CWNA Certified Wireless Network Administrator Study Guide Exam CWNA-108

by Coleman, David D.; Westcott, David A.

• ISBN13: 9781119734505
• ISBN10: 1119734509
• Edition: 6th
• Format: Paperback
• Copyright: 2021-03-09
• Publisher: Sybex

Summary

The #1 selling Wi-Fi networking reference guide in the world 

The CWNA: Certified Wireless Network Administrator Study Guide is the ultimate preparation resource for the CWNA exam. Fully updated to align with the latest version of the exam, this book features expert coverage of all exam objectives to help you pass the exam. But passing the exam is just a first step. For over 16 years, the CWNA Study Guide has helped individuals jump-start their wireless networking careers. Wireless networking professionals across the globe use this book as their workplace reference guide for enterprise Wi-Fi technology. 

Owning this book provides you with a foundation of knowledge for important Wi-Fi networking topics, including: 

• Radio frequency (RF) fundamentals
• 802.11 MAC and medium access
• Wireless LAN topologies and architecture
• WLAN design, troubleshooting and validation
• Wi-Fi networking security 

The book authors have over 40 years of combined Wi-Fi networking expertise and provide real-world insights that you can leverage in your wireless networking career. Each of the book’s 20 chapters breaks down complex topics into easy to understand nuggets of useful information. Each chapter has review questions that help you gauge your progress along the way. Additionally, hands-on exercises allow you to practice applying CWNA concepts to real-world scenarios. You also get a year of free access to the Sybex online interactive learning environment, which features additional resources and study aids, including bonus practice exam questions. 

The CWNA certification is a de facto standard for anyone working with wireless technology. It shows employers that you have demonstrated competence in critical areas, and have the knowledge and skills to perform essential duties that keep their wireless networks functioning and safe. The CWNA: Certified Wireless Network Administrator Study Guide gives you everything you need to pass the exam with flying colors. 

Author Biography

DAVID D. COLEMAN, CWNE #4, David D. Coleman, CWNE #4, is a technology evangelist and public speaker who specializes in Wi-Fi and cloud technologies. David is also Director of Product Marketing for Extreme Networks. He is the author of numerous books, white papers and videos about Wi-Fi technology. DAVID A. WESTCOTT, CWNE #7, is an independent consultant and WLAN technical trainer of thirty years. He provides vendor and custom wireless training to government agencies, corporations and universities around the world.

Table of Contents

Foreword xxxv

Introduction xxxvii

Assessment Test lvi

Chapter 1 Overview of Wireless Standards, Organizations, and Fundamentals 1

History of Wireless Local Area Networks 3

Standards Organizations 5

Federal Communications Commission 5

International Telecommunication Union Radiocommunication Sector 6

Institute of Electrical and Electronics Engineers 8

Internet Engineering Task Force 9

Wi-Fi Alliance 11

International Organization for Standardization 21

Core, Distribution, and Access 22

Communications Fundamentals 24

Communication Terminology 24

Understanding Carrier Signals 25

Understanding Keying Methods 27

Summary 33

Exam Essentials 33

Review Questions 34

Chapter 2 IEEE 802.11 Standard and Amendments 39

Original IEEE 802.11 Standard 42

IEEE 802.11-2020 Ratified Amendments 44

802.11a-1999 45

802.11b-1999 46

802.11d-2001 47

802.11e-2005 47

802.11g-2003 48

802.11h-2003 50

802.11i-2004 52

802.11j-2004 53

802.11k-2008 53

802.11n-2009 54

802.11p-2010 55

802.11r-2008 55

802.11s-2011 56

802.11u-2011 57

802.11v-2011 58

802.11w-2009 58

802.11y-2008 59

802.11z-2010 59

802.11aa-2012 59

802.11ac-2013 59

802.11ad-2012 60

802.11ae-2012 61

802.11af-2014 61

802.11ah-2016 62

802.11ai-2016 63

802.11aj-2018 63

802.11ak-2018 63

802.11aq-2018 63

IEEE 802.11 Draft Amendments 63

802.11ax (High Efficiency) 64

802.11ay (Next-Generation 60 GHz) 65

802.11az (Next-Generation Positioning) 65

802.11ba (Wake-Up Radio) 65

802.11bb (Light Communications) 65

802.11bc (Enhanced Broadcast Service) 65

802.11bd (Enhancements for Next-Generation V2X) 65

802.11be (Extremely High Throughput) 66

Defunct Amendments 66

802.11F 66

802.11T 67

IEEE Task Group m 68

Summary 69

Exam Essentials 69

Review Questions 70

Chapter 3 Radio Frequency Fundamentals 75

What is a Radio Frequency Signal? 77

Radio Frequency Characteristics 78

Wavelength 78

Frequency 83

Amplitude 85

Phase 86

Radio Frequency Behaviors 87

Wave Propagation 87

Absorption 88

Reflection 89

Scattering 91

Refraction 91

Diffraction 92

Loss (Attenuation) 94

Free Space Path Loss 96

Multipath 98

Gain (Amplification) 101

RF Analysis Tools 102

Summary 103

Exam Essentials 103

Review Questions 104

Chapter 4 Radio Frequency Components, Measurements, and Mathematics 109

Components of RF Communications 112

Transmitter 112

Antenna 113

Receiver 114

Intentional Radiator 114

Equivalent Isotropically Radiated Power 114

Units of Power and Comparison 115

Watt 116

Milliwatt 117

Decibel 117

Decibels Relative to an Isotropic Radiator (dBi) 120

Decibels Relative to a Half-Wave Dipole Antenna (dBd) 120

Decibels Relative to 1 Milliwatt (dBm) 121

Inverse Square Law 122

RF Mathematics 123

Rule of 10s and 3s 124

RF Math Summary 129

Noise Floor 130

Signal-to-Noise Ratio 130

Signal-to-Interference-Plus-Noise Ratio 131

Received Signal Strength Indicator 131

Link Budget 135

Fade Margin/System Operating Margin 138

Summary 140

Exam Essentials 142

Review Questions 143

Chapter 5 Radio Frequency Signal and Antenna Concepts 147

Azimuth and Elevation Charts (Antenna Radiation Envelopes) 150

Interpreting Polar Charts 152

Beamwidth 155

Antenna Types 157

Omnidirectional Antennas 158

Downtilt Omnidirectional Antennas 161

Semidirectional Antennas 162

Highly Directional Antennas 164

Sector Antennas 166

Antenna Arrays 167

Visual Line of Sight 169

RF Line of Sight 169

Fresnel Zone 170

Earth Bulge 174

Antenna Polarization 175

Antenna Diversity 176

Multiple-Input, Multiple-Output 177

MIMO Antennas 178

Antenna Connection and Installation 179

Voltage Standing Wave Ratio 179

Signal Loss 181

Antenna Mounting 181

Antenna Accessories 187

Cables 188

Connectors 188

Splitters 189

Amplifiers 189

Attenuators 190

Lightning Arrestors 191

Grounding Rods and Wires 192

Regulatory Compliance 192

Summary 194

Exam Essentials 194

Review Questions 195

Chapter 6 Wireless Networks and Spread Spectrum Technologies 199

Throughput vs. Bandwidth 201

Narrowband and Spread Spectrum 202

Multipath Interference 204

Frequency-Hopping Spread Spectrum 205

Hopping Sequence 206

Dwell Time 207

Hop Time 207

Modulation 207

Direct-Sequence Spread Spectrum 208

DSSS Data Encoding 208

Modulation 209

Transmit Spectrum Mask 210

Orthogonal Frequency-Division Multiplexing 211

Convolutional Coding 212

Modulation 213

Transmit Spectrum Mask 215

Orthogonal Frequency-Division Multiple Access 217

Industrial, Scientific, and Medical Bands 218

900 MHz ISM Band 218

2.4 GHz ISM Band 219

5.8 GHz ISM Band 219

5 GHz Unlicensed National Information Infrastructure Bands 220

U-NII-1 220

U-NII-2A 221

U-NII-2C 221

U-NII-3 222

U-NII-4 222

60 GHz for Wi-Fi 223

Below 1 GHz 224

2.4 GHz Channels 224

5 GHz Channels 227

Long-Term Evolution in 5 GHz 231

6 GHz Channels 232

6 GHz Incumbents 235

Automated Frequency Coordination 236

6 GHz Worldwide 237

6 GHz Wi-Fi Considerations 238

Summary 239

Exam Essentials 239

Review Questions 240

Chapter 7 Wireless LAN Topologies 245

Wireless Networking Topologies 247

Wireless Wide Area Network 248

Wireless Metropolitan Area Network 248

Wireless Personal Area Network 249

Wireless Local Area Network 250

802.11 Stations 251

Client Station 252

Access Point Station 252

Integration Service 252

Distribution System 253

Wireless Distribution System 254

802.11 Service Sets 255

Service Set Identifier 256

Basic Service Set 256

Basic Service Area 257

Basic Service Set Identifier 258

Multiple Basic Service Set Identifiers 259

Extended Service Set 261

Independent Basic Service Set 262

Personal Basic Service Set 264

Mesh Basic Service Set 264

QoS Basic Service Set 266

802.11 Configuration Modes 267

Access Point Modes 267

Client Station Modes 268

Summary 269

Exam Essentials 269

Review Questions 271

Chapter 8 802.11 Medium Access 275

CSMA/CA vs. CSMA/CD 276

Collision Detection 277

Distributed Coordination Function 278

Physical Carrier Sense 279

Virtual Carrier Sense 280

Pseudo-Random Backoff Timer 283

Interframe Space 285

Hybrid Coordination Function 286

Enhanced Distributed Channel Access 287

HCF Controlled Channel Access 288

Wi-Fi Multimedia 288

Airtime Fairness 290

Summary 292

Exam Essentials 292

Review Questions 293

Chapter 9 802.11 MAC 297

Packets, Frames, and Bits 299

Data-Link Layer 300

MAC Service Data Unit 300

MAC Protocol Data Unit 300

Physical Layer 301

PLCP Service Data Unit 301

PLCP Protocol Data Unit 302

802.11 and 802.3 Interoperability 302

802.11 MAC Header 303

Frame Control Field 304

Duration/ID Field 306

MAC Layer Addressing 307

Sequence Control Field 314

QoS Control Field 315

HT Control Field 315

802.11 Frame Body 315

802.11 Trailer 316

802.11 State Machine 317

Management Frames 318

Beacon 318

Authentication 325

Association 326

Reassociation 329

Disassociation 331

Deauthentication 331

Action Frame 331

Control Frames 333

ACK Frame 333

Block Acknowledgment 335

PS-Poll 336

RTS/CTS 336

CTS-to-Self 338

Protection Mechanisms 338

Data Frames 341

QoS and Non-QoS Data Frames 342

Non-Data Carrying Frames 343

Power Management 344

Legacy Power Management 345

WMM-Power Save and U-APSD 347

MIMO Power Management 349

802.11ax Power Management 349

Summary 350

Exam Essentials 350

Review Questions 352

Chapter 10 MIMO Technology: HT and VHT 357

MIMO 360

Radio Chains 362

Spatial Multiplexing 363

MIMO versus SISO diversity 366

Maximal Ratio Combining 366

Space-Time Block Coding 367

Cyclic Shift Diversity 368

Transmit Beamforming 368

Explicit Beamforming 370

Multi-User MIMO 371

Multi-User Beamforming 373

Channels 376

20 MHz Channels 376

40 MHz Channels 377

Forty MHz Intolerant 379

80 MHz and 160 MHz Channels 380

Guard Interval 382

256-QAM Modulation 384

802.11n/ac PPDUs 388

Non-HT 388

HT Mixed 388

VHT 389

802.11n/ac MAC 390

A-MSDU 390

A-MPDU 391

Block Acknowledgment 392

Power Management 392

Modulation and Coding Scheme 394

802.11ac Data Rates 397

HT/VHT Protection Mechanisms 399

HT Protection Modes (0–3) 399

Wi-Fi Alliance Certification 400

Summary 403

Exam Essentials 403

Review Questions 405

Chapter 11 WLAN Architecture 409

WLAN Client Devices 411

802.11 Radio Form Factors 412

802.11 Radio Chipsets 418

Client Utilities 418

Management, Control, and Data Planes 421

Management Plane 422

Control Plane 422

Data Plane 423

WLAN Architecture 423

Autonomous WLAN Architecture 423

Centralized Network Management Systems 425

Centralized WLAN Architecture 427

Distributed WLAN Architecture 434

Hybrid WLAN Architecture 436

Specialty WLAN Infrastructure 437

Enterprise WLAN Branch Routers 437

WLAN Mesh Access Points 438

WLAN Bridges 439

Real-Time Location Systems 441

VoWiFi 443

Cloud Networking 445

Application Programming Interface 448

Transport and Data Formats 449

WLAN APIs 450

Common Applications 450

Infrastructure Management 451

Protocols for Management 452

Summary 456

Exam Essentials 457

Review Questions 458

Chapter 12 Power over Ethernet (PoE) 463

History of PoE 464

Nonstandard PoE 465

IEEE 802.3af 465

IEEE Std 802.3-2005, Clause 33 465

IEEE 802.3at-2009 465

IEEE Std 802.3-2018, Clause 33 466

IEEE 802.3bt-2018 466

PoE Devices 467

Powered Device 467

Power-Sourcing Equipment 469

Endpoint PSE 470

Midspan PSE 476

Planning and Deploying PoE 484

Power Planning 484

Redundancy 487

Downgrade PoE Capabilities 488

802.3bt Power Considerations 488

Summary 490

Exam Essentials 491

Review Questions 492

Chapter 13 WLAN Design Concepts 497

WLAN Coverage Design 499

Received Signal 500

Signal-to-Noise Ratio 501

Dynamic Rate Switching 503

Transmit Power 504

Roaming Design 505

Primary and Secondary Coverage 508

Fast Secure Roaming 509

Layer 3 Roaming 510

Channel Design 512

Adjacent Channel Interference 512

2.4 GHz Channel Reuse 513

Co-Channel Interference 516

5 GHz Channel Reuse 519

DFS Channels 521

40 MHz Channel Design 527

Static Channels and Transmit Power vs. Adaptive RF 529

Single-Channel Architecture 531

Capacity Design 534

High-Density 535

Band Steering 539

Load Balancing 542

Airtime Consumption 543

Voice vs. Data 546

Dual 5 GHz and Software-Defined Radios 548

6 GHz WLAN Design 551

Client Considerations 552

Coverage Considerations 553

6 GHz Channel Reuse 553

6 GHz AP Discovery 554

6 GHz Wi-Fi Security 556

Physical Environment 557

Antennas 558

Outdoor Design 562

Summary 563

Exam Essentials 564

Review Questions 565

Chapter 14 Site Survey and Validation 569

WLAN Site Survey and Design Interview 572

Customer Briefing 572

Business Requirements 573

Capacity and Coverage Requirements 574

Existing Wireless Network 576

Upgrading an Existing WLAN 577

Infrastructure Connectivity 578

Security Expectations 580

Guest Access 581

Aesthetics 581

Outdoor Surveys 582

Vertical Market Considerations 582

Government 583

Education 583

Healthcare 583

Retail 584

Warehouses and Manufacturing 584

Multi-Tenant Buildings 585

Legacy AP-on-a-Stick Survey 585

Spectrum Analysis 586

Coverage Analysis 590

Hybrid Survey 595

Initial Site Visit 595

Predictive Design 597

Validation Survey 599

Capacity and Throughput 601

Roaming 602

Delay and Jitter 603

Connectivity 603

Aesthetics 603

Site Survey Tools 604

Indoor Site Survey Tools 604

Outdoor Site Survey Tools 607

Documents and Reports 609

Forms and Customer Documentation 610

Deliverables 612

Additional Reports 613

Summary 614

Exam Essentials 615

Review Questions 616

Chapter 15 WLAN Troubleshooting 621

Five Tenets of WLAN Troubleshooting 623

Troubleshooting Best Practices 623

Troubleshoot the OSI Model 625

Most Wi-Fi Problems Are Client Issues 627

Proper WLAN Design Reduces Problems 628

WLAN Always Gets the Blame 629

Layer 1 Troubleshooting 629

WLAN Design 629

Transmit Power 630

RF Interference 630

Drivers 634

PoE 635

Firmware Bugs 635

Layer 2 Troubleshooting 636

Layer 2 Retransmissions 636

RF Interference 639

Low SNR 639

Adjacent Channel Interference 640

Hidden Node 641

Mismatched Power 646

Multipath 648

Security Troubleshooting 648

PSK Troubleshooting 649

802.1X/EAP Troubleshooting 651

VPN Troubleshooting 659

Roaming Troubleshooting 661

Channel Utilization 665

Layers 3–7 Troubleshooting 667

WLAN Troubleshooting Tools 671

WLAN Discovery Applications 671

Spectrum Analyzers 672

Protocol Analyzers 673

Throughput Test Tools 675

Standard IP Network Test Commands 677

Secure Shell 678

Summary 679

Exam Essentials 679

Review Questions 680

Chapter 16 Wireless Attacks, Intrusion Monitoring, and Policy 687

Wireless Attacks 688

Rogue Wireless Devices 689

Peer-to-Peer Attacks 692

Eavesdropping 693

Encryption Cracking 697

KRACK Attack 698

Kr00k Vulnerability 698

Authentication Attacks 699

MAC Spoofing 701

Management Interface Exploits 701

Wireless Hijacking 702

Denial-of-Service Attacks 703

Vendor-Specific Attacks 705

Social Engineering 706

Intrusion Monitoring 706

Wireless Intrusion Prevention System 706

Rogue Detection and Mitigation 709

Spectrum Analyzers 712

Wireless Security Policies 712

General Security Policies 713

Functional Security Policies 713

Legislative Compliance 714

802.11 Wireless Policy Recommendations 715

Summary 716

Exam Essentials 717

Review Questions 718

Chapter 17 802.11 Network Security Architecture 723

802.11 Security Basics 725

Data Privacy and Integrity 726

Authentication, Authorization, and Accounting 728

Segmentation 728

Monitoring and Policy 729

Legacy 802.11 Security 729

Legacy Authentication 730

Static WEP Encryption 731

MAC Filters 735

SSID Cloaking 735

Robust Security 736

Robust Security Network 737

Authentication and Authorization 738

PSK Authentication 738

Proprietary PSK Authentication 741

Simultaneous Authentication of Equals 743

802.1X/EAP Framework 746

EAP Types 749

Dynamic Encryption-Key Generation 751

4-Way Handshake 752

WLAN Encryption 754

TKIP Encryption 755

CCMP Encryption 756

GCMP Encryption 756

Management Frame Protection 757

WPA2 757

WPA3 758

WPA3-Personal 758

WPA3-Enterprise 759

Enhanced Open 761

6 GHz Wi-Fi Security 762

Traffic Segmentation 763

VLANs 763

RBAC 765

VPN Wireless Security 766

VPN 101 767

Layer 3 VPNs 768

SSL VPNs 768

VPN Deployment 768

Summary 770

Exam Essentials 770

Review Questions 772

Chapter 18 Bring Your Own Device (BYOD) and Guest Access 777

Mobile Device Management 780

Company-Issued Devices vs. Personal Devices 781

MDM Architecture 782

MDM Enrollment 784

MDM Profiles 788

MDM Agent Software 790

Over-the-Air Management 791

Application Management 793

Self-Service Device Onboarding for Employees 795

Dual-SSID Onboarding 796

Single-SSID Onboarding 796

MDM vs. Self-Service Onboarding 797

Guest WLAN Access 798

Guest SSID 798

Guest VLAN 799

Guest Firewall Policy 800

Captive Web Portals 801

Client Isolation, Rate Limiting, and Web Content Filtering 804

Guest Management 805

Guest Self-Registration 806

Employee Sponsorship 808

Social Login 809

Encrypted Guest Access 810

Hotspot 2.0 and Passpoint 811

Access Network Query Protocol 811

Hotspot 2.0 Architecture 813

802.1X/EAP and Hotspot 2.0 814

Online Sign-Up 815

Roaming Agreements 816

Network Access Control 816

Posture 817

OS Fingerprinting 818

AAA 820

RADIUS Change of Authorization 821

Single Sign-On 822

Summary 824

Exam Essentials 825

Review Questions 826

Chapter 19 802.11ax: High Efficiency (HE) 831

802.11ax = Wi-Fi 6 833

Wi-Fi Traffic Congestion 834

HE Overview 836

Multi-User 837

OFDMA 838

Subcarriers 839

Resource Units 840

Trigger Frames 844

Downlink OFDMA 847

Uplink OFDMA 848

Buffer Status Reports 849

Operating Mode Indication 850

MU-MIMO 851

BSS Color and Spatial Reuse 855

OBSS 855

BSS Color 857

Spatial Reuse Operation 858

Target Wake Time 861

Additional 802.11ax PHY and MAC Capabilities 862

1024-QAM 862

Long Symbol Time and Guard Intervals 863

802.11ax PHY headers 864

20 MHz-Only 865

Multi-TID AMPDU 867

Wi-Fi 6 Key Questions 867

Clients 867

Multi-Gig Ethernet 868

Power over Ethernet 870

4×4:4 vs. 8×8:8 871

80 MHz and 160 MHz Channels 872

Wi-Fi CERTIFIED 6 873

Summary 874

Review Questions 875

Chapter 20 WLAN Deployment and Vertical Markets 879

Deployment Considerations for Commonly Supported WLAN Applications and Devices 881

Data 881

Voice 882

Video 882

Real-Time Location Services 883

iBeacon Proximity 883

Mobile Devices 885

Corporate Data Access and End-User Mobility 885

Network Extension to Remote Areas 886

Bridging: Building-to-Building Connectivity 887

Wireless ISP: Last-Mile Data Delivery 888

Small Office/Home Office 888

Temporary Office Networking 889

Branch Offices 890

Teleworker Wi-Fi 890

Educational/Classroom Use 891

Industrial: Warehousing and Manufacturing 892

Retail 892

Healthcare 894

Municipal Networks 895

Hotspots: Public Network Access 895

Stadium Networks 897

Transportation Networks 897

Law Enforcement Networks 898

First-Responder Networks 899

Managed Service Providers 900

Fixed Mobile Convergence 900

WLAN and Health 901

Internet of Things 901

WLAN Vendors 902

Summary 904

Exam Essentials 904

Review Questions 905

Appendix A Answers to Review Questions 909

Chapter 1: Overview of Wireless Standards, Organizations, and Fundamentals 910

Chapter 2: IEEE 802.11 Standard and Amendments 911

Chapter 3: Radio Frequency Fundamentals 914

Chapter 4: Radio Frequency Components, Measurements, and Mathematics 915

Chapter 5: Radio Frequency Signal and Antenna Concepts 918

Chapter 6: Wireless Networks and Spread Spectrum Technologies 919

Chapter 7: Wireless LAN Topologies 922

Chapter 8: 802.11 Medium Access 924

Chapter 9: 802.11 MAC 926

Chapter 10: MIMO Technology: HT and VHT 929

Chapter 11: WLAN Architecture 932

Chapter 12: Power over Ethernet (PoE) 934

Chapter 13: WLAN Design Concepts 937

Chapter 14: Site Survey and Validation 940

Chapter 15: WLAN Troubleshooting 943

Chapter 16: Wireless Attacks, Intrusion Monitoring, and Policy 946

Chapter 17: 802.11 Network Security Architecture 948

Chapter 18: Bring Your Own Device (BYOD) and Guest Access 951

Chapter 19: 802.11ax: High Efficiency (HE) 954

Chapter 20: WLAN Deployment and Vertical Markets 957

Appendix B Abbreviations and Acronyms 961

Certifications 962

Organizations and Regulations 962

Measurements 963

Technical Terms 964

Index 981