How do I play online across a firewall/router? What TCP and UDP ports do I need to open/forward?
See the following Microsoft knowledge base article ‘DirectX: Ports Required to Play on a Network, Q240429’: http://support.microsoft.com/kb/240429 . U2.0x uses DirectX 7 settings. Jeff writes: “Hardwar UIM.06 … still uses the DirectX 7 ports.” The first Hardwar client normally uses TCP port 2300 and UDP port 2350, both incremented by 1 per subsequent client. TCP port 47624 is needed to start/join a game. Mun writes: “I’ve forwarded ports 2300 and 2350 on TCP and UDP, and port 47624 on TCP (so 5 ports).” There are some reports of Hardwar also needing UDP 6073 open (a DirectX 8 setting) – your mileage may vary. On Windows XP’s firewall, Anidem writes: “I had to try to set-up a network game first. Windows Firewall was not recognizing Directplay from the joiner side.
