I have a (linux raspberry pi) that's remotely located and NATted in such a
way that I cannot control that part of the infrastructure, although do
have complete control of the machine otherwise (e.g. access to root).
What I'd like to do is access it from my local NetBSD system (which does
have a 'real' IPv4 address), something like this:
1) Start some 'daemon' on the remote linux box that attempts a connection
to ...
2) .. my local NetBSD box.
And
3) some local NetBSD program that allows me to get a shell prompt of the
remote linux machine here on my NetBSD machine via the connection set up in
(1) and (2).