I know ya'll have heard the NAT problem a million times. This might be a little different. I have the Cisco DPC3825 Gateway (it's what Cox gave me), I have a cable from that to my desktop, a cable from the gateway to a switch, and I have two Xboxes and a PS3 plugged into the switch.
No matter what I try, one of the Xboxes has a open NAT and the other is set to strict. Best Buy suggested buying a new switch (a NetGear), but I haven't noticed a difference at all. My Dad's place has three Xboxes hooked up and he's never had this problem. I can't figure out what he has that I haven't. Should I have a router instead of gateway? Or a modem? Unfortunately, networking is my weakest area when it comes to computers.