SSID Broadcast Question

By M. David Stone

In “Making the Best of WEP” ( www.pcmag.com/article2/0,1759,1429905,00.asp ), you recommend disabling the SSID broadcast for access points as a security measure for 802.11b networks. But Microsoft says, “Disabling SSID broadcasts on an access point is not considered a valid method for securing a wireless network” ( http://support.microsoft.com/default.aspx?scid=kb;en-us;811427 ).

With the SSID broadcast disabled, if there is another access point within range that is broadcasting, systems will automatically switch to the access point that’s broadcasting its SSID. This happens even if you didn’t list that broadcasting system as a preferred network and you’ve listed the access point that’s not broadcasting as preferred. It seems, then, that turning off the SSID broadcast is something you shouldn’t do. – Carey Holzman

You’re right about Microsoft’s statement, but the access point manufacturers we’ve talked to disagree. More important, the behavior you describe applies only if you are using Windows XP SP1, let Windows control the connection, and have Win-dows set to connect automatically to nonpreferred networks.

To ensure that Windows will connect to an access point that’s defined as a preferred network but has broadcasting turned off, open the Control Panel and choose Network Connections, then Wireless Network Connection, and then the Properties button. Next, choose the Wireless Networks tab and then the Advanced button. Make sure that the Automatically connect to nonpreferred networks check box is not checked. Now you should be able to connect without problems to an access point that’s not broadcasting its SSID, as described in our original tip.