From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH] ipv6: Fix for adding multicast route for loopback
 device automatically.
Date: Wed, 07 Dec 2011 15:06:15 -0500 (EST)
Message-ID: <20111207.150615.181825066035193136.davem@davemloft.net>
References: <4EDF1481.1080106@cn.fujitsu.com>
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From: Li Wei <lw@cn.fujitsu.com>
Date: Wed, 07 Dec 2011 15:23:45 +0800

> There is no obvious reason to add a default multicast route for loopback
> devices, otherwise there would be a route entry whose dst.error set to
> -ENETUNREACH that would blocking all multicast packets.
> 
> Signed-off-by: Li Wei <lw@cn.fujitsu.com>

I still do not understand the purpose of this change, what problems
does the current behavior cause?

And can you be sure that by making this change, you are not breaking
something, somewhere, that depends upon the current behavior?