When I ssh -X back in to localhost, I do get my DISPLAY set correctly.įorcing DISPLAY to get unset was not too hard. On my local workstation, where I am an administrator, I verified that /etc/ssh/sshd_config was set up to forward X11.

Here is what I did, and what you can do too. Tracking down the missing xauth part was a bit fun. I was running into this empty DISPLAY environment variable earlier today when ssh'ing into a new server that I do not administer. I prefer ssh -X you may like ssh -o ForwardX11=yes you can set this up in your ~/.ssh/config. Be certain to tell ssh to allow X11 forwarding. If you do not have xauth installed, you will run into the empty DISPLAY environment variable problem. On your server, make sure you have xauth installed. You may need to SIGHUP sshd so it picks up these changes. On your server, make sure /etc/ssh/sshd_config contains: X11Forwarding yes Soup-to-nuts, here is how to get X11 forwarding working: If you have both #1 and #2 in place but are missing #3, then you'll end up with an empty DISPLAY environment variable. Your server must be able to set up X11 authentication.Your server must be set up to allow X11 forwarding.Your client must be set up to forward X11.To get X11 forwarding working over SSH, you'll need three things in place: Note that the server won't reply either way, a security precaution of hiding details from potential attackers. To confirm that ssh is forwarding X11, check for a line containing Requesting X11 forwarding in the output of ssh -v -X. If you run ssh and DISPLAY is not set, it means ssh is not forwarding the X11 connection. DISPLAY and XAUTHORITY will automatically be set to their proper values. Note that you do not need to set any environment variables on the server. In the unlikely case xauth was installed in a nonstandard location, it can be called through ~/.ssh/rc (on the server!). If there are any X11 programs there, it's very likely that xauth will be there. The xauth program must be installed on the server side. Note that the default is no forwarding (some distributions turn it on in their default /etc/ssh/sshd_config), and that the user cannot override this setting. On the server side, X11Forwarding yes must be specified in /etc/ssh/sshd_config. On the client side, the -X (capital X) option to ssh enables X11 forwarding, and you can make this the default (for all connections or for a specific connection) with ForwardX11 yes in ~/.ssh/config.

X11 forwarding needs to be enabled on both the client side and the server side.

Ssh mobaxterm