I recently purchased some Yeelight Smart Led Lamps, actually marked with SKU label:
GPX4001RT (Yeelight LED White)
GPX4002RT (Yeelight LED Color)
Using Yeelight App I succeeded in first configuration and now I can control them by app and on my router I can see DHCP-assigned IP addresses.
So far, so good.
I can't detect any network activity on UDP multicast address 18.104.22.168 port 1982. I tried with several tools/samples (windows toolbox, yeecli, python and nodeJS samples, etc.) without success.
Also, I tried with different host machines, both windows based and linux based, but without success.