Having trouble port forwarding for Minecraft Server

[pooloop09]

For the past 3 days, I have been trying to get a Minecraft server working for me and my friends to play over winter break, but no matter what I've tried with either Minecraft or proxmox, I haven't been able to get it to a point where other people can join. The servers have all seemed like they are running correctly and after setting up several in the past on a different computer, I don't think it is the server's fault. Currently, I am using MineOS to run the server but I have tried to run the server on a Windows 10 VM with 2 different mod pack servers and a vanilla server. It should also be noted that Proxmox is on a server at my friend's house and I am remotely connecting to it with the same port that I am using for Minecraft if that might change anything (Not using the default 25565 port currently). I have checked the current port with port checkers online and it always says that it is open, but I can't connect to the server. Any help is appreciated

 

[Folke]

Hi,
it's generally not possible to run two applications on the same port, since the port is the only thing that lets an operating system decide which application a package is routed to. Usually that should even prevent your server from starting, with a failure that looks something like Failed to bind to port. To get it running correctly:

1. Choose a port for the server, that doesn't collide with your remote connection
2. Add port forwarding rules for the additional port
3. Make sure the traffic is forwarded to the IP of the MineOS VM, not the Proxmox host system

The port checkers probably report an open port, because the service you are using for remote connections is listening on that port.