Global Routing Operations P. Lucente
Internet-Draft NTT
Updates: 7854 (if approved) Y. Gu
Intended status: Standards Track Huawei
Expires: March 6, 2020 H. Smit
September 3, 2019

TLV support for BMP Route Monitoring and Peer Down Messages


Most of the message types defined by the BGP Monitoring Protocol (BMP) do provision for optional trailing data; however Route Monitoring message (to provide a snapshot of the monitored Routing Information Base) and Peer Down message (to indicate that a peering session was terminated) do not. Supporting optional data in TLV format across all BMP message types allows for an homogeneous and extensible surface that would be useful for the most different use-cases that need to convey additional data to a BMP station. While this document does not want to cover any specific utilization scenario, it defines a simple way to support optional TLV data in all message types.

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

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."

This Internet-Draft will expire on March 6, 2020.

Copyright Notice

Copyright (c) 2019 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 ( 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

The BGP Monitoring Protocol (BMP) is defined in RFC 7854.

The Route Monitoring message consists of:

The Peer Down Notification message consists of:

This means that both Route Monitoring and Peer Down messages have a non-extensible format. In the Route Monitoring case this is limiting if wanting to transmit characteristics of transported NLRIs (ie. to help stateless parsing) or vendor-specific data; in the Peer Down case this is limiting if wanting to match TLVs shipped with the Peer Up. The proposal of this document is to bump the BMP version, for backward compatibility, and allow all message types to provision for trailing TLV data.

2. Terminology

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.

3. TLV encoding

TLV data type is already defined in Section 4.4 of for the Initiation and Peer Up message types. A TLV consists of:

  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)         |
  |        Value (variable, between, 0 and 65535 octets)          |

Figure 1

TLVs SHOULD be sorted by their code point. Multiple TLVs of the same type can be repeated as part of the same message and it is left to the specific use-cases whether all, any, the first or the last TLV should be considered.

4. BMP Message Format

4.1. Common Header

Section 4.1 of defines the Common Header. While the structure remains unaltered, the following two definitions are changed:

4.2. TLV data in Route Monitoring

The Route Monitoring message type is defined in Section 4.6 of. The BGP Update PDU Section 4.3 of MAY be followed by TLV data. This document defines the following new codes to help stateless parsing of BGP Update PDUs:

4.3. TLV data in Peer Down

The Peer Down Notification message type is defined in Section 4.9 of. TLV data MAY now follow any Reason code.

4.4. TLV data in other BMP messages

All other message types defined in RFC7854 do already provision for TLV data. It is RECOMMENDED that all future BMP message types will provision for trailing TLV data.

5. Security Considerations

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

6. IANA Considerations

This document defines the following new TLV types for BMP Route Monitoring and Peer Down messages (Section 4.2):

7. Normative References

[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.
[RFC6793] Vohra, Q. and E. Chen, "BGP Support for Four-Octet Autonomous System (AS) Number Space", RFC 6793, DOI 10.17487/RFC6793, December 2012.
[RFC7854] Scudder, J., Fernando, R. and S. Stuart, "BGP Monitoring Protocol (BMP)", RFC 7854, DOI 10.17487/RFC7854, June 2016.
[RFC7911] Walton, D., Retana, A., Chen, E. and J. Scudder, "Advertisement of Multiple Paths in BGP", RFC 7911, DOI 10.17487/RFC7911, July 2016.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017.
[RFC8277] Rosen, E., "Using BGP to Bind MPLS Labels to Address Prefixes", RFC 8277, DOI 10.17487/RFC8277, October 2017.


The authors would like to thank Jeff Haas for his valuable input.

Authors' Addresses

Paolo Lucente NTT Siriusdreef 70-72 Hoofddorp, WT 2132 NL EMail:
Yunan Gu Huawei Huawei Bld., No.156 Beiqing Rd. Beijing, 100095 China EMail:
Henk Smit Independent NL EMail: