How to enable XDMCP in Red Hat Enterprise Linux

In Red Hat Enterprise Linux 4 and below the file /etc/X11/gdm/gdm.conf could be modified to enable xdmcp. With Red Hat Enterprise Linux 5 and 6, the location to enable xdmcp has changed to /etc/gdm/custom.conf.

There are two ways that xdmcp can be enabled:

Method 1:

Modify the file /etc/gdm/custom.conf and under the [xdmcp] section, add this line:

 Enable=true

Restart GDM

# init 3 # init 5