sflow
Open vSwitch is a production quality, multilayer virtual switch licensed under the open source Apache 2.0 license. It is designed to enable massive network automation through programmatic extension, while still supporting standard management interfaces and protocols (e.g. NetFlow, sFlow, IPFIX, RSPAN, CLI, LACP, 802.1ag). In addition, it is designed to support distribution across multiple physical servers similar to VMware's vNetwork distributed vswitch or Cisco's Nexus 1000V.
Related contents:
Making the Network Visible.
sFlow® is an industry standard technology for monitoring high speed switched networks. It gives complete visibility into the use of networks enabling performance optimization, accounting/billing for usage, and defense against security threats.
Flow collector, enricher and visualizer. This program receives flows (currently Netflow/IPFIX and sFlow), enrice them with interface names (using SNMP), geo information (using MaxMind), and exports them to Kafka, then ClickHouse. It also exposes a web interface to browse the collected data.
FastNetMon is a very high performance DDoS detector built on top of multiple packet capture engines: NetFlow, IPFIX, sFLOW.