From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: IPv6 routing type - not at par with IPv4 one?
Date: Thu, 06 Sep 2012 12:35:05 +0200
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Cc: netdev@vger.kernel.org, Nicolas Dichtel <nicolas.dichtel@6wind.com>
To: Markus Stenberg <markus.stenberg@iki.fi>
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On Thu, 2012-09-06 at 10:02 +0000, Markus Stenberg wrote:
> ~ # ip route add throw 1.2.3.4
> ~ # ip -6 route add throw ::1.2.3.4
> RTNETLINK answers: No such device
> ~ # ip route add blackhole 1.2.3.5
> ~ # ip -6 route add blackhole ::1.2.3.5
> RTNETLINK answers: No such device
> ~ #
> 
> The reason for this is in net/ipv6/route.c - ipv6_route_add:
> 
> Eventually code winds up at this (1423 line in 3.5.3):
> 
> 	err = -ENODEV;
> 	if (!dev)
> 		goto out;
> 
> and poof, ENODEV.
> 
> Is there some reason for this? Or should I write a patch? 
> Or does someone else want to? Support for dev=NULL 
> elsewhere in the code seems to be ok.
> 
> Based on quick googling I'm not the first one to have encountered this.

Well, it  seems you missed this : 

http://git.kernel.org/?p=linux/kernel/git/davem/net-next.git;a=commitdiff;h=ef2c7d7b59708d54213c7556a82d14de9a7e4475

At least the blackhole is now supported on IPv6, so you probably have to
add the 'throw' bit, if it makes any sense.