On Thu, Sep 1, 2011 at 5:15 AM, Bob Pearson <[email protected]> wrote: > > On Sat, Aug 20, 2011 at 4:47 PM, Bart Van Assche <[email protected]> > > More in detail, my comments with regard to multicast support in ib_rxe > are: > > 1. Using ipv6_eth_mc_map() for mapping multicast GIDs seems an > > unfortunate choice to me. That choice will cause multicast GIDs to be > > mapped to the 33-33-xx-xx-xx-xx Ethernet address range that has been > > reserved by RFC 2464 for IPv6 multicast addresses. If a collision with > > an IPv6 multicast address occurs and IPv6 MLD snooping has enabled on > > the switches in the involved network then RoCE multicast won't work > > properly. IMHO we need a separate Ethernet address range for RoCE > > multicast purposes, next to the existing ranges for IPv4 and IPv6. > > I thought this was intentional! I.e. in order to get multicast over RoCE to > work we were trying to piggyback on the behavior of intelligent switches. > Otherwise the only way to get packets forwarded without adding a new group > of multicast addresses would be to broadcast. The implementation of IGMP and > MLD at the end node is oblivious to the packet's ethertype. And switches (at > least the ones we tried) also happily multicast RoCE packets.
Shouldn't both the RoCE specification and RFC 4541 be updated according to the above ? Bart. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
