From mboxrd@z Thu Jan 1 00:00:00 1970 From: WeipingPan Subject: Re: Is 802.3ad mode in bonding useful ? Date: Fri, 29 Apr 2011 21:59:30 +0800 Message-ID: <4DBAC442.6050706@gmail.com> References: <4DB9185E.4050103@gmail.com> <20110428122102.GB4165@hmsreliant.think-freely.org> <4DBA2DDC.80502@gmail.com> <20110429104342.GA22387@hmsreliant.think-freely.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Neil Horman Return-path: Received: from mail-vx0-f174.google.com ([209.85.220.174]:56996 "EHLO mail-vx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751886Ab1D2N7K (ORCPT ); Fri, 29 Apr 2011 09:59:10 -0400 Received: by vxi39 with SMTP id 39so2768406vxi.19 for ; Fri, 29 Apr 2011 06:59:10 -0700 (PDT) In-Reply-To: <20110429104342.GA22387@hmsreliant.think-freely.org> Sender: netdev-owner@vger.kernel.org List-ID: On 04/29/2011 06:43 PM, Neil Horman wrote: > On Fri, Apr 29, 2011 at 11:17:48AM +0800, WeipingPan wrote: >> On 04/28/2011 08:21 PM, Neil Horman wrote: >>> On Thu, Apr 28, 2011 at 03:33:50PM +0800, WeipingPan wrote: >>>> Hi, all, >>>> >>>> 802.3ad mode in bonding implements 802.3ad standard. >>>> >>>> I am just wondering 802.3ad mode is useful, >>>> since bonding has many modes like balance-rr, active-backup, etc. >>>> >>> Yes, of course its usefull. For switches which support 802.3ad, this mode >>> allows for both peers to understand that the links in the bond are acting as an >>> aggregate, which makes it easier to prevent things like inadvertently looped >>> back frames, for which the other modes have to have all sorts of hacks to >>> prevent. >> What is looped back frames here ? > In this case they are frames that get received by the bond, which the bond > itself sent. In modes where more than one slave is active, and in which the > switch has no additional knoweldge of the aggregate (e.g. round robin mode), the > bond can send a frame on one slave, which the switch may broadcast to all ports, > causing the frame just sent by the bond to then get received on another slave. > >> I didn't see any special code to handle looped back frames in other >> modes in bonding, >> can you take an example ? >> > See bond_handle_frame. > > Neil > Oh, I got it. Thanks for your clear explanation ! Weiping Pan