hah, I feel you for 3. I was constantly hitting the loopback network interface and I was like, why no discovery. in hindisght bad idea to always get the first entry in an array, now go through a list of network interfaces that i spam.

for 1. i send a mutlicast of max 512 bytes on 224.0.0.167:26999 every 3 seconds 2. not really caching, just have a map of people that get discovered.

and god bless, I just rolled with this. if people will use the tool and they will complain about it, then it will be a problem for later. for me between my home devices did not notice inconveniences.

in total around 200 lines of golang.