Re: Last Call: <draft-ietf-6man-rfc1981bis-04.txt> (Path MTU Discovery for IP version 6) to Internet Standard

"Eggert, Lars" <lars@netapp.com> Thu, 02 February 2017 09:38 UTC

Return-Path: <lars@netapp.com>
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 5A0AB127078; Thu, 2 Feb 2017 01:38:26 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -10.12
X-Spam-Level:
X-Spam-Status: No, score=-10.12 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, RP_MATCHES_RCVD=-3.199, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=netapp.onmicrosoft.com
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 fLhWNrXIt3RV; Thu, 2 Feb 2017 01:38:25 -0800 (PST)
Received: from mx142.netapp.com (mx142.netapp.com [216.240.21.19]) (using TLSv1.2 with cipher RC4-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id E2F6F1293E4; Thu, 2 Feb 2017 01:38:21 -0800 (PST)
X-IronPort-AV: E=Sophos;i="5.33,323,1477983600"; d="asc'?scan'208";a="168855953"
Received: from vmwexchts03-prd.hq.netapp.com ([10.122.105.31]) by mx142-out.netapp.com with ESMTP; 02 Feb 2017 01:30:35 -0800
Received: from VMWEXCCAS04-PRD.hq.netapp.com (10.122.105.20) by VMWEXCHTS03-PRD.hq.netapp.com (10.122.105.31) with Microsoft SMTP Server (TLS) id 15.0.1210.3; Thu, 2 Feb 2017 01:37:14 -0800
Received: from NAM03-BY2-obe.outbound.protection.outlook.com (10.120.60.153) by VMWEXCCAS04-PRD.hq.netapp.com (10.122.105.20) with Microsoft SMTP Server (TLS) id 15.0.1210.3 via Frontend Transport; Thu, 2 Feb 2017 01:37:14 -0800
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netapp.onmicrosoft.com; s=selector1-netapp-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version; bh=fdruvhxcodu8xWw4CLJ7ZCjR1NTNXXUfuxgankvsGxA=; b=RRfctlqeI+KmYtitoNEDXusk+PaZGpoNvT01wFwy0BEBBFzLxF3P+Wrrc7EVZRibeCEuu5qgFWSkLfJSuAkpmzDUn670L/OcLBKqCDu1qmI8OD1Dyyuue6E25drVM6IjOzvAWAW3J7LGt4u+oxXx4mJESOAyuK4ks9yITe7Al88=
Received: from BN3PR0601MB1153.namprd06.prod.outlook.com (10.160.157.18) by BN3PR0601MB1154.namprd06.prod.outlook.com (10.160.157.19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P384) id 15.1.874.12; Thu, 2 Feb 2017 09:37:16 +0000
Received: from BN3PR0601MB1153.namprd06.prod.outlook.com ([10.160.157.18]) by BN3PR0601MB1153.namprd06.prod.outlook.com ([10.160.157.18]) with mapi id 15.01.0874.024; Thu, 2 Feb 2017 09:37:16 +0000
From: "Eggert, Lars" <lars@netapp.com>
To: "ietf@ietf.org" <ietf@ietf.org>
Subject: Re: Last Call: <draft-ietf-6man-rfc1981bis-04.txt> (Path MTU Discovery for IP version 6) to Internet Standard
Thread-Topic: Last Call: <draft-ietf-6man-rfc1981bis-04.txt> (Path MTU Discovery for IP version 6) to Internet Standard
Thread-Index: AQHSfOZWQnyqff8qTkSuzK39n1gXQaFVdhOA
Date: Thu, 2 Feb 2017 09:37:16 +0000
Message-ID: <1859B1D9-9E42-4D65-98A8-7A326EDDE560@netapp.com>
References: <148599312602.18643.4886733052828400859.idtracker@ietfa.amsl.com>
In-Reply-To: <148599312602.18643.4886733052828400859.idtracker@ietfa.amsl.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach: yes
X-MS-TNEF-Correlator:
x-mailer: Apple Mail (2.3259)
authentication-results: spf=none (sender IP is ) smtp.mailfrom=lars@netapp.com;
x-ms-exchange-messagesentrepresentingtype: 1
x-originating-ip: [217.70.211.15]
x-ms-office365-filtering-correlation-id: 97d642a3-4512-49d7-3fe6-08d44b4f1370
x-microsoft-antispam: UriScan:; BCL:0; PCL:0; RULEID:(22001); SRVR:BN3PR0601MB1154;
x-microsoft-exchange-diagnostics: 1; BN3PR0601MB1154; 7: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
x-microsoft-antispam-prvs: <BN3PR0601MB11547CBA10DD5287D821B272A74C0@BN3PR0601MB1154.namprd06.prod.outlook.com>
x-exchange-antispam-report-test: UriScan:(278428928389397);
x-exchange-antispam-report-cfa-test: BCL:0; PCL:0; RULEID:(102415395)(6040375)(601004)(2401047)(8121501046)(5005006)(10201501046)(3002001)(6055026)(6041248)(20161123558025)(20161123560025)(20161123555025)(20161123562025)(20161123564025)(6072148); SRVR:BN3PR0601MB1154; BCL:0; PCL:0; RULEID:; SRVR:BN3PR0601MB1154;
x-forefront-prvs: 02065A9E77
x-forefront-antispam-report: SFV:NSPM; SFS:(10009020)(6009001)(7916002)(39450400003)(189002)(199003)(99936001)(305945005)(5660300001)(50986999)(229853002)(7736002)(76176999)(2906002)(6436002)(106116001)(106356001)(105586002)(6506006)(77096006)(189998001)(5640700003)(25786008)(33656002)(230783001)(122556002)(54906002)(3280700002)(101416001)(2351001)(97736004)(6486002)(6512007)(86362001)(99286003)(81166006)(81156014)(1730700003)(8676002)(68736007)(8936002)(2501003)(82746002)(38730400001)(57306001)(83716003)(92566002)(66066001)(50226002)(36756003)(3846002)(102836003)(6116002)(110136003)(2950100002)(3660700001)(4326007)(6916009)(53936002)(2900100001)(104396002); DIR:OUT; SFP:1101; SCL:1; SRVR:BN3PR0601MB1154; H:BN3PR0601MB1153.namprd06.prod.outlook.com; FPR:; SPF:None; PTR:InfoNoRecords; MX:1; A:1; LANG:en;
received-spf: None (protection.outlook.com: netapp.com does not designate permitted sender hosts)
spamdiagnosticoutput: 1:99
spamdiagnosticmetadata: NSPM
Content-Type: multipart/signed; boundary="Apple-Mail=_5B28CAC1-2224-438D-B823-71DDFFAF63CA"; protocol="application/pgp-signature"; micalg=pgp-sha512
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-originalarrivaltime: 02 Feb 2017 09:37:16.5768 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 4b0911a0-929b-4715-944b-c03745165b3a
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN3PR0601MB1154
X-OriginatorOrg: netapp.com
Archived-At: <https://mailarchive.ietf.org/arch/msg/ipv6/p-vn_5AOFk4L_sVrJSyQu0DGgtY>
Cc: "tsv-area@ietf.org" <tsv-area@ietf.org>, "draft-ietf-6man-rfc1981bis@ietf.org" <draft-ietf-6man-rfc1981bis@ietf.org>, "ipv6@ietf.org" <ipv6@ietf.org>, "6man-chairs@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, 02 Feb 2017 09:38:26 -0000

Hi,

the last paragraph of the introduction reads:

   An extension to Path MTU Discovery defined in this document can be
   found in [RFC4821].  It defines a method for Packetization Layer Path
   MTU Discovery (PLPMTUD) designed for use over paths where delivery of
   ICMP messages to a host is not assured.

Given that ICMP delivery cannot be assured over the vast majority of paths in the current Internet, should this document make a recommendation to implement RFC4821?

Also, even if ICMP delivery is assured, there are additional complications for UDP, which has been seeing a lot of interest both as a tunneling encapsulation and for applications (e.g., QUIC). Many platforms do not provide UDP-sending applications any information about arriving ICMP messages that were triggered by their transmissions. So even if the path delivers ICMP, the OS makes ICMP-based PMTUD for UDP often impossible. Another reason to recommend 4821?

Lars