Re: Non-Last Small IPv6 Fragments
"Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net> Sun, 13 January 2019 23:58 UTC
Return-Path: <bzeeb-lists@lists.zabbadoz.net>
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 3CCAE12D4EB for <ipv6@ietfa.amsl.com>; Sun, 13 Jan 2019 15:58:00 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.901
X-Spam-Level:
X-Spam-Status: No, score=-1.901 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
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 cSg9S3FhS6Gt for <ipv6@ietfa.amsl.com>; Sun, 13 Jan 2019 15:57:57 -0800 (PST)
Received: from mx1.sbone.de (mx1.sbone.de [IPv6:2a01:4f8:13b:39f::9f:25]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 643BF123FFD for <ipv6@ietf.org>; Sun, 13 Jan 2019 15:57:57 -0800 (PST)
Received: from mail.sbone.de (mail.sbone.de [IPv6:fde9:577b:c1a9:31::2013:587]) (using TLSv1 with cipher ADH-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by mx1.sbone.de (Postfix) with ESMTPS id 9E29D8D4A142; Sun, 13 Jan 2019 23:57:55 +0000 (UTC)
Received: from content-filter.sbone.de (content-filter.sbone.de [IPv6:fde9:577b:c1a9:31::2013:2742]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.sbone.de (Postfix) with ESMTPS id 59106D20846; Sun, 13 Jan 2019 23:57:54 +0000 (UTC)
X-Virus-Scanned: amavisd-new at sbone.de
Received: from mail.sbone.de ([IPv6:fde9:577b:c1a9:31::2013:587]) by content-filter.sbone.de (content-filter.sbone.de [fde9:577b:c1a9:31::2013:2742]) (amavisd-new, port 10024) with ESMTP id RCfZeB7RVRdw; Sun, 13 Jan 2019 23:57:51 +0000 (UTC)
Received: from [192.168.2.110] (unknown [IPv6:fde9:577b:c1a9:31:2ef0:eeff:fe03:ee34]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.sbone.de (Postfix) with ESMTPSA id AF58DD2083A; Sun, 13 Jan 2019 23:57:51 +0000 (UTC)
From: "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net>
To: Brian E Carpenter <brian.e.carpenter@gmail.com>
Cc: IPv6 List <ipv6@ietf.org>, Bob Hinden <bob.hinden@gmail.com>
Subject: Re: Non-Last Small IPv6 Fragments
Date: Sun, 13 Jan 2019 23:57:51 +0000
X-Mailer: MailMate (2.0BETAr6133)
Message-ID: <15CFC5D4-C4E4-45E1-B648-2B9F00BA1BAC@lists.zabbadoz.net>
In-Reply-To: <146dbb4f-bebb-cce4-f0f8-f965a951dc47@gmail.com>
References: <CAOSSMjV0Vazum5OKztWhAhJrjLjXc5w5YGxdzHgbzi7YVSk7rg@mail.gmail.com> <8b43af81-1c49-5cea-6472-97703674e661@si6networks.com> <CAN-Dau1HwG5RndacpSA+si+zKuTdpSvA=QA1A11A==rMNe=4+w@mail.gmail.com> <CALx6S35KNhV2gFp9OdU+M1zy5WUuEAEvXkDXNDWWxi7uQ4e_cw@mail.gmail.com> <CAN-Dau0rTdiiF2SjByxcMG6nhPCEjUH2pYBCOeK_FSGJ_ucDQw@mail.gmail.com> <CALx6S34AyV9OpvnjQhQc56n5vfeVgU5Zd3kheP0g+XvsMbBV9g@mail.gmail.com> <1b2e318e-1a9f-bb5d-75a5-04444c42ef20@si6networks.com> <CALx6S37TJr++fC=pVoeS=mrO1fHc4gL_Wtu-XkVTswzs2XxXCA@mail.gmail.com> <CALx6S36V7vrVyoTP0G6+S5XeFNB3KWS5UaNnVi20xogRERdCfg@mail.gmail.com> <973A1649-55F6-4D97-A97F-CEF555A4D397@employees.org> <CALx6S34YbBe8xBod3VsWVO33TpZcdxh2uV1vaO8Z_NKnVXp66g@mail.gmail.com> <A3C3F9C0-0A07-41AF-9671-B9E486CB8246@employees.org> <AEA47E27-C0CB-4ABE-8ADE-51E9D599EF8F@gmail.com> <6aae7888-46a4-342d-1d76-10f8b50cebc4@gmail.com> <CALx6S35QKOqn_Ywh9yzm1JDA8Xnp7fLPPmXUvomvz_xOZP8bfg@mail.gmail.com> <146dbb4f-bebb-cce4-f0f8-f965a951dc47@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"; format="flowed"
Content-Transfer-Encoding: 8bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/ipv6/2MYlrVUViVBFkO6ByOG5c0Sj7kY>
X-BeenThere: ipv6@ietf.org
X-Mailman-Version: 2.1.29
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: Sun, 13 Jan 2019 23:58:00 -0000
On 13 Jan 2019, at 21:40, Brian E Carpenter wrote: > On 2019-01-14 08:48, Tom Herbert wrote: >> On Sun, Jan 13, 2019 at 11:25 AM Brian E Carpenter >> <brian.e.carpenter@gmail.com> wrote: >>> >>> On 2019-01-14 07:54, Bob Hinden wrote: >>>> Unleveling a bit. >>>> >>>> I think the w.g. should be very cautious about making protocol >>>> changes based on what appears to be a fragmentation resource >>>> management problem in an implementation. >>> >>> I agree. However, I wonder if we need to clarify that there is no >>> rule that non-last fragments must be at least 1280. It seems that >>> the Linux patch assumed that there is >>> such a rule. I think if you want to clarify anything than it is “What does minimum MTU of 1280 mean?” I would assume that’s where the problem comes from. To my best memory it’s formulated as loser text and not that formal (*)(**). The misunderstanding that one needs to be able to send packets with up-to 1280 doesn’t mean that one has to send packets that big. (*) and I seem to remember that I always have MTU vs. MRU on my mind when I read these paragraphs and think that’s conflated in the text. (**) Also that section 4.5 and 5 contradict each other as section 4.5 says “fragment when no fit into path’s MTU”, while section 5 says “you may fragment already for anything larger than 1280”, e.g., a path’s mtu of 1500 can sill fragment a 1432 octet packet. > Well, I'm an advocate of one step at a time. > > Step 1: As an addendum to RFC8200, state that there is no rule that > non-last fragments must be at least 1280. I am kind-of against this. Just when we find any buggy implementation we cannot amend an RFC or any other document to clarify. A bug is a bug and a OS vendor problem. The document nowhere states what was implemented so why give them special treatment? That’s a problem that community needs to solve and they’ll have good reference in public mailing list archives that what they did will break their communications and that’s it. > Step 2: Discuss whether there *should* be any rules about non-last > fragment size, given that there are legitimate cases where they will > be less than 1280. > > Step 3: TBD Now that’s a change to the current specification and that can be discussed but beware that changing current behaviour (and it was mentioned in this thread that there seem to be implementations of different sending behaviour) will mean that OS developers will have to carry “backward compatibility” for a long time (at least allowing the user to make a choice). /bz
- Non-Last Small IPv6 Fragments Timothy Winters
- Re: Non-Last Small IPv6 Fragments Bob Hinden
- Re: Non-Last Small IPv6 Fragments 神明達哉
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- RE: Non-Last Small IPv6 Fragments Ron Bonica
- Re: Non-Last Small IPv6 Fragments Erik Kline
- RE: Non-Last Small IPv6 Fragments Ron Bonica
- Re: Non-Last Small IPv6 Fragments Brian E Carpenter
- RE: Non-Last Small IPv6 Fragments Ron Bonica
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Mark Andrews
- Re: Non-Last Small IPv6 Fragments Simon Hobson
- Re: Non-Last Small IPv6 Fragments Erik Kline
- Re: Non-Last Small IPv6 Fragments David Farmer
- Re: Non-Last Small IPv6 Fragments Mark Andrews
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Erik Kline
- Re: Non-Last Small IPv6 Fragments Carsten Bormann
- Re: Non-Last Small IPv6 Fragments 神明達哉
- Re: Non-Last Small IPv6 Fragments Brian E Carpenter
- Re: Non-Last Small IPv6 Fragments Brian E Carpenter
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Mikael Abrahamsson
- Re: Non-Last Small IPv6 Fragments Mark Andrews
- Re: Non-Last Small IPv6 Fragments Bjoern A. Zeeb
- Re: Non-Last Small IPv6 Fragments Bjoern A. Zeeb
- Re: Non-Last Small IPv6 Fragments Timothy Winters
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Ole Troan
- Re: Non-Last Small IPv6 Fragments Timothy Winters
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Simon Hobson
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments David Farmer
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- RE: Non-Last Small IPv6 Fragments Ron Bonica
- Re: Non-Last Small IPv6 Fragments David Farmer
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Bob Hinden
- Re: Non-Last Small IPv6 Fragments David Farmer
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Erik Kline
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Christian Huitema
- Re: Non-Last Small IPv6 Fragments Ole Troan
- RE: Non-Last Small IPv6 Fragments Lubashev, Igor
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Ole Troan
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Ole Troan
- Re: Non-Last Small IPv6 Fragments Nick Hilliard
- Re: Non-Last Small IPv6 Fragments Bob Hinden
- Re: Non-Last Small IPv6 Fragments Brian E Carpenter
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Ole Troan
- Re: Non-Last Small IPv6 Fragments Nick Hilliard
- Re: Non-Last Small IPv6 Fragments Ole Troan
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Nick Hilliard
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Brian E Carpenter
- RE: Non-Last Small IPv6 Fragments Manfredi (US), Albert E
- Re: Non-Last Small IPv6 Fragments Bjoern A. Zeeb
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Brian E Carpenter
- Re: Non-Last Small IPv6 Fragments Erik Kline
- Re: Non-Last Small IPv6 Fragments Mark Smith
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Simon Hobson
- Re: Non-Last Small IPv6 Fragments Nick Hilliard
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Nick Hilliard
- Re: Non-Last Small IPv6 Fragments Bjoern A. Zeeb
- Re: Non-Last Small IPv6 Fragments Simon Hobson
- Re: Non-Last Small IPv6 Fragments Nick Hilliard
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- Re: Non-Last Small IPv6 Fragments Brian E Carpenter
- Re: Non-Last Small IPv6 Fragments Mark Andrews
- Re: Non-Last Small IPv6 Fragments Erik Kline
- Re: Non-Last Small IPv6 Fragments Nick Hilliard
- Re: Non-Last Small IPv6 Fragments Ole Troan
- Re: Non-Last Small IPv6 Fragments Erik Kline
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Tom Herbert
- End-to-end (was Re: Non-Last Small IPv6 Fragments) Christian Huitema
- Re: End-to-end (was Re: Non-Last Small IPv6 Fragm… Tom Herbert
- Re: End-to-end (was Re: Non-Last Small IPv6 Fragm… Nick Hilliard
- Re: Non-Last Small IPv6 Fragments Warren Kumari
- Re: Non-Last Small IPv6 Fragments Brian E Carpenter
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: End-to-end (was Re: Non-Last Small IPv6 Fragm… Fernando Gont
- Re: Non-Last Small IPv6 Fragments Mikael Abrahamsson
- Re: Non-Last Small IPv6 Fragments Tim Chown
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Warren Kumari
- Re: End-to-end (was Re: Non-Last Small IPv6 Fragm… Tom Herbert
- Re: Non-Last Small IPv6 Fragments Ole Troan
- Re: End-to-end (was Re: Non-Last Small IPv6 Fragm… Fernando Gont
- Re: Non-Last Small IPv6 Fragments Fernando Gont
- Re: Non-Last Small IPv6 Fragments Fred Baker
- Re: Non-Last Small IPv6 Fragments Tim Chown
- Re: End-to-end (was Re: Non-Last Small IPv6 Fragm… Tom Herbert
- Re: End-to-end (was Re: Non-Last Small IPv6 Fragm… Brian E Carpenter
- Re: Non-Last Small IPv6 Fragments Brian E Carpenter
- Re: Non-Last Small IPv6 Fragments Michael Richardson
- Never fragment: getting PMTU info transmitted rel… Michael Richardson
- Re: Never fragment: getting PMTU info transmitted… Joel M. Halpern
- Re: Never fragment: getting PMTU info transmitted… Brian E Carpenter
- Re: Never fragment: getting PMTU info transmitted… Tom Herbert
- Re: Never fragment: getting PMTU info transmitted… Michael Richardson
- Re: Never fragment: getting PMTU info transmitted… Brian E Carpenter
- Re: Never fragment: getting PMTU info transmitted… Mark Smith
- Re: Never fragment: getting PMTU info transmitted… Erik Kline
- Re: Never fragment: getting PMTU info transmitted… Mark Smith
- Re: Never fragment: getting PMTU info transmitted… Tom Herbert
- Re: Never fragment: getting PMTU info transmitted… Brian E Carpenter
- RE: Never fragment: getting PMTU info transmitted… Lubashev, Igor
- Re: Never fragment: getting PMTU info transmitted… Tom Herbert
- RE: Never fragment: getting PMTU info transmitted… Lubashev, Igor
- Re: Never fragment: getting PMTU info transmitted… C. M. Heard
- Re: Never fragment: getting PMTU info transmitted… Christian Huitema