Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.02.xx and greater

4-59
Wireless Local Area Networks (WLANs)
Configuring a WLAN
Check these boxes to enable the Wireless Edge Services xl Module’s
fast roaming capabilities:
– PMK Caching—The RP and the wireless station agree on a PMK
identifier for their session, which each stores even after the
station disassociates. If the wireless station roams back to the RP,
the two can quickly exchange the PMK identifier and renegotiate
necessary keys, instead of completing the entire authentication
process.
– Opportunistic Key Caching—This capability further speeds roam-
ing between RPs that are connected to the same module. The
wireless station can use the same PMK to associate to any RP that
connects to the module.
– Pre-Authentication—Pre-authentication speeds roaming for sta-
tions that move from an RP on a different Wireless Edge Services
to an RP on this module.
The station must also support pre-authentication. It listens for
beacons from other RPs that support its SSID and authenticates
to them before it roams. The station sends its EAP messages
through its current RP, and that RP’s module broadcasts the EAP
messages throughout the wired network. Pre-authentication
allows your module to listen for and respond to EAP messages
destined to its RPs. The module must be on the same subnetwork
as the original module to receive the EAP messages.
d. After you have configured all the advanced options that you desire,
click the OK button.
5. Click the OK button.
Configuring WPA/WPA2-PSK. As noted above, WPA/WPA2 typically
requires 802.1X authentication. However, for networks that do not have a
RADIUS server, you can set a password, or preshared key, instead of enforcing
802.1X. All users must enter this same preshared key to connect to the WLAN.
Although a preshared key is less secure than 802.1X authentication, the WPA/
WPA2 encryption is still quite strong. WPA/WPA2-PSK is a far better option
than static WEP for small to medium networks.
For more information on WPA/WPA2 encryption, see the introduction to
“Configuring WPA/WPA2 with 802.1X” on page 4-55. To configure WPA/WPA-
PSK on a WLAN complete these steps:
1. Access the Edit screen for the WLAN that is to use WPA/WPA2-PSK:
a. Select Network Setup > WLAN Setup and click the Configuration tab.
b. Select the WLAN and click the Edit button. The Edit screen is displayed.
(See Figure 4-30.)