From owner-freebsd-net@freebsd.org Thu Sep 22 00:02:50 2016 Return-Path: Delivered-To: freebsd-net@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 078E9BE28F2 for ; Thu, 22 Sep 2016 00:02:50 +0000 (UTC) (envelope-from glebius@FreeBSD.org) Received: from cell.glebi.us (glebi.us [96.95.210.25]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "cell.glebi.us", Issuer "cell.glebi.us" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id CA0CC1B5; Thu, 22 Sep 2016 00:02:49 +0000 (UTC) (envelope-from glebius@FreeBSD.org) Received: from cell.glebi.us (localhost [127.0.0.1]) by cell.glebi.us (8.15.2/8.15.2) with ESMTPS id u8LNv3cT015291 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 21 Sep 2016 16:57:04 -0700 (PDT) (envelope-from glebius@FreeBSD.org) Received: (from glebius@localhost) by cell.glebi.us (8.15.2/8.15.2/Submit) id u8LNv3YQ015290; Wed, 21 Sep 2016 16:57:03 -0700 (PDT) (envelope-from glebius@FreeBSD.org) X-Authentication-Warning: cell.glebi.us: glebius set sender to glebius@FreeBSD.org using -f Date: Wed, 21 Sep 2016 16:57:03 -0700 From: Gleb Smirnoff To: Kubilay Kocak Cc: Karl Pielorz , freebsd-net@freebsd.org, Steven Hartland Subject: Re: lagg Interfaces - don't do Gratuitous ARP? Message-ID: <20160921235703.GG1018@cell.glebi.us> References: <0D84203FAAFD0A8E7BBB24A3@[10.12.30.106]> <6E574F1B61786E6032824A88@[10.12.30.106]> <2c62f5f0-3fb4-f513-2a8f-02de3a1d552f@FreeBSD.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2c62f5f0-3fb4-f513-2a8f-02de3a1d552f@FreeBSD.org> User-Agent: Mutt/1.6.1 (2016-04-27) X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 22 Sep 2016 00:02:50 -0000 On Sat, Sep 10, 2016 at 10:51:36PM +1000, Kubilay Kocak wrote: K> > wrote: K> > K> >> Yes known issue I'm afraid. K> >> K> >> I created a patch set to address this but there where objections so K> >> it was removed, see the attached which is based on 10.2-RELEASE. K> > K> > Hi, K> > K> > Thanks for the reply, and the comprehensive patch. If I get a chance K> > I'll see if I can run it up one of the affected boxes, if I can find K> > one I can mess around with. K> > K> > Good to know it wasn't just "me" :) K> > K> > Cheers, K> > K> > -Karl K> K> Also see the following review, which was re-opened (after original K> commit was reverted) after said issues were raised, though I can't see K> that glebius has commented on it since: K> K> https://reviews.freebsd.org/D4111 K> K> 11.0 having this would have been awesome. Maybe (hopefully) 11.1 IMHO, the original patch was absolutely evil hack touching multiple layers, for the sake of a very special problem. I think, that in order to kick forwarding table on switches, lagg should: - allocate an mbuf itself - set its source hardware address to its own - set destination hardware to broadcast - put some payload in there, to make packet of valid size. Why should it be gratuitous ARP? A machine can be running IPv6 only, or may even use whatever higher level protocol, e.g. PPPoE. We shouldn't involve IP into this Layer 2 problem at all. - Finally, send the prepared mbuf down the lagg member(s). And please don't hack half of the network stack to achieve that :) -- Totus tuus, Glebius.