CompTIA's Network+ certification tells the world you have the skills to install, configure, and troubleshoot today's basic networking hardware peripherals and protocols. But first, you have to pass the exam! This detailed CompTIA Authorized study guide by networking guru Todd Lammle has everything you need to prepare for the CompTIA's new Network+ Exam N10-006.

Inside, Todd covers all exam objectives, explains key topics, offers plenty of practical examples, and draws upon his own invaluable 25+ years of networking experience to help you learn.

Prepare for the exam and enhance your career with the CompTIA Authorized CompTIA Network+ Study Guide, Third Edition.

Assessment Test xli

Chapter 1 Introduction to Networks 1

First Things First: What’s a Network? 2

The Local Area Network 3

Common Network Components 5

Wide Area Network 8

Network Architecture: Peer-to-Peer or Client-Server? 10

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 19

Selecting the Right Topology 19

The Network Backbone 20

Network Segments 20

Summary 21

Exam Essentials 22

Written Labs 22

Review Questions 23

Chapter 2 The Open Systems Interconnection Specifications 27

Internetworking Models 28

The Layered Approach 29

Advantages of Reference Models 29

The OSI Reference Model 30

The Application Layer 32

The Presentation Layer 33

The Session Layer 33

The Transport Layer 33

The Network Layer 40

The Data Link Layer 43

The Physical Layer 45

Introduction to Encapsulation 46

Modulation Techniques 47

Summary 47

Exam Essentials 48

Written Lab 49

Review Questions 50

Chapter 3 Networking Topologies, Connectors, and Wiring Standards 55

Physical Media 57

Coaxial Cable 58

Twisted-Pair Cable 60

Fiber-Optic Cable 64

Media Converters 69

Serial Cables 71

Cable Properties 73

Transmission Speeds 74

Distance 74

Duplex 74

Noise Immunity (Security, EMI) 74

Frequency 75

Wiring Standards 75

568A vs 568B 76

Straight-Through Cable 78

Crossover Cable 78

Rolled/Rollover Cable 80

T1 Crossover Cable 81

Installing Wiring Distributions 82

Summary 85

Exam Essentials 85

Written Lab 86

Review Questions 87

Chapter 4 The Current Ethernet Specifications 91

Network Basics 93

Ethernet Basics 95

Collision Domain 95

Broadcast Domain 96

CSMA/CD 96

Broadband/Baseband 98

Bit Rates vs Baud Rate 98

Wavelength 98

Sampling -Size 99

Half- and Full-Duplex Ethernet 99

Ethernet at the Data Link Layer 101

Binary to Decimal and Hexadecimal Conversion 102

Ethernet Addressing 105

Ethernet Frames 106

Ethernet at the Physical Layer 108

Ethernet over Other Standards (IEEE 1905.1-2013) 114

Ethernet over Power Line 114

Ethernet over HDMI 116

Summary 117

Exam Essentials 117

Written Lab 117

Review Questions 123

Chapter 5 Networking Devices 127

Common Network Connectivity Devices 129

Network Interface Card 130

Hub 131

Bridge 132

Switch 132

Router 133

Firewall 137

IDS/IPS 138

HIDS 138

Access Point 138

Dynamic Host Configuration Protocol Server 139

Other Specialized Devices 144

Multilayer Switch 144

Load Balancer 145

Domain Name Service Server 145

Proxy Server 150

Encryption Devices 151

Analog Modem 152

Packet Shaper 153

VPN Concentrator 153

Planning and Implementing a Basic SOHO Network Using Network Segmentation 154

Determining Requirements 154

Switches and Bridges at the Data Link Layer 161

Hubs at the Physical Layer 162

Environmental Considerations 163

Summary 164

Exam Essentials 164

Written Lab 165

Review Questions 166

Chapter 6 Introduction to the Internet Protocol 171

Introducing TCP/IP 173

A Brief History of TCP/IP 173

TCP/IP and the DoD Model 174

The Process/Application Layer Protocols 176

The Host-to-Host Layer Protocols 184

The Internet Layer Protocols 189

Data Encapsulation 194

Summary 198

Exam Essentials 198

Written Lab 198

Review Questions 200

Chapter 7 IP Addressing 205

IP Terminology 206

The Hierarchical IP Addressing Scheme 207

Network Addressing 208

Private IP Addresses (RFC 1918) 212

IPv4 Address Types 214

Layer 2 Broadcasts 214

Layer 3 Broadcasts 215

Unicast Address 215

Multicast Address (Class D) 215

Internet Protocol Version 6 (IPv6) 216

Why Do We Need IPv6? 216

The Benefits of and Uses for IPv6 217

IPv6 Addressing and Expressions 218

Shortened Expression 219

Address Types 219

Special Addresses 220

Stateless Autoconfiguration (EUI-64) 221

DHCPv6 (Stateful) 223

Migrating to IPv6 223

Summary 225

Exam Essentials 226

Written Lab 227

Written Lab 7.1 227

Written Lab 7.2 227

Written Lab 7.3 228

Review Questions 229

Chapter 8 IP Subnetting, Troubleshooting IP, and Introduction to NAT 233

Subnetting Basics 234

How to Create Subnets 235

Subnet Masks 236

Classless Inter-Domain Routing (CIDR) 237

Subnetting Class C Addresses 239

Subnetting Class B Addresses 249

Troubleshooting IP Addressing 256

Determining IP Address Problems 259

Introduction to Network Address Translation (NAT) 264

Types of Network Address Translation 265

NAT Names 266

How NAT Works 267

Summary 268

Exam Essentials 269

Written Labs 269

Review Questions 271

Chapter 9 Introduction to IP Routing 277

Routing Basics 278

The IP Routing Process 281

Testing Your IP Routing Understanding 287

Static and Dynamic Routing 288

Summary 291

Exam Essentials 292

Written Lab 292

Review Questions 293

Chapter 10 Routing Protocols 297

Routing Protocol Basics 299

Administrative Distances 300

Classes of Routing Protocols 302

Distance Vector Routing Protocols 303

Routing Information Protocol (RIP) 305

RIP Version 2 (RIPv2) 305

VLSM and Discontiguous Networks 306

EIGRP 309

Border Gateway Protocol (BGP) 311

Link State Routing Protocols 313

Open Shortest Path First (OSPF) 314

Intermediate System-to-Intermediate System (IS-IS) 316

High Availability 317

Hot Standby Router Protocol (HSRP) 319

Virtual Router Redundancy Protocol 324

IPv6 Routing Protocols 324

RIPng 325

EIGRPv6 325

OSPFv3 325

Summary 326

Exam Essentials 326

Written Lab 327

Review Questions 328

Chapter 11 Switching and Virtual LANs 333

Networking Before Layer 2 Switching 335

Switching Services 338

Limitations of Layer 2 Switching 339

Bridging vs LAN Switching 340

Three Switch Functions at Layer 2 340

Spanning Tree Protocol 346

Spanning Tree Port States 347

STP Convergence 347

Rapid Spanning Tree Protocol 802.1w 348

Virtual LANs 349

VLAN Basics 350

Quality of Service 353

VLAN Memberships 354

Static VLANs 354

Dynamic VLANs 355

Identifying VLANs 355

VLAN Identification Methods 357

VLAN Trunking Protocol 359

VTP Modes of Operation 360

Do We Really Need to Put an IP Address on a Switch? 361

Port Security 363

Port Bonding 364

Two Additional Advanced Features of Switches 366

Power over Ethernet (802.3af, 802.3at) 366

Port Mirroring/Spanning (SPAN/RSPAN) 368

Summary 370

Exam Essentials 370

Written Lab 371

Review Questions 372

Chapter 12 Wireless Networking 377

Introduction to Wireless Technology 380

The 802.11 Standards 383

2.4GHz (802.11b) 384

2.4GHz (802.11g) 385

5GHz (802.11a) 386

5GHz (802.11h) 387

2.4GHz/5GHz (802.11n) 388

5GHz (802.11ac) 389

Comparing 802.11 Standards 389

Range Comparisons 390

Wireless Network Components 391

Wireless Access Points 391

Wireless Network Interface Card 392

Wireless Antennas 393

Installing a Wireless Network 395

Ad Hoc Mode: Independent Basic Service Set 395

Infrastructure Mode: Basic Service Set 396

Wireless Controllers 398

Mobile Hot Spots 399

Signal Degradation 400

Other Network Infrastructure Implementations 401

Installing and Configuring WLAN Hardware 402

Site Survey 408

Wireless Security 412

Wireless Threats 412

Open Access 416

Service Set Identifiers, Wired Equivalent Privacy, and Media Access Control Address Authentication 416

Remote Authentication Dial-In User Service (802.1x) 417

Temporal Key Integrity Protocol 418

Wi-Fi Protected Access or WPA2 Pre-Shared Key 419

Summary 422

Exam Essentials 423

Written Lab 423

Review Questions 425

Chapter 13 Authentication and Access Control 429

Security Filtering 431

Access Control Lists 432

Tunneling 434

Encryption 440

Remote Access 445

Managing User Account and Password Security 447

Managing User Accounts 448

Managing Passwords 450

Single Sign-On 454

Multifactor Authentication 455

User-Authentication Methods 455

Public Key Infrastructure (PKI) 455

Kerberos 456

Authentication, Authorization, and Accounting (AAA) 458

Web Services 459

Unified Voice Services 460

Network Controllers 460

Network Access Control (NAC) 460

Challenge Handshake Authentication Protocol (CHAP) 460

MS-CHAP 461

Extensible Authentication Protocol (EAP) 462

Hashes 462

Network Access Control 462

Summary 464

Exam Essentials 464

Written Lab 465

Review Questions 466

Chapter 14 Network Threats and Mitigation 469

Recognizing Security Threats 473

Denial of Service 474

Distributed DoS (DDoS) 475

Authentication Issues 483

Viruses 484

Zero Day Attacks 487

Insider Threat/Malicious Employee 487

Vulnerabilities 488

Unnecessary Running Services 488

Open Ports 488

Unpatched/Legacy Systems 488

Unencrypted Channels 488

Clear-Text Credentials 488

TEMPEST/RF Emanation 489

Malicious Users 489

Buffer Overflow 490

Wireless Threats 490

Attackers and Their Tools 493

Misconfiguration Issues 497

Social Engineering (Phishing) 498

Understanding Mitigation Techniques 499

Active Detection 500

Passive Detection 500

Proactive Defense 500

Basic Forensic Concepts 501

Policies and Procedures 503

Security Policies 504

Security Training 509

Patches and Upgrades 510

Firmware Updates 512

Driver Updates 512

Upgrading vs Downgrading 513

Anti-malware software 514

Host-based 514

Cloud/Server-based 514

Configuration Backups 515

Updating Antivirus Components 515

Fixing an Infected Computer 518

Summary 518

Exam Essentials 518

Written Lab 519

Review Questions 520

Chapter 15 Physical Security and Risk 525

Using Hardware and Software Security Devices 527

Defining Firewalls 529

Network-Based Firewalls 530

Host-Based Firewalls 530

Firewall Technologies 530

Access Control Lists 531

Port Security 533

Demilitarized Zone 534

Protocol Switching 534

Dynamic Packet Filtering 537

Proxy Services 538

Firewalls at the Application Layer vs

the Network Layer 540

Stateful vs Stateless Network Layer Firewalls 541

Application Layer Firewalls 542

Scanning Services and Other Firewall Features 542

Content Filtering 544

Signature Identification 544

Context Awareness 544

Virtual Wire vs Routed 545

Zones 545

Intrusion Detection and Prevention Systems 547

Network-Based IDS 549

Host-Based IDS 551

Vulnerability Scanners 551

VPN Concentrators 552

Understanding Problems Affecting Device Security 553

Physical Security 554

Logical Security Configurations 558

Risk-Related Concepts 560

Summary 566

Exam Essentials 566

Written Lab 567

Review Questions 569

Chapter 16 Wide Area Networks 573

What’s a WAN? 577

Defining WAN Terms 577

The Public Switched Telephone Network 579

WAN Connection Types 580

Bandwidth or Speed 581

T-Series Connections 582

The T1 Connection 583

The T3 Connection 584

Transmission Media 584

Wired Connections 585

Wavelength Division Multiplexing 585

Passive Optical Network 586

Wireless Technologies 586

Broadband Services 588

DSL Technology and XDSL 589

Cable Modem 591

Wireless WAN Technologies 593

Cellular WAN 593

WAN Protocols 595

Integrated Services Digital Network 595

Frame Relay Technology 596

Point-to-Point Protocol 599

Asynchronous Transfer Mode 602

MPLS 603

WAN Troubleshooting 603

Loss of Internet Connectivity 603

Interface Errors/Monitoring 604

Split Horizon 607

DNS Issues 608

Router Configurations 608

Company Security Policy 609

Summary 609

Exam Essentials 609

Written Lab 610

Review Questions 611

Chapter 17 Troubleshooting Tools 615

Protocol Analyzers 616

Throughput Testers 618

Connectivity Software 619

Using Traceroute 620

Using ipconfig and ifconfig 622

Using the ipconfig Utility 622

Using the ifconfig Utility 626

Using the ping Utility 627

Using the Address Resolution Protocol 630

The Windows ARP Table 630

Using the arp Utility 631

Using the nslookup Utility 634

Resolving Names with the Hosts Table 636

Using the Mtr Command (pathping) 637

Using the route Command 638

Using the route Command Options 639

Some Examples of the route Command 641

Using the nbtstat Utility 641

The –a Switch 642

The –A Switch 644

The –c Switch 644

The –n Switch 645

The –r Switch 645

The –R Switch 646

The –S Switch 646

The –s Switch 647

Using the netstat Utility 647

The –a Switch 650

The –e Switch 651

The –r Switch 652

The –s Switch 652

The –p Switch 652

The –n Switch 654

Using the File Transfer Protocol 655

Starting FTP and Logging In to an FTP Server 656

Downloading Files 658

Uploading Files 660

Using the Telnet Utility 660

How to Enable Telnet in Windows 661

Don’t Use Telnet, Use Secure Shell 662

Summary 662

Exam Essentials 663

Written Lab 663

Review Questions 665

Chapter 18 Software and Hardware Tools 671

Understanding Network Scanners 673

Packet Sniffers/Network Monitors 673

Intrusion Detection and Prevention Software 675

Port Scanners 677

Wi-Fi Analyzer 680

Baseline 681

Network Monitoring and Logging 683

Network Monitoring 683

SNMP 684

Syslog 685

SIEM 687

Utilization 690

Identifying Hardware Tools 691

Cable Testers 692

Protocol Analyzer 695

Certifiers 696

Time-Domain Reflectometer 696

Optical Time-Domain Reflectometer 697

Multimeter 698

Toner Probe 698

Butt Set 700

Punch-Down Tool 701

Cable Stripper/Snips 702

Voltage Event Recorder (Power) 702

Environmental Monitors 703

Summary 704

Exam Essentials 704

Written Lab 705

Review Questions 706

Chapter 19 Network Troubleshooting 711

Narrowing Down the Problem 715

Did You Check the Super Simple Stuff? 716

Is Hardware or Software Causing the Problem? 720

Is It a Workstation or a Server Problem? 721

Which Segments of the Network Are Affected? 721

Is It Bad Cabling? 722

Troubleshooting Steps 729

Step 1: Identify the Problem 729

Step 2: Establish a Theory of Probable Cause 733

Step 3: Test the Theory to Determine Cause 737

Step 4: Establish a Plan of Action to Resolve the Problem and Identify Potential Effects 740

Step 5: Implement the Solution or Escalate as Necessary 741

Step 6: Verify Full System Functionality, and If Applicable, Implement Preventative Measures 744

Step 7: Document Findings, Actions, and Outcomes 745

Troubleshooting Tips 746

Don’t Overlook the Small Stuff 746

Prioritize Your Problems 746

Check the Software Configuration 747

Don’t Overlook Physical Conditions 747

Don’t Overlook Cable Problems 748

Check for Viruses 748

Summary 749

Exam Essentials 749

Written Lab 750

Review Questions 751

Chapter 20 Management, Monitoring, and Optimization 755

Managing Network Documentation 761

Using SNMP 761

Schematics and Diagrams 762

Network Monitoring 771

Baselines 771

On-Boarding and Off-Boarding of Mobile Devices 771

NAC 772

Policies, Procedures, and Regulations 772

Safety Practices 775

Implementing Network Segmentation 780

Network Optimization 783

Reasons to Optimize Your Network’s Performance 783

How to Optimize Performance 786

Unified Communications 788

Traffic Shaping 788

Load Balancing 789

High Availability 789

Caching Engines 789

Fault Tolerance 790

Archives/Backups 790

Common Address Redundancy Protocol 791

Virtual Networking 791

Locating and Installing Equipment 797

Change Management Procedures 803

Summary 805

Exam Essentials 806

Written Lab 807

Review Questions 808

Appendix A Answers to the Written Labs 813

Chapter 1 814

Chapter 2 814

Chapter 3 815

Chapter 4 815

Chapter 5 818

Chapter 6 818

Chapter 7 819

Written Lab 7.1 819

Written Lab 7.2 820

Written Lab 7.3 820

Chapter 8 820

Chapter 9 821

Chapter 10 821

Chapter 11 822

Chapter 12 822

Chapter 13 823

Chapter 14 823

Chapter 15 824

Chapter 16 824

Chapter 17 825

Chapter 18 825

Chapter 19 825

Chapter 20 826

Appendix B Answers to Review Questions 827

Chapter 1 828

Chapter 2 829

Chapter 3 830

Chapter 4 832

Chapter 5 833

Chapter 6 834

Chapter 7 835

Chapter 8 837

Chapter 9 839

Chapter 10 840

Chapter 11 842

Chapter 12 843

Chapter 13 845

Chapter 14 846

Chapter 15 848

Chapter 16 849

Chapter 17 851

Chapter 18 852

Chapter 19 853

Chapter 20 855

Appendix C Subnetting Class A 857

Subnetting Practice Examples: Class A Addresses 858

Practice Example #1A: 255.255.0.0 (/16) 859

Practice Example #2A: 255.255.240.0 (/20) 859

Practice Example #3A: 255.255.255.192 (/26) 860

Subnetting in Your Head: Class A Addresses 861

Written Lab 1 861

Written Lab 2 862

Answers to Written Lab 1 863

Answers to Written Lab 2 864

Index 865

Todd Lammle, CompTIA Network+, CCSI, CCNA/CCNP, is the authority on network certification and internetworking. He is a world-renowned author, speaker, trainer, and consultant. Todd has over 25 years of experience working with LANs, WANs, and large licensed and unlicensed wireless networks. He's president and CEO of GlobalNet Training and Consulting, Inc., a network integration and training firm located in Boulder, Colorado; Dallas, Texas; and San Francisco, California. You can reach Todd through his forum at www. lammle.com/forum.