To Find the MAC Address in Xbox 360 Console (New Xbox Experience)
1. Go to My Xbox in the Xbox Dashboard and select System Settings.
2. Click Network Settings, Configure Network.
3. Select Advanced Settings from the Additional Settings tab, then select Alternate Mac Address.
4. 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.
Please Note: It is not possible to use the Xbox wirelessly on the LSU campus.
Referenced from: www.xbox.com