How to keep the same inet address?

I am trying to connect my mac to my xbox and have done it before. At times it doesn't connect just because my inet address on my mac is constantly changing when i am about to play. The xbox will only recognize my address as xxx.xxx.3.1, not xxx.xxx.2.1 which is displaying now. Is there a way that I can just keep it as xxx.xxx.3.1?How to keep the same inet address?
You can try checking with the Xbox site. though I find it funny that you're trying to hook up a Microsoft Product on an Apple Product.

I'm assuming that inet address is just an ip address. I suggest changing your Mac's inet address to xxx.xxx.3.1 so both your Xbox and Mac can be on the same inet address, but you can try looking it up with the Xbox site.