[Unwise]

To expand a bit, “port forwarding” is an operation in which you open a port in your router’s firewall and any traffic that comes into that port gets sent to a specified machine. It is set up in your router’s configuration page.

It should ask you to specify the IP of the machine that you want the forwarding to go to, which might mean that you have to turn DHCP off.

You then set up the server on the machine and set the port number to be the port that you just opened. When the server comes up, it will identify itself as having the IP of your computer (e.g., 192.168.0.101), but that is not the IP you want to give your friends – give them the IP of the router.

Incidentally, this is only needed for hosting – contacting a server does not require doing anything to your router.