All of the sACN projects I've done have used a node with a non-multicast address in the standard class C, B, or A IP address ranges.?
While the traffic may be sent multicast, the node you're controlling shouldn't solely have a multicast IP address. There should be a "control" IP address, similar to NVX.
We have used the DMXKing units as well as Chauvet DMX-AN and the Net-X. All three have standard class C, B, or A IP addresses.?
The CP4 should be smart enough to route traffic to the correct port based on the IP range. So if your LAN port is 192.168.x.x and your control subnet is 172.16.x.x, if the node's control IP is on 192.168.x.x, it should send from the correct port.?
Maybe I'm missing something major here.?