Enable xdmcp in RHEL 5.1

If you want to be able of exporting your X system in another computer, you should keep an eye on this:
vi /etc/gdm/custom.conf

[xdmcp]
Enable=true
[security]
DisallowTCP=true
AllowRemoteRoot=true

After adding up the above lines:

# gdm-restart

Now in your client:

X -query :1

Somehow it can be unsafe to leave available the root access , so I won’t make that decision for you. : )