Modem not giving Xbox 360 an ip address

I am having a problem with my modem not giving my 360 an assigned ip address. Becuase my router all of a sudden just quit working I have to plug an ethernet cable into my 360 directly from the modem. While in theory that should have worked, it didn't. I know its not the cable because right now I have the ethernet cable plugged into my computer from the modem and it is giving me Internet. What is the problem here? Any help would be greatly appreciated.

I am having a problem with my modem not giving my 360 an assigned ip address. Becuase my router all of a sudden just quit working I have to plug an ethernet cable into my 360 directly from the modem. While in theory that should have worked, it didn't. I know its not the cable because right now I have the ethernet cable plugged into my computer from the modem and it is giving me Internet. What is the problem here? Any help would be greatly appreciated.

oneMoreComment

I am having a problem with my modem not giving my 360 an assigned ip address. Becuase my router all of a sudden just quit working I have to plug an ethernet cable into my 360 directly from the modem. While in theory that should have worked, it didn't. I know its not the cable because right now I have the ethernet cable plugged into my computer from the modem and it is giving me Internet. What is the problem here? Any help would be greatly appreciated.

oneMoreComment

Might be cos your 360 is set to auto assign an IP and is giving one outside the range from the modem, if your Modems range is 192.168.100.1 - 100 for example try setting the IP address manually on the 360 within that range, so 192.168.100.10 as this should be far enough out to not mess up any ips already on the network (PC, laptop, iphone etc..) let me know how you get on