vRouters support the NetFlow Version 9 and IP Flow Information Export (IPFIX), which is based on the Internet Engineering Task Force (IETF) standard. This standard defines how IP flow information is formatted and transferred from an exporter (in this case, a vRouter) to a NetFlow collector, a system that collects IPv4 and IPv6 flow information, as shown in the following figure.

The exporter periodically collects information about packets that flow through the router into a flow record. Then, the exporter packs the record into a UDP packet and sends it to the collector. For more information about the NetFlow Version 9, refer to RFC 3954 and for more information about the IPFIX, refer to RFC 7011 export format.

The user can also choose the choose the packet and information fields to aggregate and export.

The NetFlow Version 9 and IPFIX export format is based on templates, which allows for an extensible design of the record format. This means that future enhancements of the Flow Monitoring service do not require changes to the export protocol.

The following tables describe the data that is extracted by the Flow Monitoring service from the sampled packets and exported to the NetFlow collector.