How can I find the MAC address of my Xbox 360?
To locate your Xbox 360's MAC address:
  1. Go to the System area of the Xbox Dashboard and select Network Settings.
  2. Select Edit Settings.
  3. Under Basic Settings, check to make sure the IP Settings is on Automatic.
  4. Go to Additional Settings, select Advanced Settings.
  5. At the bottom of this screen locate the Wired MAC Address heading.