[SOLVED] People can't connect to my server ( Minecraft ) anymore.

[g0dafk]

Today I encountered a pretty strange issue:
First I should mention that my router was restarted and my public IP changed because it is dynamic. All good, I just provided the new IP to my friends and they were able to join the server. It worked for about 2-3 hours, but after that, they were suddenly kicked and not able to join anymore. The server was online, I was logged in. I closed my client, and when I tried to log in again it failed. Now I can only connect with localhost or 127.0.0.1, I can't connect with mypublicip:25565 anymore. It looks like the port forward broke or something, but I checked and it's fine.
I should also mention that my IP suddenly changed while my router was turned on. As far as I know this should not happen. My IP should only change when I restart the router ( but I may be wrong ).
I would also want to mention that when I connect using localhost as the address to my server, I can see in console that I'm connected with 127.0.0.1 not with my public IP address as I was before. What happened?

 

[gggplaya]

I suggest you get a dynamicDNS like duckdns, have it update every few hours. That way your friends can just type in YOURMADEUPNAME.duckdns.org:25665 and have that permenantly saved as a connection in minecraft. Duckdns will take care of updating the ipaddress.

As for why it's not connecting. I don't know. I would start from scratch and redo your port forwarding.

 

[g0dafk]

I did the port forwarding again. I even reinstalled the server from scratch, but it just doesn't work.
Also thank you for the DynamicDNS tip.

 

[SamirD]

Reboot your modem and router again and see if that fixes the issue. Some of the routing sounds like it got messed up.

 

[g0dafk]

Did that... still nothing. Turned off firewall, went on portchecker, port is offline. Server was online so something is listening on that port.

 

[Ralston18]

Make and model router?

The router's logs (if available and enabled) may provide some clue.

Who has full admin rights to the router? You will need help from that person.

 

[gggplaya]

I would just change the port to something else. You can change the port in the server.properties (open with notepad) file for the minecraft server. Sometimes some other program uses upnp to open up the port for itself and your router is confused.