Ok guys I'm going to try pitbulls technique, not sure if it works or not but here it goes.
I'm in a halo lan game right now. If you don't already, make a desktop shortcut of halo and right click it and go to properties...
on the target line put this:
"C:\Program Files\Microsoft Games\Halo\halo.exe" -220.127.116.11:2249
I added the port (the :2249). If it doesnt work, then try without the port. I want to see if anyone can come connect to me. Good luck