Can not get remote X connections to work on CentOS 4.1

[james-p at moving-picture.com (James Pearson)]

Alfred von Campe wrote:
> I've encountered a strange problem in CentOS 4.1.  I've never had this 
> problem before, and I've been using X Windows since 1990, but I can't 
> get remote X connections to work:
> 
>   $ hostname
>   host00
>   $ echo $DISPLAY
>   :0.0
>   $ xhost +
>   access control disabled, clients can connect from any host
>   $ rsh host01
>   $ xdpyinfo -d host00:0.0
>   xdpyinfo:  unable to open display "host00:0.0"
> 
> Both hosts are running CentOS 4.1 and SELinux is disabled.  I know I can 
> get this to wok with ssh, but that is not the point.  Also, it's not a 
> host name resolution problem, as substituting the IP address in the 
> above command gives the same error.  Finally, note that there is about a 
> 3-4 second delay before the error message appears.

If you are using gdm - try setting:

DisallowTCP=false

in /etc/X11/gdm/gdm.conf

James Pearson