Private Match - Force Host - End game through host menu - Go online.

You must be the host for them to work. Make sure to get a patch with force host. You can find this under the "Host" menu make sure to toggle that to on the you will have a good possibility of getting host. But remember it depends of your internet contention. Hope i helped

Force host ftw, or private matches obviously.

Moved to MW2 Hacking Questions.