Subject: Re: IFF_SIMPLEX and multicast
To: enami tsugutomo <email@example.com>
From: None <firstname.lastname@example.org>
Date: 04/09/2001 19:00:04
>> sys/net/if_ethersubr.c has IFF_SIMPLEX checks for broadcast cases
>> (M_BCAST) and not for multicast (M_MCAST). are there specific
>> reasons for this? if multicast handling was introduced after
>> IFF_SIMPLEX is invented, it may be a bug in L2 multicast support.
>Unless explicitly disabled, multicast packets are looped back in L3,
oops, you right. i still have one question - should we put a check
for "multicast outgoing packet looped back to myself" packets,
in sys/net/if_ethersubr.c? we have a couple of ethernet
chips/drivers that do this. for example, see sys/dev/ic/smc91cxx.c.
(the chip loops outgoing multicast packets back to itself, while
it does not loop back broadcasts)