Cannot Get X11 Forwarding to Work via SSH

I am having problems getting X Forwarding to work via an SSH tunnel
from my Mandrake 10.1 Linux box to my Windows XP Pro box.

I have installed sshd and updated sshd.conf in /etc/ssh/ so that:
X11Forwarding yes
X11DisplayOffset 10

The X server is started on the linux box.

I have installed Cygwin/X on the XP box, following the directions
there to get X11 running and openSSH running on the XP machine. I can
successfully ssh to the linux machine, and I connect using the -X ssh
option.

BTW, Mandrake was installed with the 'paranoid' option and the
firewall is running. Not sure if that makes a difference as I
understand X11 uses ports on localhost address.

Once connection is made (I did start X on the XP box first), I try
running an X program (such as xterm or kedit) and get an error message
like "Unable to connecto to X server".

I did notice that on the linux machine when I ssh, there is no DISPLAY
env var set. I have tried setting it manually to localhost:10.0 and to
machinename:10.0 but neither works. I am thinking this is part of the
problem. Shouldn't this variable be set automatically?

Any help or suggestions would be greatly appreciated. I am fairly new
to Linux and have not been able to find any answers though Googling on
X Forwarding SSH that solve my problem.

-Brian

Brian Boorman wrote:

> I am having problems getting X Forwarding to work via an SSH tunnel
> from my Mandrake 10.1 Linux box to my Windows XP Pro box.
>
> I have installed sshd and updated sshd.conf in /etc/ssh/ so that:
> X11Forwarding yes
> X11DisplayOffset 10
>
> The X server is started on the linux box.
>
> I have installed Cygwin/X on the XP box, following the directions
> there to get X11 running and openSSH running on the XP machine. I can
> successfully ssh to the linux machine, and I connect using the -X ssh
> option.
>
> BTW, Mandrake was installed with the 'paranoid' option and the
> firewall is running. Not sure if that makes a difference as I
> understand X11 uses ports on localhost address.
>
> Once connection is made (I did start X on the XP box first), I try
> running an X program (such as xterm or kedit) and get an error message
> like "Unable to connecto to X server".
>
> I did notice that on the linux machine when I ssh, there is no DISPLAY
> env var set. I have tried setting it manually to localhost:10.0 and to
> machinename:10.0 but neither works. I am thinking this is part of the
> problem. Shouldn't this variable be set automatically?
>
> Any help or suggestions would be greatly appreciated. I am fairly new
> to Linux and have not been able to find any answers though Googling on
> X Forwarding SSH that solve my problem.
>
> -Brian


When I had this problem I went ahead in the sshd_configure file and set
X11 forwarding on also. I don't know if that will help you or not as I
am not using Windows on my machines but it works with Linux.

I demand that on Sat, 06 Nov 2004 15:09:32 -0800, Brian Boorman may or may
not have written:

> BTW, Mandrake was installed with the 'paranoid' option and the
> firewall is running. Not sure if that makes a difference as I
> understand X11 uses ports on localhost address.

The paranoid option in Mandrake is a little extreme. Try bumping it down a
notch and see what happens.

--
Jafar Calley
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Registered Linux User #359623
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