[tmerr]

I mean. I've owned several IoT devices that work either locally or over the internet. Some of this you can just blame on local networks being fiddly in ways that are difficult to control.

Over local network it's an unreliable assumption that device A can discover device B through some form of broadcast. There are ways to intentionally or unintentionally block that. And then even if you know each party's IP, some networks will intentionally isolate different users for security reasons.

Is it an Apple/Android limitation or a more basic networking limitation that drives devices to communicate with centralized servers on the internet?

And yes I agree it does seem ridiculous.

[skrebbel]

> Over local network it's an unreliable assumption that device A can discover device B through some form of broadcast.

Yes and I’m 100% sure people at wifi consortia and the likes could design a thing that fixes that. They came up with DHCP which smells vaguely like this, I’m sure there’s a way.