Description
Detect your NAT quickly and easily, and that's the bottom line.
Stunner is a small Go CLI tool that sends STUN Binding Requests to multiple Tailscale DERP servers (or any STUN servers you specify) and reports the resulting NAT classification. This helps you determine whether you're behind a Full Cone, Symmetric NAT, Restricted, or otherwise, by analyzing how multiple STUN servers perceive your external IP/port mapping.