Marc is correct. The ARP table is not involved in multicast. The multicast MAC is just mapped from the multicast IP.
Wesley New South African SKA Project +2721 506 7300 www.ska.ac.za On Thu, Nov 5, 2015 at 12:51 PM, Marc Welz <[email protected]> wrote: > David MacMhaon wrote: > > >> I think multicast transmit is easy (just populate the ARP table > >> appropriately). I think multicast receive is also supported with recent > >> versions of the 10GbE yellow block. You could probably check the > >> mlib_devel git commit logs for the yellow block code to find clues. > > Not sure if the arp table is involved in this - the destination mac is > (should be) > generated algorithmically from the destination multicast IP address, though > the above might be a unusual workaround. > > Sending is reasonably straighforward, as there is no control traffic > involved. > Reception does require a newer romfs/tcpborphserver where we get the kernel > to issue IGMP requests on the 10Gbe interfaces, so that the traffic arrives > at the particular port. > > regards > > marc > >
