My PS3 is 192.168.1.19 and Xbox is 192.168.1.20, i have also reserved these IP addresses so no other equipment can lease them, you do this in LAN IP Setup.
Your Gateway would be 192.168.1.1
DNS 192.168.1.1, you have no secondary.
No proxy
I leave everything else are std settings.
I did these settings on the ports:
http://portforward.com/english/route...on_Network.htm
Hope this helps.