You may need the MAC Address of your 360 when connecting your 360 to a Wireless router, to enter into a wireless client access list. To find your MAC Address do the following:-
  1. Start up the 360
  2. Go to My Xbox/System Settings/Network Settings
  3. Edit settings
  4. Additional settings
  5. Advanced settings.
  6. Take a note of the letters and numbers under the "Wired Mac Address" or "Wireless Mac Address" They should be both the same anyway.
  7. The MAC Address will look something like this 00-0D-61-53-E2-52