[openib-general] Multicast address aliasing in IPoIB

[Roland Dreier]

    Dror> For gen2, will it be possible to define a new medium for the
    Dror> IPoIB driver (not ARPHRD_ETHER), such that arp_mc_map() will
    Dror> map the entire IP address into the HW address ?  Today it
    Dror> looks impossible, because arp_mc_map() just overrides bits
    Dror> 31:24 of the IP address.

I guess when we merge the IPoIB driver we will need to include a patch
to the networking core that treats ARPHRD_INFINIBAND properly for IPv4
and IPv6 multicast addresses.

    Dror> For gen1, what is that we can do ? Is there a way to obtain
    Dror> such an event from the in_device ?  If not, then I don't see
    Dror> any clean escape. Is it possible to periodically check out
    Dror> the in_device multicast list and see if anything has changed
    Dror> ? would that cause any problem during the transition periods
    Dror> ? Any other idea of how to do that without a kernel patch ?
 
We're not developing the gen1 tree anymore so I don't think we need to
worry about this.

 - Roland