On Wed, May 12, 2010 at 01:14:33PM -0700, Roland Dreier wrote: > > Multicast GIDs are always mapped to multicast MACs > > as is done in IPv6. Some helper functions are added to ib_addr.h. IPv4 > > multicast is enabled by translating IPv4 multicast addresses to IPv6 > multicast > > as described in > > http://www.mail-archive.com/[email protected]/msg02134.html. > > I guess it's a bit unfortunate that the RoCE annex completely ignored > how to map multicast GIDs to ethernet addresses (I suppose as part of > the larger decision to ignore address resolution entirely). Anyway, > looking at the email message you reference, it seems to be someone > asking what the right way to map IPv4 multicast addresses to IPv6 > addresses is. Is there a more definitive document you can point to?
I am not aware of any definitive document that addresses this issue. > > It seems that unfortunately the way the layering of addresses is done, > there's no way to just use the standard mapping of IPv4 multicast > addresses to Ethernet addresses (since IBoE is does addressing via > the CMA mapping to GIDs followed by an unspecified mapping from GIDs to > Ethernet addresses). > It is natural to treat gids as IPv6 addresses, so using the standard mapping from IPv6 multicast addresses to mac addresses seems reasonable. -- 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
