[RndTbl] double-natted ssh weirdness

[Trevor Cordes]

On 2024-03-15 Adam Thompson wrote:
> Also if you want to be sure of avoiding all MSS issues, aim low, like
> 1024, instead of "just low enough" like 1396.  You won't likely be
> able to measure the difference. -Adam

I did try lowering it a bit more.  It turns out there were 2 problems
(as usual): the mtu issue *and* some intermediate router in the
double-nat had a really short conntrack keepalive.  The latter was the
fine-now-pauses-later problem and was overcome by setting stricter
keepalive settings on sshd.  (Should have remembered this, as I'm sure
I've seen that before.)

All works great now!