> Ideally, the 10 GbE block would be modified to recognize multicast > destination IP addressed and then add in the derived MAC address > automatically instead of getting it from the ARP table. Then it could send > both multicast and unicast packets.
I think this is easy, and I thought it had actually already been done. > It would be another matter to get the core to listen to multicast packets > (especially multiple multicast groups). I think that would be a little more > complicated (unless you set its IP address to a single multicast IP and > that's the only multicast group you want it to join). This is the tricky part. We've thrown around a number of ideas. A true multicast receiver is probably beyond the scope of our needs, or willingness to implement. For our purposes, I think we can architect things that a single receiver only needs to subscribe to consecutive/adjacent multicast addresses. In this case, we can implement something like a multicast subnet mask, where the least-significant-bits of the address are configurably ignored. Has anyone built a multicast receiver on an FPGA? Jason
