I've been struggling to make Apple devices find each other (Bonjour, Airplay, AirPrint, etc...) across multiple subnets despite spending many hours trying to make IGMP Proxy and PIM perform the function. The primary issues is that Apple uses UDP 5353 broadcasts on address 224.0.0.251 which has TTL=1, therefore ROS will not forward it outside of the subnet. How about a ROS implementation of something like Avahi (avahi.org) which allows mDNS broadcasts to be repeated across any number of interfaces/subnets that are attached to the router? It certainly would make life with Apple devices much easier and it would be nice to accomplish this inside a RouterBoard rather than setting up a separate Ubuntu server just to perform mDNS repeating.
Thanks!
Jeff Wade