My roommates and I like to play Diablo III and World of Warcraft at the same time, but we experience frequent disconnects. If one of the machines is in the DMZ on the router it doesn't disconnect when the other two do. I've turned the router firewall off and this does nothing to help. Any ideas? Can I just forward all the appropriate ports to ALL of the computers?
If I plug straight into the modem I do not experience disconnects.
Router model: FR-300RTR (rebranded d-link)
Router firmware: DD-WRT c24-sp2
Router firewall: off
UPnP: on
dmz: off
manual port forwarding: off
All machines are running windows 7
Best Answer
You absolutely don't need port forwarding. Port forwarding is only necessary if you host a (game) server behind your router/firewall which is not the case, neither with Diablo III nor with World of Warcraft. In both games all game sessions are hosted on Blizzard's servers.
The following router setup should work no matter how many people are playing World of Warcraft or Diablo III behind the router:
Don't use the DMZ (quite a security risk - if necessary, use port forwarding instead)
Disable your router firewall since you most probably don't need it. Outgoing traffic shouldn't be blocked and incoming traffic which is not initiated by yourself will not reach you since you are using a NAT router.
Only enable port forwarding if necessary. This is the case if you want to host some kind of service behind the router where clients from the Internet need to connect to (e.g. a web server). Some older games require port forwarding though (e.g. WarCraft III, StarCraft I) but Diablo III and WoW don't.
Enable UPNP to make port forwarding easier (will be done automatically) but be careful since this can also be a security risk.
In my opinion your frequent disconnects seem to come from a broken router/modem.