This web site is about a tool that will automatically associate your wireless (802.11) network card with SSIDs according to a preference list, and fall back to any available SSID in case none of the preferred SSIDs are available.
The software is available for download here.
The software is a perl script wifiassocd.pl, which periodically checks your wireless interface. It looks for available SSIDs (using iwlist ethN scan) and associates with the best SSID available, according to preferences specified by you, the user. If no preferred SSIDs are available, it will associate with any available SSID, and append it to the bottom of the preferred list, so that next time it'll use the same SSID again.
If your wireless card driver does not support the iwlist ethN scan interface, wifiassocd will try to associate your wireless card with each preferred SSID in turn, and stop when one of them works. If none of them work, it will associate your card with any available SSID (using iwconfig ethN essid any).
The software also comes with an init.wifiassocd script that can be installed in /etc/init.d for RedHat Linux, and has proper annotations for chkconfig, so you should be able to simply run:
root# chkconfig --add wifiassocd
after installing init.wifiassocd in /etc/init.d
The distributed tarball also comes with a sample configuration file, wifiassocd.conf, which needs to be installed as /etc/wifiassocd.conf. You can look at this sample configuration file here. The precedence of the SSIDs used by wifiassocd is the order in which the SSIDs are specified in the configuration file. For example, the sample configuration file instructs wifiassocd to always associate with the SSID kolya if possible. If that SSID is not available, SSID WaveLAN Network will be tried next, and so on.
Feel free to send questions or comments to kolya@mit.edu.