Killing the OpenSSH server doesn't cause the Windows OpenSSH client to die

[Darren Tucker]

On Sat, 8 Apr 2023 at 08:46, Yuri <yuri at rawbw.com> wrote:
> The fact that '-o ServerAliveInterval=50' makes no difference suggests
> that there is a bug in the OpenSSH client.
> It either fails to sent heartbeats or it gets stuck in some Windows
> system call and this makes it to fail to send heartbeats.

Not necessarily.  Setting the ServerAliveInterval by itself is not
sufficient to detect some classes of problems, for example if the
remote end becomes completely non-responsive or the packets are
dropped by a firewall.  If the heartbeats do not provoke a response
from the peer (a TCP reset in this example), ssh won't know it's
really gone.   You need to add ServerAliveCountMax  to tell the client
to give up after some number of unacknowledged ServerAlives.

-- 
Darren Tucker (dtucker at dtucker.net)
GPG key 11EAA6FA / A86E 3E07 5B19 5880 E860  37F4 9357 ECEF 11EA A6FA
    Good judgement comes with experience. Unfortunately, the experience
usually comes from bad judgement.