From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: Re: [PATCH net-next v4] IPv6: use anycast addresses as source addresses in echo reply Date: Tue, 7 Jan 2014 14:09:38 +0100 Message-ID: <20140107130938.GE24730@order.stressinduktion.org> References: <1389098318.83283.YahooMailBasic@web125506.mail.ne1.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev@vger.kernel.org, "David S. Miller" , Alexey Kuznetsov , James Morris , Hideaki Yoshifuji , Patrick McHardy To: =?utf-8?Q?Fran=C3=A7ois-Xavier?= Le Bail Return-path: Received: from order.stressinduktion.org ([87.106.68.36]:45029 "EHLO order.stressinduktion.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750966AbaAGNJk (ORCPT ); Tue, 7 Jan 2014 08:09:40 -0500 Content-Disposition: inline In-Reply-To: <1389098318.83283.YahooMailBasic@web125506.mail.ne1.yahoo.com> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, Jan 07, 2014 at 04:38:38AM -0800, Fran=C3=A7ois-Xavier Le Bail = wrote: > On Mon, 1/6/14, Hannes Frederic Sowa wro= te: >=20 > >>But if an echo request arrive on an interface > >> which do not listen at this LL anycast, is a reply can occur ? > =20 > > I thought quite the opposite with anycast + forwarding > > enabled, that=C2=A0 we would process the packet. >=20 > yes, for a global scope anycast. > But a routers must not forward any packets with link-local source or = destination addresses to other links, thus also ll anycast. Of course, but in this case I hesitated because I haven't dealt a lot with anycast recently in routing code and it seemed like RTF_ANYCAST is exclusive-or with RTF_LOCAL. So I was really unsure if this protection was really in place. We already had some illegal forwarding/input paths in the past. ;) Greetings, Hannes