Re: Last Call: <draft-ietf-6man-rfc4291bis-07.txt> (IP Version 6 Addressing Architecture) to Internet Standard

David Farmer <farmer@umn.edu> Thu, 23 February 2017 22:43 UTC

Return-Path: <farmer@umn.edu>
X-Original-To: ipv6@ietfa.amsl.com
Delivered-To: ipv6@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 99C46129BC2 for <ipv6@ietfa.amsl.com>; Thu, 23 Feb 2017 14:43:57 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -3.8
X-Spam-Level:
X-Spam-Status: No, score=-3.8 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_SORBS_SPAM=0.5, RP_MATCHES_RCVD=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=unavailable autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=umn.edu
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id xkYs8_lpruWB for <ipv6@ietfa.amsl.com>; Thu, 23 Feb 2017 14:43:56 -0800 (PST)
Received: from mta-p5.oit.umn.edu (mta-p5.oit.umn.edu [134.84.196.205]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 2250E129BCB for <ipv6@ietf.org>; Thu, 23 Feb 2017 14:43:55 -0800 (PST)
Received: from localhost (unknown [127.0.0.1]) by mta-p5.oit.umn.edu (Postfix) with ESMTP id CD494C8E for <ipv6@ietf.org>; Thu, 23 Feb 2017 22:43:53 +0000 (UTC)
X-Virus-Scanned: amavisd-new at umn.edu
Received: from mta-p5.oit.umn.edu ([127.0.0.1]) by localhost (mta-p5.oit.umn.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id KThCLv2X3B0i for <ipv6@ietf.org>; Thu, 23 Feb 2017 16:43:53 -0600 (CST)
Received: from mail-ua0-f198.google.com (mail-ua0-f198.google.com [209.85.217.198]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mta-p5.oit.umn.edu (Postfix) with ESMTPS id 99007BA4 for <ipv6@ietf.org>; Thu, 23 Feb 2017 16:43:53 -0600 (CST)
Received: by mail-ua0-f198.google.com with SMTP id g30so3450656uac.5 for <ipv6@ietf.org>; Thu, 23 Feb 2017 14:43:53 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=umn.edu; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=xJ/eh1msA8dUkCsdpC9At06kkb5RUxs3jyr6X/lZQ/E=; b=EnYTdOQ/5lcOPYsxa2IlSdAb7MScSaviYY6RqFSVtcJVF9yYiWJnewVPHS17+7hu9Q szUkQ0t2sg1se4mvip9qhfZqn9EkbKRG2Mod8GNdU3+P9THFfc+joEGdP5kTXp6/WV4J pSmH473h2icQo369tluWdFYyz9x0qwcTZvMxqfgzSHjP3FYQMlyXuD+x90mKh3b6cNLb PrbO4EfrhOPttTE/tAl7Iky4y83/9UPeYQIS9WwmSgpmV0YZ5eo1vB7AKvkbKScuAIlD q1Cb1gIp6yDeBwWx5ucwy6NsF/uUa7CzwSZIU11zqyFt1BNMMEvDs0mimpNRh1Ab5G8U RqCw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=xJ/eh1msA8dUkCsdpC9At06kkb5RUxs3jyr6X/lZQ/E=; b=Qjoz5Un9qnveXqNP4dtZv/ZeDdeOxhu6SrCNeVuJIWzuRrz2ELeFh2tnXI18rifhSf 6CXzVCVN8ZzKT58bwNIv/MJa3hmzYI3NjYdYajD+E+Gm8XUIrZ5HTM37Mj+dEKN+ps8G pQOa70Vyd8hu+MvO7x7GZjUaVNUWKhUbYCIg7w3VUUnd0MByHWCngjCElnkss+U3kiCz ygycLKT+f/29oYvOGvakwF8Y5JsgdkedxPvPowvoOP1HDc4zFvPseFgNP4XSE3fiW6j2 FFgmAe5i2X4dyGP8PWFbWxEWnljdCVbVkd1WXagPsRA19JZ7sWN5o1cj3yGksm3gE048 lkTA==
X-Gm-Message-State: AMke39lchNkpKgU/cAjUs4yM0u3mSroN02saE8dx/dp4lhzQsUWNFeWEiJSOIQxF4/uj7VEtmI8JEbJS5MNGW8k+GCW2IP+WqbXyjtRODUHXs48nUpHAMIr1bRLiH9msZwMVutugoa8np/0OyRk=
X-Received: by 10.31.49.81 with SMTP id x78mr19802504vkx.82.1487889833012; Thu, 23 Feb 2017 14:43:53 -0800 (PST)
X-Received: by 10.31.49.81 with SMTP id x78mr19802487vkx.82.1487889832766; Thu, 23 Feb 2017 14:43:52 -0800 (PST)
MIME-Version: 1.0
Received: by 10.103.89.71 with HTTP; Thu, 23 Feb 2017 14:43:51 -0800 (PST)
In-Reply-To: <CAKD1Yr1yRTUPVTTicaTkA8fAFxHiHxdLG8ZzEHjCUDDzKg5zJg@mail.gmail.com>
References: <20170221001940.GB84656@Vurt.local> <068ce975-8b1e-a7c5-abba-2bfc1d904d70@gmail.com> <20170221101339.GC84656@Vurt.local> <CAKD1Yr33oQb=gMGaEM++hLgmMtxMdihiDrUihEsjs63vy8qRbA@mail.gmail.com> <54c81141-e4f5-4436-9479-9c02be6c09bb@Spark> <CAKD1Yr28iQHt0iuLvR3ndrT3Hfct=4k9dxjJeu3MAjDjOogEvA@mail.gmail.com> <CAL9jLaZgTp++PJ9KGHEWuPoVm6t3b8QfVDCEhz5h4fv-0fuUAA@mail.gmail.com> <CAKD1Yr3SbR=xt3RPu7+q1o14wKuUuwUc6oG+BgZtEK1O+m5sWw@mail.gmail.com> <4936e96b-fc82-4de0-9188-ced9547deb2f@Spark> <CAKD1Yr3K+SJb_4ksZ96yNypVKJE-fXopuVaXNhhKp1gkh1=QEg@mail.gmail.com> <20170222144147.GC89584@hanna.meerval.net> <7960ff2d-359f-429c-6e82-ef592f90bf53@gmail.com> <CAKD1Yr1W+AVt4Dixo9epB5VazxBsVMD+mrshwaE=n7SuX6eGDw@mail.gmail.com> <5ce34926-6bde-6410-9b1e-3f61e48e9a1d@gmail.com> <CAKD1Yr1yRTUPVTTicaTkA8fAFxHiHxdLG8ZzEHjCUDDzKg5zJg@mail.gmail.com>
From: David Farmer <farmer@umn.edu>
Date: Thu, 23 Feb 2017 16:43:51 -0600
Message-ID: <CAN-Dau0xpjB4Z8CgSfW0W7y4F_wnXNS+Ws1UNBC-YnBDrPiTjQ@mail.gmail.com>
Subject: Re: Last Call: <draft-ietf-6man-rfc4291bis-07.txt> (IP Version 6 Addressing Architecture) to Internet Standard
To: Lorenzo Colitti <lorenzo@google.com>
Content-Type: multipart/alternative; boundary="001a114388b0f2872f05493a5864"
Archived-At: <https://mailarchive.ietf.org/arch/msg/ipv6/sztSRTOxPMOGlf7U1RVy4CoMHik>
Cc: 6man WG <ipv6@ietf.org>, IETF-Discussion Discussion <ietf@ietf.org>, draft-ietf-6man-rfc4291bis@ietf.org, 6man-chairs@ietf.org
X-BeenThere: ipv6@ietf.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: "IPv6 Maintenance Working Group \(6man\)" <ipv6.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ipv6>, <mailto:ipv6-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ipv6/>
List-Post: <mailto:ipv6@ietf.org>
List-Help: <mailto:ipv6-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ipv6>, <mailto:ipv6-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 23 Feb 2017 22:43:57 -0000

On Wed, Feb 22, 2017 at 10:16 PM, Lorenzo Colitti <lorenzo@google.com>
wrote:
>
> Help he understand, then. There is widely-deployed code that assumes that
> the interface ID is 64 and does not work on anything other than 64 bit
> prefix lengths. Currently that code is correct on all unicast space. If you
> change RFC 4291, won't that code be incorrect?
>

OK, what if we said something like this;

   IPv6 unicast routing is based on prefixes of any valid length up to
   128 [BCP198]. However, all implementations of IPv6 are REQUIRED to
   support an IID length of 64 bits, other IID lengths are OPTIONAL.
   Subnet prefixes of /64 are RECOMMENDED for general purpose use,
   subnet prefixes of /127 are RECOMMENDED for point-to-point router
   links [RFC6164], other subnet prefix lengths are NOT RECOMMENDED,
   as their use could be incompatible with some implementations of IPv6.
   The rationale for the 64 bit boundary in IPv6 addresses can be found
   in [RFC7421].

I'd prefer other IID lengths to be RECOMMENDED for implementations, but I
can live with OPTIONAL.



-- 
===============================================
David Farmer               Email:farmer@umn.edu
Networking & Telecommunication Services
Office of Information Technology
University of Minnesota
2218 University Ave SE        Phone: 612-626-0815
Minneapolis, MN 55414-3029   Cell: 612-812-9952
===============================================