X11 forwarding over SSH

Sunday, May 28, 2006 by Nate Murray.  

Setting up X11 port forwarding via SSH is a pretty simple task. Here is how to do it between a Slackware and Mac OSX machine. The process should be general enough to expand other *NIX machines. The first step is to setup your sshd to forward X11.

*On the server machine (Linux in this case) add the following line to

/etc/ssh/sshd_config

X11Forwarding yes

*Also in /etc/ssh/ssh_config add these lines:

ForwardAgent yes
ForwardX11 yes

*Then as root restart sshd:

root@slackware# /etc/rd.d/rc.sshd restart

Running an Application from the Mac

• Then startup /Applications/Utilities/X11.app on the Mac.
• Open up an xterm and type the following commands:

user@slackware: ssh -X user@slackware
user@slackware: echo $DISPLAY
:10.0
user@slackware: xclock

Notes:

• The -X tells ssh to forward X11.
• If you do not get a reponse when you echo $DISPLAY you do not have the X11 forwarding setup correctly.

See also SSH: X11 Forwarding