The official llcon jam server is llcon.dyndns.org.
If you have installed your own server and want to share it with other users, please post the internet address of your server in this forum thread.
In the newest version of the llcon software which is 3.2.0 there is a functionality included to simply add your private llcon server to a public server list. You simply start the server and check the "Register Server" check box if not already checked. If enabled, the local server will contact the main llcon server and register itself. This server will then show up in a server list which will be available in each client software.
The server list manager also takes care about the port forwarding issue. No extra port forwarding has to be set up in your internet router.
Under Windows, an option is available that your llcon server is automatically started when the computer is turned on.