GROW N. Geng Internet-Draft S. Zhuang Intended status: Standards Track Huawei Technologies Expires: 4 September 2025 3 March 2025 Synchronizing BMP Monitoring Options and State draft-geng-grow-bmp-sync-options-and-state-00 Abstract This document proposes methods to facilitate correction of BGP Routing Information Base inconsistencies in a non-disruptive manner from the BMP Sender to the BMP Collector. 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 4 September 2025. Copyright Notice Copyright (c) 2025 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 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. Geng & Zhuang Expires 4 September 2025 [Page 1] Internet-Draft BMP Sync Mechanism March 2025 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2 2. BMP Route-Refresh message . . . . . . . . . . . . . . . . . . 2 2.1. Example of using BMP Route-Refresh messages . . . . . . . 3 3. BMP Monitoring Options message . . . . . . . . . . . . . . . 4 3.1. Example of using BMP Monitoring Options message . . . . . 6 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 5. Security Considerations of Inter-domain SPD . . . . . . . . . 8 6. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 8 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 8.1. Normative References . . . . . . . . . . . . . . . . . . 8 8.2. Informative References . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9 1. Introduction The generation of BGP Adj-RIB-In, Loc-RIB and Adj-RIB-Out comes from BGP route exchange and route policy processing. BGP Monitoring Protocol (BMP) provides the monitoring of BGP Adj-RIB-In [RFC7854], BGP Loc-RIB [RFC9069] and BGP Adj-RIB-Out [RFC8671]. The RIB view inconsistency may occur between the BMP sender and BMP collector due to message loss, network flapping, instability, and faults. In this document, we define methods to facilitate correction of BGP Routing Information Base (RIB) inconsistencies in a non-disruptive manner from the BMP Sender to the BMP Collector. 1.1. 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. BMP Route-Refresh message This document defines a new BMP Route-Refresh message type (TBD1) that is used to synchronize the RIB view from the BMP sender to the BMP collector. Following the common BMP header and per-peer header is a Route-Refresh PDU. The Route-Refresh PDU is a ROUTE-REFRESH message defined in [RFC2918] and updated by [RFC7313], and its format is as follows: Type: 5 - ROUTE-REFRESH Geng & Zhuang Expires 4 September 2025 [Page 2] Internet-Draft BMP Sync Mechanism March 2025 Message Format: One tuple encoded as: 0 1 2 3 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | AFI | Sub-Type | SAFI | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: ROUTE-REFRESH Message The meaning, usage, and encoding of this tuple are defined in [RFC2918] and updated by [RFC7313] as follows: * AFI - Address Family Identifier (2 octets) * Sub-Type - Message Subtype (1 octet): - 0 - Normal route refresh request [RFC2918] with/without Outbound Route Filtering (ORF) [RFC5291] - 1 - Demarcation of the beginning of a route refresh (BoRR) operation - 2 - Demarcation of the ending of a route refresh (EoRR) operation - 255 - Reserved * SAFI - Subsequent Address Family Identifier (1 octet). 2.1. Example of using BMP Route-Refresh messages The sequences of BMP messages transmissions shown as follows: Geng & Zhuang Expires 4 September 2025 [Page 3] Internet-Draft BMP Sync Mechanism March 2025 BMP Sender BMP Collector ~ ~ | ------- BMP BoRR ---------> | Sender notifies BoRR operation | | | | Collector marks the routes of | | the specific RIB view as | | stale/historical or purges | | them directly | | | ------- BMP RM Msg.-------> | Sender sends zero or more | --------........----------> | Route Monitoring Messages for | ------- BMP RM Msg.-------> | the specific RIB view | | Collector uses the new routes | | to update the stale/historical | | routes | ------- BMP EoRR ---------> | Sender notifies EoRR operation | | | | Collector purges the routes | | remaining the stale/historical | | state | | ~ ~ Figure 2: An example of using BMP Route-Refresh messages 3. BMP Monitoring Options message This document defines a new Monitoring Options (MO) message type (TBD2) that is used to synchronize the monitoring options from the BMP sender to BMP collector. Following the common BMP header and per-peer header is a BMP Monitoring Options PDU. The BMP Monitoring Options PDU is defined as follows: 0 1 2 3 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 | SubType | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flags | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | AFI1 | Res. | SAFI1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | AFI2 | Res. | SAFI2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ...... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | AFIn | Res. | SAFIn | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Geng & Zhuang Expires 4 September 2025 [Page 4] Internet-Draft BMP Sync Mechanism March 2025 Figure 3: The BMP Monitoring Options PDU Where: * Type - 2 octets, It indicates as follows: - 1 - Adj-RIB-In - 2 - Adj-RIB-Out - 3 - Loc-RIB * SubType - 2 octets, It indicates as follows: - 1 - pre-policy - 2 - post-policy * Flags - 2 octets, the least significant bit of Flags Indicates whether the options are enabled or disabled, and other bits are reserved. * Length - 2 octets * The list of (AFI, SAFI) follows the Length field. - AFI - Address Family Identifier (2 octets) - SAFI - Subsequent Address Family Identifier (1 octet) - Res. - Reserved field that will be set Zero (1 octet) 0 1 2 3 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flags | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Stat Type 1 | Stat Type 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ...... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Stat Type n-1 | Stat Type n | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: The BMP Monitoring Options PDU Geng & Zhuang Expires 4 September 2025 [Page 5] Internet-Draft BMP Sync Mechanism March 2025 Where: * Type - 2 octets, It indicates as follows: - 4 - Stats * Flags - 2 octets, the least significant bit of Flags Indicates whether the options are enabled or disabled, and other bits are reserved. * Length - 2 octets * The list of Stat Types follows the Length field. - Stat Type - Defines the type of the statistic [RFC7854]. (2 octets) 3.1. Example of using BMP Monitoring Options message In the following scenario, a BGP session is established between Router1 and Router2, and IPv4 unicast, IPv4 multicast, and IPv4 labeled unicast address families are enabled on both the BGP speakers. The two BGP speakers exchange IPv4 unicast, IPv4 multicast, and IPv4 labeled unicast address family routes. Router1 as the BMP Sender sends BMP messages to the BMP Collector. BMP Collector | | | BGP Session Router1(BMP Sender)----------------Router2 Figure 5: BGP Monitoring Example Sender initiates the BMP protocol with the Collector: BMP Sender BMP Collector ~ ~ |------ Initial Export -------> | Sender Sends Route Monitoring | | messages for IPv4 unicast, | | IPv4 multicast and IPv4 | | labeled unicast address | | families | | Collector stores the RIB info | | for the Sender Figure 6: Sender sends Initial Export to Collector Geng & Zhuang Expires 4 September 2025 [Page 6] Internet-Draft BMP Sync Mechanism March 2025 Sender disabled the monitoring on IPv4 multicast address family: BMP Sender BMP Collector |-MO with(AFI 1/SAFI 2) disable-| Sender sends an MO message | | to Collector | | Collector purges the IPv4 | | multicast RIB view of the | | specific BGP peer Figure 7: Sender disabled the monitoring on IPv4 multicast address family Sender disabled the monitoring on IPv4 labeled unicast address family: BMP Sender BMP Collector |-MO with(AFI 1/SAFI 4) disable-| Sender sends an MO message | | to Collector | | Collector purges the IPv4 | | labeled unicast RIB view | | of the specific BGP peer | | Figure 8: Sender disabled the monitoring on IPv4 labeled unicast address family Sender enabled the monitoring on IPv4 multicast address family: BMP Sender BMP Collector |-MO with(AFI 1/SAFI 2) enabled-| Sender sends an MO message | | to Collector |-------BMP RM(AFI 1/SAFI 2)--> | Sender sends zero or more | | Route Monitoring Messages | | for theIPv4 multicast | | address family of the | | specific BGP peer | | Collector stores the RIB | | info for IPv4 multicast | | address family of the | | specific BGP peer Figure 9: Sender enabled the monitoring on IPv4 multicast address family 4. IANA Considerations TBD Geng & Zhuang Expires 4 September 2025 [Page 7] Internet-Draft BMP Sync Mechanism March 2025 5. Security Considerations of Inter-domain SPD The same considerations as in Section 11 of [RFC7854] apply to this document. Implementations of this protocol SHOULD require that sessions only be established with authorized and trusted monitoring devices. It is also believed that this document does not introduce any additional security considerations. 6. Contributors The following people made significant contributions to this document: To be added. 7. Acknowledgements The authors would like to acknowledge the review and inputs from xxx. 8. References 8.1. Normative References [RFC2918] Chen, E., "Route Refresh Capability for BGP-4", RFC 2918, DOI 10.17487/RFC2918, September 2000, . [RFC7313] Patel, K., Chen, E., and B. Venkatachalapathy, "Enhanced Route Refresh Capability for BGP-4", RFC 7313, DOI 10.17487/RFC7313, July 2014, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . 8.2. Informative References [RFC5291] Chen, E. and Y. Rekhter, "Outbound Route Filtering Capability for BGP-4", RFC 5291, DOI 10.17487/RFC5291, August 2008, . Geng & Zhuang Expires 4 September 2025 [Page 8] Internet-Draft BMP Sync Mechanism March 2025 [RFC7854] Scudder, J., Ed., Fernando, R., and S. Stuart, "BGP Monitoring Protocol (BMP)", RFC 7854, DOI 10.17487/RFC7854, June 2016, . [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, . Authors' Addresses Nan Geng Huawei Technologies Beijing China Email: gengnan@huawei.com Shunwan Zhuang Huawei Technologies Beijing China Email: zhuangshunwan@huawei.com Geng & Zhuang Expires 4 September 2025 [Page 9]