Looked up how to do multiplayer.
1. Host needs to go into his router settings and port forward 21025, both TCP/UDP
2. Host needs to make sure that that port is forwarded to the correct computer IP for his computer on the router.
3. Host can go to start menu, run, cmd or start menu, search, cmd.
4. Once cmd is open type in 'ipconfig' (No ''s)
5. IPV4 Adress: or something along the lines of xxx.xxx.x.xxx The number at the end of that is the port number that the hosts PC is plugged into. We're going to call this IP-X
7. The host needs to make sure that the IP of the computer he forwarded port 21025 to is the same as IP-X
6. The host needs to go to google, google search "What's my IP?" it will give the host a second IP address, we'll call this IP-Y.
7. Now the host needs to start the Starbound launcher, and launch Starbound server.
8. After the CMD opens up the host can start his own Starbound game.
9. The host will connect to his own multiplayer server using IP-X
10. Everyone else will join the hosts multiplayer server using IP-Y
http://community.playstarbound.com/index.php?threads/fix-starbound-multiplayer.48762/