DNS Queries to discovery server - but global discovery is disabled

Hi Guys,

Checked the Firewall Logs today because I got an alert of a connection to an Asian country and found out that my MacBook connected (or at least tried to) discovery-3.syncthing.net - but I disabled global discovery!

So I searched this forum and its basically this: discovery dns queries but discovery is not enabled, but the solution provided there (restart) did not work for me.

From the thread:

  • Double Checked settings:

  • I dont know if I have the “correct” config, I just use the web UI and there is only one? Activity Monitor is showing 2 syncthing processes (one started by launchcontrol one by the other syncthing process).

  • Here are the logs searching for “discovery”:

2023-05-20 00:41:39 Using discovery mechanism: IPv4 local broadcast discovery on port 21027 2023-05-20 00:41:39 Using discovery mechanism: IPv6 local multicast discovery on address [ff12::8384]:21027

Version: v1.23.2, macOS (64-bit Intel/AMD)

Should I open an Issue in GitHub or have I overseen something?

The host of discovery-3.syncthing.net ( is also one of the servers hosting stun.syncthing.net, syncthing’s STUN service. Since you have NAT traversal (+ QUIC, apparently) enabled, syncthing uses a STUN service to help with NAT traversal.