Appendix B Wireless LANs
NWA-3500/NWA-3550 User’s Guide
330
keys. This prevent all wireless devices sharing the same encryption keys. (a
weakness of WEP)
User Authentication
WPA and WPA2 apply IEEE 802.1x and Extensible Authentication Protocol (EAP) to
authenticate wireless clients using an external RADIUS database. WPA2 reduces
the number of key exchange messages from six to four (CCMP 4-way handshake)
and shortens the time required to connect to a network. Other WPA2
authentication features that are different from WPA include key caching and pre-
authentication. These two features are optional and may not be supported in all
wireless devices.
Key caching allows a wireless client to store the PMK it derived through a
successful authentication with an AP. The wireless client uses the PMK when it tries
to connect to the same AP and does not need to go with the authentication
process again.
Pre-authentication enables fast roaming by allowing the wireless client (already
connecting to an AP) to perform IEEE 802.1x authentication with another AP
before connecting to it.
Wireless Client WPA Supplicants
A wireless client supplicant is the software that runs on an operating system
instructing the wireless client how to use WPA. At the time of writing, the most
widely available supplicant is the
WPA patch for Windows XP, Funk Software's
Odyssey client.
The Windows XP patch is a free download that adds WPA capability to Windows
XP's built-in "Zero Configuration" wireless client. However, you must run Windows
XP to use it.
WPA(2) with RADIUS Application Example
You need the IP address of the RADIUS server, its port number (default is 1812),
and the RADIUS shared secret. A WPA(2) application example with an external
RADIUS server looks as follows. "A" is the RADIUS server. "DS" is the distribution
system.
1
The AP passes the wireless client's authentication request to the RADIUS server.
2
The RADIUS server then checks the user's identification against its database and
grants or denies network access accordingly.
Summary of Contents for 802.11a/g Wireless CardBus Card ZyXEL AG-120
Page 2: ......
Page 8: ...Safety Warnings NWA 3500 NWA 3550 User s Guide 8...
Page 10: ...Contents Overview NWA 3500 NWA 3550 User s Guide 10...
Page 20: ...Table of Contents NWA 3500 NWA 3550 User s Guide 20...
Page 22: ...22...
Page 34: ...Chapter 1 Introducing the NWA NWA 3500 NWA 3550 User s Guide 34...
Page 52: ...Chapter 4 Management Mode NWA 3500 NWA 3550 User s Guide 52...
Page 108: ...108...
Page 146: ...Chapter 9 SSID Screen NWA 3500 NWA 3550 User s Guide 146...
Page 160: ...Chapter 10 Wireless Security Screen NWA 3500 NWA 3550 User s Guide 160...
Page 178: ...Chapter 14 IP Screen NWA 3500 NWA 3550 User s Guide 178...
Page 186: ...Chapter 15 Rogue AP Detection NWA 3500 NWA 3550 User s Guide 186...
Page 198: ...Chapter 16 Remote Management Screens NWA 3500 NWA 3550 User s Guide 198...
Page 260: ...Chapter 21 Load Balancing NWA 3160 Series User s Guide 260...
Page 264: ...Chapter 22 Dynamic Channel Selection NWA 3160 Series User s Guide 264...
Page 276: ...Chapter 23 Maintenance NWA 3500 NWA 3550 User s Guide 276...
Page 277: ...277 PART III Troubleshooting and Specifications Troubleshooting 279 Product Specifications 285...
Page 278: ...278...
Page 284: ...Chapter 24 Troubleshooting NWA 3500 NWA 3550 User s Guide 284...
Page 292: ...292...
Page 368: ...Appendix D Importing Certificates NWA 3500 NWA 3550 User s Guide 368...
Page 386: ...Appendix F Text File Based Auto Configuration NWA 3500 NWA 3550 User s Guide 386...