I use Internet Sharing at work to create a local WiFi network (sharing the GigE connection) for my various iOS and tablet devices to connect through. After the 10.7.3 update, I cannot turn sharing off after I unplug the Ethernet cable. All the checkboxes in the system pref pane are cleared, but I am unable to join a WiFi network.
After I plug the Ethernet back in, I can then disable sharing, but only while it's plugged in.
As best I can guess, there might be some xinetd cruft laying around, but I haven't the slightest clue as to how to look for it or fix it. Any ideas?
Best Answer
I found a relatively simple solution not involving a system restart - just bring the WiFi interface down and then back up:
In my case
en0
is the AirPort interface of my MacBook Air.Note that turning the AirPort off and on again doesn't work, but bringing the interface down does the job.