X and SSH X Forwarding

English Network/Internet
1

Hello

I posted a summary of my issue below as a reply to a thread I came across on here, thinking it was a solution I had found to my issue in that thread. But it wasn’t it seems so I would be pleased if any one can help me.

There appears to be some issues for me in forwarding X over ssh. It used to just ‘work’ in 11.4, but after 12.1 upgrade a few things have me stumped, including this X forwarding.

Firstly I was not getting DISPLAY set at all on the remote machine. I checked sshd-config and X11Forwarding is set ‘yes’. I uncommented X11UseLocalhost and set it to ‘no’.

I now get msg’s at the remote prompt (when i ssh -X e.g. ssh -X fred@192.168.0.10) like:
/usr/bin/xauth: (stdin):1: bad display name “linux-e4rt5.site:10.0” in “remove” command

Also, I have tried using xhost +x (not safe i know) to see if that helped… it didnt.

Do the YAST network settings have any effect - e.g. ‘Assign hostname to loopback IP’, ‘change hostname via DHCP’ and if so how should they be configured please ?

What is the correct set up in sshd_config and ssh_config to allow x forwarding please?

as I say, it used to just work fine in 11.4. without me having to delve around…although I am learning more now why this stuff works or it doesn’t… i think a good thing !

thanks for any assistance.

2

Hi badbetty,

For one thing I guess you should put the X11UseLocalhost back to yes - in that manner the DISPLAY will get a value like localhost:10.0 which will be then tunneled via ssh to your local machine. The current setup wouldn’t work since your local machine doesn’t have a fully qualified domain name.

With the unsafe option of xhost +x you can manually set DISPLAY to your real X port, like your ip and then :0. . If you firewall isn’t blocking the incoming X connections this should work in any case.
Also, try the -v option to ssh, see if it gives any more information on what’s wrong.
Another thing to check are the permissions on the remote server - if for some reason read/write access is blocked in the home directory (network drive mounted or so) this could also cause xauth to fail…
Good luck!

3

i think i have come across the ‘answer’.

https://bugzilla.novell.com/show_bug.cgi?id=618068

it seems to be something to do with ssh and ipv6 ! i changed ‘address family’ as described and voila.
i’ve no idea why unless any one can shed some light.

i will now go back and put everything back to ‘normal’ and see what happens with just this latest change.
thanks,