During a stay in a Hotel I had the issue that I got locked out of the WLAN after trying to push my private blog [blog.strnad.ch] to git. I hitted proabbly some limitation, or something. The lock seemed to persist so it was time to spoof the MAC Address to get reentry to the Wireless :)

First you have to make sure that you are disconnected from the Wireless Network, specify the correct adapter, in my case it was en0.

1

sudo /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport en0 -z

Then you are good to go to use the MAC you always wanted

1

sudo /sbin/ifconfig en0 ether de:ad:be:ef:01:23

You can verify that the MAC was changed via ifconfig

1
2

ifconfig en0 | grep ether
        ether de:ad:be:ef:01:23