

Wireshark is the best way as it’ll show you exactly what’s going on; DNS addresses, traffic type, etc. (But not inside encrypted packets)
But to do that it (you) need to see all the traffic between the ceiling light and the internet, so if you’re on wifi and it’s on wifi, that won’t work.
Hopefully your router has the ability to either do a packet capture, or, mirror traffic to a physical port.
















I came from Nextcloud to syncthing, you’re in the right place.