From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: Re: IPv6 route to gateway on fe80::1%eth0 when I have fe80::1%br0 locally Date: Mon, 22 Feb 2016 16:12:36 +0100 Message-ID: <56CB2564.9030003@stressinduktion.org> References: <20151212195830.GA18286@torres.zugschlus.de> <56796902.8080703@stressinduktion.org> <20151222212843.GE4424@torres.zugschlus.de> <5679C58C.2090308@stressinduktion.org> <20160222150443.GV26042@torres.zugschlus.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Marc Haber Return-path: Received: from out4-smtp.messagingengine.com ([66.111.4.28]:51045 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751592AbcBVPMl (ORCPT ); Mon, 22 Feb 2016 10:12:41 -0500 Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailout.nyi.internal (Postfix) with ESMTP id 4325220C76 for ; Mon, 22 Feb 2016 10:12:41 -0500 (EST) In-Reply-To: <20160222150443.GV26042@torres.zugschlus.de> Sender: netdev-owner@vger.kernel.org List-ID: Hi Marc, On 22.02.2016 16:04, Marc Haber wrote: > In prose: > > The host is a host for KVM VMs. It receives IPv6 connectivity via RA > on eth0, where the default gateway announces its address as fe80::1. > It also provides IPv6 connectivity to the VMs via the br0 interface. > It is running radvd on br0, and for statically configured VMs it has > also fe80::1 on br0. > > If accept_ra_from_local on eth0 were 0, the system would not accept > the RA from the default gateway and and up with no IPv6 since fe80::1 > is locally configured with br0. Isn't this behavior fixed with commit c1a9a291cee0890eb0f435243f3fb84fefb04348 Author: Hannes Frederic Sowa Date: Wed Dec 23 22:44:37 2015 +0100 ipv6: honor ifindex in case we receive ll addresses in router advertisements $ git describe --contains c1a9a291cee0890eb0f435243f3fb84fefb04348 v4.4-rc8~5^2~10 ? If you don't have fe80::1%br0 bound on exactly that interface, it should work, no? So, no need for accept_ra_from_local, which has dubious semantics anyway. > If accept_ra_from_local on eth0 is 1, the system accepts both the RA > from the default gateway on eth0 _AND_ its own RA sent out and > received on br0, and, making things worse, is setting the IP address > and default route not on br0, but on eth0. Understood. Thanks, I was just able to easily reproduce it. Was already wondering why someone would enable accept_ra_from_local besides only testing. I check it out, thanks! Thanks, Hannes