[vollbrecht]

The mere existence of Tailscale should give a hint that NAT is only a speedbump and not any protection whatsoever. It protects you against nothing. Every method that Tailscale uses to traverse NAT can be in isolation used by any other piece of software. For more info about that you can read the following article.

https://tailscale.com/blog/how-nat-traversal-works

[immibis]

What people really want is a firewall, and since NAT acts as a firewall, they confuse it with that.

My university has a public IP for every computer, but you could still only connect to the servers, not random computers, from the outside. Because they had a firewall.

[username332211]

What ordinary people (as opposed to IT departments) really want is firewall that can't be accidentally disabled by pushing an overly permissive firewall rule.

NAT/port forwarding, for all their faults make it rather difficult to write rules allowing traffic to a machine you didn't intend to expose to the world.

[lupusreal]

Yeah but the average person wouldn't know to set up a firewall (and can't count on their ISP to have their best interests at heart.) Therefore the general public benefits from the degree of protection that NAT provides.

[phendrenad2]

"not any protection whatsoever" is way too strong a statement. NAT does raise the bar to exploiting a random smart lightbulb in your house significantly higher.

[kccqzy]

The big distinction is that for Tailscale both endpoints know they want to talk to each other, and that both have Internet access. That's not the usual case firewalls are designed for.

Tailscale doesn't strictly need NAT traversal. They can run only their DERP servers and still continue to work. If your firewall tries to block two devices from communicating and yet allows both devices internet access, you have already lost.