29

Exit nodes and subnet routes: a node with exit: true (or -exit) carries traffic for networks beyond the mesh, and a client lists in routes which prefixes go to which exits; the prefixes are routed into its TUN device and each flow keeps its exit. The exit's system forwards and, for the internet, NATs.

A node runs without a TUN device with -no-tun, and by default when started with -sshd; -tun or a tun name in the config keeps the device. Such a node relays and serves SSH and DNS to peers.

A node is reachable only while some node observes a link from it; the last record of a node that went away no longer keeps a route into it.

Graph records carry a flags byte: nodes on releases before 29 exchange no graph records with this release; update peers together.