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Installation Kernel & Hardware Networks Portage Software System X Server Gaming Non-x86 Emulators Misc



XDMCP stands for "X Display Manager Control Protocol" and is a network protocol. It allows a way of running X-Terminal on your PC (or Mac) and uses the X Server to provide a client/server interface between display hardware (the mouse, keyboard, and video displays) and the desktop environment while also providing both the windowing infrastructure and a standardized application interface. The X-Terminal can be displayed with an individual window or multiple windows, based on your X window system's software capabilities and setup.

Editing Configuration

On your X-Server, you must tweak the configuration of your graphical login manager (displaymanager).


You need to comment out DisplayManager.requestPort: 0 in your configfile xdm-config:

File: /etc/X11/xdm/xdm-config
! SECURITY: do not listen for XDMCP or Chooser requests
! Comment out this line if you want to manage X terminals with xdm
#  DisplayManager.requestPort: 0

I also had to remove a commented line in the Xaccess configfile:

File: /etc/X11/xdm/Xaccess
*                                       #any host can get a login window


You need to change the [xdmcp]-section in your configfile gdm.conf:

--For ME The config file is /etc/X11/gdm/custom.conf
File: /etc/X11/gdm/gdm.conf

Depending on how your gdm.conf/custom.conf is set up, you might also need to add or change the [greeter] section as shown below. Without this, you will not be able to XDMCP in to your server.

File: /etc/X11/gdm/gdm.conf


You need to change the [xdmcp]-section in your configfile kdmrc:

File: /usr/kde/3.5/share/config/kdm/kdmrc
Enable = true

Restarting XDM/KDM/GDM

You can restart the display manager by running $ /etc/init.d/xdm restart

How to use XDMCP

On the remote machine you can either use Xnest or simply X:

$ X -ac -query servername :1


$ Xnest -ac -query servername :1

Replace servername with your servername or IP. :1 is the display number. (:0 should be your running X-Server)

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Last modified: Fri, 06 Jun 2008 17:24:00 +0000 Hits: 36,933