check_by_ssh returning UNKNOWN

[Paul L. Allen]

Rasmus Plewe writes: 

> Just for the records: even though there were no ssh complaints, 
> upgrading the ssh version on the client fixed the problem. 
> Or perhaps I should, more accurately, say: since the ssh version was
> updated, the problems are gone. I still have no explanation, but as 
> long as everything works I don't neccessarily need one...

Some possibilities: 

 1) SSH version mismatch between client and server with some sort of
 interopability problem that shows up occasionally (such as generating
 a bad session key occasionally or being unable to handle a session key
 that matches certain mathematical patterns).  There might be something
 in the release notes about that. 

 2) Same version of SSH but again some subtle bug that shows up
 occasionally (such as the examples above).  There probably will
 be something in the release notes about that. 

 3) A vulnerability.  Most upgrades of SSH deal with security issues.
 Some exploits on older versions can cause sshd to get confused.
 There probably will be something in the release notes about that, but
 it's probably not the cause because you didn't mention anything about
 having to restart sshd. 

-- 
Paul Allen
Softflare Support 




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