Cisco devices are able to support advanced capabilities, including the ability to filter or sample particular flows. This helps narrow down the NetFlow data that is sent to the software and also reduces the CPU consumption of the device. NetFlow input filtering and random-sampled NetFlow features can set up the device to collect data from specific subsets of traffic.

The NetFlow input filters provide NetFlow data for a specific subset of traffic by creating filters for selected flows. By creating a class map for input filtering, this helps focus the NetFlow data on the desired types of traffic. The random-sampled NetFlow feature randomly selects a packet from a sequence of packets or provides the random sampling from the device’s NetFlow cache. The sampling period can be adjusted depending on the amount of granularity desired. Additional information on configuring these options can be found on the Cisco website.