[openib-general] Re: [PATCH] IPoIB: Set hardware header on packet receive

[Hal Rosenstock]

On Mon, 2005-03-28 at 12:45, Roland Dreier wrote: 
>     Hal> I was wondering about this myself as to whether this matters
>     Hal> or not.  Other drivers determine this from the destination
>     Hal> MAC address. Does it affect the incoming delivery if more
>     Hal> than one process is receiving an IP broadcast or multicast ? 
>     Hal> I didn't chase it all the way down in the Linux kernel. Do
>     Hal> you know ?
> 
> There's a lot of places where the field is checked.

I see it set in a number of places but not checked much in the kernel.

> However all the
> ones I've seen are just ignoring packets that aren't PACKET_HOST or
> sometimes looking for PACKET_LOOPBACK packets.  So PACKET_BROADCAST or
> PACKET_MULTICAST may be checked somewhere but I'm not aware of
> anywhere that they are.

Is this used by netfilter ? 

Does this make a difference to any of the routing protocols ?

Has anyone run IP unicast routing using (one or more) IPoIB interfaces ?
What about multicast ? Do we care about these ?

-- Hal