CWNA Certified Wireless Network Administrator Study Guide Exam CWNA-108

1091 Pages·2021·83.771 MB·English

by  David D. Coleman, David A. Westcott

CWNA®
Certified Wireless Network
Administrator
Study Guide
Sixth Edition

CWNA®
Certified Wireless
Network Administrator
Study Guide
Exam CWNA-108
Sixth Edition
David D. Coleman, CWNE #4
David A. Westcott, CWNE #7
Copyright © 2021 by John Wiley & Sons, Inc., Indianapolis, Indiana
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ISBN: 978-1-119-73633-2 (ebk.)
ISBN: 978-1-119-73453-6 (ebk.)
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“An investment in knowledge always pays the best interest.”
Benjamin Franklin, one of the Founding Fathers of the United States
Almost 17 years ago, we were approached by our publisher to co-author a study guide
for the Certified Wireless Network Administrator (CWNA) certification exam. At the time,
the phrase “Wi-Fi” was only a few years old and had yet to become ingrained in our culture.
802.11g technology had begun to emerge, and we were so excited by the blazing speeds of
54 Mbps available on the 2.4 GHz frequency band. We agreed to author the book. Six
editions later, 802.11 WLAN technology has drastically evolved and Wi-Fi is now an integral
part of our day-to-day lives.
The CWNA certification has long been recognized as the foundation-level certification for
network professionals looking to validate their knowledge of 802.11 WLAN technology. As
authors, we have been humbled by the tens of thousands of individuals who have purchased
the CWNA Study Guide to assist in their pursuit of the CWNA certification. We are also
humbled that many universities and colleges have selected the book as part of their curric-
ulum for wireless technology classes. In our travels, we have met and become friends with
many of our readers of the past five editions of the book. We discovered that a large number
of people who purchase the book use it as a reference guide in the workplace and not just as
a study guide. We have also had many people tell us that the book has helped them advance
in their Wi-Fi careers. Once again, we are very humbled, and we would like to dedicate the
6th edition of the CWNA Study Guide to our readers.
Our goal has always been to educate as many people as possible about WLAN tech-
nology. If you are a newcomer to 802.11 wireless networking, we hope this book will be
your first investment in Wi-Fi knowledge. If you are a veteran WLAN professional, we hope
that when you are done reading this book, you will pass it along to a friend or a colleague.
Sharing the Wi-Fi knowledge will be a sound investment.
Sincerely,
David Coleman and David Westcott

Acknowledgments
When we wrote the first edition of the CWNA Study Guide, David Coleman’s children,
Brantley and Carolina, were young children. Carolina now holds a master’s degree in public
policy from the University of Southern California (USC). Brantley graduated from Boston
University and recently earned his Ph.D. in biochemistry at the University of Washington.
David would like to thank his now adult children for years of support and for making their
dad very proud. David would also like to thank his mother, Marjorie Barnes, stepfather,
William Barnes, and brother, Rob Coleman, for many years of support and encouragement.
David would especially like to thank his wife, Valla Ann, for bringing joy and laughter into
his life every day.
David Coleman would also like to thank his friends and family at Extreme Networks
(www.extremenetworks.com) and the former Aerohive Networks. There are many past
and present Aerohive and Extreme employees he would like to thank, but there simply is not
enough room. So thank you to all of his co-workers. It has been one wild ride the past 11
years!
David Westcott would like to thank his wife, Janie, for her love and support, and for
being the cornerstone of his family. Her love and daily support of four generations of family
does not go unnoticed or unappreciated.
David Westcott also would like to thank the training department at Aruba Networks. In
2004 Aruba Networks hired him as their first contract trainer. Much has changed over the
years, but it is still a fun and exciting journey.
Writing CWNA: Certified Wireless Network Administrator Study Guide has once again
been an adventure. We would like to thank the following individuals for their support and
contributions during the entire process.
We must first thank Sybex acquisitions editor Jim Minatel for reaching out to us and
encouraging us to write this sixth edition of our book. We would also like to thank our
development editor, Kim Wimpsett, who has been a pleasure to work with on multiple book
projects. We also need to send special thanks to our editorial manager, Pete Gaughan; our
content refinement specialist, Barath Kumar Rajasekaran; Elizabeth Welch, our copyeditor;
and Louise Watson, our proofreader.
We also need to give a big shout-out to our technical editor, Ben Wilson of Fortinet
(www.fortinet.com). Ben has accumulated years of Wi-Fi experience working for three
major WLAN vendors. The feedback and input provided by Ben was invaluable.
Special thanks must also go out to both Andrew vonNagy, CWNE #84, and Marcus Bur-
ton, CWNE #78, for their expertise as technical editors in earlier editions of the book.
Andrew Crocker has again provided us with wonderful photographs and some amaz-
ing editing of some not so wonderful photographs that we provided him. You can see much
more of his work and talent at www.andrewcrocker.photography.
Thanks to Proxim and to Ken Ruppel ([email protected]) for allowing us to
include the video Beam Patterns and Polarization of Directional Antennas with the book’s
online resources, which can be accessed at www.wiley.com/go/cwnasg6e.
viii Acknowledgments
Special thanks goes to Andras Szilagyi, for creating the EMANIM web application that
is used with the exercises in Chapter 3, “Radio Frequency Fundamentals.” You can reach
Andras at www.szialab.org.
Thanks to Chris DePuy of the technology research firm 650 Group (www.650group
.com) for the WLAN industry trend analysis.
Thanks to Marko Tisler, CWNE #126, for his content contribution about APIs. Thanks
to Gregor Vucajnk, CWNE #96, for his copy regarding LTE. Thanks to Karl Benedict for
his input and content about directional antennas. Thanks to Perry Correll for his input
regarding 802.11ax and Wi-Fi 6E.
Most gracious appreciation to Rick Murphy, CWNE #10, for his content regarding
OFDM. Rick offers some outstanding WLAN training resources at howwirelessworks
.com.
Very special thanks to Adrian Granados for all of his contributions to the wireless
community. Be sure and check out his cool Wi-Fi applications at www.intuitibits.com.
We have to give a big shout-out to Lee Badman, CWNE #200, for his parody blogs and
memes that he has created about past editions of this book. (He writes great technical blogs
as well.)
Some other WLAN rock stars that are mentioned in the copy of this book: Sam
Clements, CWNE #101; Nigel Bowden, CWNE #135; Mike Albano, CWNE #150; Eddie
Forero, CWNE #160; James Garringer, CWNE #179; Glen Cate, CWNE #181; Jerome
Henry, CWNE #45; François Vergès, CWNE #180; Rowell Dionicio, CWNE #210; Manon
Lessard, CWNE #275; Phil Morgan, CWNE #322; Mac Deryng, CWNE #357, and Matt
Starling, CWNE #369.
We would also like to thank the following individuals and companies for their support
and contributions to the book:
Devin Akin, CWNE #1, of Divergent Dynamics (www.divdyn.com)
Dennis Burrell, Product Innovation Technologist at Ventev (www.ventev.com)
Kelly Burroughs, Product Marketing Manager at iBwave (www.ibwave.com)
Mike Cirello, Co-founder of HiveRadar (www.hiveradar.com)
Jaime Fábregas Fernández, R&D Manager at Tarlogic Research S.L.
(www.acrylicwifi.com)
Tina Hanzlik, Director, Marketing Communications and Cari Eissler, Senior Marketing
Communications Manager at the Wi-Fi Alliance (www.wi-fi.org)
James Kahkoska, CTO of NetAlly (www.netally.com)
Brian Long, CWNE #159, VP, Global Professional Services and Education at Masimo
(www.masimo.com)
Tauni Odia, Director of Product Marketing at Ekahau (www.ekahau.com)
Scott Thompson, President of Oberon, Inc. (www.oberoninc.com)
Ryan Woodings, Founder of MetaGeek (www.metageek.com)