Connectivity Problem with Valheim - Instance runs, but my friends can't connect

System Information

Field Value
Operating System Linux - Ubuntu 24.04.4 on x86_64
Product AMP ‘Deimos’ v2.7.2.2 (Mainline)
Virtualization ProxmoxLXC
Application Valheim
Module GenericModule
Running in Container No
Current State Sleeping

Problem Description

Issue

Created a generic valheim instance. I can join the server through steam using the local IP address, but using the public IP address does not allow my friends to join even though my router has the ports 2456-2458 forwarded.

Reproduction Steps

  • Created basic valheim instance
  • port forwarded router
  • friend tries to connect and can’t

Have you tested your IP with an open port scanner eg port-scanner ?