Netflow Tool ((free)) -

To understand the power of NetFlow, one must first understand what it discards. Unlike Deep Packet Inspection (DPI), which looks at the actual payload of data (the emails, the images, the files), NetFlow is concerned solely with metadata. It records the "who, what, where, and when" of a conversation, ignoring the "what was said." A NetFlow record answers five key questions: Who is the source IP? Who is the destination IP? What ports are they using? What protocol is involved? And how much data was transferred?

Unlike packet capture tools like Wireshark which record every bit of a packet, a NetFlow tool focuses on "flows"—unidirectional streams of packets sharing common attributes. A standard NetFlow record typically includes: Source and Destination Ports (TCP/UDP) Protocol Type Type of Service (ToS) / DSCP Byte and Packet Counts Input and Output Interface Numbers netflow tool

NetFlow tools are essential for network administrators seeking high-level visibility into IP traffic, bandwidth usage, and security anomalies without the heavy resource overhead of full packet capture. To understand the power of NetFlow, one must

On your router (Cisco example):