Key Management

Encryption Algorithm

User Authentication

WPA with RADIUS provides dynamically-generated keys that are periodically refreshed.

There are different Unicast keys for each station.

•Temporal Key Integrity Protocol (TKIP)

•Counter mode/CBC-MAC Protocol (CCMP) Advanced Encryption Standard (AES)

Remote Authentication Dial-In User Service (RADIUS)

You have a choice of using the Gateway 7001 Series self-managed AP embedded RADIUS server or an external RADIUS server. The embedded RADIUS server supports Protected EAP (PEAP) and MSCHAP V2.

Recommendations

WPA with RADIUS mode is the recommended mode. The CCMP (AES) and TKIP encryption algorithms used with WPA modes are far superior to the RC4 algorithm used for Static WEP or IEEE 802.1x modes. Therefore, CCMP (AES) or TKIP should be used whenever possible. All WPA modes allow you to use these encryption schemes, so WPA security modes are recommended above the others when using WPA is an option.

Additionally, this mode (WPA with RADIUS) incorporates a RADIUS server for user authentication which gives it an edge over WPA-PSK.

Use the following guidelines for choosing options within the WPA with RADIUS security mode:

■The best security you can have to date on a wireless network is WPA with RADIUS using CCMP (AES) encryption algorithm. AES is a symmetric 128-bit block data encryption technique that works on multiple layers of the network. It is the most effective encryption system currently available for wireless networks. If all clients or other APs on the network are WPA/CCMP compatible, use this encryption algorithm.

■The second best choice is WPA with RADIUS with the encryption algorithm set to “Both” (that is, both TKIP and CCMP). This lets WPA client stations without CCMP associate, uses TKIP for encrypting Multicast and Broadcast frames, and lets you select whether to use CCMP or TKIP for Unicast (AP-to-single-station) frames. This WPA configuration allows more interoperability, at the expense of some security. Client stations that support CCMP can use it for their Unicast frames. If you encounter AP-to-station interoperability problems with the “Both” encryption algorithm setting, then you will need to select TKIP instead.

■The third best choice is WPA with RADIUS with the encryption algorithm set to TKIP. Some clients have interoperability issues with CCMP and TKIP enabled at same time. If you encounter this problem, then choose TKIP as the encryption algorithm. This is the standard WPA mode, and most interoperable mode with client wireless software security features. TKIP is the only encryption algorithm that is being tested in Wi-Fi WPA certification.

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