Question

A network engineer configured Flexible NetFlow exporting to a v9 collector on R1. The collector receives flow data records, but for the first several minutes after a device reboot it shows records with unresolved or blank fields, then begins displaying data correctly. Traffic flows through R1 normally. What is the MOST likely cause of the initial period of unusable records at the collector?

Accepted Answer

The NetFlow template refresh/timeout interval is too long, so the collector receives data records before it has received the template describing the field layout.

Answer

The flow monitor cache timeout active value is set too low, causing premature flow expiration.

Answer

The exporter is configured with the wrong transport protocol, so UDP records are silently dropped.

Answer

The flow record is missing a 'match' key field, so the collector cannot build a flow key.