Can't get xterm to work. DISPLAY not set.

Question

Here are my settings:

$ xterm
xterm Xt error: Can't open display: 
xterm:  DISPLAY is not set

$ echo $DISPLAY

$ cat /etc/ssh/sshd_config | grep X
X11Forwarding yes
X11DisplayOffset 10

Answer 1

You need to use the -X flag

ssh -X user@server

Answer 2

In my case I was missing the xauth program on the target machine

How to debug these situations:

1. On the target host, run another sshd daemon to debug on another port:

   /usr/sbin/sshd -d -p 222
   

2. On the source host:

   ssh -v -Y [email protected] -p 222
   

In my situation I could see:

debug1: Remote: No xauth program; cannot forward with spoofing.

(Note: to run sshd on another port you may need to modify or temporarily disable iptables : /etc/init.d/iptables stop, or equivalent)

Answer 3

Try with this command:

DISPLAY=:0 xterm

Answer 4

Did you run vncpasswd in the account you used to write the configuration file?

I had this problem because I configured the root account but the vnc user is another, run the vncpasswd again in the right account and everything will be ok.