RE: Info on "Can't open display"

[Suhaib Siddiqi <ssiddiqi at inspirepharm dot com>]

May be if you read the X11 socket and display basics here 
 http://www.madisonlinux.org/minutes/X-presentation.html
you might understand more how an x client display on an x-server...
basically
in Xwindows world nothing works without TCP/IP. 

X is a network protocol as much as anything. All X communications between
the X server and client programs is done through TCP/IP and sockets (even
locally). There is little to no distinction with regard to where a program
runs, and where the output is displayed. 

So if something modify and conrols the network, then you will face a display
problem.

Suhaib

> -----Original Message-----
> From: Christopher Landrieu [mailto:landrieu@hotmail.com] 
> Sent: Thursday, June 14, 2001 2:06 PM
> To: cygwin-xfree@cygwin.com
> Subject: RE: Info on "Can't open display"
> 
> 
> >Well, I am not convienced with your tests and explainations ;-)
> >
> >BECAUSE, I tested a several VPN and Firewall software, 
> except Aventail,
> >and none of them interfere with X-server.  Though, a couple of them
> >prompt, "client X is trying to connect to port so and so, 
> Allow or deny" 
> >and
> >I
> >can add a rule to allow permanently, instead of clicking a YES button
> >eachtime.
> 
> But the problem doesn't seem to be with the X server.  Remote 
> and local 
> xclients (other than the xfree86 ones) can connect and 
> display with no 
> problem.
> 
> >As I see from mailing list, majority of the users who have 
> display problems
> >are using Aventail.
> >It is not xclient as you try to explain in your reasonings... it is 
> >Aventail stopping the Xclient to connect to X-server.
> 
> There are also many users who have this problem but are not 
> using Aventail.  
> As well the local xclients can't even connect to a remote 
> display (non 
> cygwin/xfree86).  Also, eXceed  works with Aventail with no problems.
> 
> By your reasoning, telneting to port 6000 should also be stopped by 
> Aventail, but it isn't.  If telnet can make a successful 
> TCP/IP connection 
> to localhost port 6000, why wouldn't the cygwin/xfree86 
> xterm?  This is the 
> point that I would like explained.  What is telnet doing 
> different than the 
> X libraries?
> 
> Chris
> 
> _________________________________________________________________
> Get your FREE download of MSN Explorer at http://explorer.msn.com
>