46

Written Lab 47

Review Questions 48

Chapter 3 Networking Topologies, Connectors, and Wiring Standards 53

Physical Media 55

Coaxial Cable 55

Twisted-Pair Cable 58

Fiber-Optic Cable 61

Media Converters 66

Broadband over Power Line 67

Serial Cables 68

Cable Properties 71

Transmission Speeds 71

Distance 71

Duplex 71

Noise Immunity (Security, EMI) 71

Frequency 72

Wiring Standards 72

568A vs. 568B 73

Straight-Through Cable 75

Crossover Cable 75

T1 Crossover Cable 76

Installing Wiring Distributions 79

Summary 80

Exam Essentials 81

Written Lab 81

Review Questions 83

Chapter 4 The Current Ethernet Specifications 87

Network Basics 88

Ethernet Basics 90

Collision Domain 90

Broadcast Domain 90

CSMA/CD 91

Half- and Full-Duplex Ethernet 92

Ethernet at the Data Link Layer 94

Binary to Decimal and Hexadecimal Conversion 94

Ethernet Addressing 98

Ethernet Frames 98

Channel Bonding 101

Ethernet at the Physical Layer 101

Summary 106

Exam Essentials 107

Written Lab 107

Review Questions 111

Chapter 5 Networking Devices 115

Common Network Connectivity Devices 117

Hub 118

Network Interface Card 118

Bridge 120

Switch 120

Router 121

Firewall 125

Dynamic Host Configuration Protocol Server 126

Other Specialized Devices 129

Multilayer Switch 130

Load Balancer 130

Domain Name Service Server 130

Proxy Server 135

Encryption Devices 136

VPN Concentrator 137

Planning and Implementing a Basic SOHO Network Using Network Segmentation 137

Determining Requirements 138

Switches and Bridges at the Data Link Layer 144

Hubs at the Physical Layer 146

Environmental Considerations 147

Summary 147

Exam Essentials 148

Written Lab 149

Review Questions 150

Chapter 6 Introduction to the Internet Protocol 155

Introducing TCP/IP 157

A Brief History of TCP/IP 157

TCP/IP and the DoD Model 158

The Process/Application Layer Protocols 159

The Host-to-Host Layer Protocols 168

The Internet Layer Protocols 173

Data Encapsulation 178

Summary 182

Exam Essentials 182

Written Lab 183

Review Questions 184

Chapter 7 IP Addressing 189

IP Terminology 190

The Hierarchical IP Addressing Scheme 191

Network Addressing 192

Private IP Addresses 196

IPv4 Address Types 198

Layer 2 Broadcasts 198

Layer 3 Broadcasts 198

Unicast Address 199

Multicast Address 199

Internet Protocol Version 6 (IPv6) 200

Why Do We Need IPv6? 200

The Benefits of and Uses for IPv6 201

IPv6 Addressing and Expressions 202

Shortened Expression 203

Address Types 203

Special Addresses 204

Summary 205

Exam Essentials 205

Written Lab 206

Review Questions 207

Chapter 8 IP Subnetting, Troubleshooting IP, and Introduction to NAT 211

Subnetting Basics 212

How to Create Subnets 213

Subnet Masks 214

Classless Inter-Domain Routing (CIDR) 215

Subnetting Class C Addresses 217

Subnetting Class B Addresses 226

Troubleshooting IP Addressing 234

Determining IP Address Problems 237

Introduction to Network Address Translation (NAT) 241

Types of Network Address Translation 243

NAT Names 243

How NAT Works 244

Summary 245

Exam Essentials 246

Written Labs 246

Review Questions 247

Chapter 9 Introduction to IP Routing 253

Routing Basics 254

The IP Routing Process 257

Testing Your IP Routing Understanding 263

Static and Dynamic Routing 264

Summary 267

Exam Essentials 267

Written Lab 267

Review Questions 269

Chapter 10 Routing Protocols 273

Routing Protocol Basics 274

Administrative Distances 275

Classes of Routing Protocols 277

Distance Vector Routing Protocols 278

Routing Information Protocol (RIP) 279

RIP Version 2 (RIPv2) 280

VLSM and Discontiguous Networks 280

EIGRP 282

Border Gateway Protocol (BGP) 285

Link State Routing Protocols 286

Open Shortest Path First (OSPF) 287

Intermediate System-to-Intermediate System (IS-IS) 289

IPv6 Routing Protocols 290

RIPng 290

EIGRPv6 291

OSPFv3 291

Summary 291

Exam Essentials 292

Written Lab 292

Review Questions 293

Chapter 11 Switching and Virtual LANs 297

Networking Before Layer 2 Switching 298

Switching Services 302

Limitations of Layer 2 Switching 303

Bridging vs. LAN Switching 303

Three Switch Functions at Layer 2 304

Spanning Tree Protocol 309

Spanning-Tree Port States 310

STP Convergence 311

Rapid Spanning Tree Protocol 802.1w 311

Virtual LANs 313

VLAN Basics 313

Quality of Service 316

VLAN Memberships 317

Static VLANs 317

Dynamic VLANs 318

Identifying VLANs 318

VLAN Identification Methods 320

VLAN Trunking Protocol 321

VTP Modes of Operation 322

Configuring VTP 323

Two Additional Advanced Features of Switches 324

Power over Ethernet 324

Port Mirroring/Spanning 326

Summary 328

Exam Essentials 328

Written Lab 329

Review Questions 330

Chapter 12 Wireless Networking 335

Introduction to Wireless Technology 337

The 802.11 Standards 340

2.4GHz (802.11b) 341

2.4GHz (802.11g) 342

5GHz (802.11a) 343

5GHz (802.11h) 344

2.4GHz/5GHz (802.11n) 345

Comparing 802.11 Standards 346

Range Comparisons 346

Wireless Network Components 347

Wireless Access Points 347

Wireless Network Interface Card 348

Wireless Antennas 349

Installing a Wireless Network 351

Ad Hoc Mode: Independent Basic Service Set 351

Infrastructure Mode: Basic Service Set 352

Signal Degradation 354

Installing and Configuring Hardware 355

Wireless Security 362

Open Access 363

Service Set Identifiers, Wired Equivalent Privacy, and Media Access Control Address Authentication 364

Remote Authentication Dial In User Service 365

Temporal Key Integrity Protocol 366

Wi-Fi Protected Access or WPA 2 Pre-Shared Key 367

Summary 368

Exam Essentials 369

Written Lab 369

Review Questions 370

Chapter 13 Authentication and Access Control 375

Security Filtering 377

Access Control Lists 378

Tunneling 379

Encryption 386

Remote Access 390

Managing User Account and Password Security 393

Managing User Accounts 393

Managing Passwords 396

Single Sign-On 400

Multifactor Authentication 400

User-Authentication Methods 400

Public Key Infrastructure (PKI) 401

Kerberos 402

Authentication, Authorization, and Accounting (AAA) 402

Network Access Control (NAC) 405

Challenge Handshake Authentication Protocol (CHAP) 405

MS-CHAP 405

Extensible Authentication Protocol (EAP) 406

Summary 406

Exam Essentials 407

Written Lab 407

Review Questions 409

Chapter 14 Network Threats and Mitigation 413

Recognizing Security Threats 414

Denial of Service 415

Viruses 417

Worms 421

Buffer Overflow 421

Wireless Threats 421

Attackers and Their Tools 424

Social Engineering (Phishing) 427

Understanding Mitigation Techniques 428

Active Detection 429

Passive Detection 429

Proactive Defense 429

Policies and Procedures 430

Security Policies 431

Security Training 436

Patches and Upgrades 437

Updating Antivirus Components 439

Fixing an Infected Computer 441

Summary 441

Exam Essentials 442

Written Lab 442

Review Questions 444

Chapter 15 Physical and Hardware Security 449

Using Hardware and Software Security Devices 450

Defining Firewalls 452

Network-Based Firewalls 453

Host-Based Firewalls 453

Firewall Technologies 453

Access Control Lists 453

Port Security 456

Demilitarized Zone 456

Protocol Switching 457

Dynamic Packet Filtering 459

Proxy Services 460

Firewalls at the Application Layer vs. the Network Layer 461

Stateful vs. Stateless Network Layer Firewalls 462

Application Layer Firewalls 463

Scanning Services and Other Firewall Features 464

Content Filtering 465

Signature Identification 466

Zones 466

Intrusion Detection and Prevention Systems 468

Network-Based IDS 469

Host-Based IDS 471

Vulnerability Scanners 472

VPN Concentrators 473

Understanding Problems Affecting Device Security 474

Physical Security 474

Logical Security Configurations 476

Summary 478

Exam Essentials 479

Written Lab 480

Review Questions 481

Chapter 16 Wide Area Networks 485

What’s a WAN? 488

Defining WAN Terms 488

The Public Switched Telephone Network 489

WAN Connection Types 490

Bandwidth or Speed 492

T-Series Connections 492

The T1 Connection 494

The T3 Connection 494

Transmission Media 495

Wired Connections 495

Dense Wavelength Division Multiplexing 496

Passive Optical Network 496

Wireless Technologies 497

Broadband Services 498

DSL Technology and xDSL 500

Cable Modem 501

Wireless WAN Technologies 503

Cellular WAN 503

WAN Protocols 504

Integrated Services Digital Network 504

Frame Relay Technology 506

Asynchronous Transfer Mode 508

Summary 509

Exam Essentials 509

Written Lab 510

Review Questions 511

Chapter 17 Troubleshooting Tools 515

Protocol Analyzers 517

Throughput Testers 518

Connectivity Software 519

Using Traceroute 520

Using ipconfig and ifconfig 521

Using the ipconfig Utility 521

Using the ifconfig Utility 525

Using the ping Utility 526

Using the Address Resolution Protocol 529

The Windows ARP Table 529

Using the arp Utility 530

Using the nslookup Utility 533

Resolving Names with the Hosts Table 535

Using the Mtr Command 536

Using the route Command 537

Using the route Command Options 538

Some Examples of the route Command 540

Using the nbtstat Utility 540

The –a Switch 541

The –A Switch 543

The –c Switch 543

The –n Switch 544

The –r Switch 544

The –R Switch 545

The –S Switch 545

The –s Switch 546

Using the netstat Utility 546

The –a Switch 549

The –e Switch 550

The –r Switch 551

The –s Switch 551

The –p Switch 551

The –n Switch 553

Using the File Transfer Protocol 554

Starting FTP and Logging In to an FTP Server 555

Downloading Files 557

Uploading Files 559

Using the Telnet Utility 560

How to Enable Telnet in Vista 560

Don’t Use Telnet, Use Secure Shell 561

Summary 562

Exam Essentials 562

Written Lab 563

Review Questions 564

Chapter 18 Software and Hardware Tools 569

Understanding Network Scanners 570

Packet Sniffers 570

Intrusion Detection and Prevention Software 572

Port Scanners 574

Identifying Hardware Tools 576

Cable Testers 577

Protocol Analyzer 579

Certifiers 580

Time-Domain Reflectometer 581

Optical Time-Domain Reflectometer 581

Multimeter 582

Toner Probe 582

Butt Set 584

Punch-Down Tool 585

Cable Stripper/Snips 586

Voltage Event Recorder 587

Environmental Monitors 588

Summary 589

Exam Essentials 589

Written Lab 590

Review Questions 591

Chapter 19 Network Troubleshooting 595

Narrowing Down the Problem 598

Are There Any Cabling Issues? Did You Check

the Super Simple Stuff? 599

Is Hardware or Software Causing the Problem? 603

Is It a Workstation or a Server Problem? 604

Which Segments of the Network Are Affected? 604

Is It Bad Cabling? 604

Troubleshooting Steps 609

Step 1: Identify the Problem 610

Step 2: Establish a Theory of Probable Cause 613

Step 3: Test the Theory to Determine Cause 616

Step 4: Establish a Plan of Action to Resolve the Problem and Identify Potential Effects 618

Step 5: Implement the Solution or Escalate as Necessary 620

Step 6: Verify Full System Functionality and If Applicable Implement Preventative Measures 622

Step 7: Document Findings, Actions, and Outcomes 623

Troubleshooting Tips 623

Don’t Overlook the Small Stuff 624

Prioritize Your Problems 624

Check the Software Configuration 625

Don’t Overlook Physical Conditions 625

Don’t Overlook Cable Problems 626

Check for Viruses 626

Summary 626

Exam Essentials 627

Written Lab 628

Review Questions 629

Chapter 20 Management, Monitoring, and Optimization 635

Managing Network Documentation 638

Using SNMP 638

Schematics and Diagrams 639

Baselines 645

Policies, Procedures, and Regulations 647

Monitoring the Network and Optimizing Its Performance 649

Network Monitoring and Logging 650

Reasons to Optimize Your Network’s Performance 652

How to Optimize Performance 654

Virtual Networking 658

Summary 661

Exam Essentials 662

Written Lab 663

Review Questions 664

Appendix A Answers to Review Questions 669

Chapter 1: Introduction to Networks 670

Chapter 2: The Open Systems Interconnection Specifications 672

Chapter 3: Networking Topologies, Connectors, and Wiring Standards 673

Chapter 4: The Current Ethernet Specifications 675

Chapter 5: Networking Devices 676

Chapter 6: Introduction to the Internet Protocol 677

Chapter 7: IP Addressing 679

Chapter 8: IP Subnetting, Troubleshooting IP, and Introduction to NAT 681

Chapter 9: Introduction to IP Routing 683

Chapter 10: Routing Protocols 684

Chapter 11: Switching and Virtual LANs 686

Chapter 12: Wireless Networking 688

Chapter 13: Authentication and Access Control 689

Chapter 14: Network Threats and Mitigation 691

Chapter 15: Physical and Hardware Security 692

Chapter 16: Wide Area Networks 694

Chapter 17: Troubleshooting Tools 695

Chapter 18: Software and Hardware Tools 697

Chapter 19: Network Troubleshooting 699

Chapter 20: Management, Monitoring, and Optimization 700

Appendix B Answers to Written Labs 703

Chapter 1: Introduction to Networks 704

Chapter 2: The Open Systems Interconnection Specifications 704

Chapter 3: Networking Topologies, Connectors, and Wiring Standards 705

Chapter 4: The Current Ethernet Specifications 705

Chapter 5: Networking Devices 708

Chapter 6: Introduction to the Internet Protocol 708

Chapter 7: IP Addressing 709

Chapter 8: IP Subnetting, Troubleshooting IP, and Introduction to NAT 710

Chapter 9: Introduction to IP Routing 710

Chapter 10: Routing Protocols 711

Chapter 11: Switching and Virtual LANs 711

Chapter 12: Wireless Networking 712

Chapter 13: Authentication and Access Control 712

Chapter 14: Network Threats and Mitigation 712

Chapter 15: Physical and Hardware Security 713

Chapter 16: Wide Area Networks 713

Chapter 17: Troubleshooting Tools 714

Chapter 18: Software and Hardware Tools 714

Chapter 19: Network Troubleshooting 715

Chapter 20: Management, Monitoring, and Optimization 715

Appendix C Subnetting Class A 717

Subnetting Practice Examples: Class A Addresses 718

Practice Example #1A: 255.255.0.0 (/16) 719

Practice Example #2A: 255.255.240.0 (/20) 719

Practice Example #3A: 255.255.255.192 (/26) 720

Subnetting in Your Head: Class A Addresses 720

Written Lab 1 721

Written Lab 2 722

Answers to Written Lab 1 722

Answers to Written Lab 2 723

Appendix D About the Companion CD 725

What You’ll Find on the CD 726

Sybex Test Engine 726

Electronic Flashcards 726

E-book in All Formats 726

CompTIA Network+ Virtual Lab 727

PDF of Glossary of Terms 727

Adobe Reader 727

System Requirements 727

Using CD 728

Troubleshooting 728

Customer Care 728

Index 729

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