[TriLUG] Unusual X11Forwarding Problem in OpenSuse 11.3

[Paul Boyle]

Hi,

This is a sort of public service announcement for anyone who is planning on installing opensuse 11.3.  I've just spent a day and some getting X11 forwarding to work on opensuse 11.3 (x86_64 version).  I wasn't able to display X11  apps remotely.  I had sshd and ssh configured to accept X11Forwarding in the usual way (I've done this for years without a problem). However, with this install/distribution, I kept getting this error in the system log:


sshd[10128]: error: Failed to allocate internet-domain X11 display socket.

Googling around for this error, I was able to find a fix, which is to modify the start up script for sshd so that sshd starts with the "-4" option (which forces sshd to use only IPv4 addresses).  I've also turned off the "enable IPv6" option in the opensuse networking configuration. For those opensuse users, the best place to put the fix is in the /etc/sysconfig/ssh file.  Mine now reads:
## Path:        Network/Remote access/SSH
## Description: SSH server settings
## Type:        string
## Default:     ""
## ServiceRestart: sshd
#
# Options for sshd
#
#P. Boyle NCSU local mod. Force sshd to only use IPv4 addresses
#See:  http://www.kraftek.com/blog/index.php?/archives/281-sshd419-error-Failed-to-allocate-internet-domain-X11-display-socket..html
SSHD_OPTS="-4"

#### end file
The line wrap on my email client broke the comment with the URL, so caution with copy and paste operations.

I hope this saves people time and the frustration which I've experienced over the last day or so.

By the way, the openssh version used on this distribution of opensuse is 5.4.  Do users of any other distributions see this problem?

Paul