Re: [OSPF] Alexey Melnikov's Discuss on draft-ietf-ospf-segment-routing-extensions-23: (with DISCUSS and COMMENT)

"Acee Lindem (acee)" <acee@cisco.com> Thu, 14 December 2017 13:32 UTC

Return-Path: <acee@cisco.com>
X-Original-To: ospf@ietfa.amsl.com
Delivered-To: ospf@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 96B561250B8; Thu, 14 Dec 2017 05:32:18 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -14.52
X-Spam-Level:
X-Spam-Status: No, score=-14.52 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_PASS=-0.001, URIBL_BLOCKED=0.001, 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 5hiZZ9P-ypIh; Thu, 14 Dec 2017 05:32:16 -0800 (PST)
Received: from alln-iport-4.cisco.com (alln-iport-4.cisco.com [173.37.142.91]) (using TLSv1.2 with cipher DHE-RSA-SEED-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 7AB16124205; Thu, 14 Dec 2017 05:32:16 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=6402; q=dns/txt; s=iport; t=1513258336; x=1514467936; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-id:content-transfer-encoding: mime-version; bh=53lJ894Z7d9JcmSscfgee6fnJUf95ksO1k/YY90gIKw=; b=CW8le1ItuahOsiGFk0ESbexg+fE9M8peCd912wc4/V523hgugWtWNeNf lpt99sGGWHe4sRuhGV1mfEpB+HoiZgGL4cAQ0j0cKvO1FpQ2CRBt2yGLM Z+MsbNOz67IxCNWGlt4h4SGSWWSv/3XkCkCI/+5g6QPLKWGy0NBIhF9rm g=;
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: A0DbAABCfDJa/5NdJa1dGQEBAQEBAQEBAQEBAQcBAQEBAYM+ZnQnB4N7iiGPBoF9lxYUggEKJYUWAhqEXD8YAQEBAQEBAQEBayiFJAEFIxFFEAIBCA4KAgIfBwICAjAVEAIEAQ0FiioQqHyCJ4pgAQEBAQEBAQEBAQEBAQEBAQEBAQEBGAWBD4JRgg6DP4Mrgy4BAYE6ARIBCRaDFYJjBYpLmFoCh3uDcYk8ghaGEoQQhzSNFYkrAhEZAYE6AR85YFYYbxWCY4MIgU54AYgRgSSBFQEBAQ
X-IronPort-AV: E=Sophos;i="5.45,400,1508803200"; d="scan'208";a="44576180"
Received: from rcdn-core-11.cisco.com ([173.37.93.147]) by alln-iport-4.cisco.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Dec 2017 13:32:15 +0000
Received: from XCH-RTP-011.cisco.com (xch-rtp-011.cisco.com [64.101.220.151]) by rcdn-core-11.cisco.com (8.14.5/8.14.5) with ESMTP id vBEDWFCX013393 (version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=FAIL); Thu, 14 Dec 2017 13:32:15 GMT
Received: from xch-rtp-015.cisco.com (64.101.220.155) by XCH-RTP-011.cisco.com (64.101.220.151) with Microsoft SMTP Server (TLS) id 15.0.1320.4; Thu, 14 Dec 2017 08:32:14 -0500
Received: from xch-rtp-015.cisco.com ([64.101.220.155]) by XCH-RTP-015.cisco.com ([64.101.220.155]) with mapi id 15.00.1320.000; Thu, 14 Dec 2017 08:32:14 -0500
From: "Acee Lindem (acee)" <acee@cisco.com>
To: Alexey Melnikov <aamelnikov@fastmail.fm>, The IESG <iesg@ietf.org>
CC: "draft-ietf-ospf-segment-routing-extensions@ietf.org" <draft-ietf-ospf-segment-routing-extensions@ietf.org>, "ospf-chairs@ietf.org" <ospf-chairs@ietf.org>, "ospf@ietf.org" <ospf@ietf.org>
Thread-Topic: Alexey Melnikov's Discuss on draft-ietf-ospf-segment-routing-extensions-23: (with DISCUSS and COMMENT)
Thread-Index: AQHTc//QW8KMe4rBDkeHYsGEb/PtbKNBr9QAgAFy0wD//7UzgA==
Date: Thu, 14 Dec 2017 13:32:14 +0000
Message-ID: <D657E73A.E1764%acee@cisco.com>
References: <151316206521.30067.6744549826451674092.idtracker@ietfa.amsl.com> <D656EBBC.E14BF%acee@cisco.com> <1513256386.2380101.1204908824.6B6A1C47@webmail.messagingengine.com>
In-Reply-To: <1513256386.2380101.1204908824.6B6A1C47@webmail.messagingengine.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-ms-exchange-messagesentrepresentingtype: 1
x-ms-exchange-transport-fromentityheader: Hosted
x-originating-ip: [10.116.152.198]
Content-Type: text/plain; charset="utf-8"
Content-ID: <FDA4E178AE34A74A99FD2C74ACC48FB8@emea.cisco.com>
Content-Transfer-Encoding: base64
MIME-Version: 1.0
Archived-At: <https://mailarchive.ietf.org/arch/msg/ospf/WpFsfGMBw_XVq1lUyhXlJzRu3j8>
Subject: Re: [OSPF] Alexey Melnikov's Discuss on draft-ietf-ospf-segment-routing-extensions-23: (with DISCUSS and COMMENT)
X-BeenThere: ospf@ietf.org
X-Mailman-Version: 2.1.22
Precedence: list
List-Id: The Official IETF OSPG WG Mailing List <ospf.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ospf>, <mailto:ospf-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/ospf/>
List-Post: <mailto:ospf@ietf.org>
List-Help: <mailto:ospf-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ospf>, <mailto:ospf-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 14 Dec 2017 13:32:19 -0000


On 12/14/17, 7:59 AM, "Alexey Melnikov" <aamelnikov@fastmail.fm> wrote:

>On Wed, Dec 13, 2017, at 07:52 PM, Acee Lindem (acee) wrote:
>> Hi Alexey
>> 
>> These all seem to be valid comments except for the one on byte order.
>> Note
>> that section 3.1 of RFC 2360 already states that IETF document packet
>> encodings are in Network-Byte Order (NBO).
>> https://www.ietf.org/rfc/rfc2360.txt
>
>Well, lots of recent RFCs violate this, so repeating it doesn't hurt.

Can you provide an example? IETF standard packets should always be in
Network-Byte Order.

Thanks,
Acee 
>
>> Typically, we have not defined Reserved field usage. However, I guess we
>> could say that they SHOULD be set to 0 on transmission and MUST be
>> ignored
>> on reception.
>
>Yes, please. Just mention it once early in the document.
>
>> This will allow for future reuse in a backward compatible
>> manner. 
>> Thanks,
>> Acee 
>> 
>> 
>> 
>> 
>> 
>> On 12/13/17, 5:47 AM, "Alexey Melnikov" <aamelnikov@fastmail.fm> wrote:
>> 
>> >Alexey Melnikov has entered the following ballot position for
>> >draft-ietf-ospf-segment-routing-extensions-23: Discuss
>> >
>> >When responding, please keep the subject line intact and reply to all
>> >email addresses included in the To and CC lines. (Feel free to cut this
>> >introductory paragraph, however.)
>> >
>> >
>> >Please refer to
>>https://www.ietf.org/iesg/statement/discuss-criteria.html
>> >for more information about IESG DISCUSS and COMMENT positions.
>> >
>> >
>> >The document, along with other ballot positions, can be found here:
>> 
>>>https://datatracker.ietf.org/doc/draft-ietf-ospf-segment-routing-extensi
>>>on
>> >s/
>> >
>> >
>> >
>> >----------------------------------------------------------------------
>> >DISCUSS:
>> >----------------------------------------------------------------------
>> >
>> >This is generally a clearly written document, but it needs a few minor
>> >changes
>> >before I can recommend its approval for publication.
>> >
>> >1) In Section 3.2:
>> >
>> >   o  When a router receives multiple overlapping ranges, it MUST
>> >      conform to the procedures defined in
>> >      [I-D.ietf-spring-conflict-resolution].
>> >
>> >RFC 2119 keyword usage makes the reference a Normative reference, yet
>>it
>> >is
>> >currently listed as informative.
>> >
>> >3.4.  SRMS Preference TLV
>> >
>> >   The Segment Routing Mapping Server Preference TLV (SRMS Preference
>> >   TLV) is used to advertise a preference associated with the node that
>> >   acts as an SR Mapping Server.  The role of an SRMS is described in
>> >   [I-D.ietf-spring-segment-routing-ldp-interop].
>> >
>> >As draff-ietf-spring-segment-routing-ldp-interop needs to be read in
>> >order to
>> >understand what SR Mapping Server is, this reference must also be
>> >Normative.
>> >
>> >  SRMS preference is defined in [I-D.ietf-spring-conflict-resolution].
>> >
>> >This just confirms that this reference must be Normative.
>> >
>> >2) In Section 3.1:
>> >
>> >   When multiple SR-Algorithm TLVs are received from a given router,
>>the
>> >   receiver SHOULD use the first occurrence of the TLV in the Router
>> >   Information LSA.  If the SR-Algorithm TLV appears in multiple Router
>> >   Information LSAs that have different flooding scopes, the SR-
>> >   Algorithm TLV in the Router Information LSA with the area-scoped
>> >   flooding scope SHOULD be used.  If the SR-Algorithm TLV appears in
>> >   multiple Router Information LSAs that have the same flooding scope,
>> >   the SR-Algorithm TLV in the Router Information (RI) LSA with the
>> >   numerically smallest Instance ID SHOULD be used and subsequent
>> >   instances of the SR-Algorithm TLV SHOULD be ignored.
>> >
>> >In the last 2 sentences: why are you using SHOULD (twice) instead of
>> >MUST? This
>> >seems to affect interoperability.
>> >
>> >(I think there is similar text in another section.)
>> >
>> >
>> >----------------------------------------------------------------------
>> >COMMENT:
>> >----------------------------------------------------------------------
>> >
>> >Several TLVs have "Reserved" fields, yet you never explain what
>>"Reserved"
>> >means. You do explain what reserved flags mean in some of them. I
>>suggest
>> >either explicitly explaining what Reserved means in each case or
>>specify
>> >this
>> >in the terminology section near the beginning of the document.
>> >
>> >The document never specifies byte order for length fields.
>> >
>> >The acronym NSSA is never explained and it has no reference.
>> >
>> >
>>