where do you find the necessary protocol information for the various devices? that (and the trickiness of getting the firewall rules just right) seems to be a b

where do you find the necessary protocol information for the various devices? that (and the trickiness of getting the firewall rules just right) seems to be a barrier to adoption for vlan'ing all the things. i still have issues with this on my little home network, typically with service discovery (e.g., mdns) and control app to device(s) communications (e.g., tradfri) across vlan boundaries.