Sorry mate, didn't understand much.
I would really apreciate it if you can describe your setup, starting from where does your internet cable connect to, where does it goes from there, how it derivates, etc.
For example, this is my setup:
I've got cable internet, that is hooked to a wired Linksys 4 port router/gateway, from the router and using 2 of the ports, it goes to my main and secondary PC's using regular CAT-5 cable, and from my 3rd port, also using regular cat-5 cable (not crossover), I connected my XBOX.
Each of this devices is set up manually with static IP's and comcast's DNS numbers, so the ports for my PC will stay unblocked, and my XBOX internal IP don't change so I can FTP back and forth.
My router/gateway IP is 192.168.1.1
Main PC: 192.168.1.100
Sec. PC: 192.168.1.101
XBOX : 192.168.1.102
Good luck mate.