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I have two laptops, one running CentOS 7 and recently installed latest RHEL 8 on another one. The issue is that I am unable to launch any X program from RHEL 8 over ssh -X but reverse works okay (tried various, xeyes, gnome-terminal, calculator etc) . Let me elaborate

  1. firewall on both the machines are disabled
  2. X11Forwarding is set to yes on box the laptops by default (/etc/ssh/sshd_config)
  3. from CentOs 7, ssh -X root@rhel8 to login to RHEL 8 box.
  4. from ssh shell, echo $DISPLAY shows localhost:10.0
  5. from ssh shell, launch gnome-terminal. I expected this to be shown on centos laptop display but instead it shows on RHEL 8 laptop itself.

Interestingly, if I do the reverse, login to CentOS 7 from RHEL 8 using `ssh -X' and try to run any program in ssh shell, it is showing on RHEL8 laptop as expected.

Is there anything changed in RHEL8 the way X Forwarding works?

Rahul
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    Do you have the same problem with programs like xterm, xev or xeyes or just with gnome-terminal? gnome-terminal is known to implement its own "application server", completely ignoring and breaking the X11 model, users' expectations, and any sane software engineering principles ;-) –  Jun 23 '19 at 07:47
  • every thing, even gnome-calculator – Rahul Jun 23 '19 at 16:23
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    Are you sure you're running X11 and not Wayland on the RHEL8 machine? Please also try with some classical X11 app like xev(1), xlogo(1) or xclock(1) not just some gnome-*. –  Jun 23 '19 at 16:41
  • nothing working, not even xeyes. Also, I like to use gnome-terminal all of which works fine with CentOS 7. So kindly answer only if you have used RHEL 8 and solved this. – Rahul Jun 23 '19 at 17:00
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    I have used RHEL8 with X11 forwarding, but I won't annoy you anymore. –  Jun 23 '19 at 17:02
  • If you can't run any X program, then you should double check whether you're running Wayland, as mosvy suggested. – muru Jun 23 '19 at 17:07
  • well, as I mentioned, X runs fine, it's just that forwarding does not work. Read point 5. I also check /etc/gdm/custom.conf and I see uncommented WaylandEnable=false. Is there anything else I need to check? – Rahul Jun 23 '19 at 17:14
  • Well, no, you haven't given any evidence of X11 running on RHEL 8. GNOME Terminal runs fine on Wayland, so point 5 means nothing. Wayland supports running X11 applications, so forwarding from CentOS 7 also means nothing. Try some of the methods in https://unix.stackexchange.com/q/202891/70524 to check whether you're running X or Wayland. – muru Jun 23 '19 at 17:37
  • ok it's wayland. so X forwarding does not work? – Rahul Jun 23 '19 at 17:53
  • You only need an X server on the computer running the ssh -X client. Running wayland on the remote side is inconsequential. – jsbillings Jun 23 '19 at 19:38
  • Also, gnome-terminal is kinda special, because if you are already running it in a local login session, it starts a systemd user unit that launches all local gnome-terminal processes, so you might be talking to that daemon for the ssh session. – jsbillings Jun 23 '19 at 19:42
  • see this: enter link description here – P.Goli Jun 24 '19 at 10:16
  • see this link: enter link description here – P.Goli Jun 24 '19 at 10:17

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