I want to run a minecraft server (port 25565) and have it send to my external address for others to play, then to my hostname (I am assuming this is automatic - Do I need a rule for this too?).
But I need to map my ipv4 address (or port 25565) to my external address. I have opened the ports on my router config, so this is all I need. Thanks!
I assume you have the minecraft server behind a router and your Internet Service Provider (ISP) assigns a dynamic IP to you.
In your router settings you have to enable port forwarding. That is, any data sent to port 25565 will have to be forwarded to your minecraft server's internal IP address.
At this point you can find out your external IP by Googling "Whats my IP" (no quotes). and tell your friends the IP address to use to login to the server. If the ISP changes the IP address, you will have to tell them again the new one.
If you subscribe to a dyndns host name, you can give your friends the host name and have the router update the dyndsn service when your external IP changes. See DynDNS updater?
None of this has anything to to with Ubuntu. Therefore this question is off topic here.
Hope this helps
