That's just the Xbox detecting your behind a router.
You have to forward ports in the router to use your Xbox.
You need to first ASSIGN A STATIC IP TO YOUR XBOX
Use this:
IP = 192.168.0.50, SUBNET = 255.255.255.0, GATEWAY = 192.168.0.1
Leave DNS at automatic
Then go into the D-Link configuration page
Go to the ADVANCED TAB, then to PORT FORWARDING
- put in the IP address 192.168.0.50, and put in the ports that need to be forwarded. You can get that information online or by calling Xbox.