Question

A network engineer configures Flexible NetFlow to export IPFIX records from a WAN edge router to a collector reachable only through a VRF named MGMT. The flow monitor is applied and 'show flow monitor WAN-MON cache' shows thousands of flows being captured correctly. However, the collector never receives any flow records, and 'show flow exporter WAN-EXP statistics' shows the packets-sent counter incrementing but 'export packets dropped' also increasing. The exporter is configured with 'destination 10.99.0.10' and 'source Loopback0'. Loopback0 is in the global routing table. What is the most likely cause?

Accepted Answer

The exporter lacks the 'destination ... vrf MGMT' option, so packets are routed via the global table where the collector is unreachable.

Answer

The exporter is missing an 'export-protocol ipfix' statement, so records are dropped before transmission.

Answer

The flow record is using 'match' fields that are incompatible with IPFIX and must be changed to 'collect' fields.

Answer

The active flow timeout is set too high, causing the cache to hold flows until they age out before export.