kair: Tiger and Lost Wireless Network Connectivity

Some people may have chosen the option in the AirPort Tab to Connect to a Specific Network, instead of allowing the Automatic setting to select your network. You may have chosen this option because there are several networks in your neighborhood, and you wanted to connect to your network when booting up, or when waking from Sleep. Oftentimes, connecting to a specific network, coupled with Manual IP Addressing would alleviate common problems with AirPort connection.

After upgrading to Tiger (Mac OS X 10.4), the upgrade process imports your previous Network Preference setting. Tiger offers a different set of Network Preferences choices when setting up a New Location than existed in previous iterations of the Mac OS. The Automatic wake from sleep option still exists in Tiger, but the Specific Network option has been replaced by Preferred Networks window. In previous Mac OS versions, in the Specified Network screen, you filled in the name and password of the network to which you wish to attach upon waking from sleep. With Tiger, you now simply choose the Preferred Network from a scrolling window, which apparently uses your Keychain to fill in the necessary information.

Unfortunately, it appears that while upgrading from an previous Mac OS to Tiger, the required transition from Specific Network to Preferred Network is less than perfect. After upgrading to Tiger, you may notice that the pulldown menu in the AirPort tab of your imported Locations contains only the option for Specific Network, Automatic is not listed, nor is Preferred Network. This anomaly appears to cause a connection failure when waking from sleep, or on a reboot.

In order to return the correct wake from sleep behavior to your upgraded system, you have two options for regaining connectivity. You can go to the AirPort tab and delete your old WEP key (password) for your Specific Network, and retype it in the required spot. You should now be able to connect to your network. This option leaves the pulldown menu with only Specific Network visible, and Automatic and Preferred Networks will not show in the menu.

I find it preferable to create a New, uniquely named Location in System Preferences>Network filling in the correct TCP/IP information (either using DHCP or your Manual IP settings). Then simply return to the AirPort Tab and select the "By default, join:" preference you wish (Automatic or Preferred Network). Apply your settings and you should be good to go. You should then return to the System Preferences pane and delete your old Location. It has been noted that in some instances, you may need to delete your old Trusted Networks from the Preferred Networks listing. This option allows you to align your System Preferences>Network preference pane with the configuration that the Apple design team intended, just in case some future upgrade needs the preference pane in this configuration.

If you are experiencing problems with your computer losing its connection to a Roaming AirPort Network, see also this KB Article.

Thanks to Duane, Henry B. iFelix, Alan Macdougal, Dr. Smoke.