I am running syncthing on a router and want to understand what ports it is using. I read that it needs one TCP and one UDP ports. The TCP portion is fine: it is listening on a single port on each interface I bound it to. At the same time I see syncthing on two UDP ports: one that I configured and the other one is random and is changing every time it restarts. Any idea what the second random port it is using and why?
Port 27948 is configured; the other ports are random.
udp 0 0 0.0.0.0:27948 0.0.0.0:* 13813/syncthing udp 0 0 0.0.0.0:35295 0.0.0.0:* 13813/syncthing udp 0 0 :::27948 :::* 13813/syncthing udp 0 0 :::50834 :::* 13813/syncthing