softflowd - Network traffic analyser capable of Cisco NetFlow data export
SoftFlowd is a software implementation of a flow-based network traffic
monitor. softflowd reads network traffic and gathers information about
active traffic flows. A "traffic flow" is communication between two IP
addresses or (if the overlying protocol is TCP or UDP) address/port tuples.
The intended use of softflowd is as a software implementation of Cisco’s
NetFlow traffic account system. softflowd supports data export using
versions 1, 5 or 9 of the NetFlow protocol.