Xdmcp
From ArchWiki
This page intends to allow remote sessions using "X Display Manager Control Protocol" (XDMCP).
Contents |
KDM
One way to start the X server is through kdm, and if you want to be able to login remotely to your kde session from a remote machine, you need to allow xdmcp. To do this edit your kdmrc ( /opt/kde/share/config/kdm/kdmrc [KDE 3x] or /usr/share/config/kdm/kdmrc (KDE 4x] ) and at the end there should be something like this:
[Xdmcp] Enable=true
Then you need to restart your X server so the change you just made takes effect:
/etc/rc.d/kdm restart
GDM
If you prefer to use GDM instead of KDM, the manipulation is basically the same. Edit /etc/gdm/custom.conf according to the following snippet:
[xdmcp] Enable=true
The restart the Gnome Display Manager:
/etc/rc.d/gdm restart
It is even possible to do all this using the graphical GDM configuration tool (gdmsetup) from a local X session or through the network using ssh -X.
Now you should be able to login remotely using your prefered session/WM. Enjoy!
SLiM
SLiM doesn't support Xdmcp.
Troubleshooting
XDMCP fatal error: Manager unwilling Host unwilling
When connecting to the X server from a remote host you get:
Fatal server error: XDMCP fatal error: Manager unwilling Host unwilling
Your current settings are too restrictive. Edit /etc/hosts.allow to allow remote connexions to display manager. Add this line if you use GDM:
gdm: ALL
and/or
This is usually caused by an entry missing from the "/etc/kde3/kdm/Xaccess" file. This file controls which machines can connect to the server via KDM. The trick is to add a line that starts with an Aster- isk '*'. Look for a line that looks like:
# * #any host can get a login window
and remove the hash '#' sign at the beginning of the line. Then, you need to restart KDM.
/etc/rc.d/kdm restart
Test in Ubuntu Server 8.04. Source: http://www.bogor.net/idkf/idkf-wireless/aplikasi/linux/low-cost-thinclient/lts_tsguide_v2.2.txt