Ok, I've been fighting with my router, isp, xbox, and myself for about 2 years now dealing with this open/closed NAT issue and I'm finally breaking down to ask for help.
Currently, we have two xboxes trying to connect via a linksys E900, which connects to a speedstream 4300 DSL modem, with Windstream as our DSL provider. Before our roommate moved in, it was just one xbox, and only recently did we move to the linksys router, before that was a Belkin F7D6301 (Which is on the compatibility list). After moving to the Linksys, our NAT claims to be Open, but we still can't connect.
I currently have an open ticket with Linksys over how to configure the router, but I've been given the run around from multiple different people and forum posts during my research, regarding this question: Can we have multiple Xboxes connected to Live, With open NAT. Some say yes, Some say no.
Information on the ticket: the Linksys Tech told me to put the Modem in Full Bridged Mode. When I called Windstream to make sure I was doing it properly, the lady had me to do a couple steps from the modems webgui and then claimed I was done. But I was still receiving a 192.168.x.x IP. When I called Linksys back with a "bridged" modem, the new tech told me it still wasn't and that because I have DSL, i wouldn't be able to have both set to open.
I don't remember what firmware version my Belkin Router was at, I do know it was the most current. According to the sticky posts I read here before I posted, I should be able to put my modem into bridged mode, and let the Belkins UPnP run the show. Is this my best bet? If so, I guess I should probably give Windstream another "Friendly" call and get the modem sorted.
Thank you for your help!