



GROW                                                           H. Sharma
Internet-Draft                                                 S. Clarke
Updates: 7854 (if approved)                                     Vodafone
Intended status: Informational                             7 August 2025
Expires: 8 February 2026


       BMPS: Transport Layer Security for BGP Monitoring Protocol
                    draft-hmntsharma-bmp-over-tls-03

Abstract

   The BGP Monitoring Protocol (BMP) defines the communication between a
   BMP station and multiple routers, referred to as network elements
   (NEs).  This document describes BMP over TLS, which uses Transport
   Layer Security (TLS) to ensure secure transport between the NE and
   the BMP monitoring station.  It updates [RFC7854] regarding BMP
   session establishment and termination.

Status of This Memo

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

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   This Internet-Draft will expire on 8 February 2026.

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Table of Contents

   1.  Requirements Language . . . . . . . . . . . . . . . . . . . .   2
   2.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   3.  BMP over TLS (BMPS) . . . . . . . . . . . . . . . . . . . . .   3
     3.1.  Operational Summary . . . . . . . . . . . . . . . . . . .   3
     3.2.  Transport Layer Security  . . . . . . . . . . . . . . . .   4
     3.3.  Operational Recommendations for BMPS  . . . . . . . . . .   5
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     6.2.  Informative References  . . . . . . . . . . . . . . . . .   6
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  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 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

2.  Introduction

   The BGP Monitoring Protocol (BMP), as defined in [RFC7854],
   facilitates communication between NEs and a BMP station.  Keeping
   this communication secure is important because it includes sharing
   sensitive information about BGP peers and monitored prefixes.

   The Section 11 of [RFC7854] , "Security Considerations" acknowledges
   that while routes in public networks are generally not confidential,
   BGP is also utilized in private L3VPN [RFC4364] networks where
   confidentiality is crucial.  It highlights that without mutual
   authentication through secure transport mechanisms, the channel is
   vulnerable to various attacks and recommends using IPSec [RFC4303] in
   tunnel mode with pre-shared keys for enhanced security in such
   scenarios.

   Additionally, a recent draft proposal, [I-D.ietf-grow-bmp-tcp-ao],
   titled "TCP-AO Protection for BGP Monitoring Protocol (BMP)" suggests
   an alternative approach using the TCP Authentication Option
   [RFC5925].  This method authenticates the endpoints of the TCP
   session, thereby safeguarding its integrity.  TCP-AO is beneficial in
   situations where full IPSec security may not be feasible, although
   unlike IPSec, it does not encrypt the session traffic.




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   Alternatively, Transport Layer Security (TLS), offers endpoint
   authentication, data encryption, and data integrity defined in the
   Transport Layer Security (TLS) Protocol Version 1.3 [RFC8446].

   The BGP Monitoring Protocol (BMP) [RFC7854] relies on the TCP
   protocol to establish BGP sessions between routers.  There are
   ongoing discussions within the IETF
   [I-D.draft-liu-grow-bmp-over-quic] to replace TCP with the QUIC
   protocol [RFC9000].  QUIC brings many features compared to TCP
   including security, the support of multiple streams or datagrams.

   QUIC is suitable for BMP transport [I-D.draft-liu-grow-bmp-over-quic]
   and has the potential to replace a BMP connection for each "logical
   router" by a single QUIC connection with streams for the messages
   from each "logical router".  However it's deployment is dependent on
   the adoption of QUIC in router management stacks which have
   historically lagged behind server developments due to their cautious
   approach and slower development rate.

   This document describes how BMP can operate over TCP/TLS.  Experience
   in implementing BGP over TLS/TCP [I-D.draft-wirtgen-bgp-tls] showed
   that this is less costly than porting a BGP implementation over QUIC
   and the similarities suggest that the same is true for BMP.

   This document describes how to utilize TLS to secure BMP sessions
   between a monitoring station (acting as the server) and a Network
   Element (acting as the client).  Unlike BGP, where either side can
   act as the server, BMP's role distinction simplifies the
   implementation of TLS in a client-server model.  Henceforth, the term
   BMP over TLS will be referred to as BMPS.

3.  BMP over TLS (BMPS)

3.1.  Operational Summary

   The operation of BMPS is virtually the same as the original BMP
   specification defined in [RFC7854], but with an additional layer of
   security using TLS.

   In BMPS, the BMP station functions as the TLS server, while NEs act
   as TLS clients.  Following the completion of the TCP three-way
   handshake, as defined in Section 3.4 of [RFC793], each NE,
   functioning as a TLS client, initiates a TLS handshake with the BMP
   monitoring station, acting as the TLS server.  Once the TLS
   connection is successfully established, NEs can immediately start
   transmitting BMP messages, as there is no separate BMP initiation or
   handshake phase.




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   The following steps summarize the operational flow of BMPS:

   1.  The NE initiates and completes a TCP handshake.

   2.  The NE initiates and completes a TLS handshake with the BMP
       monitoring station.

   3.  BMP messages are transmitted by the NE according to [RFC7854].

   A BMPS session ends when the underlying TCP or TLS session is
   terminated for any reason.

   The Section 3.2 of [RFC7854] states, "No BMP message is ever sent
   from the monitoring station to the router."  To adhere to this
   standard, the monitoring station MUST listen on separate ports for
   BMP (non-TLS) and BMPS (TLS) sessions.  This approach also offers a
   simplified "make before break" migration from BMP to BMPS.

3.2.  Transport Layer Security

   In regular TLS connections, the server has a TLS certificate along
   with a public/private key pair, whereas the client does not.

   For BMP over TLS (BMPS), it is REQUIRED to implement mutual TLS
   (mTLS), wherein both the server (BMP station) and the client (network
   element) have certificates, and both sides authenticate each other
   using their respective public/private key pairs.

   A self-signed "root" TLS certificate is REQUIRED for mTLS, allowing
   an organization to act as its own certificate authority.  The
   certificates issued to both the BMP station and NEs should correspond
   to this root certificate.

   The operational flow of BMP over TLS is similar to standard TLS
   operations:

   1.  The NE initiates the connection to the BMP station.

   2.  The station presents its TLS certificate.

   3.  The NE verifies the station's certificate.

   4.  The NE presents its TLS certificate.

   5.  The station verifies the NE's certificate.

   6.  The TLS connection is established.




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   7.  The NE begins transmitting BMP data to the station over the
       encrypted TLS channel.

   TLS version 1.3, defined in [RFC8446], streamlines the handshake
   process and supports more robust cipher suites compared to the
   previous versions, enhancing both speed and security.

   The BMPS is REQUIRED to support TLS 1.3 which has become a dominant
   standard.

3.3.  Operational Recommendations for BMPS

   The BMP over TLS (BMPS) is RECOMMENDED as an alternative mechanism to
   safeguard BMP sessions in scenarios where alternative protections
   like IPSec may not be feasible or deployed.

4.  Security Considerations

   The BMPS implementation increases computational demands due to
   continuous encryption and decryption processes, resulting in high CPU
   utilization and potential vulnerability to denial-of-service attacks.

   The TLS cipher suites that provide only data integrity validation
   without encryption SHOULD NOT be used by default.

   The BMPS implementation SHOULD follow the best practices and
   recommendations for using TLS, as per the Recommendations for Secure
   Use of Transport Layer Security (TLS) and Datagram Transport Layer
   Security (DTLS) as defined in [RFC7525].

5.  IANA Considerations

   This document has no IANA actions.

6.  References

6.1.  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,
              <https://www.rfc-editor.org/rfc/rfc2119>.

   [RFC7525]  Sheffer, Y., Holz, R., and P. Saint-Andre,
              "Recommendations for Secure Use of Transport Layer
              Security (TLS) and Datagram Transport Layer Security
              (DTLS)", RFC 7525, DOI 10.17487/RFC7525, May 2015,
              <https://www.rfc-editor.org/rfc/rfc7525>.



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   [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/rfc/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/rfc/rfc8174>.

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/rfc/rfc8446>.

6.2.  Informative References

   [I-D.draft-liu-grow-bmp-over-quic]
              Liu, Y., Lin, C., Graf, T., and P. Lucente, "Using BMP
              over QUIC connection", Work in Progress, Internet-Draft,
              draft-liu-grow-bmp-over-quic-02, 19 February 2025,
              <https://datatracker.ietf.org/doc/html/draft-liu-grow-bmp-
              over-quic-02>.

   [I-D.draft-wirtgen-bgp-tls]
              Wirtgen, T. and O. Bonaventure, "BGP over TLS/TCP", Work
              in Progress, Internet-Draft, draft-wirtgen-bgp-tls-03, 7
              July 2025, <https://datatracker.ietf.org/doc/html/draft-
              wirtgen-bgp-tls-03>.

   [I-D.ietf-grow-bmp-tcp-ao]
              Sharma, H. and J. Haas, "TCP-AO Protection for BGP
              Monitoring Protocol (BMP)", Work in Progress, Internet-
              Draft, draft-ietf-grow-bmp-tcp-ao-02, 22 July 2025,
              <https://datatracker.ietf.org/doc/html/draft-ietf-grow-
              bmp-tcp-ao-02>.

   [RFC2818]  Rescorla, E., "HTTP Over TLS", RFC 2818,
              DOI 10.17487/RFC2818, May 2000,
              <https://www.rfc-editor.org/rfc/rfc2818>.

   [RFC4303]  Kent, S., "IP Encapsulating Security Payload (ESP)",
              RFC 4303, DOI 10.17487/RFC4303, December 2005,
              <https://www.rfc-editor.org/rfc/rfc4303>.

   [RFC4364]  Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
              Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
              2006, <https://www.rfc-editor.org/rfc/rfc4364>.





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   [RFC5925]  Touch, J., Mankin, A., and R. Bonica, "The TCP
              Authentication Option", RFC 5925, DOI 10.17487/RFC5925,
              June 2010, <https://www.rfc-editor.org/rfc/rfc5925>.

   [RFC793]   Postel, J., "Transmission Control Protocol", RFC 793,
              DOI 10.17487/RFC0793, September 1981,
              <https://www.rfc-editor.org/rfc/rfc793>.

   [RFC8253]  Lopez, D., Gonzalez de Dios, O., Wu, Q., and D. Dhody,
              "PCEPS: Usage of TLS to Provide a Secure Transport for the
              Path Computation Element Communication Protocol (PCEP)",
              RFC 8253, DOI 10.17487/RFC8253, October 2017,
              <https://www.rfc-editor.org/rfc/rfc8253>.

   [RFC9000]  Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
              Multiplexed and Secure Transport", RFC 9000,
              DOI 10.17487/RFC9000, May 2021,
              <https://www.rfc-editor.org/rfc/rfc9000>.

Acknowledgments

   This document is the result of studying all the referenced RFCs and
   drawing some parallels from PCEPS [RFC8253], leading to the
   specification for BMP over TLS (BMPS).

   We are grateful to the contributors of the RFCs listed in the
   References section.  Their work has been instrumental in shaping and
   inspiring the development of this specification.

Authors' Addresses

   Hemant Sharma
   Vodafone
   Email: hemant.sharma@vodafone.com


   Steven Clarke
   Vodafone
   Email: steven.clarke@vodafone.com












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