Can't open display -- SOLVED

[Wojciech Komornicki]

I was getting the message
        Can't open display: xxx.xxx.xxx.xxx:0.0
It terns out that by default on my FC4, X does not listen to tcp.  You
can enable listening to the TCP port by running 
        gdmsetup
as root or be editing the file
        gdm.conf
The relevant setting is
        DisallowTCP
If you want X to listen the tcp set this to false

You will have to restart the X server after making changes. To run a
program (prog) on the client (light.unix) which will have its display on
the server (dark.unix) you need to
      1) tell the server that you allow light.unix to talk to it with
            xhost +light.unix
      2) start prog (on light.unix) with the command
            prog -display dark.unix:0.0
         (or you can set the DISPLAY environment variable)

I have not been able to get authentication working using xauth which
should allow you to run programs without using xhost.
--
Wojciech Komornicki