Computer freezes when switching network locations

For many notebook users, when switching between network configurations using the "locations" menu in the Network system preference pane or from the Apple menu, the computer will lock up and stop responding. This problem has been ongoing despite operating system upgrades and updates, and also seems to not be related to any specific operating system as it occurs under both OS 10.5 and 10.4. Additionally, it has happened with relatively new computers that have factory-installed software on it (no OS upgrades or anything). As Gary Fluitt writes:

"I don't think it could have anything to do with how the OS was installed. My MBP is about 4 weeks old (should've waited for the 2.6Mhz) with 10.5.2 factory installed. Should be a pretty clean system. My crashes happen when switching from Wireless to Wired. Only happens when I've put machine to sleep in home wireless network, wake in work wireless environment (that I don't connect to), and make the location switch to the work LAN. "

Fixes

While the main problem is currently unresolved as it will probably have to come in the form of a software update from Apple, there are several workarounds (besides previously reported deletion of relevant .plist files):

Shut off Airport before switching locations Some users have found that this seems to occur when the Airport connection is actively searching or scanning for networks, and the crashing can be avoided by either waiting for the scanning to stop before changing network locations, or by manually turning off Airport before switching locations. Unfortunately this is not a fix that works for everyone.

Fix corrupted keychains While this fix has not been tested long enough to ensure it's a more than just a temporary fix, it has seemed to have fixed the problem for a few users. Open the "Keychain Access" utility and run a repair on the keychains. If a corrupt keychain entry is interfering with the network settings, then that may be contributing to the freezes.

Do not use locations if it can be avoided Try setting up the network system preferences so that you use only one location. For instance, if one network requires Airport, and the other uses Ethernet, just set up one location to have both Airport and Ethernet services available. It appears many users are creating location configurations with only the ports and services they use at that location. While this may seem convenient and organized, some folks have found that lumping them all together avoids the freezing problem. Granted this may not be doable for people who require two different configurations for the same service, depending on the location, but it may be useful for others.

• Freezes when switching network locations/ports: Parallels to blame?

Resources