How do I get Half-Life:Team Fortress to work with the Gateway?
The default client port for Half-Life is 27005. The PCs on your LAN must have “+clientport 2700x” in the HL shortcut command line; the x would be 6, 7, 8, and on up. This allows multiple PCs to connect to the same server. One exception: version 1.0.1.6 will not let multiple PCs with the same CD key connect at the same time, even if they are on the same LAN (it is not a problem with version 1.0.1.3). For hosting games, the HL server does not need to be in the DMZ. Just forward port 27015 to the local IP of the server PC. There remains, however, a problem with people being booted after a few minutes with an illegible server message.