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.

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 RFC 8174 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/.

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

Copyright Notice

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Table of Contents

1. Introduction

BGP Monitoring Protocol (BMP) 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 draft-ietf-grow-bmp-peer-up. draft-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. 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.

 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 

Each RM Message allows at most one Path Information TLV. As stated in Appendix F.1 of 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

[I-D.grow-bmp-tlv] Lucente, P., Gu, Y. and H. Smit, "TLV support for BMP Route Monitoring and Peer Down Messages", Internet-Draft draft-grow-bmp-tlv-00, September 2019.
[I-D.ietf-grow-bmp-peer-up] Scudder, J., "BMP Peer Up Message Namespace", Internet-Draft draft-ietf-grow-bmp-peer-up-00, 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.
[RFC4271] Rekhter, Y., Li, T. and S. Hares, "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, DOI 10.17487/RFC4271, January 2006.
[RFC7854] Scudder, J., Fernando, R. and S. Stuart, "BGP Monitoring Protocol (BMP)", RFC 7854, DOI 10.17487/RFC7854, June 2016.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017.

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
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