My 360 disconnects my brother's 360

[reddragon6450]

Ok, here's the problem, my 360 and my brother's 360 are connected to the same router. When we both turn on our 360s we both log in to xbox live. If I play a game I'm still login to xbox live, but if my brother pops in a game it logs me out of live and I can't reconnect unless if I goto the Dashboard, but if I pop in a game, while my brother is login to live and is playing a game on live, it will log my brother out of live, but let me play on live, and my brother can only login to live when he is in the dashboard, this resently is happening today, hasn't happen before just today.

Things I ruled out:
- cables being loose
- cables
- ip might of been the same
- the router
- the modem
- internet service prodiver

Things I tried:
- resetting the modem
- resetting the router
- tightening cables
- loosening the cables
- different cables
- new cables
- switching cables
- moving the 360s around the room
- resetting 360s to factory defaults
- erasing cashe

Things that I think might of been the problem:
- I put my Hard Drive in my brother's 360 and tried to get live, but didn't
even load the window with the type of live bundles to buy. It just let me
press A on the ad, but didn't load anything.

Please help me out bros.

[woody101]

At a guess, I would suspect that both 360s are allocating the same port on the router via the UPnP, try disabling the UPnP. This will be more restrictive when connecting to online games, but would at least let you know if its the problem.

[spooner]

Have you changed ANYTHING on your network recently?
Do you have an internet ethernet switch/are you running both off the same port on the router?? if so, then maybe what's happening is since the 2 xboxs are on the same port they are logging each other out since in some cases they cannot both communicate at the same time on 1 port...(I get away with it with 2 computers on the switch, but try allocating each xbox it's own port on the router anyway if you have not already done so!)
I don't know much about networks but I think someone told me you can't use two computers at once on the internet switch.
If you aren't using an internet switch then check out your router instructions-your router may be programmed to do this but I think you will be able to change that.

[Kaos2K]

Try to put at least one Xbox on the router DMZ zone (You will need to reserve or assign it a static IP first).

[wikilicious]

Even I am looking for the solution to the same problem :(