RFC 9487 defines new IPFIX (IP Flow Information Export) Information Elements for exporting SRv6-related data from network nodes to collectors. As SRv6 deployments grow, operators need visibility into how SRv6 traffic is forwarded -- which SIDs are being used, what segment lists packets carry, and how traffic maps to SR Policies. This RFC provides the telemetry building blocks to answer those questions.
The document specifies 11 new IPFIX Information Elements that capture the essential SRv6 forwarding state observed at a metering point. These elements cover the active SID in the IPv6 destination address, the full segment list from the SRH, the Segments Left value, Section Tag, and flags. Together, they enable a collector to reconstruct the SRv6 forwarding path a packet is following.
These IPFIX elements are essential for SRv6 network operations, enabling use cases such as traffic engineering validation (confirming packets follow the intended SR Policy), SLA monitoring (measuring per-path latency and loss), capacity planning (understanding per-SID traffic volumes), and troubleshooting (identifying packets with unexpected segment lists).
IPv6 DA (active SID); SRH if configured to inspect
Monitor per-SID traffic load
Endpoint (egress)
Final SID processing, decapsulated inner packet
End-to-end path validation
Common Pitfalls
Not all hardware supports deep SRH inspection for IPFIX export. Transit routers often only see the IPv6 destination address (active SID) and cannot export the full segment list without SRH parsing support.
The srhSegmentIPv6BasicList IE uses the IPFIX basicList structured data type (RFC 6313). Collectors must support structured data to parse this field correctly.
Large segment lists may exceed IPFIX template or record size limits. The srhSegmentIPv6ListSection and srhIPv6Section IEs provide a mechanism for sectioned export, but collector support varies.
SRv6 compressed SIDs (uSID, RFC 9800) appear as standard 128-bit IPv6 addresses in IPFIX. The collector needs additional context (the GIB prefix and C-SID length) to decompose containers into individual micro-SIDs.
IPFIX sampling configuration significantly affects telemetry accuracy for SRv6. Low sampling rates may miss short-lived or low-volume SRv6 flows entirely.