gdm issues

[D-Man <dsh8290 rit edu>]

I have RH6.1 installed on my computer (Intel Pentium) with Gnome and
WindowMaker (whatever versions come with RH, I couldn't find ver.
numbers).

In the labs are Sun Sparc stations (Ultra1 and Ultra10) running Solaris
and using their dt login.  I can login to CDE or "OpenWindows"
(OpenWindows uses my .xinitrc which runs Afterstep right now).  I can
also specifiy "remote login".  This would work for any of the machines
in the lab.

My problem is that I can't remote login to my computer from the lab.  I
get an error saying that the host name was valid, but that no dtlogin or
display manager running.  I am running gdm (or maybe xdm, whatever the
default is, I get the Gnome logo when I boot).  And, yes, my computer
was running when I tried to remote login ( ;-) ).

What would I need to do to fix this problem?  Also, what is required to
allow XDMCP (for X-Win)?

Thank you for all your help,
-D