From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Westphal Subject: Re: [PATCH] ipv4: arp: process only if ipv4 address configured Date: Wed, 12 Feb 2014 23:01:43 +0100 Message-ID: <20140212220143.GD25153@breakpoint.cc> References: <1392226067-21736-1-git-send-email-fw@strlen.de> <1392229587.1752.11.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Florian Westphal , netdev@vger.kernel.org To: Eric Dumazet Return-path: Received: from Chamillionaire.breakpoint.cc ([80.244.247.6]:40847 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753563AbaBLWBo (ORCPT ); Wed, 12 Feb 2014 17:01:44 -0500 Content-Disposition: inline In-Reply-To: <1392229587.1752.11.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: Eric Dumazet wrote: > On Wed, 2014-02-12 at 18:27 +0100, Florian Westphal wrote: > > 8030f54499925d073a88c09f ([IPV4] devinet: Register inetdev earlier.) > > changed arp behaviour (2.6.22 onwards). > > > > Before this, inetdev_init() was called only when the first address was > > added to the interface, i.e. arp_process always dropped incoming arp > > packets as __in_dev_get_rcu() returned NULL when no IP address was set > > on the interface. > > > > With >= 2.6.22 we now process arp packets even if no address is assigned. > > It can cause issues if the machine has several interfaces in the same > > segment; requests receive answers from multiple macs. > > What about arp_filter value/meaning ? Sure, arp_filter=1 avoids this. If you mean "we don't care, its been like this for years and if you don't want it then set arp_filter=1" -- fine with me. Sorry if this wasn't clear -- its more about the change in behaviour and if we should care.