Re: X server shutdown or killed/destroyed

[Jon TURNEY <jon dot turney at dronecode dot org dot uk>]

On 08/08/2011 17:49, Howard Feil wrote:
> The OS of the target machines was CENTOS 5.5 and 5.4
>
> [root@MQWKS4 ~]# ssh -V
> OpenSSH_4.3p2, OpenSSL 0.9.8e-fips-rhel5 01 Jul 2008
[logs snipped]

Thanks very much for the information. I am now able to reproduce this issue.

This appears to be a change in the ssh client so that ForwardX11Timeout 
applies, even if untrusted authentication cookie generation failed (See [1]).

It looks like this change first appeared in openssh 5.6, although I can't see 
it mentioned in the announce email.

Note that if you had run ssh -v, you should have got a "Rejected X11 
connection after ForwardX11Timeout expired" explaining what was happening :-)

I guess I'll add something in the Cygwin/X FAQ about this.

[1] 
http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/clientloop.c.diff?r1=1.220;r2=1.221;f=h

> Sent: Monday, August 1, 2011 2:43 PM
> Subject: Re: X server shutdown or killed/destroyed
>
> On 29/07/2011 15:27, Howard Feil wrote:
> > Thanks for the reply.
> >
> > So far ssh -Y seems to be doing the trick.
>
> Good.
>
> I'd like to know a bit more about why this is happening, though, so if you
> could share the OS and sshd version which is running on the machine you are
> sshd-ing to, and the output when you connect using ssh -vvv -X, that would be
> interesting.
>
> > On 26/07/2011 14:20, Howard Feil wrote:
> > > I have installed cygwin on several windows XP 32bit machines.  To do the install I used the defaults and then installed all of X11 and
> > > Networks.  After a little while
> >
> > about 20 minutes?
> >
> > > when opening a new windows, I get the
> > > error:
> > >
> > >
> > > The application 'gedit' lost its connection to the display localhost:11.0;
> > > most likely the X server was shut down or you killed/destroyed
> > > the application.
> > >
> > > It doesn't matter what I do next, nothing simple makes the x-server come back alive.
> > >
> > > This
> > >       is happening on multiple machines.  For some reasons I have other
> > > machines that never have a problem.  These machines may have older
> > > installations.
> > >
> > >
> > > Any advice is appreciated.
> >
> > Use ssh -Y
> >
> > [1] http://cygwin.com/ml/cygwin/2011-05/msg00394.html

--
Jon TURNEY
Volunteer Cygwin/X X Server maintainer

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