After many years, I felt like Minecraft again and wanted to create a server, but I can't set it up so that friends (via the Internet, not LAN) can join.
As soon as I enter my IPv4 address under IP address in the server settings (.txt), even I can't join the server (the public IP address will be entered when searching). I can only join it, if I leave the IP address under the server settings free and in the server search in the Launchet 'localhost' enter. However, I believe that the server is then only locally available, because my girlfriend could not join.
Portweiterlung I have made. It should not be that.
You can also leave… You must in your router, the port 25565 as UDP and TCP free, that's it.
I recommend you Aternos, there you can easily create minecraft server for you and your friends. The waiting time until the server is online takes time but you can try it.
TCP is enough
