X2Go server does not work with servers behind OpenMPTCProuter

[BigFanOpenmptcprouter]

Expected Behavior

When I connect to server behind OpenMPTCProuter the X2Go server should be reachable.

Current Behavior

When I connect to server behind OpenMPTCProuter the X2Go server is not reachable. However SSH server is reachable (uses the same port/protocol). When I disable the OpenMPTCProuter and use any other router with port forward function the X2Go Server works fine.

Possible Solution

The workaround is to connect to another machine that is not using the the OpenMPTCProuter and then via LAN connect (within local network) to the server using OpenMPTCProuter as default gateway.

Steps to Reproduce the Problem

1. Setup X2Go Server that is serving desktop .
2. Setup OpenMPTCProuter.
3. Try to connect from other network towards that X2Go Server behind a OpenMPTCProuter router.

Detailed X2Go server installation: apt update && apt dist-upgrade apt install openssh-server apt-get install x2goserver x2goserver-xsession xfce4 reboot (that's it on server side) Detailed X2Go client installation: apt install x2goclient setup the client side to use xfce4 (that's it on client side)

Context (Environment)

I have a reason to believe it's somehow a latency issue. Connecting to an X2Go Server takes usually long time (up to 20 seconds) depending on the line quality and distance (latency) between location A and location B, maybe the connection is somehow dropped in the OpenMPTCProuter in the meantime.

How to install x2go (both the server and the client parts are in repositories of Ubuntu 22.04 and newer - no need for PPA): https://wiki.x2go.org/doku.php/doc:installation:x2goserver https://wiki.x2go.org/doku.php/wiki:advanced:x2goserver-in-detail

Specifications

• OpenMPTCProuter version: v0.60-6.1 r0+24843-acf40c022e
• OpenMPTCProuter VPS version: 0.1030 6.1.0-22-cloud-amd64
• OpenMPTCProuter VPS provider: OVH
• OpenMPTCProuter platform: x86_64
• Country: No restrictions but high latency (up to 400ms).

[github-actions[bot]]

This issue is stale because it has been open 90 days with no activity. Remove stale label or comment or this will be closed in 5 days

[BigFanOpenmptcprouter]

The problem still persist.