Re: [Lsr] Benjamin Kaduk's No Objection on draft-ietf-ospf-segment-routing-msd-23: (with COMMENT)

"Acee Lindem (acee)" <acee@cisco.com> Tue, 16 October 2018 11:02 UTC

Return-Path: <acee@cisco.com>
X-Original-To: lsr@ietfa.amsl.com
Delivered-To: lsr@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C5215130DC1; Tue, 16 Oct 2018 04:02:40 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -14.502
X-Spam-Level:
X-Spam-Status: No, score=-14.502 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_MED=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_HI=-5, SPF_PASS=-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 VhfbdukRBXzq; Tue, 16 Oct 2018 04:02:38 -0700 (PDT)
Received: from rcdn-iport-8.cisco.com (rcdn-iport-8.cisco.com [173.37.86.79]) (using TLSv1.2 with cipher DHE-RSA-SEED-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 80EAC127333; Tue, 16 Oct 2018 04:02:38 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=4044; q=dns/txt; s=iport; t=1539687758; x=1540897358; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-id:content-transfer-encoding: mime-version; bh=UaaQMB3RWoH0UmM+Hk0hGZg/sw+jCeHaOC4x1XxYIt0=; b=PGAaOwfAucwkvNB8SyXGOANRX4VHC3OfbImK5Y5cM/JShvf3qZtEXiaK eCsYOddLknJFk9IqTSKNZpsd1NCRa2QU6jqhxS05NmZn9afygqNSLL8B/ fydkALVhXJ2K4VL8Xnl+r72gP9n0DLr4T8dZG0hK9MOvddtuksqReEiH/ M=;
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: =?us-ascii?q?A0ADAABsxMVb/5BdJa1kDgsBAQEBAQE?= =?us-ascii?q?BAQEBAQEHAQEBAQEBgVEEAQEBAQELAYFUL2Z/KAqDa4gXjC6ZFBSBZgoBAQE?= =?us-ascii?q?jhEkCF4RYITQNDQEDAQECAQECbRwMhToGIxFFEAIBCBoCJgICAjAVEAIEAQ0?= =?us-ascii?q?FgyABggEPpXGBLoQ+P4UgBYELikEXggCBESgfgkyDGwIBAgGBKgESAYMiMYI?= =?us-ascii?q?mAoholUIJAoZTgxaGcBeBT4RwiV+MQ4lDAhEUgSYdOGRYEQhwFTsqAYJBgiY?= =?us-ascii?q?XEYhKhQQ6bwEBiSeBH4EfAQE?=
X-IronPort-AV: E=Sophos;i="5.54,388,1534809600"; d="scan'208";a="465055735"
Received: from rcdn-core-8.cisco.com ([173.37.93.144]) by rcdn-iport-8.cisco.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Oct 2018 11:02:37 +0000
Received: from XCH-RTP-013.cisco.com (xch-rtp-013.cisco.com [64.101.220.153]) by rcdn-core-8.cisco.com (8.15.2/8.15.2) with ESMTPS id w9GB2bKk014503 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=FAIL); Tue, 16 Oct 2018 11:02:37 GMT
Received: from xch-rtp-015.cisco.com (64.101.220.155) by XCH-RTP-013.cisco.com (64.101.220.153) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Tue, 16 Oct 2018 07:02:36 -0400
Received: from xch-rtp-015.cisco.com ([64.101.220.155]) by XCH-RTP-015.cisco.com ([64.101.220.155]) with mapi id 15.00.1395.000; Tue, 16 Oct 2018 07:02:36 -0400
From: "Acee Lindem (acee)" <acee@cisco.com>
To: Benjamin Kaduk <kaduk@mit.edu>, The IESG <iesg@ietf.org>
CC: "draft-ietf-ospf-segment-routing-msd@ietf.org" <draft-ietf-ospf-segment-routing-msd@ietf.org>, "aretana.ietf@gmail.com" <aretana.ietf@gmail.com>, "lsr-chairs@ietf.org" <lsr-chairs@ietf.org>, "lsr@ietf.org" <lsr@ietf.org>
Thread-Topic: Benjamin Kaduk's No Objection on draft-ietf-ospf-segment-routing-msd-23: (with COMMENT)
Thread-Index: AQHUZPOti56jKlMrkUm7CN3ZXH/SlaUhtZWA
Date: Tue, 16 Oct 2018 11:02:36 +0000
Message-ID: <1DC0EB57-D664-45E0-95B9-832A91C0947B@cisco.com>
References: <153965508262.3391.1781068849431952694.idtracker@ietfa.amsl.com>
In-Reply-To: <153965508262.3391.1781068849431952694.idtracker@ietfa.amsl.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: [10.116.152.197]
Content-Type: text/plain; charset="utf-8"
Content-ID: <40E4148EB018FA40ADFBBB1D3743FD72@emea.cisco.com>
Content-Transfer-Encoding: base64
MIME-Version: 1.0
X-Outbound-SMTP-Client: 64.101.220.153, xch-rtp-013.cisco.com
X-Outbound-Node: rcdn-core-8.cisco.com
Archived-At: <https://mailarchive.ietf.org/arch/msg/lsr/Mj-tZPkROgUgHR6qR1XX4hOxHTs>
Subject: Re: [Lsr] Benjamin Kaduk's No Objection on draft-ietf-ospf-segment-routing-msd-23: (with COMMENT)
X-BeenThere: lsr@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Link State Routing Working Group <lsr.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/lsr>, <mailto:lsr-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/lsr/>
List-Post: <mailto:lsr@ietf.org>
List-Help: <mailto:lsr-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/lsr>, <mailto:lsr-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 16 Oct 2018 11:02:41 -0000

Hi Ben, 

´╗┐On 10/15/18, 9:58 PM, "Benjamin Kaduk" <kaduk@mit.edu>; wrote:

    Benjamin Kaduk has entered the following ballot position for
    draft-ietf-ospf-segment-routing-msd-23: No Objection
    
    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-msd/
    
    
    
    ----------------------------------------------------------------------
    COMMENT:
    ----------------------------------------------------------------------
    
    Thanks for addressing my Discuss point; original ballot comment preserved below.
    
    Can SID be expanded on first usage --
    https://www.rfc-editor.org/materials/abbrev.expansion.txt does not list it
    as "well known".  (It also doesn't appear to list "Segment Identifier" as
    one of the expansions.)
    
    This is basically the same thing I said for the IS-IS document that creates
    the MSD types registry, but I'm not sure I followed correctly the meaning
    of MSD type 1 for SR-enabled vs.  non-SR-enabled networks.  In particular,
    I still don't really understand why it's okay to use the same codepoint for
    the max SID depth in SR-enabled networks and for the max label depth in
    non-SR MPLS networks.  Why couldn't they just be separate MSD Type
    codepoints?
    
    Section-by-section comments follow.
    
    Section 2
    
                      If the Node MSD TLV appears in multiple Router
       Information LSAs that have the same flooding scope, the Node MSD TLV
       in the Router Information (RI) LSA with the numerically smallest
       Instance ID MUST be used and subsequent instances of the Node MSD TLV
       MUST be ignored. [...]
    
    Unless there is a sorting requirement I've forgotten about, shouldn't this
    be "other" rather than "subsequent"?

In this context, "subsequent" refers to the instance ID rather than the ordering of RI LSAs. However, it would be rare that an OSPF router would not originate RI LSAs in order. 

Thanks,
Acee 
    
    Section 6
    
    Thanks for the updates in response to the secdir review; they help a lot.
    
       If the value is larger than supported - instantiation of a path that
       can't be supported by the head-end (the node performing the SID
       imposition).
    
    This is supposed to mean "(instantiation by the head-end) of a (path that
    can't be supported)", not "instantiation of a path (that can't be supported
    by the head-end)", right?