Broadcast/multicast packet notification through pfhooks [PSARC/2007/666 FastTrack timeout 12/03/2007]

[Darren Reed]

James Carlson wrote:

>Darren Reed writes:
>  
>
>>These two bit values indicate if the packet is multicast or if it
>>is broadcast, however, using DLPI in Solaris today, it is not possible to
>>know if a packet that reaches IP is multicast or broadcast by looking
>>at the dl_group_address field and nor is there any other mechanism
>>available.  In light of this, setting both flags together is supported
>>as an indication that the packet might be one or the other:
>>
>>#define HPE_MBCAST              0x03
>>    
>>
>
>Do the clients using this interface need to know the difference
>between multicast and broadcast in order to function correctly?
>  
>

No.

>If so, then why not have this interface resolve the amibiguity?  That
>can be done by checking the destination address (dl_dest_addr_*) when
>you see that dl_group_address is set.
>  
>

Even if they did, once the packet reaches IP, it's beyond the
scope of IP to determine what the MAC destination address
meant at the MAC layer.

Darren