cunicu
A zeroconf peer-to-peer mesh VPN using Wireguard
...Thanks to Interactive Connectivity Establishment (ICE), cunīcu is capable of establishing direct connections between peers that are located behind NAT firewalls such as home routers. In situations where ICE fails, or direct UDP connectivity is not available, cunīcu falls back to using TURN relays to reroute traffic over an intermediate hop or encapsulate the WireGuard traffic via TURN-TCP.