Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!samsung!think!ames!amdahl!rtech!wrs!hwajin
From: hwajin@wrs.wrs.com (Hwa Jin Bae)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: IP Multicasting in SunOS
Message-ID: <819@wrs.wrs.com>
Date: 8 Jan 90 20:56:52 GMT
References: <9001052140.AA01228@risci.TN.CORNELL.EDU> <43507@lll-winken.LLNL.GOV>
Reply-To: hwajin@wrs.wrs.com ()
Organization: Wind River Systems, Emeryville, CA
Lines: 16

While newer ethernet boards designed around recent chip sets such
as LANCE and National's NIC (DP8390) family do provide ability to program
your multicast addresses this is not yet available every where.
Even the boards built around such advanced chips do not provide 
direct access to the chip registers (e.g. some of cmc and excelan boards)
thus making the multicast address programming less than straight forward
at the driver level.  The complexity involved shouldn't be ignored
either.  A well maintained ARP cache, in my opinion, is a good 
compromise.  Besides, in the real world most people do not forward
random broadcast packets via gateways, thereby restricting the local
broadcast traffic.  The only big problem I can see is the occasional
broadcast storms caused by early 4.2bsd derived systems which sent
out ARP's for certain unrecognized broadcast IP addresses, but this
bug is quickly disapearing.

hwajin