X over SSH and xauth not working

linuxputtysshxauthxorg

I have 2 Linux Boxes (S1 – 192.168.0.98 and C1 – 192.168.0.76) and a Windows 7 Box (W1 – 192.168.0.91).

One of the Linux machines (S1) was setup with SSH and X forwarding, and the windows box (W1) has Xming server on 0.0.

I can run Putty, then xeyes on the windows box(W1) and it displays fine.

On the second linux box C1), I cannot get remote x running over ssh.

I can log in from C1 to S1 via ssh -X but when I run a graphical program, it doesn't display on the remote machine, it just sits there until a "Can't open display: 192.168.0.76:0.0" comes up.

What am I doing wrong?

Best Answer

Your error message "Can't open display: 192.168.0.76:0.0" doesn't sound like SSH X11 forwarding is in use. Instead, programs on the remote host are trying to connect directly to C1, which won't work for quite a few reasons (Xorg does not listen for TCP connections by default; your firewall blocks them; the Xauth data was not sent correctly...) If X11 forwarding was in effect, then $DISPLAY would point back at the same machine (localhost), and the display number would start at :10.

First, check the $DISPLAY value on C1, and make sure clients on C1 can connect to the X server.

Then retry the connection C1→S1 using ssh -X -v -v S1 and make sure there are no error messages regarding X11 forwarding; it might be disabled on the server. (If you connect with PuTTY, then Ctrl+rightclick the console and select "Event Log".)

To see the server logs, add LogLevel DEBUG2 to /etc/ssh/sshd_config and restart sshd.

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