i had the same problem,2 xbox's and a ps3.after dealing with d-link tech support they first told me to use the router as a switch and hook up a 2nd router.basically a 200.00 switch.after replying that back this was there response "Based on your e-mail, if you want to configure your router for internet, we will suggest you to configure your isp modem in Bridge mode, connect your isp modem to the internet port of the dlink router and configure the D-Link router in PPPoE mode, else, if you enable NAT on both, there will be an issue of double natting and the internet connectivity will be very poor. "? if this makes sense to anybody please fill me in.my internet works fine.and 1 xbox 360 is open nat.but the fancy dgl-4500 gameing router only allows 1 ip to be gameing.tried all other tcp port that are common and none work except for 80.upnp doesnt help at all when configuring nat problems on these 2 gameing systems.if anybody has figured out how to run 3 GAMEING system through the open nat port please reply.Thanks