CWNA Certified Wireless Network Administrator Study Guide: Exam CWNA-108

ISBN-13: 9781119734505 / Angielski / Miękka / 2021 / 1088 str.

David D. Coleman; David A. Westcott

Spis treści

Foreword xxxvIntroduction xxxviiAssessment Test lviChapter 1 Overview of Wireless Standards, Organizations, and Fundamentals 1History of Wireless Local Area Networks 3Standards Organizations 5Federal Communications Commission 5International Telecommunication Union Radiocommunication Sector 6Institute of Electrical and Electronics Engineers 8Internet Engineering Task Force 9Wi-Fi Alliance 11International Organization for Standardization 21Core, Distribution, and Access 22Communications Fundamentals 24Communication Terminology 24Understanding Carrier Signals 25Understanding Keying Methods 27Summary 33Exam Essentials 33Review Questions 34Chapter 2 IEEE 802.11 Standard and Amendments 39Original IEEE 802.11 Standard 42IEEE 802.11-2020 Ratified Amendments 44802.11a-1999 45802.11b-1999 46802.11d-2001 47802.11e-2005 47802.11g-2003 48802.11h-2003 50802.11i-2004 52802.11j-2004 53802.11k-2008 53802.11n-2009 54802.11p-2010 55802.11r-2008 55802.11s-2011 56802.11u-2011 57802.11v-2011 58802.11w-2009 58802.11y-2008 59802.11z-2010 59802.11aa-2012 59802.11ac-2013 59802.11ad-2012 60802.11ae-2012 61802.11af-2014 61802.11ah-2016 62802.11ai-2016 63802.11aj-2018 63802.11ak-2018 63802.11aq-2018 63IEEE 802.11 Draft Amendments 63802.11ax (High Efficiency) 64802.11ay (Next-Generation 60 GHz) 65802.11az (Next-Generation Positioning) 65802.11ba (Wake-Up Radio) 65802.11bb (Light Communications) 65802.11bc (Enhanced Broadcast Service) 65802.11bd (Enhancements for Next-Generation V2X) 65802.11be (Extremely High Throughput) 66Defunct Amendments 66802.11F 66802.11T 67IEEE Task Group m 68Summary 69Exam Essentials 69Review Questions 70Chapter 3 Radio Frequency Fundamentals 75What is a Radio Frequency Signal? 77Radio Frequency Characteristics 78Wavelength 78Frequency 83Amplitude 85Phase 86Radio Frequency Behaviors 87Wave Propagation 87Absorption 88Reflection 89Scattering 91Refraction 91Diffraction 92Loss (Attenuation) 94Free Space Path Loss 96Multipath 98Gain (Amplification) 101RF Analysis Tools 102Summary 103Exam Essentials 103Review Questions 104Chapter 4 Radio Frequency Components, Measurements, and Mathematics 109Components of RF Communications 112Transmitter 112Antenna 113Receiver 114Intentional Radiator 114Equivalent Isotropically Radiated Power 114Units of Power and Comparison 115Watt 116Milliwatt 117Decibel 117Decibels Relative to an Isotropic Radiator (dBi) 120Decibels Relative to a Half-Wave Dipole Antenna (dBd) 120Decibels Relative to 1 Milliwatt (dBm) 121Inverse Square Law 122RF Mathematics 123Rule of 10s and 3s 124RF Math Summary 129Noise Floor 130Signal-to-Noise Ratio 130Signal-to-Interference-Plus-Noise Ratio 131Received Signal Strength Indicator 131Link Budget 135Fade Margin/System Operating Margin 138Summary 140Exam Essentials 142Review Questions 143Chapter 5 Radio Frequency Signal and Antenna Concepts 147Azimuth and Elevation Charts (Antenna Radiation Envelopes) 150Interpreting Polar Charts 152Beamwidth 155Antenna Types 157Omnidirectional Antennas 158Downtilt Omnidirectional Antennas 161Semidirectional Antennas 162Highly Directional Antennas 164Sector Antennas 166Antenna Arrays 167Visual Line of Sight 169RF Line of Sight 169Fresnel Zone 170Earth Bulge 174Antenna Polarization 175Antenna Diversity 176Multiple-Input, Multiple-Output 177MIMO Antennas 178Antenna Connection and Installation 179Voltage Standing Wave Ratio 179Signal Loss 181Antenna Mounting 181Antenna Accessories 187Cables 188Connectors 188Splitters 189Amplifiers 189Attenuators 190Lightning Arrestors 191Grounding Rods and Wires 192Regulatory Compliance 192Summary 194Exam Essentials 194Review Questions 195Chapter 6 Wireless Networks and Spread Spectrum Technologies 199Throughput vs. Bandwidth 201Narrowband and Spread Spectrum 202Multipath Interference 204Frequency-Hopping Spread Spectrum 205Hopping Sequence 206Dwell Time 207Hop Time 207Modulation 207Direct-Sequence Spread Spectrum 208DSSS Data Encoding 208Modulation 209Transmit Spectrum Mask 210Orthogonal Frequency-Division Multiplexing 211Convolutional Coding 212Modulation 213Transmit Spectrum Mask 215Orthogonal Frequency-Division Multiple Access 217Industrial, Scientific, and Medical Bands 218900 MHz ISM Band 2182.4 GHz ISM Band 2195.8 GHz ISM Band 2195 GHz Unlicensed National Information Infrastructure Bands 220U-NII-1 220U-NII-2A 221U-NII-2C 221U-NII-3 222U-NII-4 22260 GHz for Wi-Fi 223Below 1 GHz 2242.4 GHz Channels 2245 GHz Channels 227Long-Term Evolution in 5 GHz 2316 GHz Channels 2326 GHz Incumbents 235Automated Frequency Coordination 2366 GHz Worldwide 2376 GHz Wi-Fi Considerations 238Summary 239Exam Essentials 239Review Questions 240Chapter 7 Wireless LAN Topologies 245Wireless Networking Topologies 247Wireless Wide Area Network 248Wireless Metropolitan Area Network 248Wireless Personal Area Network 249Wireless Local Area Network 250802.11 Stations 251Client Station 252Access Point Station 252Integration Service 252Distribution System 253Wireless Distribution System 254802.11 Service Sets 255Service Set Identifier 256Basic Service Set 256Basic Service Area 257Basic Service Set Identifier 258Multiple Basic Service Set Identifiers 259Extended Service Set 261Independent Basic Service Set 262Personal Basic Service Set 264Mesh Basic Service Set 264QoS Basic Service Set 266802.11 Configuration Modes 267Access Point Modes 267Client Station Modes 268Summary 269Exam Essentials 269Review Questions 271Chapter 8 802.11 Medium Access 275CSMA/CA vs. CSMA/CD 276Collision Detection 277Distributed Coordination Function 278Physical Carrier Sense 279Virtual Carrier Sense 280Pseudo-Random Backoff Timer 283Interframe Space 285Hybrid Coordination Function 286Enhanced Distributed Channel Access 287HCF Controlled Channel Access 288Wi-Fi Multimedia 288Airtime Fairness 290Summary 292Exam Essentials 292Review Questions 293Chapter 9 802.11 MAC 297Packets, Frames, and Bits 299Data-Link Layer 300MAC Service Data Unit 300MAC Protocol Data Unit 300Physical Layer 301PLCP Service Data Unit 301PLCP Protocol Data Unit 302802.11 and 802.3 Interoperability 302802.11 MAC Header 303Frame Control Field 304Duration/ID Field 306MAC Layer Addressing 307Sequence Control Field 314QoS Control Field 315HT Control Field 315802.11 Frame Body 315802.11 Trailer 316802.11 State Machine 317Management Frames 318Beacon 318Authentication 325Association 326Reassociation 329Disassociation 331Deauthentication 331Action Frame 331Control Frames 333ACK Frame 333Block Acknowledgment 335PS-Poll 336RTS/CTS 336CTS-to-Self 338Protection Mechanisms 338Data Frames 341QoS and Non-QoS Data Frames 342Non-Data Carrying Frames 343Power Management 344Legacy Power Management 345WMM-Power Save and U-APSD 347MIMO Power Management 349802.11ax Power Management 349Summary 350Exam Essentials 350Review Questions 352Chapter 10 MIMO Technology: HT and VHT 357MIMO 360Radio Chains 362Spatial Multiplexing 363MIMO versus SISO diversity 366Maximal Ratio Combining 366Space-Time Block Coding 367Cyclic Shift Diversity 368Transmit Beamforming 368Explicit Beamforming 370Multi-User MIMO 371Multi-User Beamforming 373Channels 37620 MHz Channels 37640 MHz Channels 377Forty MHz Intolerant 37980 MHz and 160 MHz Channels 380Guard Interval 382256-QAM Modulation 384802.11n/ac PPDUs 388Non-HT 388HT Mixed 388VHT 389802.11n/ac MAC 390A-MSDU 390A-MPDU 391Block Acknowledgment 392Power Management 392Modulation and Coding Scheme 394802.11ac Data Rates 397HT/VHT Protection Mechanisms 399HT Protection Modes (0-3) 399Wi-Fi Alliance Certification 400Summary 403Exam Essentials 403Review Questions 405Chapter 11 WLAN Architecture 409WLAN Client Devices 411802.11 Radio Form Factors 412802.11 Radio Chipsets 418Client Utilities 418Management, Control, and Data Planes 421Management Plane 422Control Plane 422Data Plane 423WLAN Architecture 423Autonomous WLAN Architecture 423Centralized Network Management Systems 425Centralized WLAN Architecture 427Distributed WLAN Architecture 434Hybrid WLAN Architecture 436Specialty WLAN Infrastructure 437Enterprise WLAN Branch Routers 437WLAN Mesh Access Points 438WLAN Bridges 439Real-Time Location Systems 441VoWiFi 443Cloud Networking 445Application Programming Interface 448Transport and Data Formats 449WLAN APIs 450Common Applications 450Infrastructure Management 451Protocols for Management 452Summary 456Exam Essentials 457Review Questions 458Chapter 12 Power over Ethernet (PoE) 463History of PoE 464Nonstandard PoE 465IEEE 802.3af 465IEEE Std 802.3-2005, Clause 33 465IEEE 802.3at-2009 465IEEE Std 802.3-2018, Clause 33 466IEEE 802.3bt-2018 466PoE Devices 467Powered Device 467Power-Sourcing Equipment 469Endpoint PSE 470Midspan PSE 476Planning and Deploying PoE 484Power Planning 484Redundancy 487Downgrade PoE Capabilities 488802.3bt Power Considerations 488Summary 490Exam Essentials 491Review Questions 492Chapter 13 WLAN Design Concepts 497WLAN Coverage Design 499Received Signal 500Signal-to-Noise Ratio 501Dynamic Rate Switching 503Transmit Power 504Roaming Design 505Primary and Secondary Coverage 508Fast Secure Roaming 509Layer 3 Roaming 510Channel Design 512Adjacent Channel Interference 5122.4 GHz Channel Reuse 513Co-Channel Interference 5165 GHz Channel Reuse 519DFS Channels 52140 MHz Channel Design 527Static Channels and Transmit Power vs. Adaptive RF 529Single-Channel Architecture 531Capacity Design 534High-Density 535Band Steering 539Load Balancing 542Airtime Consumption 543Voice vs. Data 546Dual 5 GHz and Software-Defined Radios 5486 GHz WLAN Design 551Client Considerations 552Coverage Considerations 5536 GHz Channel Reuse 5536 GHz AP Discovery 5546 GHz Wi-Fi Security 556Physical Environment 557Antennas 558Outdoor Design 562Summary 563Exam Essentials 564Review Questions 565Chapter 14 Site Survey and Validation 569WLAN Site Survey and Design Interview 572Customer Briefing 572Business Requirements 573Capacity and Coverage Requirements 574Existing Wireless Network 576Upgrading an Existing WLAN 577Infrastructure Connectivity 578Security Expectations 580Guest Access 581Aesthetics 581Outdoor Surveys 582Vertical Market Considerations 582Government 583Education 583Healthcare 583Retail 584Warehouses and Manufacturing 584Multi-Tenant Buildings 585Legacy AP-on-a-Stick Survey 585Spectrum Analysis 586Coverage Analysis 590Hybrid Survey 595Initial Site Visit 595Predictive Design 597Validation Survey 599Capacity and Throughput 601Roaming 602Delay and Jitter 603Connectivity 603Aesthetics 603Site Survey Tools 604Indoor Site Survey Tools 604Outdoor Site Survey Tools 607Documents and Reports 609Forms and Customer Documentation 610Deliverables 612Additional Reports 613Summary 614Exam Essentials 615Review Questions 616Chapter 15 WLAN Troubleshooting 621Five Tenets of WLAN Troubleshooting 623Troubleshooting Best Practices 623Troubleshoot the OSI Model 625Most Wi-Fi Problems Are Client Issues 627Proper WLAN Design Reduces Problems 628WLAN Always Gets the Blame 629Layer 1 Troubleshooting 629WLAN Design 629Transmit Power 630RF Interference 630Drivers 634PoE 635Firmware Bugs 635Layer 2 Troubleshooting 636Layer 2 Retransmissions 636RF Interference 639Low SNR 639Adjacent Channel Interference 640Hidden Node 641Mismatched Power 646Multipath 648Security Troubleshooting 648PSK Troubleshooting 649802.1X/EAP Troubleshooting 651VPN Troubleshooting 659Roaming Troubleshooting 661Channel Utilization 665Layers 3-7 Troubleshooting 667WLAN Troubleshooting Tools 671WLAN Discovery Applications 671Spectrum Analyzers 672Protocol Analyzers 673Throughput Test Tools 675Standard IP Network Test Commands 677Secure Shell 678Summary 679Exam Essentials 679Review Questions 680Chapter 16 Wireless Attacks, Intrusion Monitoring, and Policy 687Wireless Attacks 688Rogue Wireless Devices 689Peer-to-Peer Attacks 692Eavesdropping 693Encryption Cracking 697KRACK Attack 698Kr00k Vulnerability 698Authentication Attacks 699MAC Spoofing 701Management Interface Exploits 701Wireless Hijacking 702Denial-of-Service Attacks 703Vendor-Specific Attacks 705Social Engineering 706Intrusion Monitoring 706Wireless Intrusion Prevention System 706Rogue Detection and Mitigation 709Spectrum Analyzers 712Wireless Security Policies 712General Security Policies 713Functional Security Policies 713Legislative Compliance 714802.11 Wireless Policy Recommendations 715Summary 716Exam Essentials 717Review Questions 718Chapter 17 802.11 Network Security Architecture 723802.11 Security Basics 725Data Privacy and Integrity 726Authentication, Authorization, and Accounting 728Segmentation 728Monitoring and Policy 729Legacy 802.11 Security 729Legacy Authentication 730Static WEP Encryption 731MAC Filters 735SSID Cloaking 735Robust Security 736Robust Security Network 737Authentication and Authorization 738PSK Authentication 738Proprietary PSK Authentication 741Simultaneous Authentication of Equals 743802.1X/EAP Framework 746EAP Types 749Dynamic Encryption-Key Generation 7514-Way Handshake 752WLAN Encryption 754TKIP Encryption 755CCMP Encryption 756GCMP Encryption 756Management Frame Protection 757WPA2 757WPA3 758WPA3-Personal 758WPA3-Enterprise 759Enhanced Open 7616 GHz Wi-Fi Security 762Traffic Segmentation 763VLANs 763RBAC 765VPN Wireless Security 766VPN 101 767Layer 3 VPNs 768SSL VPNs 768VPN Deployment 768Summary 770Exam Essentials 770Review Questions 772Chapter 18 Bring Your Own Device (BYOD) and Guest Access 777Mobile Device Management 780Company-Issued Devices vs. Personal Devices 781MDM Architecture 782MDM Enrollment 784MDM Profiles 788MDM Agent Software 790Over-the-Air Management 791Application Management 793Self-Service Device Onboarding for Employees 795Dual-SSID Onboarding 796Single-SSID Onboarding 796MDM vs. Self-Service Onboarding 797Guest WLAN Access 798Guest SSID 798Guest VLAN 799Guest Firewall Policy 800Captive Web Portals 801Client Isolation, Rate Limiting, and Web Content Filtering 804Guest Management 805Guest Self-Registration 806Employee Sponsorship 808Social Login 809Encrypted Guest Access 810Hotspot 2.0 and Passpoint 811Access Network Query Protocol 811Hotspot 2.0 Architecture 813802.1X/EAP and Hotspot 2.0 814Online Sign-Up 815Roaming Agreements 816Network Access Control 816Posture 817OS Fingerprinting 818AAA 820RADIUS Change of Authorization 821Single Sign-On 822Summary 824Exam Essentials 825Review Questions 826Chapter 19 802.11ax: High Efficiency (HE) 831802.11ax = Wi-Fi 6 833Wi-Fi Traffic Congestion 834HE Overview 836Multi-User 837OFDMA 838Subcarriers 839Resource Units 840Trigger Frames 844Downlink OFDMA 847Uplink OFDMA 848Buffer Status Reports 849Operating Mode Indication 850MU-MIMO 851BSS Color and Spatial Reuse 855OBSS 855BSS Color 857Spatial Reuse Operation 858Target Wake Time 861Additional 802.11ax PHY and MAC Capabilities 8621024-QAM 862Long Symbol Time and Guard Intervals 863802.11ax PHY headers 86420 MHz-Only 865Multi-TID AMPDU 867Wi-Fi 6 Key Questions 867Clients 867Multi-Gig Ethernet 868Power over Ethernet 8704×4:4 vs. 8×8:8 87180 MHz and 160 MHz Channels 872Wi-Fi CERTIFIED 6 873Summary 874Review Questions 875Chapter 20 WLAN Deployment and Vertical Markets 879Deployment Considerations for Commonly Supported WLAN Applications and Devices 881Data 881Voice 882Video 882Real-Time Location Services 883iBeacon Proximity 883Mobile Devices 885Corporate Data Access and End-User Mobility 885Network Extension to Remote Areas 886Bridging: Building-to-Building Connectivity 887Wireless ISP: Last-Mile Data Delivery 888Small Office/Home Office 888Temporary Office Networking 889Branch Offices 890Teleworker Wi-Fi 890Educational/Classroom Use 891Industrial: Warehousing and Manufacturing 892Retail 892Healthcare 894Municipal Networks 895Hotspots: Public Network Access 895Stadium Networks 897Transportation Networks 897Law Enforcement Networks 898First-Responder Networks 899Managed Service Providers 900Fixed Mobile Convergence 900WLAN and Health 901Internet of Things 901WLAN Vendors 902Summary 904Exam Essentials 904Review Questions 905Appendix A Answers to Review Questions 909Chapter 1: Overview of Wireless Standards, Organizations, and Fundamentals 910Chapter 2: IEEE 802.11 Standard and Amendments 911Chapter 3: Radio Frequency Fundamentals 914Chapter 4: Radio Frequency Components, Measurements, and Mathematics 915Chapter 5: Radio Frequency Signal and Antenna Concepts 918Chapter 6: Wireless Networks and Spread Spectrum Technologies 919Chapter 7: Wireless LAN Topologies 922Chapter 8: 802.11 Medium Access 924Chapter 9: 802.11 MAC 926Chapter 10: MIMO Technology: HT and VHT 929Chapter 11: WLAN Architecture 932Chapter 12: Power over Ethernet (PoE) 934Chapter 13: WLAN Design Concepts 937Chapter 14: Site Survey and Validation 940Chapter 15: WLAN Troubleshooting 943Chapter 16: Wireless Attacks, Intrusion Monitoring, and Policy 946Chapter 17: 802.11 Network Security Architecture 948Chapter 18: Bring Your Own Device (BYOD) and Guest Access 951Chapter 19: 802.11ax: High Efficiency (HE) 954Chapter 20: WLAN Deployment and Vertical Markets 957Appendix B Abbreviations and Acronyms 961Certifications 962Organizations and Regulations 962Measurements 963Technical Terms 964Index 981

O autorze

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.