Using your routers firewall
Routers by nature block all incomming port addresses. The newer routers come with options to forward incomming ports. If your connecting through a router, you will need to configure the router to accept an incomming port. Newer routers are commonly conigured by keying in the routers IP address, in internet explorer. Some of the older routers may require a utility program that came from the original manufacturer.
The router configuration should have a chart of IP addresses, and the port number. Sometimes this is under Firewall settings, Game applications, or some other similar menu.
Key in the number you picked (6112) and your computers local IP address (192.168.100.1) for both TCP and UDP. If your router does not have the BOTH option, you will need to key in one for TCP, and one for UDP.
...