Flexible NetFlow (FNF) uses flows to provide statistics for accounting, network monitoring, and network planning. VXLAN-aware
FNF provides information about the VXLAN-encapsulated IPV4 and IPV6 packets in the network. VXLAN-aware FNF captures the VXLAN
flow information for both bridged and routed traffic.
A flow is a unidirectional stream of packets that arrives on a source interface and has the same values for the keys. A key
is an identified value for a field within the packet. You create a flow using a flow record to define the unique keys for
your flow. FNF allows you to define an optimal flow record for a particular application by selecting the keys from a large
collection of predefined fields. All key values must match for the packet to count in a given flow. Flows are stored in the
FNF cache. You can export the data FNF gathers for your flow by using an exporter.
In a BGP EVPN VXLAN fabric, an FNF monitor is configured on the NVE interface on a VTEP and on the physical interface on a
spine switch. For more information about FNF, see Configuring Flexible NetFlow module of the Network Management Configuration Guide.