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Port Forwarding for Blizzard Battle.net Games



Diablo, Warcraft II Battle.net Edition, and StarCraft:
Allow port 6112-6119 TCP and UDP out and in

Diablo II:
Allow port 6112 TCP out and allow established sessions in
Allow port 4000 TCP out (realm games)
Allow port 4000 TCP out and in (hosting open games only)

Warcraft III:
Allow port 6112 TCP out and allow established sessions in
Allow port 6112 TCP in (hosting custom games)
Allow port 6113-6119 TCP out and in (hosting custom games if you've changed the default port in the Options/Gameplay screen)

If you are still having problems after you open up the required ports, try opening 116(TCP) and 118(TCP). I don't really know if these ports are required or not.
I have had people tell me that opening up those two ports have helped them connect to battle.net.