Re: [core] Chair's review of draft-ietf-core-hop-limit-02.txt

<mohamed.boucadair@orange.com> Mon, 25 February 2019 07:22 UTC

Return-Path: <mohamed.boucadair@orange.com>
X-Original-To: core@ietfa.amsl.com
Delivered-To: core@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 1B169130E5B; Sun, 24 Feb 2019 23:22:28 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.599
X-Spam-Level:
X-Spam-Status: No, score=-2.599 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001, UNPARSEABLE_RELAY=0.001, URIBL_BLOCKED=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 2JC2y_NgoG5A; Sun, 24 Feb 2019 23:22:26 -0800 (PST)
Received: from orange.com (mta241.mail.business.static.orange.com [80.12.66.41]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 45BD1130E0A; Sun, 24 Feb 2019 23:22:26 -0800 (PST)
Received: from opfedar05.francetelecom.fr (unknown [xx.xx.xx.7]) by opfedar21.francetelecom.fr (ESMTP service) with ESMTP id 447D0w2cDXz7ttX; Mon, 25 Feb 2019 08:22:24 +0100 (CET)
Received: from Exchangemail-eme6.itn.ftgroup (unknown [xx.xx.13.92]) by opfedar05.francetelecom.fr (ESMTP service) with ESMTP id 447D0w1rR7z2xCT; Mon, 25 Feb 2019 08:22:24 +0100 (CET)
Received: from OPEXCAUBMA2.corporate.adroot.infra.ftgroup ([fe80::e878:bd0:c89e:5b42]) by OPEXCAUBM34.corporate.adroot.infra.ftgroup ([fe80::7873:1668:636f:52c%21]) with mapi id 14.03.0435.000; Mon, 25 Feb 2019 08:22:24 +0100
From: <mohamed.boucadair@orange.com>
To: Carsten Bormann <cabo@tzi.org>, Jim Schaad <ietf@augustcellars.com>
CC: core <core@ietf.org>, "draft-ietf-core-hop-limit@ietf.org" <draft-ietf-core-hop-limit@ietf.org>
Thread-Topic: [core] Chair's review of draft-ietf-core-hop-limit-02.txt
Thread-Index: AQHYz3v1ePoYqh77aS9g7esO8Fa65wKEfZudpdAsjoCAAHlDgIADS6DA
Date: Mon, 25 Feb 2019 07:22:23 +0000
Message-ID: <787AE7BB302AE849A7480A190F8B93302EA24AAE@OPEXCAUBMA2.corporate.adroot.infra.ftgroup>
References: <7185933E-6816-435E-B668-2DB1367C279E@tzi.org> <787AE7BB302AE849A7480A190F8B93302EA23CEA@OPEXCAUBMA2.corporate.adroot.infra.ftgroup> <039e01d4caf8$25b9c9e0$712d5da0$@augustcellars.com> <A645E161-A46F-4315-B96F-9FEC47122502@tzi.org>
In-Reply-To: <A645E161-A46F-4315-B96F-9FEC47122502@tzi.org>
Accept-Language: fr-FR, en-US
Content-Language: fr-FR
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [10.114.13.247]
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64
MIME-Version: 1.0
Archived-At: <https://mailarchive.ietf.org/arch/msg/core/ywKK184-jsyYtSCMWGITHdU3vpM>
Subject: Re: [core] Chair's review of draft-ietf-core-hop-limit-02.txt
X-BeenThere: core@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Constrained RESTful Environments \(CoRE\) Working Group list" <core.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/core>, <mailto:core-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/core/>
List-Post: <mailto:core@ietf.org>
List-Help: <mailto:core-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/core>, <mailto:core-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 25 Feb 2019 07:22:28 -0000

Hi Carsten, Jim, all,

I do agree with Jim that it is early to have a “SHOULD deploy” level. At least that is not the intent of the text which triggered the comment. 

The intent is to allow for a configurable behavior of proxies which support the option. That wording can be updated to avoid misinterpretation, e.g.,:

OLD:
   If a CoAP proxy receives a request which does not include a Hop-Limit
   option, it SHOULD insert a Hop-Limit option when relaying the request
   to a next hop (absent explicit policy/configuration otherwise). 

NEW:
   A CoAP proxy MAY be instructed, using a configuration parameter, to
   insert a Hop-Limit option when relaying a request which do not
   include the Hop-Limit option.

Cheers,
Med

> -----Message d'origine-----
> De : Carsten Bormann [mailto:cabo@tzi.org]
> Envoyé : samedi 23 février 2019 06:58
> À : Jim Schaad
> Cc : BOUCADAIR Mohamed TGI/OLN; core; draft-ietf-core-hop-limit@ietf.org
> Objet : Re: [core] Chair's review of draft-ietf-core-hop-limit-02.txt
> 
> On Feb 22, 2019, at 22:47, Jim Schaad <ietf@augustcellars.com> wrote:
> >
> > My gut feeling is that the answer should be yes it should become a
> recommended option for all CoAP proxies.  I am not sure that this is the time
> for that to happen.  I think that in the next couple of years there may be a
> larger need to develop some BCPs for proxies and that would be the time to
> make the recommendation.
> 
> Right.  So the specific question for the WG is:
> 
> Are we ready to strongly recommend (on a “SHOULD deploy” level) hop-limit as
> our proxy loop mitigation technique now?
> 
> Or should we wait with such a recommendation until we have had a broader view
> at proxy requirements?  (E.g., then, MAYBE we might want to go for Via-like
> loop prevention instead — very big MAYBE, as Via is expensive with IPv6.)
> 
> I don’t have a strong opinion either way and therefore would like some more
> feedback from the WG.
> 
> In any case, the place in DOTS where it says how CoAP is used for DOTS should
> also say “please do deploy hop-limit where proxies are used” in the strength
> that the DOTS people are comfortable with.
> 
> While the hop-limit draft is not heavily associated with DOTS, maybe it would
> be useful to add some “not just for DOTS” language as well (after all, that
> was the point of splitting it out).
> 
> Grüße, Carsten