The article here mentions:
By default remote x-windows (port
6000) is disabled in Ubuntu. Now one
easy way around this is just to use
ssh to login with port forwarding like
$ ssh -X host
This will set the
DISPLAY variable automatically and any
X program you run will be
automatically tunneled back through
the ssh connection.
Otherwise we're going to need to
enable it. Here's how:
- Go to System->Administration->Login Window (or run gdmsetup as root)
- Under the security tab uncheck "Deny TCP connections to Xserver"
Now we have to restart gdm which will kill our Xsession.
kill -HUP `cat /var/run/gdm.pid`
or if you prefer to edit
by hand, make sure there are no
overriding settings in
/etc/gdm.conf-custom. Under the
security section change