GROW

IETF 125 - Bangkok, Thailand Chairs: Job Snijders, Paolo Lucente Secretary: (Present in room)

Summary

The Global Routing Operations (GROW) Working Group met at IETF 125 to discuss advancements in the BGP Monitoring Protocol (BMP), focusing on the transition to BMP v4, YANG data modeling, and monitoring RPKI-related operational states. Key topics included the introduction of TLV support across BMP messages, new event-logging capabilities for Flowspec and Segment Routing (SR), and strategies for synchronizing RIB views between senders and collectors. The session concluded with an operational discussion on RPKI Route Origin Validation (ROV) data accuracy and propagation.

Key Discussion Points

BMP YANG Model for Network Telemetry Messages

Presenter: Thomas Graf Slides: BMP YANG Model for Network Telemetry Messages

Thomas Graf introduced a new document focused on integrating BMP data into message brokers (e.g., Kafka, Pulsar) using YANG schemas.
The goal is to allow network engineers to use SQL-like queries against a message broker instead of manual show commands on routers.
The draft utilizes draft-ietf-grow-bmp-yang for subscription and operational statistics.
Discussion: Prasad (Cisco) questioned the overhead of translation at the collector. Thomas Graf clarified that this transformation (BMP to JSON/YANG) has been done in production for years; the new element is the standardized YANG schema to preserve semantics.

RPKI Monitoring Requirements

Presenter: Shuhao Wang Slides: Requirements for Monitoring RPKI-Related Processes on Routers Using BMP

Shuhao Wang detailed requirements for monitoring the RPKI lifecycle on routers: data acquisition, policy configuration, route validation, and routing actions.
Recent updates include support for multiple data sources (beyond RTR), "route features" to describe large rule sets, and a dedicated RPKI impact message.
Discussion: The presenter addressed concerns regarding scope creep into RTR monitoring, noting that the focus is on the effect of RPKI on routing, not the RTR protocol itself. Future revisions will consider the use of CCR hashes and SLURM monitoring.

BMP v4: TLV Support

Presenter: Paolo Lucente Slides: BMP v4: TLV Support Draft: draft-ietf-grow-bmp-tlv

Paolo Lucente announced the merger of the SNTS (Sequence Numbers and Timestamps) draft into the TLV draft.
Key changes: Timestamps are now mandatory; sequence numbers and extended flags (to overcome per-peer header limitations) are introduced.
Discussion: A debate occurred regarding TLV ordering. Job Snijders noted that while ordering might have a small exporter cost, it could simplify future data replication. Paolo Lucente indicated that as a consumer, ordering is less critical, but exporter preference varies.

BMP Route Event Logging (REL)

Presenter: Paolo Lucente / Nan Geng Slides: BMP Route Event Logging / Log More Routing Events in the BGP Monitoring Protocol Draft: draft-ietf-grow-bmp-rel

Paolo Lucente discussed generalizing REL to include non-BGP PDU events, such as health events (e.g., peering flaps).
Nan Geng proposed new REL code points for BGP Flowspec (redirection/validation failures) and SR Policy (invalid candidate paths).
Discussion: Jeff Haas cautioned against using free-form UTF-8 text strings in protocol elements, suggesting structured data is easier for applications to parse. Prasad warned about the "chattiness" of route-related events for unstable neighbors.

BMP RIB Synchronization and Monitoring Options

Presenter: Nan Geng Slides: BGP Monitoring Protocol (BMP) Enhancements for RIB View Synchronization and Monitoring Options Notification

Proposed two new messages: Route Refresh (to sync RIBs non-disruptively) and Monitoring Options (to notify collectors when monitoring of specific AFIs/SAFIs is enabled or disabled).
Discussion: Prasad suggested coordinating with Luke H. (NLnet Labs), who has explored similar Route Refresh mechanisms.

Extension for BMP Peer Header

Presenter: Changwang Lin Slides: Extension for BMP Peer Header

Addressed the issue of parallel EBGP sessions (e.g., link-local IPv6 or unnumbered IPv4) where peer address, AS, and BGP ID are identical.
Proposed adding the Interface Index to the per-peer header to distinguish these sessions.
Discussion: Pierre noted overlap with draft-ietf-grow-bmp-loc-peer. Jeff Haas suggested that instead of a new field, the "peer address" could simply be lengthened to include the interface index.

BMP Statistics Enhancements (Stats Info, Policy, and EVPN)

Presenter: Mukul Srivastava Slides: BMP Statistics Information TLV Draft | Route Change Statistics Based on Policy | EVPN specific BMP RIB statistics

Stats Info TLV: Proposed sending distributional data (min, max, average, median) over a reporting interval to reduce the need for high-frequency polling while maintaining visibility into "churn."
Policy Statistics: Proposed tracking how often BGP attributes are modified by specific routing policies. Susan Hares (IDR Chair) requested more clarity on the definition of "modified" (e.g., wire vs. RIB).
EVPN Stats: Updates to include Route Distinguisher (RD) information for per-EVI (EVPN Instance) statistics.

Operational Issues: RPKI ROV and "Bad" Data

Presenters: Susan Hares, Ming-Quan Huang Slides: Open Microphone segment: Operational issues - RPKI ROV Bad data from Origin

The discussion centered on how to handle cryptographically valid but operationally incorrect RPKI ROAs (e.g., typos in origin AS).
Discussion: Job Snijders clarified that such data is "correct" from a protocol perspective (CA Intent) even if it's a mistake. He emphasized the importance of using IPAM systems to automate ROA creation and noted that current "invalid" counts in monitors are often statistical noise from unused space.
The group discussed propagation times for ROA corrections, estimated at approximately one hour.

Decisions and Action Items

draft-ietf-grow-bmp-tlv: The authors will refine the integration of sequence numbers and timestamps, specifically deciding how to handle the legacy timestamp field in the per-peer header.
REL and Route Event Monitoring: Authors of the REL enhancement and the base REL draft will collaborate to ensure structural alignment.
Peer Header Extension: Changwang Lin and the authors of draft-ietf-grow-bmp-loc-peer will meet to discuss potential merging of the interface index requirements.

Next Steps

Authors of the BMP Statistics Information TLV and Route Change Statistics drafts will refine their definitions based on feedback and seek working group adoption in future cycles.
The chairs will monitor list discussion regarding the placement of the BMP YANG telemetry work (GROW vs. NMOP).
The working group will continue to refine the BMP v4 specification as a priority.

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