1

I want to ssh to a WSL2 instance using X11 forwarding from another machine using MobaXterm. The WSL2 host machine and remote machine are literally sitting beside each other and connected to the same switch on a private network so security shouldn't be an issue. MobaXterm is the app I'm using for my ssh server and it has a built in X Server. I'm assuming the approach would be similar using other tools.

It's currently easy to do this from the host machine. I create a WSL Session in MobaXterm and start it. X11 forwarding is configured by default. From there launching UI apps works without any issues or changes to configuration. This automatically sets the DISPLAY variable in the shell to something like 'localhost:10.0' where 10, the display number, will increment for ever session that is opened.

To ssh from the remote machine I followed the steps outlined by x11 forwarding from WSL2 to remote machine: "THE EASY WAY how to SSH into Bash and WSL2 on Windows 10 from an external machine" https://www.hanselman.com/blog/the-easy-way-how-to-ssh-into-bash-and-wsl2-on-windows-10-from-an-external-machine

This allows me to ssh from the remote machine. However, the DISPLAY shell variable isn't set and I can't run any UI apps. If I'm running a WSL session already on the host as I explained in the first step; I can manually set DISPLAY (ex: export DISPLAY=localhost:10.0) and that will work but not too surprisingly it will open the UI on the host machine rather than the remote machine. I assume I need to somehow create a new display on the remote mobaXterm server and set DISPLAY to use that, but I don't know how to do this. I've opened up the related X11 ports in the firewall. ex: 6000-6020.

Scott Hanselman also outlines another approach, where he doesn't replace the default ssh shell. But he recommends against this for various reasons. I've had some success setting up my own SSH server directly in WSL linux, but this is also a bit of a pain in part because the WSL IP address is always changing on reboot.

There are a few related posts already:

Using:

  • MobaXterm version: V21.2 Build 4642
  • WSL2 version: 5.10.16
Mike
  • 791
  • 8
  • 18
  • Welcome to Stack Overflow. Just a friendly, neighborhood reminder that questions on this site should be about *"specific coding, algorithm, or language problems."* The way this question is phrased, at least, it is about *configuration* and would likely be better suited for [Super User](https://superuser.com). I would recommend either editing it to clarify if it really is a programming question or deleting it here and reposting it on the proper site. But I would also point you to [this answer](https://superuser.com/a/1622603/1210833), where my normal solution for this is to use a jumphost. – NotTheDr01ds Aug 09 '21 at 20:36
  • Pretty sure the method that I outline there will work for X11 forwarding since you will ultimately be connecting to the actual *Linux* OpenSSH server running in the WSL2 instance. I have a feeling that Hansalman's method of replacing the Windows OpenSSH shell command wouldn't handle that scenario, since you are still *only* connecting to Windows OpenSSH, but I'm not 100% certain since I haven't tested it. – NotTheDr01ds Aug 09 '21 at 20:43
  • @NotTheDr01ds Thanks very much for providing a way to ssh remote wsl2. I've tried your method. But GUI is shown on remote windows10 instead of local windows10. Any idea how to solve it? – Yue JIN Mar 11 '22 at 17:03
  • @YueJIN Are you using the `-X` or `-Y` argument to `ssh` to forward the X connection? If so, you may want to open a new question on one of the other sites mentioned in my comment above. As long as it's tagged [tag:windows-subsystem-for-linux] on the other site, I should see it. – NotTheDr01ds Mar 11 '22 at 18:21
  • I am facing the same issue. I have setup a way to ssh into WSL2 using ProxyJump from a remote machine. When trying to open a GUI (eg. Gedit) the window opens in the Windows host and not the remote machine. I have tried "ssh", "ssh -X", "ssh -Y" and got the same result from all three. – Shantnav Aug 10 '23 at 09:08

0 Answers0