Subject: Re: bpf write() to local host
To: None <>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
List: tech-net
Date: 01/23/2003 13:01:38
>> Adding an alias really requires that the ethernet hardare support
>> multiple MAC addresses, some modern ones do.
> All that I have ever seen do.  You have to have this to support
> multicast.

They have to support multiple _multicast_ MAC addresses.  There is no
particular reason why they should support multiple _unicast_ MAC
addresses.  (There's no reason obvious to me why they should care, but
they may.  Why does NetBSD refuse to accept ff:ff:ff:ff:ff:ff as MAC
address?  I don't know, and it prevents a few potentially useful hacks.
Something must have happened to "...doesn't stop you from doing stupid
things because that also stops you from doing clever things".  Some
Ethernet chip designer may have similarly thought to check that
supposedly-multicast addresses are in fact multicast....)

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