jschoubben
8e2a1e762d
The host parses MTU from the found [Interface] and reports it, so the mesh's interface can come up with the same MTU when it takes the tunnel over. A path tuned to 1380 regresses to the 1420 default otherwise — invisible to ping, fatal to TLS handshakes and transfers over that path (novox/hq: the mesh had no MTU concept). Zero when the config named none, and the mesh writes no MTU line then.