Since WSC Guard is a web-based service, what happens if your Internet connection goes down? That's handled by Fallback mode, which switches your WLAN over to either static WEP encryption or WPA-PSK mode (depending on what you're using) but without authentication. You can enter Fallback manually (or restore normal operation) from any client running the WSC Guard application, or better yet, use the Automated Fallback feature.

WSC recommends you set up Automated Fallback on an Ethernet-connected PC. All you need to do is run the WSC Guard installer and answer no to just about every question. Once your system reboots, just bring up the WSG Guard, log into the network and check the box shown in Figure 5.

Figure 5: Automated Fallback

The log in Figure 5 shows that since check in with the WSC authentication server happens only every two minutes (this can't be adjusted), there will be at least that much of a lag in the switchover to Fallback, unless it's done manually.

During switchover to Fallback, wireless clients will temporarily disconnect from the WLAN and should automatically reconnect via either a static WEP key or WPA-PSK. According to WSC, when in Fallback, the WSC Guard application retrieves an encrypted version of the WEP / WPA-PSK key from the Windows registry. The retrieved key is decrypted and entered as a static key if WEP is used.

If WPA is used, the retrieved, decrypted key is entered as a Pre-Shared Key and WPA handshaking is performed. Note that XP Zero Config is told that the AP is still in full WPA mode and the key fields will be greyed out .

When the link to WSC's authentication server comes back up, all clients are disconnected and required to authenticate via the WSG Guard login box. This shouldn't be a problem if your Internet connection is reliable, but it could become a real drag if it isn't!