MarleTangible

Let's not forget that each DNA sample also includes information about their relatives as well. I believe that's how the Golden State Killer was caught.

> The website identified 10 to 20 people who had the same great-great-great-grandparents as the Golden State Killer ...

https://en.wikipedia.org/wiki/Joseph_James_DeAngelo#Investig...

What I understood is similar to making any device accessible on the internet. You would need to open the UDP 12345 on your router and forward the traffic to your server.

It sounds like each peer would first access the peer relay to coordinate how they could establish a direct point-to-point connection with each other.

I would assume you only need to make sure that the other clients can access the UDP port, so not like public internet in the sense of 0.0.0.0/0 but just accessible by other peers, whatever their public facing IP addresses will be.

> It’s also similar to running your own derp server (which works also in TCP), but without the hassle of doing so, and perhaps without having to open ports to the internet (needed in derp) so long as the relay is reachable by peers.

I think most folks will need to open a port to the internet, because otherwise you wouldn't need the tailscale to begin with. e.g. connecting your cloud network to your on premise network etc.

Of course exceptions apply, like both clients can reach the peer relay, but not each other directly.

> It allows customers to make just one firewall exception for connections only coming from their tailnet.

You'll need to open a single UDP port on your firewall, so it's your public facing IP address. You don't need an entire VM somewhere, just a single port.

Regarding the speed question. You'd use the derp when it's not possible to make a peer to peer connection, which limits your speed to derp server's speed and load. Which the peer relay, you can practically use the entire bandwidth you have between your devices.