[CentOS] CentOS 6 and XDMCP

Hi all,

I am trying to use XDMCP from a Mac (OSX Lion, XQuartz) to an updated CentOS 6 64Bit host.

I am tunneling through SSH, so I use XDMCP on the remote host locally via Xnest like this:

ssh -X -C -l $LOGINUSER $HOST -n "Xnest :1 -ac -geometry 1440x850 -once -query localhost

I get a black screen without any login window or desktop background.

My /etc/gdm/custom.conf looks like this:

# GDM configuration storage [daemon] [security] DisallowTCP=false AllowRemoteRoot=true [xdmcp] Enable=true [greeter] IncludeAll=true [chooser] [debug]

According to the howtos on the net this should be sufficient, so I am quite stuck. How can I figure out if this is a problem of the CentOS config or of XQuartz?

Any hint or help would be appreciated.

Dirk