Global Routing Operations P. Lucente Internet-Draft C. Cardona Updates: 7854 (if approved) NTT Intended status: Standards Track M. Srivastava Expires: 24 January 2025 Juniper Networks 23 July 2024 Filtering Adj-Rib-In and Adj-Rib-Out to BMP receivers draft-pcmy-grow-bmp-adj-ribs-filtered-00 Abstract Filtering RIBs in BMP (BGP Monitoring Protocol) can be desirable for several use-cases like, for example, limiting the amount of data a collector station has to process or allow a sender to export only a certain afi/safi of interest. This document defines a light way to inform a collector station that a Adj-Rib-In / Adj-Rib-Out data feed is being filtered. 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." This Internet-Draft will expire on 24 January 2025. Copyright Notice Copyright (c) 2024 IETF Trust and the persons identified as the document authors. All rights reserved. Lucente, et al. Expires 24 January 2025 [Page 1] Internet-Draft Filtering Adj-Rib-In and Adj-Rib-Out to July 2024 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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Filtered RIB Flag . . . . . . . . . . . . . . . . . . . . . . 2 4. Operational Considerations . . . . . . . . . . . . . . . . . 3 5. Security Considerations . . . . . . . . . . . . . . . . . . . 3 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 7. Normative References . . . . . . . . . . . . . . . . . . . . 3 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 4 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction While RFC9069 [RFC9069] does define a light way to mark a Loc-Rib as filtered, there is no equivalent mechanism for Adj-Rib-In RFC7854 [RFC7854] and Adj-Rib-Out RFC8671 [RFC8671]. This can be easily addressed through the introduction of a Peer F Flag in the "BMP Peer Flags for Peer Types 0 through 2" registry. 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 [RFC2119] RFC 8174 [RFC8174] when, and only when, they appear in all capitals, as shown here. 3. Filtered RIB Flag As a recap, a BMP session is regarded as carrying Adj-Rib-In by defining the Peer Type to 0, 1 or 2 values and setting the O flag to zero (0) in the BMP Peer Flags (for Peer Types 0 through 2) registry. Similarly, Adj-Rib-Out is set by defining the Peer Type to 0, 1 or 2 values and setting the O flag to one (1) in the BMP Peer Flags (for Peer Types 0 through 2) registry. Both Adj-Rib-In and Adj-Rib-Out can be further defined as Pre-Policy, setting the Peer L Flag to zero (0), or Post-Policy, setting the Peer L Flag to one (1). Lucente, et al. Expires 24 January 2025 [Page 2] Internet-Draft Filtering Adj-Rib-In and Adj-Rib-Out to July 2024 For both Adj-Rib-In and Adj-Rib-Out, for both Pre-Policy and Post- Policy cases, a new Peer F Flag is defined in the "BMP Peer Flags for Peer Types 0 through 2" registry. If the RIB was filtered, the flag MUST be set to one (1). In Stats messages, counts MUST reflect the filtered RIB numbers and not the original RIB ones. Also should any characteristic of the filtering change, the sender MUST trigger a Peer Down then followed by a new Peer Up. 4. Operational Considerations It is recommended that when filtering RIBs, the VRF/Table Name TLV - as defined in RFC9069 [RFC9069], TLV support for BMP Route Monitoring and Peer Down Messages [I-D.ietf-grow-bmp-tlv] and BMP Peer Up Namespace [I-D.ietf-grow-bmp-peer-up] - is specified to a meaningful string that can help discriminate the nature of filtering. The VRF/Table Name TLV can be either set in the Peer Up message, so to implicitely apply to all NLRIs received by the peer, or set via a Group TLV in Route Monitoring messages, to esplicitely apply to all NLRIs in the group. Going down the Peer Up model is certainly optimal on the wire and simplifies packing at the sender side; going down the Route Monitoring model, instead, allows the receiver side to operate non-contextually (ie. no need to look back at the Peer Up to make due associations). 5. Security Considerations It is not believed that this document adds any additional security considerations. 6. IANA Considerations This document asks IANA to add a new F Flag to the "BMP Peer Flags for Peer Types 0 through 2" registry. The recommended value for the registry is 4. 7. Normative References [I-D.ietf-grow-bmp-peer-up] Scudder, J. and P. Lucente, "BMP Peer Up Message Namespace", Work in Progress, Internet-Draft, draft-ietf- grow-bmp-peer-up-04, 11 June 2024, . Lucente, et al. Expires 24 January 2025 [Page 3] Internet-Draft Filtering Adj-Rib-In and Adj-Rib-Out to July 2024 [I-D.ietf-grow-bmp-tlv] Lucente, P. and Y. Gu, "BMP v4: TLV support for BMP Route Monitoring and Peer Down Messages", Work in Progress, Internet-Draft, draft-ietf-grow-bmp-tlv-14, 18 March 2024, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC7854] Scudder, J., Ed., 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, . [RFC8671] Evens, T., Bayraktar, S., Lucente, P., Mi, P., and S. Zhuang, "Support for Adj-RIB-Out in the BGP Monitoring Protocol (BMP)", RFC 8671, DOI 10.17487/RFC8671, November 2019, . [RFC9069] Evens, T., Bayraktar, S., Bhardwaj, M., and P. Lucente, "Support for Local RIB in the BGP Monitoring Protocol (BMP)", RFC 9069, DOI 10.17487/RFC9069, February 2022, . Acknowledgements The authors would like to thank Jeff Haas for his valuable input. Authors' Addresses Paolo Lucente NTT Veemweg 23 3771 Barneveld Netherlands Email: paolo@ntt.net Lucente, et al. Expires 24 January 2025 [Page 4] Internet-Draft Filtering Adj-Rib-In and Adj-Rib-Out to July 2024 Camilo Cardona NTT 164-168, Carrer de Numancia 08029 Barcelona Spain Email: camilo@ntt.net Mukul Srivastava Juniper Networks 10 Technology Park Dr Westford, MA 01886 United States of America Email: msri@juniper.net Lucente, et al. Expires 24 January 2025 [Page 5]