We've run into a problem with ssh X11 forwarding, apparently since
the 8/23/2008 yum update of openssh packages.

In the very recent past we were able to 'ssh -X' from an SL 4.6 host
to another SL 4.6 system, and from there do an 'ssh -X' to a third
SL 4.6 system and have X11 traffic pipe its way back to the original
host with no problems.

Now, in the last few days, we find that the 'ssh -X' from first host
to second works fine, but then an 'ssh -X' to the third results in:

Warning: untrusted X11 forwarding setup failed: xauth key data not generated
Warning: No xauth data; using fake authentication data for X11 forwarding.

And firing up any X11 app on the third host fails with:

X11 connection rejected because of wrong authentication.
X connection to localhost:12.0 broken (explicit kill or server shutdown).

I've started googling for this, but thought I'd throw it out in case
others are experiencing the same problem or maybe Troy/Connie have a
thought or fix.

Thanks!
- Larry
-- 
P. Larry Nelson (217-244-9855) | Systems/Network Administrator
461 Loomis Lab                 | High Energy Physics Group
1110 W. Green St., Urbana, IL  | Physics Dept., Univ. of Ill.
MailTo:[log in to unmask]        | http://www.roadkill.com/lnelson/
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  "Information without accountability is just noise."  - P.L. Nelson