NetFlow is a network protocol developed by Cisco for collecting IP traffic information and monitoring network traffic. By enabling NetFlow on network devices like routers and switches, administrators can gain valuable insights into the types of traffic moving through the network, including the source, destination, and volume of traffic.

Key features and uses of NetFlow include:

  1. Traffic Analysis: NetFlow provides detailed information about network traffic patterns and volume, which is crucial for understanding how the network is being used.

  2. Capacity Planning: By analyzing traffic trends, network administrators can make informed decisions about network expansion and capacity upgrades.

  3. Network Performance Monitoring: NetFlow helps in identifying the causes of congestion and bottlenecks in the network, leading to more efficient network management.

  4. Security Analysis: By monitoring traffic flows, NetFlow can help in identifying unusual traffic patterns or potential security breaches.

  5. Application Monitoring: Understanding which applications are consuming the most bandwidth helps in resource allocation and management.

NetFlow typically works by enabling network devices to collect and export traffic data to a central collector, where the data is processed and analyzed. The standard version of NetFlow is v5, which provides basic flow information. However, newer versions like v9 offer extensibility and support for IPv6 and multicast.