IETF Logo Mail Archive

[6lo] 6CIO in rfc 6775 update

"Pascal Thubert (pthubert)" <pthubert@cisco.com> Mon, 26 February 2018 18:01 UTC

Return-Path: <pthubert@cisco.com>
X-Original-To: 6lo@ietfa.amsl.com
Delivered-To: 6lo@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 6F97E12704A for <6lo@ietfa.amsl.com>; Mon, 26 Feb 2018 10:01:32 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -14.51
X-Spam-Level:
X-Spam-Status: No, score=-14.51 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_HI=-5, SPF_PASS=-0.001, T_RP_MATCHES_RCVD=-0.01, USER_IN_DEF_DKIM_WL=-7.5] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=cisco.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 KFbAxjdSSOKH for <6lo@ietfa.amsl.com>; Mon, 26 Feb 2018 10:01:30 -0800 (PST)
Received: from alln-iport-7.cisco.com (alln-iport-7.cisco.com [173.37.142.94]) (using TLSv1.2 with cipher DHE-RSA-SEED-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id A5E9C12025C for <6lo@ietf.org>; Mon, 26 Feb 2018 10:01:30 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=6235; q=dns/txt; s=iport; t=1519668090; x=1520877690; h=from:to:cc:subject:date:message-id:mime-version; bh=RqEX3FPF9aR21hFe6ayMDjKSWxtEkTuRXeeN0IcKYb0=; b=PGMMlodARVq+8ZyTaVoaYdcw8ecjKI9Qb/FpWFoHnvlf56IuUKmubVrk bjQTqEYKvXo2oIJ2jfuP3zYY4rQr5/WcLKgSteiMSGN6E+NFEd4w479Vp wOs2UyR57g2F3EsttQLOT0U4vBSEeoZsJogsKJre5dKO5mpTUXtZRuVHl I=;
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: A0A4AQAAS5Ra/4cNJK1dGQEBAQEBAQEBAQEBAQcBAQEBAYJadWZwKAqNbI1+gxiQNoVPFIICCiWFDoJHVBgBAgEBAQEBAQJrHQuFJQQuTAUNAYEAJgEEDg2EJFwIEK1oiG2CFAEBAQEBAQEBAQEBAQEBAQEBAQEBARgFh0KBV4FmhlsBAQIBgTaGKgWhYQkChzeMXoIPkFqJZ4JqiHcCERkBgS4BHjiBUXAVgn6CQhyBe3cBAQ+LM4EXAQEB
X-IronPort-AV: E=Sophos; i="5.47,397,1515456000"; d="scan'208,217"; a="75687335"
Received: from alln-core-2.cisco.com ([173.36.13.135]) by alln-iport-7.cisco.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Feb 2018 18:01:29 +0000
Received: from XCH-ALN-001.cisco.com (xch-aln-001.cisco.com [173.36.7.11]) by alln-core-2.cisco.com (8.14.5/8.14.5) with ESMTP id w1QI1TRk019066 (version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=FAIL); Mon, 26 Feb 2018 18:01:29 GMT
Received: from xch-rcd-001.cisco.com (173.37.102.11) by XCH-ALN-001.cisco.com (173.36.7.11) with Microsoft SMTP Server (TLS) id 15.0.1320.4; Mon, 26 Feb 2018 12:01:29 -0600
Received: from xch-rcd-001.cisco.com ([173.37.102.11]) by XCH-RCD-001.cisco.com ([173.37.102.11]) with mapi id 15.00.1320.000; Mon, 26 Feb 2018 12:01:29 -0600
From: "Pascal Thubert (pthubert)" <pthubert@cisco.com>
To: "6lo@ietf.org" <6lo@ietf.org>
CC: "Adrian Farrel (adrian@olddog.co.uk)" <adrian@olddog.co.uk>
Thread-Topic: 6CIO in rfc 6775 update
Thread-Index: AdOvKob8MIOQKIGhQxqzOabFPhE5cw==
Date: Mon, 26 Feb 2018 18:00:59 +0000
Deferred-Delivery: Mon, 26 Feb 2018 18:00:29 +0000
Message-ID: <438c2179adf344c78ded9de0c4674156@XCH-RCD-001.cisco.com>
Accept-Language: fr-FR, en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-ms-exchange-transport-fromentityheader: Hosted
x-originating-ip: [10.61.212.148]
Content-Type: multipart/alternative; boundary="_000_438c2179adf344c78ded9de0c4674156XCHRCD001ciscocom_"
MIME-Version: 1.0
Archived-At: <https://mailarchive.ietf.org/arch/msg/6lo/iAoi5VuPJKWYBy_kjcDixRxy1wg>
Subject: [6lo] 6CIO in rfc 6775 update
X-BeenThere: 6lo@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: "Mailing list for the 6lo WG for Internet Area issues in IPv6 over constrained node networks." <6lo.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/6lo>, <mailto:6lo-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/6lo/>
List-Post: <mailto:6lo@ietf.org>
List-Help: <mailto:6lo-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/6lo>, <mailto:6lo-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 26 Feb 2018 18:01:32 -0000

Dear all

Quoting Adrian's RTG DIR review:


> 7.1.2

>

>    One alternate way for a 6LN to discover the router's capabilities is

>    to start by registering...

>

> You went to a lot of trouble to define the E-flag. You then made the use of the

> 6CIO (and hence the E-flag) only a SHOULD, and you defined an alternate

> mechanism. (Note: you say "one alternate" implying there are

> more!)

>

> Choice is not good. It complicates the specification and the implementation.

> Why go there? Can't you settle on one mechanism and make it necessary and

> sufficient?

>

https://tools.ietf.org/html/draft-ietf-6lo-rfc6775-update-14#section-7.1.1 defines new capability bits for use in the 6CIO,  which was introduced by RFC7400 to announce support of the spec.
When there is no 6CIO, there's a plan B using EUI-64 as RUID and IID in a NS(EARO), which is fully backward compatible, and see if the response has an EARO or not from the T flag.
Adrian indicates that a double mechanism is complexity. For backwards compatibility we need to be able to live without 6CIO. Still 6CIO seems to be a good mechanism to generalize and that's why we used it.

So should we keep the CIO mechanism, or should we drop it?

Pascal

v2.23.0 | Report a Bug | By Email