Will it respond to multicast messages
multicast works just fine on a subnet. there is a need for IGMP when routing is involved, but a lot can be done on a single subnet. so, multicast UDP is quite useful.so, does the ethernet library support UDP send with a multicast address in the destination and can a listener receive said multicast packets is a valid question. does anyone have an answer?
Beyond that, you also likely need to have a multicast router - as otherwise there really isn't a point in simply not broadcasting, which will carry only on the same segment.