Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751762AbcKAQZO (ORCPT ); Tue, 1 Nov 2016 12:25:14 -0400 Received: from out2-smtp.messagingengine.com ([66.111.4.26]:43369 "EHLO out2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751128AbcKAQZM (ORCPT ); Tue, 1 Nov 2016 12:25:12 -0400 X-ME-Sender: X-Sasl-enc: ND00OEU/4O6GREZHfwaI0lBKhcM6c0Wowh2flpXt+hBP 1478017511 Subject: Re: [PATCH net-next 5/5] ipv6: Compute multipath hash for forwarded ICMP errors from offending packet To: Tom Herbert , Jakub Sitnicki References: <8760oa9egg.fsf@redhat.com> Cc: Linux Kernel Network Developers , LKML , "David S. Miller" , Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Patrick McHardy From: Hannes Frederic Sowa Message-ID: Date: Tue, 1 Nov 2016 17:25:07 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 742 Lines: 15 On 31.10.2016 20:25, Tom Herbert wrote: > The normal hash for TCP or UDP using ECMP is over dstIP, srcPort, dstPort>. For an ICMP packet ECMP would most likely be > done over . There really is no way to ensure > that an ICMP packet will follow the same path as TCP or any other > protocol. Fortunately, this is really isn't so terrible. The Internet > has worked this way ever since routers started using ports as input to > ECMP and that hasn't caused any major meltdown. The normal hash for forwarding is without srcPort or dstPort, so the same as ICMP and especially also because of fragmentation problematic I don't think a lot of routers use L4 port information for ECMP either. Bye, Hannes