Forward X11

Very few systems here are configured to forward X11 via SSH. And this will generally be reserved for request by the faculty and not for classroom computers. If you require a GUI environment then you are strongly encouraged to use the Guacamole server by logging in at


and choosing a system (desktop) to log into.

If, however, for some reason you want to access a workstation and have it display a specific application via X11 back to your remote system via SSH, then please contact the Systems Administrator and have them update the SSH server configuration on that workstation. In addition to this you will need to add the following three lines to both your remote (e.g. home device) and CS Dept (local, department account) ${HOME}/.ssh/config files either at the top of the file in the globals section or in a specific stanza for your the system that you are trying to SSH connect to.

        ForwardAgent yes
        ForwardX11 yes
        ForwardX11Trusted yes

Please note that when you make your SSH connection to a remote system from which you want to forward the X11 traffic back through SSH, that you need to use the “-X” option as in

        ssh -X hostname

There is a caveat to this setup, however. If you use X Forwarding through SSH, disabling IPv6 can break this configuration. To fix this specific issue, edit /etc/ssh/sshd_config and change “#AddressFamily any” to “AddressFamily inet”. Save the file and restart sshd using “systemctl restart sshd”.