[lug] remote clients can't display on FC3/KRUD

[D. Stimits]

Michael J. Hammel wrote:
> I recently installed KRUD on a laptop and gave it the same name/IP as my
> old laptop (which is now retired).  I'd like to run X clients on a
> server and display on the laptop, but I can't seem to make it work.
> 
> I've run "xhost+ <remotehost>" on the laptop.
> I've updated the Xauthority file on the remotehost and merged into the
> laptop.
> I've disabled SELinux on the laptop (it seems to get in the way for
> things like this).  I also disabled the firewall on the laptop (I enable
> it manually when I use the laptop on public wireless nets).  
> I run "xterm -display laptop:0" but the connection is refused.
> 
> I updated the Xauthority file like so:
> 
> On the server:
>    xauth add <laptop IP>:0 . `mcookie`
> 
> On the laptop:
>    ssh <remote server> /path/to/xauth extract - <laptop IP>:0 | xauth
> merge -
> 
> When I run xterm on the remote host, I just get "Can't open display:".
> Running strace on it I see that it gets "connection refused."  There
> must be some other security mechanism I've not enabled or disabled.  Or
> else the remote host thinks this is the old laptop and the new laptop
> doesn't authorize correctly because of that.
> 
> Anyone have any ideas?

By default the X11 servers accept only UDP connections...remote machines 
use TCP. You have to turn on the TCP option in
/etc/X11/gdm/gdm.conf
There is a line there, DisallowTCP=true. Kind of misleading, as not 
having this parameter still disallows TCP. Change it to DisallowTCP=false.

Be sure you firewall the tcp port 6000. Restart the display manager, 
init 3 then back to init 5. Or reboot. Don't forget your xhost is still 
required (or something similar).

D. Stimits, stimits AT comcast DOT net