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Message-ID: <45C77164.1020801@FreeBSD.org>
Date: Mon, 05 Feb 2007 18:03:16 +0000
From: "Bruce M. Simpson" <bms@FreeBSD.org>
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To: Gleb Smirnoff <glebius@FreeBSD.org>
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Cc: cvs-src@FreeBSD.org, src-committers@FreeBSD.org, cvs-all@FreeBSD.org
Subject: Re: cvs commit: src/sys/net if_tap.c
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Bruce M. Simpson wrote:
> Gleb Smirnoff wrote:
>> ...
>> Moreover, in case of promisc + net.inet.ip.forwarding=1 our box will 
>> resend
>> all the received foreign packets :(
>>   
>
> NetBSD has M_PROMISC presumably for detecting situations like this:
>    http://fxr.watson.org/fxr/ident?v=NETBSD&i=M_PROMISC

The other cool thing is the opportunities for functional separation 
which it offers.

For example: wi(4) is known to have a broken IFF_ALLMULTI mode, as do 
other cards. If we added an ifnet capability 'has working hardware 
allmulti', M_PROMISC lets you do the right thing in either case at the 
cost of checking a bit.

Rehards,
BMS