Using GDM and XDMCP with remote client

How to run Xorg session on client machine.

On the server (IP 10.10.10.1) by default GDM remote connect via XDMCP is disabled. We need to enable it. Configuration file is /etc/gdm/custom.conf (on RHEL/Oracle Linux) and /etc/gdm3/daemon.conf (on Debian). Example is from Oracle Linux 6.4:

# cat /etc/gdm/custom.conf
# GDM configuration storage

[daemon]

[security]

[xdmcp]

[greeter]

[chooser]

[debug]

Add these lines:

# cat /etc/gdm/custom.conf
# GDM configuration storage

[daemon]

[security]
DisallowTCP=false

[xdmcp]
Enable=true

[greeter]

[chooser]

[debug]

GDM must be restarted for this to work.

On client machine start the Xorg server like this (assuming that you have already X running on :0):

# X :1 -query 10.10.10.1

This will bring GDM to your display at display :1 and now you can login and work on client machine as you are logged directly to the server and switch between local and remote X with Alt + Fxx.