I'm guessing from your question that you're having issues with Xbox Live. You're going to have to find your router's port forwarding screen (I don't know Netgear) and forward UDP 53, 88, and 3074 and TCP 53, 80, and 3074 to the Xbox. (Setting a static IP for the Xbox will help. The easiest way to do this is probably from the Xbox itself; most commercial routers comply with any request that doesn't cause a conflict.)