XDMCP and GDM3

[Martin Feuersänger <m@feuersaenger.de>]

Hi list,

a while ago we played a bit with XDMCP at the local LUG gathering here in
Frankfurt, Germany.

One machine was running KDE 4.6.5 (sid) and the other Gnome 3 (squeeze).

We managed to get a Chooser on each machine from the respective other
machine by issuing
X :1 -broadcast -indirect <IP of remote machine>
Each time the Chooser offered both machines.

Now to my question.

I know which files control the KDM behavior in regard to XDMCP (kdmrc and
Xaccess, both in /etc/kde4/kdm/).
But for GDM3 I have no idea where this is done. It just worked. Xaccess at
/etc/X11/xdm/ had no influence so it must be somewhere else.

But where?

Any clues?

Thanks,
  Martin