A Field Guide To Wireless LANs for Administrators and Power Users

Ray Janus contributes this review of Thomas Maufer's Field Guide To Wireless LANs for Administrators, writing "Have you wondered about how the magic of wireless networks for PC's happens? If so, this is a very comprehensive manual on how your bits and bytes move through the ether, and the hazards that they face along the way. Having worked with LANs and WLANs in both personal and business solutions, I was pleased to receive a copy of the Guide at a Sonoran Desert User's Group Meeting, compliments of Addison-Wesley Professional/ Prentice Hall. On first glancing at the title, I expected a 'how to' manual on how to implement and manage a WLAN." While that's not exactly what he found, Janus has mostly good things to say about this book. Read on for his review. A Field Guide To Wireless LANs for Administrators and Power Users author Thomas Maufer pages 333 publisher Prentice Hall/PTR rating 8 reviewer Ray Janus ISBN 0131014064 summary This book takes you under the hood of WLAN technology, providing detailed insights and recommendations along the way.

This book starts out an excellent historical overview of the evolution of local area networks and the migration of TCP/IP technology to a wireless environment. In the process, it provides a definitive reference manual on the 802.11 protocol stack, discussing the evolution and future direction of this standard. The issues associated with reliably transmitting data in the very chaotic wireless world are discussed, but the real meat comes in the book's addressing of the logic behind the radio circuitry in WLANs. Along with these insights that an RF engineer will love, the book is a great guide for anyone with protocol analysis tools looking at wireless traffic, especially given the clear illustrations in the text.

Acknowledging the rapid evolution of 802.11 standards over the last few years, an excellent summary is provided, from the venerable 802.11b standard through the -a and -g standards, and moving into future standards being developed by the 802.11 TGs. Maufer provides some key insights on future directions and capabilities of WLANs, too.

The book covers the principal areas of wireless networking, including security, the hot topic for every LAN administrator. While the book does a great job of addressing the theoretical security issues (and other aspects of wireless LANs operation), it is light on practical recommendations in day-to-day WLAN management. The Guide delves into creating strong passwords for use with WLANs, though, and addresses the strengths and weaknesses of the WEP architecture. It is especially rich in providing insights into the handshake and authentication procedures within WEP. A number of proposed security enhancements are discussed, including the deployment of RADIUS servers to provide authentication in enterprise WLANs. In closing on this section, Thomas provides good insights into WPA, which is becoming the future standard to WLAN security.

For a WLAN component designer, this is probably one of the best reference guides available, and this is also true for power users who really want to get under the hood of today's WLAN systems. However, for a network administrator seeking advice on how to address a herd of WLAN devices, my recommendation would be to seek elsewhere. Maufer offers little information about vendors' product types/models, making the detailed technology discussions independent of real-world products. For the administrator able to glean the technical details of their chosen WLAN products elsewhere, though, this book can be an invaluable guide in deciding the pros and cons of a particular product solution.

Along the way, Maufer provides a series of helpful screenshots, as guides to the technical discussions addressed in the various chapters. He provides a very balanced overview in the use of WLAN technologies for Apple, Linux and Windows platforms.

I recommend this Guide as an excellent text, rich in technical details, and protocol/logic illustrations. A "must read" for understanding WLAN technology in depth. With the rapid advances in WLAN technology, this book represents a excellent benchmark on 802.11 technology, from the perspective of its 2004 timeframe, and a sequel from the author would be an excellent additional resource for WLAN system designers and architects.

You can purchase A Field Guide To Wireless LANs for Administrators and Power Users from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.

Comments

Existing wireless LAN security standards

[slakr]

One of the most common methods of protecting a WLAN, that I think is ignored by most people and this text, is not protecting it much at all, but restricting the use so that its unusable for anyone other than an authorized user. You turn on WAP or MAC-Address filtering to make it inconvinient to attach (though since both of these are vulnerable, this is not enough security in itself). Then you only allow access from the WLAN to your corporate VPN servers. Most machines (laptops) that make use of this will already be equipped for corporate VPN access, and so you rely on the security of your VPN in an unsecured (or relatively unsecure) network. Why are we working on all sorts of new standards when a simple combination of available standards will do just as well? Its not like using Radius auth (via SecureID or password) to your VPN is any harder for the user than any of the other suggestions coming out. Truthfully, its easier for IT since you don't have to build new security infrastructure, and you don't have to retrain users.

this book is outstanding

[Anonymous Coward]

This is an EXCELLENT book for detailed frame analysis, especially if you need the guts of the new security protocols. I read most every wireless LAN book that hits the market, and have written a few of my own. This book is definitely a winner. Thomas does a great job of bringing out hidden and vague areas of the 802.11 standards, and answered several detailed questions that nobody else has been able to answer. Kudos on a job well done.

Use existing VPN technologies to Secure WiFi

[Pii]

I have deployed numerous WiFi networks in corporate environments...

Rather than succumbing to the hassle of the various emerging authentication schemes, I've had good luck in convincing my clients to deploy their WiFi networks behind a VPN concentrator. (Or in cases where they wanted WiFi internet access for guests, putting the WiFi outside their firewall, and having the corporate users come in through a VPN concentrator.)

This is a far simpler, and equally secure method.

Re:VPN isn't always an option.

[slakr]

Maybe its a difference in the way our corporate VPN infrastructure works. But we associate our VPN client with a personal firewall, so that when you're VPN-ed in, ALL data flows the VPN to the corporate network before getting out to the internet. So your POP3 password is securely transmitted (over the IPSec tunnel) to the inside, and then goes out from there. Similarly web broswing goes inside, then through our corporate proxy server and then outside. But if thats not the case with your implementation, then I agree that VPN alone is not a solution for HotSpots and the like. What really bothers me is when companies try to use these new security protocols for in-building wireless. In those cases, the VPN should be the right answer.

not totally secure, just less attractive to attack

[newdamage]

My belief for securing access points in this day and age is to just make yourself secure enough that the attacker decides that it'd just be easier to look for an unsecured AP. If you have such critical information on your network that you need super-secure wireless access, you probably shouldn't be using wireless in the first place.

Casual war-driving studies have been done in the past, and if I remember correctly, on average 60% of APs that were broadcasting were still in their default out-of-box configuration (no WAP, no MAC filtering, default password for adminstration). If you just enable WAP (please use a good random key generator, folks), and MAC filtering, more than likely it just won't be worth it for somebody to try to break in to access your network.

Also, just in case somebody does break into your AP and does something nasty, this is what the daily logs are for, so enable logging on your AP and back them up to disk regularly. Because, yes, you are responsible what goes through your connection, so you better be able to prove there was unauthorized entry, limiting your liability.