Re: [dhcwg] Load Balancing for DHCPv6

Donald Eastlake <d3e3e3@gmail.com> Fri, 07 September 2012 21:37 UTC

Return-Path: <d3e3e3@gmail.com>
X-Original-To: dhcwg@ietfa.amsl.com
Delivered-To: dhcwg@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 53EFB21E80CB for <dhcwg@ietfa.amsl.com>; Fri, 7 Sep 2012 14:37:42 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -103.599
X-Spam-Level:
X-Spam-Status: No, score=-103.599 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, RCVD_IN_DNSWL_LOW=-1, USER_IN_WHITELIST=-100]
Received: from mail.ietf.org ([64.170.98.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id wXsuA5JWkWLE for <dhcwg@ietfa.amsl.com>; Fri, 7 Sep 2012 14:37:40 -0700 (PDT)
Received: from mail-ob0-f172.google.com (mail-ob0-f172.google.com [209.85.214.172]) by ietfa.amsl.com (Postfix) with ESMTP id B77D321E808F for <dhcwg@ietf.org>; Fri, 7 Sep 2012 14:37:40 -0700 (PDT)
Received: by obbwc20 with SMTP id wc20so76781obb.31 for <dhcwg@ietf.org>; Fri, 07 Sep 2012 14:37:40 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; bh=OuisrMBw+si0z/fxWLm8+i1qggpyFUx2VoXwREMzADE=; b=QiUd8GHI9Cb3A4/V4dE3Ivc6jvrd33xqLnftu2O2hzs9Ha/h3ah0WY0l6ciYWHEeIp r2s4+7OlRI2xU5uMEO71v+wTQlOcIrk3b9et+QHDtk6zHpwiXMUQYPc1TylVS71gVqRe AvQDPPTYOcYavCIiOHjwMqIebNjVlql11hKA5DyGt9E7JJuQ7zcZemGH862Ak4W+chiP 8AbBMjZ0TCG8xQvOBywXeIl3E/uPyyZerT41Tu2mveWIl59xwEg3e4+fZZFQU9JbNqiH RAVPhbuYxplXrfXQmCWaIIeu1csCm5x5u0jFWGMnRQESyIac/Ak2biOFAotXyC4kpmXe xzoA==
Received: by 10.60.1.106 with SMTP id 10mr3344107oel.84.1347053860201; Fri, 07 Sep 2012 14:37:40 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.60.135.1 with HTTP; Fri, 7 Sep 2012 14:37:19 -0700 (PDT)
In-Reply-To: <71F17433-B2D9-4366-9B32-F0E4D294EDB5@nominum.com>
References: <CAL10_Bqa4ftiVhyyf0ezwKR7mzAEOLNi_K3EJFPFUzPnz7QGPw@mail.gmail.com> <489D13FBFA9B3E41812EA89F188F018E0F4F3093@xmb-rcd-x04.cisco.com> <CAL10_Br=OcWZuar1fDOopevTy_W-3g9TsYqo61rOWm4tKkuYgg@mail.gmail.com> <2D09D61DDFA73D4C884805CC7865E61118003F@GAALPA1MSGUSR9N.ITServices.sbc.com> <CAL10_BpXdx03WfV1PeMKg1zYc1dAFKe1CDNdrcNf45+_EVCBPg@mail.gmail.com> <CDDB9016-BE11-489A-9361-0172D96A464C@nominum.com> <CAOpJ=k2CJS=FuUvFwOq=s2m871_qfo=xROsW=fx0E48w2wxAqQ@mail.gmail.com> <CAL10_BoLsdppYKNSfHheYrZg+SfaggoynQf2X11HEdy=ELFUiQ@mail.gmail.com> <5049C317.7090603@gmail.com> <94FA926F-2432-4AE7-BC20-AE7458AB40D9@cisco.com> <CAF4+nEHqRFHbz9qfQuOqpLCNeZqkT=+f53_eCboECfWX8QCt6A@mail.gmail.com> <71F17433-B2D9-4366-9B32-F0E4D294EDB5@nominum.com>
From: Donald Eastlake <d3e3e3@gmail.com>
Date: Fri, 07 Sep 2012 17:37:19 -0400
Message-ID: <CAF4+nEE6pbmO_ss+3UEpRG1kh2YD20P2KD4CFQ7LwoRZ6gyxsg@mail.gmail.com>
To: Ted Lemon <Ted.Lemon@nominum.com>
Content-Type: text/plain; charset="ISO-8859-1"
Cc: "dhcwg@ietf.org" <dhcwg@ietf.org>, "Bernie Volz (volz)" <volz@cisco.com>
Subject: Re: [dhcwg] Load Balancing for DHCPv6
X-BeenThere: dhcwg@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: <dhcwg.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dhcwg>, <mailto:dhcwg-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/dhcwg>
List-Post: <mailto:dhcwg@ietf.org>
List-Help: <mailto:dhcwg-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dhcwg>, <mailto:dhcwg-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 07 Sep 2012 21:37:42 -0000

Hi Ted,

On Fri, Sep 7, 2012 at 11:27 AM, Ted Lemon <Ted.Lemon@nominum.com> wrote:
> On Sep 7, 2012, at 10:44 AM, Donald Eastlake <d3e3e3@gmail.com> wrote:
>> If it is working fine, there is certainly no reason to change it,
>> which could lead to interoperability problems. But I'd be willing to
>> bet that FNV is superior...
>
> There's no risk of an interoperability problem, since DHCPv6 and DHCPv4 never interoperate.   However, the advantages of the hash mentioned in the draft are pretty handwavy.  Is there any more detailed analysis somewhere?

Here is one study done by Brian Carpenter related to equal cost
multi-path hashing based on the IP 5-tuple:
https://researchspace.auckland.ac.nz/bitstream/handle/2292/13240/flowhashRep.pdf?sequence=2

Here is a study done by Puneet Agarwal (of Broadcom) related to equal
cost multi-path hashing based on Layer 2 headers:
http://www.ieee802.org/1/files/public/docs2011/bp-agarwal-hash-proposal-0411-v03.pdf

FNV takes a little more effort than Pearson. It also has a smaller
footprint in memory. And I believe it will produce statistically
better results. What are the relative weights of these or other
factors in this case?

Thanks,
Donald
=============================
 Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
 155 Beaver Street, Milford, MA 01757 USA
 d3e3e3@gmail.com