XDMCP stands for X Display manager control protocol.

The display system used in Linux was designed from the beginning as a network protocol, where the system and programs run in one computer and the display being shown on another.

The XDMCP protocol allows you to login graphically to a remote computer.

It is not a very fast protocol and these days there are better ways to achieve the same effect in a more efficient manner.

As of Gnome 2.2 and KDE 4 support for XDMCP login on the GDM/KDM login screen was dropped.

It is still possible to configure and setup XDMCP under those environments but it was easier when the distributions set it up from the get-go.


If you are using a version earlier than Gnome 2.2:
On the computer you want to log in to. XDMCP must be enabled:
1. From the main menu open
"Administration | Login Window"
2. On the "Remote" tab select a style

On the local computer
1. On the Login manager select "Session"
2. On the session Menu select "Secure remote connection"
3. Select the server you want to connect to and login.

If you are using Gnome 2.2 or newer you need to do it all by hand

On the computer you want to log in to. XDMCP must be enabled:
1. modify /etc/gdm/gdm.conf-custom to enable xdmcp


Reboot computer

On the local computer:
There are several ways, xinit, Xephyr, xnest, and others

For example
sudo xinit -- :2 -query

Xephyr -query :1 -host-cursor -screen 800x600


Here it is explained quite nice

For more detailed information

File Attachments

Attachment Size
loginpreferences.png 47.28 KB
sessions.png 243.22 KB