question on x windows

[Boris Devouge]

Aaron Bliss wrote:
> Hi everyone,
> I have a user who would like to connect to x windows on one of our linux
> servers.  I'm not use to offering up x windows to any end users (I'm a
> command line guy) so I'm struggling with this a bit.  I've installed x
> font server, daemon is running, and I installed xfce.  Server is running
> at run level 5 right now.  I'm not sure what ports I need to open on the
> firewall to allow them to connect to the server or what other config
> files that might be preventing them from displaying an x session on
> their desktop (they have a windows x server running on their machines). 
> I know that x windows sessions are insecure, so I would also be in favor
> of forwarding the session over ssh, but I would like to know how to
> connect with and without ssh to the xfs server.  Thanks for your help.
> 
> Aaron
> 

X runs on 6000/tcp. By default, majority of distros will disable tcp
with the --no-listen-tcp option when launching the X server. X sessions
are indeed insecure. However, the magic cookie offers minimal protection
with the xauth mechanism (man xauth, man xhost has more).
An ssh tunnel, or applications like freenx / vnc could help to encrypt
the session and ensure better security, but usually at the expense of
performance.