Yes, you'll need either IGMP snooping or an IGMP proxy on the switch. Most L3 switches support IGMP snooping.
Jayanth On Tue, Oct 1, 2013 at 1:21 PM, David MacMahon <[email protected]>wrote: > Hi, Jason, > > On Oct 1, 2013, at 4:35 AM, Jason Manley wrote: > > >> 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. > > I agree that it would not be very hard (not sure about "easy" :-)), but I > don't think it's 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? > > I think building a multicast receiver is non-trivial. Doing multicast > "the right way" requires that hosts implement IGMP (Internet Group > Management Protocol) and that the switch(es) implement IGMP snooping. > Using a switch without IGMP snooping will result in multicast packets > being delivered to every port, which can overload ports leading to dropped > packets. I think using a switch that supports IGMP snooping with hosts > that do NOT implement IGMP will lead to multicast packets not being > delivered to those hosts. > > Maybe the multicast group membership can be statically configured in the > switch? > > Dave > > >
