Re: Abnormal behavior after bumping net.inet6.udp6.sendspace

> On amd64 10.1_STABLE, if I increase net.inet6.udp6.sendspace to
> 209716 or larger, the machine in question ceases to serve new SSH
> sessions [...]

Even though the variable you changed is udp, not tcp?  Does it matter
whether the attempted ssh connection is over v4 or v6?  Do other TCP
connections fail, similarly or differently (eg, netcat or the like on
each end)?

> (the connection gets closed immediately)

How immediately?  Lots of things are "immediate" to human perception
that actually take significant time - for example, it may be failing
only when it's trying to grab a pty and create the login session, or
only when it's trying to log a successful login, or ....

Just thinking of possibly-relevant details.  I don't know 10.x's stack
well enough to even speculate as to what's wrong, but I know the kind
of thing that helps me hypothesize failure modes....

I do not have 10.x.  I tried on 5.2/amd64 (using my ssh daemon, not
OpenSSH's) and I do not see the syndrome you describe.  I suspect the
networking stack has changed enough for that to mean little, though.

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