To locate the MAC address of your Xbox 360 console:
Go to the System area of the Xbox Dashboard and select Network Settings.
Select Edit Settings.
From Additional Settings, select Advanced Settings.
At the bottom of this screen you'll see a heading called Wired MAC Address. Enter this 12-digit sequence into your WAP, router, gateway, or wireless bridge to create a wireless connection to your Xbox 360 console and a connected Xbox 360 Wireless Networking Adapter.