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From: Mills@LOUIE.UDEL.EDU.UUCP
Newsgroups: mod.protocols.tcp-ip
Subject: Re:  Inappropriate responses to broadcasts
Message-ID: <8702072302.a014307@Huey.UDEL.EDU>
Date: Sat, 7-Feb-87 23:02:16 EST
Article-I.D.: Huey.8702072302.a014307
Posted: Sat Feb  7 23:02:16 1987
Date-Received: Tue, 10-Feb-87 06:32:26 EST
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Organization: The ARPA Internet
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Approved: tcp-ip@sri-nic.arpa

Phil,

The fuzzball gateways used on the NSFNET Backbone, among other places, incorporate
a "martian filter" that grounds packets for the various IP braodcast addresses,
as well as other reserved addresses (see RFC-990). At least one other gateway
system (cisco) allegedly does the same. As you know from my previous messages
to this list, gateways that forward IP broadcast packets can creat astonishing
mischief in quite surprising places.

Your suggestion on a mechanism to prevent forwarding of multicast packets was
suggested to the INENG Task Force some time back; however, implementation in
the various Unix bsd's hasn't happened yet. See also the appendix to RFC-985
for further suggestions. Your comments and advice on the issues raised there
would be welcome.

Dave