From owner-freebsd-hackers  Wed Aug 23 13:03:05 1995
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To: "Michael C. Newell" <mnewell@lupine.nsi.nasa.gov>
cc: hackers@freebsd.org
Subject: Re: Multicast on PPP devices 
In-reply-to: Your message of "Wed, 23 Aug 95 12:49:55 PDT."
             <Pine.SUN.3.91.950823154651.15155M-100000@lupine.nsi.nasa.gov> 
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Date: Wed, 23 Aug 1995 13:02:02 PDT
From: Bill Fenner <fenner@parc.xerox.com>
Message-Id: <95Aug23.130207pdt.177475@crevenia.parc.xerox.com>
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I am well aware that it is an accepted practice (esp. see rfc1812) to re-use 
local addresses.  That practice breaks some of the original assumptions of the 
BSD networking code, in particular, that interfaces are on subnets.  The 
multicast routing code was written with that assumption strongly in mind, and 
thus multicast routing doesn't work on interfaces which use the same local 
address.

I'm not saying that it's an incorrect practice; I'm saying that if you do 
this, the current multicast routing code won't work.

  Bill