I was playing around with a banned box this week and just for a dafty used an alternative mac adress of 000000000000 on the advanced config in network settings. I was surprised to see all of the checks pass on the live connection test apart from the xbox live test of course.
There was one strange thing though, even though the IP address test passed when checking the error message that normally shows the 'your banned' message, instead of it saying that the message was that the IP address was not valid for use on that console or something of the sort.
The other strange thing was that any other mac address used in the advanced settings section would just make the IP address check fail and the rest of the tests would not run.
Has anyone else tried this, i wonder why the console is accepting 000000000000 as a valid mac address?