NetFlow is a feature that provides the ability to collect IP network traffic as it enters or exits an interface. By analyzing the data provided by NetFlow, a network administrator can determine items such as the source and destination of traffic, class of service, and the causes of congestion.
NetFlow records are traditionally exported using User Datagram Protocol (UDP) and collected using a NetFlow collector. The IP address of the NetFlow collector and the destination UDP port must be configured on the sending device (in this case, it is the FortiGate).