Reminds me of the network a friend described. After a couple of mergers and sales, they had so much NAT that one particular cron job tab used an internal server-to-server connection that passed through five NAT instances.
And this tailscale product seems to say "this product makes that kind of situation less awful" which I'm sure is somehow good but I can't help thinking that "less awful" is going to mean "still awful" for most deployments.
Years ago I was responsible for consolidating three separate office locations into a new, larger, office.
We had some on-premise hosting, and I figured the easiest thing would be to keep the existing network LAN addressing. Each LAN had a different IP range, so it would be no problem for them to share the same ethernet network, as long as only one of the three LANs provided DHCP for the PCs.
We already had a Cisco router for internet access. That should be able to provide routing between our three LANs, right?
That was a terrible idea, as local traffic was bottlenecked on this small router that wasn't designed for the job. Transfers between LANs were as slow as they'd been when we in different physical locations.
I spent an hour or two consolidating the LAN onto a single IP subnet, and everything worked as you'd expect.
And this tailscale product seems to say "this product makes that kind of situation less awful" which I'm sure is somehow good but I can't help thinking that "less awful" is going to mean "still awful" for most deployments.