Skimmed through their excellent design docs. The code is open source, but requires running a centralized control plane sever and may also require running a data

Skimmed through their excellent design docs. The code is open source, but requires running a centralized control plane sever and may also require running a data plane relay server to cover some relatively common NAT configurations. https://tailscale.com/blog/how-tailscale-works https://tailscale.com/blog/how-tailscale-works