I have a MacBook Pro and would like to set a custom MAC address for either my Airport WiFi card, or Ethernet port. In older versions of Mac OS X, you could do it like this:
$ sudo ifconfig en0 ether 00:11:22:33:44:55 // Ethernet
$ sudo ifconfig en1 lladdr AA:BB:CC:DD:EE:FF // Airport
For it to work on Airport, you'd have to power it on (e.g. $ sudo ifconfig en1 up), ensure it's not connected to any wireless network, and execute the command. I'm aware such a change won't propagate across reboots.
Unfortunately, this doesn't work on Mac OS X 10.6.6 anymore. Apple appears to have removed the functionality (the command fails silently). Does anyone have any idea how to do it? Thanks for any help you can offer! :)
UPDATE: Automated Python script: https://github.com/dave-gallagher/MacSpoofer

networksetuponly allows read-access to the MAC address using-getmacaddress. – Daniel Beck Jan 12 '11 at 15:40