You need to be setting a static ip on your xbox else each time you start it up it could potentially be a different ip.

Especially if you have multiple devices hooked up to your network. The last number in your IP will always change depending on the order your devices connect to the network. You can just change the IP on the network settings manually.

I got tired of doing all that, so I bought a router that was compatible with my xbox. Absolutely no problems.

Hmm I'll have to check next time I get on. I thought I had a good router, never really had problems with it before Halo. It's a WRT 54g I think. Oh well thanks for responding and for the advice I appreciate it.

http://forums.xbox.com/xbox_forums/xbox_support/networking-hardware/02-routers/linksys/default.aspx

Very odd, that router is in the list. Supposedly, Xbox Live compatible routers don't need anything done to them for them to work properly. At least, I didn't do anything to it... just plug n' play.

Linksys from what I understand are usually pretty good and reliable. Like I said I never had any problems although recently our internet was just upgraded so maybe that had something to do with it? Last couple days since I posted this though its stayed open so I think its fixed. I opened the ports for the Xbox, enabled upnp, and did the dmz thing.