Network Working Group                                         C. Cardona
Internet-Draft                                                P. Lucente
Intended status: Standards Track                                     NTT
Expires: January 13, 2021                                    P. Francois
                                                               INSA-Lyon
                                                                   Y. Gu
                                                                  Huawei
                                                                 T. Graf
                                                                Swisscom
                                                           July 12, 2020


                 BMP Extension for Path Information TLV
                  draft-cppy-grow-bmp-path-info-tlv-00

Abstract

   The BGP Monitoring Protocol (BMP) provides an interface for obtaining
   BGP path information.  BGP Path Information is conveyed within BMP
   Route Monitoring (RM) messages.  This document proposes an extension
   to BMP to convey additional path information that is not already
   encapsulated in the BGP Update PDU, e.g., BPG path status.  This
   extension makes use of the TLV mechanims described in draft-grow-bmp-
   tlv [I-D.grow-bmp-tlv].

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 RFC 2119 [RFC2119] RFC 8174 [RFC8174] when, and only when, they
   appear in all capitals, as shown here.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."




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   This Internet-Draft will expire on January 13, 2021.

Copyright Notice

   Copyright (c) 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Path Information TLV for the RM Message . . . . . . . . . . .   2
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   5.  Normative References  . . . . . . . . . . . . . . . . . . . .   3
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   4

1.  Introduction

   BGP Monitoring Protocol (BMP) RFC7854 [RFC7854] is used to monitor
   BGP sessions.  Additional information is allowed to be carried in the
   format of TLV with the BMP Initiation, Peer Up, and Termination
   Messages RFC7854 [RFC7854] draft-ietf-grow-bmp-peer-up
   [I-D.ietf-grow-bmp-peer-up].  draft-grow-bmp-tlv [I-D.grow-bmp-tlv]
   provides the capability of conveying optional data in TLV format in
   BMP Route Monitoring (RM) and Peer Down Messages, and such TLV types
   are to be defined for each application.  This document defines the
   Path Information TLV, making use of the TLV mechanism defined for BMP
   RM Message draft-grow-bmp-tlv [I-D.grow-bmp-tlv].  The Path
   Information TLV is used to describe the path information, e.g., path
   status (best, best-external), out interface, and so on.  Specific
   path information can be defined as sub-TLVs encapsulated within the
   Path Information TLV.

2.  Path Information TLV for the RM Message

   The Path Information TLV is defined as follows.





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    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-------------------------------+-------------------------------+
   |        Type (2 octets)        |       Length (2 octets)       |
   +---------------------------------------------------------------+
   |        Count (2 octets)       |
   +-------------------------------+-------------------------------+
   |                   Path Information value(variable)            |
   +---------------------------------------------------------------+

                   Figure 1: Path Information TLV

   o  Type = TBD1 (2 Octets): indicates that it's the Path Information
      TLV.

   o  Length (2 Octets): indicates the length of the value field of the
      Path Information TLV.

   o  Count (2 Octets): indicates the number of sub TLVs followed in the
      Path Information Value field.

   o  Path Information value (Variable): indicates the value of the Path
      Informtion TLV, which consists of one or multiple sub TLVs.

   Each RM Message allows at most one Path Information TLV.  As stated
   in Appendix F.1 of RFC4271 [RFC4271], multiple address prefixes
   (i.e., NLRI) with the same path attributes are allowed to be
   specified in one BGP message.  However, such multiple prefixes may
   have different path information.  Thus, to distinguish the sub-TLV
   for different prefixes, the order of the sub-TLVs MUST be in
   accordance with the prefix order encapsulated in the Update PDU.

3.  IANA Considerations

   This document requests that IANA assign the following new parameters
   to the BMP parameters name space.

   Type = TBD1 (2 Octets): indicates that it's the Path Information TLV.

4.  Security Considerations

   It is not believed that this document adds any additional security
   considerations.

5.  Normative References







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   [I-D.grow-bmp-tlv]
              Lucente, P., Gu, Y., and H. Smit, "TLV support for BMP
              Route Monitoring and Peer Down Messages", draft-grow-bmp-
              tlv-00 (work in progress), September 2019.

   [I-D.ietf-grow-bmp-peer-up]
              Scudder, J., "BMP Peer Up Message Namespace", draft-ietf-
              grow-bmp-peer-up-00 (work in progress), July 2019.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC4271]  Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
              Border Gateway Protocol 4 (BGP-4)", RFC 4271,
              DOI 10.17487/RFC4271, January 2006,
              <https://www.rfc-editor.org/info/rfc4271>.

   [RFC7854]  Scudder, J., Ed., Fernando, R., and S. Stuart, "BGP
              Monitoring Protocol (BMP)", RFC 7854,
              DOI 10.17487/RFC7854, June 2016,
              <https://www.rfc-editor.org/info/rfc7854>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

Authors' Addresses

   Camilo Cardona
   NTT
   164-168, Carrer de Numancia
   Barcelona  08029
   Spain

   Email: camilo@ntt.net


   Paolo Lucente
   NTT
   Siriusdreef 70-72
   Hoofddorp, WT  2132
   Netherlands

   Email: paolo@ntt.net





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   Pierre Francois
   INSA-Lyon
   Lyon
   France

   Email: Pierre.Francois@insa-lyon.fr


   Yunan Gu
   Huawei
   Huawei Bld., No.156 Beiqing Rd.
   Beijing  100095
   China

   Email: guyunan@huawei.com


   Thomas Graf
   Swisscom
   Binzring 17
   Zurich  8045
   Switzerland

   Email: thomas.graf@swisscom.com



























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