topic Re: X11 forward in SSH in Operating System - HP-UX

X11 forward in SSH

YLTan — Thu, 03 Apr 2003 06:14:44 GMT

What the different bet. setting X11Forwarding and not setting it at the SSH server? I noticed in both cases I can still use Xwindows by putting up the appropiate DISPLAY parameters and able to spawn the Xwindows on my PC's. Is there a diff. in terms of encrypted X11 traffic in both cases?

Re: X11 forward in SSH

Jerome Baron — Thu, 03 Apr 2003 07:37:03 GMT

Hi,

Effectively with X11 forwarding you can lunch graphical application with a ssh session. The only problem is your lan connection speed!
Without X11 forwarding I mean that you can't use graphical interface by ssh.

Configuration on server in /etc/ssh/sshd_config:
X11Forwarding yes
X11DisplayOffset 10
# Change the port for more security
Port 5522

restart ssd daemon

Configuration on client in /etc/ssh/ssh_config or??/.ssh/config :
ForwardX11 yes
Compression yes
Port 5522 # the same port that on server

Without client configuration :
# ssh -XC -p 5522 -l

Regards,
Jerome

Re: X11 forward in SSH

Jerome Baron — Thu, 03 Apr 2003 08:01:43 GMT

oups I give you linux config file....

On HP-UX config file are in /opt/ssh/etc.

Regards,
Jerome

Re: X11 forward in SSH

YLTan — Thu, 03 Apr 2003 09:05:48 GMT

Hi Jerome,

I test on both cases for X11Forward is yes and No, in both cases i can use the Xwindows graphic interface. It seems there is no diff. whether X11Forward is set or not. Did i miss something??

Re: X11 forward in SSH

Jerome Baron — Thu, 03 Apr 2003 09:16:04 GMT

Hi,

For me the only way to disable X11 is to put no at X11Forwarding. I try on m??y system and have the same result (graphical application run in all case.
I suspect a "bug".

Regards,
Jerome

Re: X11 forward in SSH

Christian Gebhardt — Thu, 03 Apr 2003 09:17:29 GMT

Hi

if you have
X11Forwarding yes
in the sshd_config file (don't forget to restart the sshd after changing the parameter) the sshd set the Variable DISPLAY to something like this:

DISPLAY=:10.0

you do not have to set the display manually, all X11-windows are forwarded to your client automatically.

If the ssh-Server is behind a firewall
xterm -display :0
doesn't work
but with X11forwarding enabled and typing
xterm
the display is tunneled via the ssh-connection

Chris

Re: X11 forward in SSH

YLTan — Thu, 03 Apr 2003 11:05:42 GMT

Hi Christian,

Does this means with X11Forward enable, the Xwindows traffic actually forced to use SSH connection which is encrypted?

Without X11Forward enable, Xwindows traffic are travelling in CLEAR TEXT even I am connecting to the SSH server using SSH client and have the DISPLAY=:10.0

Re: X11 forward in SSH

Christian Gebhardt — Thu, 03 Apr 2003 11:15:55 GMT

yes