Segment routing traffic statistics

This section describes capabilities and procedures applicable to IS-IS, OSPFv2, and OSPFv3.

SR OS can enable and collect SID traffic statistics on the ingress and egress data paths. Statistics can also be shown, monitored, and cleared, as well as accessed using telemetry.

IS-IS and OSPFv2 support Node SID, Adjacency SID, and Adjacency Set statistics. OSPFv3 supports Node SID and Adjacency SID statistics. The following commands are used to enter the context that allows for configuring the types of SIDs for which to collect traffic statistics:

configure router isis segment-routing egress-statistics
configure router ospf segment-routing egress-statistics
configure router ospf3 segment-routing egress-statistics
configure router isis segment-routing ingress-statistics
configure router ospf segment-routing ingress-statistics
configure router ospf3 segment-routing ingress-statistics

By default, statistics collection is disabled on all types of SIDs. If statistics are disabled (after having been enabled), the statistics indexes that were allocated are released and the counter values are cleared.

On ingress, depending on which types of SIDs have statistics enabled, the following apply:

The system allocates a statistic index to each programmed ILM, corresponding to the local node SID (including backup node SID) and to the local adjacency SIDs (including adjacencies advertised as set m embers).
The system allocates a statistic index to each programmed ILM, corresponding to the received node SID advertisements.

On egress, depending on which types of SIDs have statistics enabled, the following apply:

The system allocates a statistic index shared by the programmed NHLFEs (primary, and backup if any) corresponding to the local Adjacency SIDs and to the received Adjacency SIDs advertisements, and a statistic index shared by the primary NHLFEs (as many as members) of each adjacency set.
The system allocates a statistic index shared by the programmed NHLFEs (one or more primaries, and backup if any) corresponding to each of the received node SID advertisements.

Note: The statistic indexes constitute a finite resource. The system may not be able to allocate as many indexes as needed. In this case, the system issues a notification and automatically retries to allocate statistic indexes, but does not issue further notifications in case it still fails to allocate the needed statistic indexes. If the system successfully allocates all the required statistic indexes to IGP SIDs, then a second notification is issued to inform the user. A state variable records whether a SID has an index allocated.

Note: The allocation of statistic indexes is non-deterministic. If more statistic indexes are required system-wide, for example, upon a reboot, the system may not be able to re-allocate the statistic indexes to the same entities as before the reboot.