ContentsForeword xxv

Introduction xxix

Assessment Test li

Chapter 1 Introduction to Networks 1

First Things First: What’s a Network? 2The Local Area Network (LAN) 3Common Network Components 5Wide Area Network (WAN) 7Network Architecture: Peer-to-Peer or Client-Server? 9

Physical Network Topologies 12Bus Topology 12Star Topology 13Ring Topology 14Mesh Topology 15Point-to-Point Topology 16Point-to-Multipoint Topology 17Hybrid Topology 18

Topology Selection, Backbones, and Segments 18Selecting the Right Topology 19The Network Backbone 20Network Segments 21

Summary 21Exam Essentials 21Written Labs 22Review Questions 23

Chapter 2 The Open Systems Interconnection Specifications 27

Internetworking Models 28The Layered Approach 28Advantages of Reference Models 29

The OSI Reference Model 30The Application Layer 31The Presentation Layer 33The Session Layer 33The Transport Layer 33The Network Layer 39The Data Link Layer 42The Physical Layer 44

Introduction to Encapsulation 45

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Summary 46Exam Essentials 46Written Lab 47Review Questions 48

Chapter 3 Networking Topologies, Connectors, and Wiring Standards 53

Physical Media 55Coaxial Cable 55Twisted-Pair Cable 58Fiber-Optic Cable 61Media Converters 66Broadband over Power Line 67Serial Cables 68

Cable Properties 71Transmission Speeds 71Distance 71Duplex 71Noise Immunity (Security, EMI) 71Frequency 72

Wiring Standards 72568A vs. 568B 73Straight-Through Cable 75Crossover Cable 75T1 Crossover Cable 76

Installing Wiring Distributions 79Summary 80Exam Essentials 81Written Lab 81Review Questions 83

Chapter 4 The Current Ethernet Specifications 87

Network Basics 88Ethernet Basics 90

Collision Domain 90Broadcast Domain 90CSMA/CD 91Half- and Full-Duplex Ethernet 92

Ethernet at the Data Link Layer 94Binary to Decimal and Hexadecimal Conversion 94Ethernet Addressing 98Ethernet Frames 98Channel Bonding 101

Ethernet at the Physical Layer 101Summary 106

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Contents xiii

Exam Essentials 107Written Lab 107Review Questions 111

Chapter 5 Networking Devices 115

Common Network Connectivity Devices 117Hub 118Network Interface Card 118Bridge 120Switch 120Router 121Firewall 125Dynamic Host Configuration Protocol Server 126

Other Specialized Devices 129Multilayer Switch 130Load Balancer 130Domain Name Service Server 130Proxy Server 135Encryption Devices 136VPN Concentrator 137

Planning and Implementing a Basic SOHO Network Using Network Segmentation 137

Determining Requirements 138Switches and Bridges at the Data Link Layer 144Hubs at the Physical Layer 146Environmental Considerations 147

Summary 147Exam Essentials 148Written Lab 149Review Questions 150

Chapter 6 Introduction to the Internet Protocol 155

Introducing TCP/IP 157A Brief History of TCP/IP 157TCP/IP and the DoD Model 158The Process/Application Layer Protocols 159The Host-to-Host Layer Protocols 168The Internet Layer Protocols 173

Data Encapsulation 178Summary 182Exam Essentials 182Written Lab 183Review Questions 184

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Chapter 7 IP Addressing 189

IP Terminology 190The Hierarchical IP Addressing Scheme 191

Network Addressing 192Private IP Addresses 196

IPv4 Address Types 198Layer 2 Broadcasts 198Layer 3 Broadcasts 198Unicast Address 199Multicast Address 199

Internet Protocol Version 6 (IPv6) 200Why Do We Need IPv6? 200The Benefits of and Uses for IPv6 201IPv6 Addressing and Expressions 202Shortened Expression 203Address Types 203Special Addresses 204

Summary 205Exam Essentials 205Written Lab 206Review Questions 207

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

Subnetting Basics 212How to Create Subnets 213Subnet Masks 214Classless Inter-Domain Routing (CIDR) 215Subnetting Class C Addresses 217Subnetting Class B Addresses 226

Troubleshooting IP Addressing 234Determining IP Address Problems 237

Introduction to Network Address Translation (NAT) 241Types of Network Address Translation 243NAT Names 243How NAT Works 244

Summary 245Exam Essentials 246Written Labs 246Review Questions 247

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Contents xv

Chapter 9 Introduction to IP Routing 253

Routing Basics 254The IP Routing Process 257Testing Your IP Routing Understanding 263Static and Dynamic Routing 264Summary 267Exam Essentials 267Written Lab 267Review Questions 269

Chapter 10 Routing Protocols 273

Routing Protocol Basics 274Administrative Distances 275Classes of Routing Protocols 277

Distance Vector Routing Protocols 278Routing Information Protocol (RIP) 279RIP Version 2 (RIPv2) 280VLSM and Discontiguous Networks 280EIGRP 282Border Gateway Protocol (BGP) 285

Link State Routing Protocols 286Open Shortest Path First (OSPF) 287Intermediate System-to-Intermediate System (IS-IS) 289

IPv6 Routing Protocols 290RIPng 290EIGRPv6 291OSPFv3 291

Summary 291Exam Essentials 292Written Lab 292Review Questions 293

Chapter 11 Switching and Virtual LANs 297

Networking Before Layer 2 Switching 298Switching Services 302

Limitations of Layer 2 Switching 303Bridging vs. LAN Switching 303Three Switch Functions at Layer 2 304

Spanning Tree Protocol 309Spanning-Tree Port States 310STP Convergence 311Rapid Spanning Tree Protocol 802.1w 311

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Virtual LANs 313VLAN Basics 313Quality of Service 316VLAN Memberships 317Static VLANs 317Dynamic VLANs 318Identifying VLANs 318VLAN Identification Methods 320

VLAN Trunking Protocol 321VTP Modes of Operation 322Configuring VTP 323

Two Additional Advanced Features of Switches 324Power over Ethernet 324Port Mirroring/Spanning 326

Summary 328Exam Essentials 328Written Lab 329Review Questions 330

Chapter 12 Wireless Networking 335

Introduction to Wireless Technology 337The 802.11 Standards 340

2.4GHz (802.11b) 3412.4GHz (802.11g) 3425GHz (802.11a) 3435GHz (802.11h) 3442.4GHz/5GHz (802.11n) 345

Comparing 802.11 Standards 346Range Comparisons 346

Wireless Network Components 347Wireless Access Points 347Wireless Network Interface Card 348Wireless Antennas 349

Installing a Wireless Network 351Ad Hoc Mode: Independent Basic Service Set 351Infrastructure Mode: Basic Service Set 352Signal Degradation 354Installing and Configuring Hardware 355

Wireless Security 362Open Access 363Service Set Identifiers, Wired Equivalent Privacy,

and Media Access Control Address Authentication 364Remote Authentication Dial In User Service 365

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Temporal Key Integrity Protocol 366Wi-Fi Protected Access or WPA 2 Pre-Shared Key 367

Summary 368Exam Essentials 369Written Lab 369Review Questions 370

Chapter 13 Authentication and Access Control 375

Security Filtering 377Access Control Lists 378Tunneling 379Encryption 386Remote Access 390

Managing User Account and Password Security 393Managing User Accounts 393Managing Passwords 396Single Sign-On 400Multifactor Authentication 400

User-Authentication Methods 400Public Key Infrastructure (PKI) 401Kerberos 402Authentication, Authorization, and Accounting (AAA) 402Network Access Control (NAC) 405Challenge Handshake Authentication Protocol (CHAP) 405MS-CHAP 405Extensible Authentication Protocol (EAP) 406

Summary 406Exam Essentials 407Written Lab 407Review Questions 409

Chapter 14 Network Threats and Mitigation 413

Recognizing Security Threats 414Denial of Service 415Viruses 417Worms 421Buffer Overflow 421Wireless Threats 421Attackers and Their Tools 424Social Engineering (Phishing) 427

Understanding Mitigation Techniques 428Active Detection 429Passive Detection 429Proactive Defense 429

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Policies and Procedures 430Security Policies 431Security Training 436Patches and Upgrades 437Updating Antivirus Components 439Fixing an Infected Computer 441

Summary 441Exam Essentials 442Written Lab 442Review Questions 444

Chapter 15 Physical and Hardware Security 449

Using Hardware and Software Security Devices 450Defining Firewalls 452

Network-Based Firewalls 453Host-Based Firewalls 453

Firewall Technologies 453Access Control Lists 453Port Security 456Demilitarized Zone 456Protocol Switching 457Dynamic Packet Filtering 459Proxy Services 460

Firewalls at the Application Layer vs. the Network Layer 461Stateful vs. Stateless Network Layer Firewalls 462Application Layer Firewalls 463

Scanning Services and Other Firewall Features 464Content Filtering 465Signature Identification 466Zones 466

Intrusion Detection and Prevention Systems 468Network-Based IDS 469Host-Based IDS 471Vulnerability Scanners 472

VPN Concentrators 473Understanding Problems Affecting Device Security 474

Physical Security 474Logical Security Configurations 476

Summary 478Exam Essentials 479Written Lab 480Review Questions 481

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Contents xix

Chapter 16 Wide Area Networks 485

What’s a WAN? 488Defining WAN Terms 488The Public Switched Telephone Network 489WAN Connection Types 490Bandwidth or Speed 492

T-Series Connections 492The T1 Connection 494The T3 Connection 494

Transmission Media 495Wired Connections 495Dense Wavelength Division Multiplexing 496Passive Optical Network 496Wireless Technologies 497

Broadband Services 498DSL Technology and xDSL 500Cable Modem 501

Wireless WAN Technologies 503Cellular WAN 503

WAN Protocols 504Integrated Services Digital Network 504Frame Relay Technology 506Asynchronous Transfer Mode 508

Summary 509Exam Essentials 509Written Lab 510Review Questions 511

Chapter 17 Troubleshooting Tools 515

Protocol Analyzers 517Throughput Testers 518Connectivity Software 519Using Traceroute 520Using ipconfig and ifconfig 521

Using the ipconfig Utility 521Using the ifconfig Utility 525

Using the ping Utility 526Using the Address Resolution Protocol 529

The Windows ARP Table 529Using the arp Utility 530

Using the nslookup Utility 533Resolving Names with the Hosts Table 535Using the Mtr Command 536

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xx Contents

Using the route Command 537Using the route Command Options 538Some Examples of the route Command 540

Using the nbtstat Utility 540The –a Switch 541The –A Switch 543The –c Switch 543The –n Switch 544The –r Switch 544The –R Switch 545The –S Switch 545The –s Switch 546

Using the netstat Utility 546The –a Switch 549The –e Switch 550The –r Switch 551The –s Switch 551The –p Switch 551The –n Switch 553

Using the File Transfer Protocol 554Starting FTP and Logging In to an FTP Server 555Downloading Files 557Uploading Files 559

Using the Telnet Utility 560How to Enable Telnet in Vista 560Don’t Use Telnet, Use Secure Shell 561

Summary 562Exam Essentials 562Written Lab 563Review Questions 564

Chapter 18 Software and Hardware Tools 569

Understanding Network Scanners 570Packet Sniffers 570Intrusion Detection and Prevention Software 572Port Scanners 574

Identifying Hardware Tools 576Cable Testers 577Protocol Analyzer 579Certifiers 580Time-Domain Reflectometer 581Optical Time-Domain Reflectometer 581

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Contents xxi

Multimeter 582Toner Probe 582Butt Set 584Punch-Down Tool 585Cable Stripper/Snips 586Voltage Event Recorder 587Environmental Monitors 588

Summary 589Exam Essentials 589Written Lab 590Review Questions 591

Chapter 19 Network Troubleshooting 595

Narrowing Down the Problem 598Are There Any Cabling Issues? Did You Check

the Super Simple Stuff? 599Is Hardware or Software Causing the Problem? 603Is It a Workstation or a Server Problem? 604Which Segments of the Network Are Affected? 604Is It Bad Cabling? 604

Troubleshooting Steps 609Step 1: Identify the Problem 610Step 2: Establish a Theory of Probable Cause 613Step 3: Test the Theory to Determine Cause 616Step 4: Establish a Plan of Action to Resolve the 

Problem and Identify Potential Effects 618Step 5: Implement the Solution or Escalate as Necessary 620Step 6: Verify Full System Functionality and

If Applicable Implement Preventative Measures 622Step 7: Document Findings, Actions, and Outcomes 623

Troubleshooting Tips 623Don’t Overlook the Small Stuff 624Prioritize Your Problems 624Check the Software Configuration 625Don’t Overlook Physical Conditions 625Don’t Overlook Cable Problems 626Check for Viruses 626

Summary 626Exam Essentials 627Written Lab 628Review Questions 629

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Chapter 20 Management, Monitoring, and Optimization 635

Managing Network Documentation 638Using SNMP 638Schematics and Diagrams 639Baselines 645Policies, Procedures, and Regulations 647

Monitoring the Network and Optimizing Its Performance 649Network Monitoring and Logging 650Reasons to Optimize Your Network’s Performance 652How to Optimize Performance 654Virtual Networking 658

Summary 661Exam Essentials 662Written Lab 663Review Questions 664

Appendix A Answers to Review Questions 669

Chapter 1: Introduction to Networks 670Chapter 2: The Open Systems Interconnection Specifications 672Chapter 3: Networking Topologies, Connectors, and

Wiring Standards 673Chapter 4: The Current Ethernet Specifications 675Chapter 5: Networking Devices 676Chapter 6: Introduction to the Internet Protocol 677Chapter 7: IP Addressing 679Chapter 8: IP Subnetting, Troubleshooting IP, and

Introduction to NAT 681Chapter 9: Introduction to IP Routing 683Chapter 10: Routing Protocols 684Chapter 11: Switching and Virtual LANs 686Chapter 12: Wireless Networking 688Chapter 13: Authentication and Access Control 689Chapter 14: Network Threats and Mitigation 691Chapter 15: Physical and Hardware Security 692Chapter 16: Wide Area Networks 694Chapter 17: Troubleshooting Tools 695Chapter 18: Software and Hardware Tools 697Chapter 19: Network Troubleshooting 699Chapter 20: Management, Monitoring, and Optimization 700

Appendix B Answers to Written Labs 703

Chapter 1: Introduction to Networks 704Chapter 2: The Open Systems Interconnection Specifications 704Chapter 3: Networking Topologies, Connectors, and

Wiring Standards 705

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Contents xxiii

Chapter 4: The Current Ethernet Specifications 705Chapter 5: Networking Devices 708Chapter 6: Introduction to the Internet Protocol 708Chapter 7: IP Addressing 709Chapter 8: IP Subnetting, Troubleshooting IP, and

Introduction to NAT 710Chapter 9: Introduction to IP Routing 710Chapter 10: Routing Protocols 711Chapter 11: Switching and Virtual LANs 711Chapter 12: Wireless Networking 712Chapter 13: Authentication and Access Control 712Chapter 14: Network Threats and Mitigation 712Chapter 15: Physical and Hardware Security 713Chapter 16: Wide Area Networks 713Chapter 17: Troubleshooting Tools 714Chapter 18: Software and Hardware Tools 714Chapter 19: Network Troubleshooting 715Chapter 20: Management, Monitoring, and Optimization 715

Appendix C Subnetting Class A 717

Subnetting Practice Examples: Class A Addresses 718Practice Example #1A: 255.255.0.0 (/16) 719Practice Example #2A: 255.255.240.0 (/20) 719Practice Example #3A: 255.255.255.192 (/26) 720

Subnetting in Your Head: Class A Addresses 720Written Lab 1 721Written Lab 2 722Answers to Written Lab 1 722Answers to Written Lab 2 723

Appendix D About the Additional Study Tools 725

Additional Study Tools 726Sybex Test Engine 726Electronic Flashcards 726PDF of Glossary of Terms 726Adobe Reader 726

System Requirements 727Using the Study Tools 727Troubleshooting 727

Customer Care 728

Index 729

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