Which ports to forward?

[BehaartesEtwas]

@Bob Dole: wtf?

@Anders118: I don't know your router, so I have to guess a bit, but try this:
service name: pick some name so you remember what this is
service type: udp
starting port: your server port, e.g. 27015
ending port: same as starting port
server IP address: the internal address of your server

beware: often (depending on your router) you will not be able to reach your server from inside your home network via the outside address (as the port forwarding does not work from inside), so ask some friend to check if it's working. you might want to use some dynamic dns service if your external address is not fixed, so other will have some fixed domain name to connect to. and rcon will not work unless you forward also the port on the tcp protocol.