Copy-paste of: https://github.com/syncthing/syncthing/issues/4558#issue-277467027 , as this isn’t a bug (but a feature?)
Syncthing running on my Android phone is getting a (kcp) connection from a unknown device, which match my laptop (and vice-versa). As the smartphone and laptop doesn’t contain each other as remote device, this shouldn’t happen.
Log line (on my Android phone):
Connection from at <ip of my server, where syncthing is running> (kcp-client) rejected: unknown device
Smartphone: Local 192.168.xx.xx ip
Laptop: Local 192.168.xx.xx ip
Server: Local 192.168.xx.xx ip and external xx.xx.xx.xx ip
I’m not sure why this is happening from time to time, but I think local discovery and the fact that my server is available through both a internal and external ip has something to say.
Syncthing Version: v0.14.40 (laptop, smartphone and server), 0.10.0 (Syncthing android UI)
OS Version: ArchLinux (laptop + server), Android 7.1.2 (LineageOS)