Question About Ethernet Internet Sharing to Game Console via Wireless

This is probably in the wrong section, and I apologize but I wasn't sure where to put it.

I am at college and we do not have wireless internet here. It is all ethernet. I am trying to share my ethernet connection via AirPort to my x-Box 360 as I am currently doing successfully with my iPhone. However my x-Box will not connect to the shared connection from my MacBook. How do I get it to connect or set up a connection so that it will?

I have done a lot of searching and everything I have found is the opposite of this where it is sharing a wireless connection via ethernet cable to the 360. I want to share the ethernet via wireless to my 360.

And the reason I am doing this is because I can connect it to the ethernet, however the network will kick the 360 off because it is not a computer. I submitted a request form to the IT people here to register my 360's mac address so it doesn't kick it off but I am sick of waiting for them to do it so I would rather just run it through my computer in the meantime.

So is there any way to do this?

Thanks,
Alex