Network Flows
A key to NetFlow, as its name implies, is the fact that it breaks down TCP/IP communications for statistical record keeping using the concept of a flow. What is a flow according to the NetFlow application? A flow is a unidirectional stream of packets between a specific source system and a specific destination system. For NetFlow, obviously built around TCP/IP, the source and destination are defined by their network layer IP addresses and their transport layer source and destination port numbers.
NetFlow technology has seen several generations that provide more sophistication in defining traffic flows, but “classic” NetFlow distinguished flows using a combination of seven key fields. Should one of these fields vary in value from ...
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