Relay

When a direct connection between two machines cannot be established, then the only way to communicate is through an intermediate relay that both machines are able to communicate with. Tailscale’s relay servers are known as Designated Encrypted Relay for Packets, or DERP. In a vast majority of cases, machines can establish a direct connection, and only a small amount of traffic must instead be routed through DERP.

Relays are distributed globally — New York City, Dallas, Seattle, London, San Francisco, Frankfurt, Tokyo, Sydney, Bangalore, Singapore… and we keep adding more relays as we go along.