Re: Cant connect Xbox360 wirelessly to 2Wire 3801HGV, help!
Go to your router and check the mtu on the status page. If you are having an Xbox issue you will likely see it set at 576. Mine is and so are many, many others. Go check the Xbox forums and you will see the same issue with everyone. It is also posted by Microsoft on the Xbox support status page. Definitely a know issue with MTU at this time.
I had to reset the network configuration to default settings on the xbox. Something I completely looked over thinking it was the gateway's fault. After that I had no problems connecting to the gateway or my router's wireless networks. I decided to stick with using my old router and just using the gateway as a modem though, since I had already set it up... *Smacks forehead*