From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next v5] net: ipv6: Make address flushing on ifdown optional Date: Wed, 14 Oct 2015 05:18:14 -0700 (PDT) Message-ID: <20151014.051814.801287755321309990.davem@davemloft.net> References: <1444815241.2154853.409816321.48710CD1@webmail.messagingengine.com> <561E29A3.9080101@6wind.com> <1444820621.2175377.409880265.37A31E2D@webmail.messagingengine.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: nicolas.dichtel@6wind.com, dsa@cumulusnetworks.com, netdev@vger.kernel.org, hannes@redhat.com To: hannes@stressinduktion.org Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:59394 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752157AbbJNMCN convert rfc822-to-8bit (ORCPT ); Wed, 14 Oct 2015 08:02:13 -0400 In-Reply-To: <1444820621.2175377.409880265.37A31E2D@webmail.messagingengine.com> Sender: netdev-owner@vger.kernel.org List-ID: =46rom: Hannes Frederic Sowa Date: Wed, 14 Oct 2015 13:03:41 +0200 > On Wed, Oct 14, 2015, at 12:08, Nicolas Dichtel wrote: >> Le 14/10/2015 11:34, Hannes Frederic Sowa a =E9crit : >> [sni] >> > This sysctl is on my list to be enabled soon by default by any sys= temd >> > based distribution. For that reason, could you maybe remove all th= e >> I'm not sure to understand why we add a sysctl then. Or at least, wh= y the >> linux >> default value is different from all standard distrib. I will be like >> rp_filter :/ >=20 > The difference is that people upgrade (in case of fedora they get a > .rpmnew file) or install a distribution and don't wonder or have > assumptions about old behavior. In case companies integrate kernel in > products/appliances without a way to manage those sysctls we cannot > simply change them as this would break assumptions for them. I think > those are two different cases. The thing that is similar is that people set rp_filter inappropriately (no end host should have that knob enabled, ever, it's totally unnecesary). And the risk here is similar, distribution X will set it so Y will say "we probably should set it too even though we really don't understand it fully". I really hate situations like this.