XDMCP for remote login

Here's how to enable xdmcp in the terminal server client (tsclient/rdesktop) for Ubuntu (tested under dapper). By default the terminal server client program has xdmcp disabled. To fix this just install xnest:
# apt-get install xnest

Alternatively, if you are looking to enable xdmcp in BOSS:

1. Go to System -> Administration -> Login window (or run gdmsetup).
2. Under the Remote tab change Style to same as local. The different choices just change what login screen the user sees.
3. You will need to restart GDM which will kill your X session.
# kill -HUP `cat /var/run/gdm.pid`

Or if you prefer to edit the files by hand:

1. Edit /etc/gdm/gdm.conf (make sure there is no overriding settings in gdm.conf-custom)
2. Uncomment RemoteGreeter in the daemon section.
3. Under the xdmcp section, change Enable to true.
4. Do step 3 above to restart gdm.

also change setting @security..