While it’s not the right tool for the job, it is possible to connect two networks together using SSH as the secure transport. Many (most?) good network folks will recoil in horror though about tunneling TCP inside TCP.
Re Full network: How?, without additional software e.g. ppp+socat+ssh along with TUN/TAP or similar, or running a non standard SSH client/server and having various nonstandard utilities on both ends, which imho obviates OP's claim of SSH 'simplicity'/'ubiquity'..
I've seen it done before where it was fully transparent to both networks. This required the tunnel to be setup on the default gateway for both networks. Again, as mentioned before and you agreed too, this is not a solution I would ever want to see in production for a company I was at.
> which imho obviates OP's claim of SSH 'simplicity'/'ubiquity'
Which I agree, it isn't simple, but I was replying to someone saying it wasn't possible, not that it is easy to do.
