Re: SSH

From: Dimitri Maziuk (dima_at_127.0.0.1)
Date: 10/07/03 

Date: Tue, 7 Oct 2003 18:04:03 +0000 (UTC)

Dave Uhring sez:
> On Tue, 07 Oct 2003 09:14:19 +0200, UNIX admin wrote:
...
>> Turning debugging on the SSH server and when trying to connect with an
>> OpenSSH client, SSH server will report at least one or more implementation
>> bugs in the negotiating protocol. Perhaps that has been fixed, but I doubt
>> it, since I suspect it's been done on purpose. When using an SSH client to
>> an OpenSSH server, the connection will hang when you log out, because
>> there's apparently some bit about the OpenSSH server not closing some
>> descriptors properly. OpenSSH debugging doesn't pick it up of course, but
>> commercial SSH does.
>
> I did not observe any "hanging" on exit from the ssh session nor has the
> one remote client using SSH.

Consider yourself lucky. About any client will hang on exit with IRIX
OpenSSH 2.9 server. It happens less frequently with newer versions of
OpenSSH & other OSen. It happens more frequently with tunnelled stuff
(e.g. CVS server over ssh) than with plain remote logins.

We had a seriously screwed up system at one time because hanging ssh
connections filled up cron run queue... (and then there's IRIX where
cron run queue size >= process table size. Ouchie.)

The best part is that they're left hanging on purpose & it'll never
be fixed. And OpenSSH folks won't even put a timeout in there.

Dima 

-- 
We're sysadmins. Sanity happens to other people.                  -- Chris King

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