From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Farnsworth Subject: Re: Use of 802.3ad bonding for increasing link throughput Date: Wed, 10 Aug 2011 14:50:40 +0100 Message-ID: References: <4E427499.8060108@cyconix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7Bit To: netdev@vger.kernel.org Return-path: Received: from lo.gmane.org ([80.91.229.12]:33097 "EHLO lo.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750768Ab1HJNuy (ORCPT ); Wed, 10 Aug 2011 09:50:54 -0400 Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1Qr9BN-0001a7-Jl for netdev@vger.kernel.org; Wed, 10 Aug 2011 15:50:53 +0200 Received: from 110.100.155.90.in-addr.arpa ([90.155.100.110]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 10 Aug 2011 15:50:53 +0200 Received: from simon by 110.100.155.90.in-addr.arpa with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 10 Aug 2011 15:50:53 +0200 Sender: netdev-owner@vger.kernel.org List-ID: Tom Brown wrote: > [couldn't thread with '802.3ad bonding brain damaged', as I've just > signed up] > > So, under what circumstances would a user actually use 802.3ad mode to > "increase" link throughput, rather than just for redundancy? Are there > any circumstances in which a single file, for example, could be > transferred at multiple-NIC speed? The 3 hashing options are: > As an example, from my server room here; I have an install server (TFTP, FTP and HTTP) connected by a 2x1G LACP bond to the switch. When I have multiple clients installing simultaneously, the layer2 hash distributes the load nicely across both NICs - I can reach saturation on both NICs together. If I had routers between my clients and the install server, I'd need layer2+3 hashing to spread the clients over the links, but I'd still be able to push over a gigabit per second to the clients, despite being limited to 1GBit/s to each individual client by the packet distribution. I'm sure that you can think of lots of other situations in which you have multiple conversations sharing a link - those are the situations that gain speed from 802.3ad. -- Simon Farnsworth