NAT type unavailable

NAT type unavailable
NAT issues are rough fix because of the number of variables that come in to play. I'll give you some information since I've run into similar issues numerous times in the past. First I want to add that the modem/router combo provided at a fee from Comcast
do not have the software or firmware to have open NAT on 2 Xboxs at the same time, one will always be strict or moderate and its normally the first one that's connected to the network and given a port that stays open. Secondly, when connecting via wifi you
have no options for port forwarding or setting your Xbox up under a DMC.

Basically because comcast equipment has limited capabilities, your options are VERY limited. So to attempt to troubleshoot this and remedy the issue, we need to eliminate variables. Basically the first thing I would suggest is eliminating if its an issue
with the xbox or not on the wireless end.

Since its not really clear, the first thing I need to know is if your brothers xbox is direct connected or wireless (This shouldn't effect anything either way, however it will give us a starting point.)

If his is hardwired, I suggest unplugging the ethernet and attempting to connect to your router, if its wireless, I would have the xbox forget the wireless connection, login in to your comcast router, and make sure it isn't remembering the console, then
attempt to connect via wireless. You may also want to soft reset your modem/router throughout this process to "clear" things. Based on the results of these test we can essentially eliminate if its a conflict between the two Xboxs or if you s has a bad wireless
card in it.

I will do my best to try to assist you in this, feel free to pm me if you wish.

:)