Since I upgraded from Ubuntu 18.04 to 19.10 my remote TCP-XWindows broke, and I need it for work.
I'm working on a really old currently-in-production system which uses old-style X11 TCP connections. It cannot use SSH X-forwarding. I need to make Ubuntu accept remote TCP connections (from an aging Solaris box).
This is closely related to How to make X.org listen to remote connections on port 6000?. However, I have done everything in the answers and the problem remains.
I need to be able to run a remote X-Windows application, e.g.:
xeyes -display 192.168.1.111:0.0
And have it appear on my local workstation. But what I get is (of course):
Error: Can't open display: 192.168.1.111:0.0
I have edited
/etc/gdm3/custom.conf, to contain:
[security] DisallowTCP=false [xdmcp] ServerArguments=-listen tcp
I am definitely running
gdm, and not
I have also edited
/etc/X11/xinit/xserverrc, such that it now says:
exec /usr/bin/X -listen tcp "$@"
Although I expect that
gdm modifies this anyway.
I have issued the command
xhost +remote_server_name and
xhost + (in desperation).
I can see X11 listening on port 6001. (x11-1 is 6001 in
/etc/services ... why is this not x11-0 / 6000?)
$ netstat -a | grep x11 tcp 0 0 0.0.0.0:x11-1 0.0.0.0:* LISTEN tcp6 0 0 [::]:x11-1 [::]:* LISTEN
(and rebooted after these changes).
Has some "extra layer" of configuration been added in Ubuntu 19 to prevent X11 running in this manner?
EDIT: It seems like the processes are running OK:
2196 tty2 Ssl+ 0:00 /usr/lib/gdm3/gdm-x-session --register-session --run-script --allow-remote-connections cinnamon-session-cinnamon 2198 tty2 Sl+ 16:53 /usr/lib/xorg/Xorg vt2 -displayfd 3 -auth /run/user/1000/gdm/Xauthority -listen tcp -background none -noreset -keeptty -verbose 3
EDIT2: Update for commenters
The old application is passed the display on the command-line, e.g.:
--display 192.168.1.111:0.0 It then takes it upon itself to open further windows on the remote display.
I have tried
xhost +, it made no difference.