Local discovery on large network with IPv4


I am using Syncthing on a large IPv4 only network (>1000 IPs) with multiple subnets. I don’t control this network. IPs are private. I am testing Syncthing with 2 hosts but I want to expand to more later. I opened 22000 (tcp) and 21026 (udp) on both hosts. If I manually put the IP addresses, everything works. But these IPs can change. So I need some type of discovery.

  • Global discovery doesn’t work as both clients report the public IP of the gateway. Maybe an option to report the actual host IP (and not the public IP) would be nice? (not sure isn’t a good solution though)
  • Local discovery doesn’t work as the broadcast on IPv4 is too “narrow”. Machine A has IP, machine B Machine A broadcast to which machine B doesn’t get. Is there a way to broadcast to

Thanks for your help.


You can run a discovery server within the organization, which should work.