Ubuntu 11.10 export DISPALY to X Server

to enable the redirection of the GUI on a linux server towards your descktop with unbuntu 11.10 is necessary to make some changes.

11.10 Ubuntu version no longer uses the GDM (GNOME Display Manager) but uses lightDM (Light Display Manager), which by default launches the 'X Server with the -nolisten tcp parameters, which prevents the reception in the GUI.

is sufficient to enable it edit the file /etc/lightdm/lightdm.conf

and add

xserver-command = X
xserver-allow-tcp = true

restart the lightDM with the command

sudo restart lightdm.

verify that the X Server is listening on port 6000 with the command:

netstat-tulpn

for example:

tcp         0      0 0.0.0.0:902             0.0.0.0:*               LISTEN      -              
tcp6       0      0 :::6000                 :::*                    LISTEN      -              
tcp6       0      0 ::1:631                 :::*                    LISTEN      -              
 
if everything is OK, you can open ssh into your remote server and run

xhost +
export DISPLAY =<your IP>: 0.0

Now all that has a GUI will be redirected to your monitor.

for example:

xterm
firefox
etc etc