When you rely on the network as a mission-critical resource, monitoring the amount and type of traffic is imperative. NetFlow is an ideal solution to this need, providing customized summaries of traffic statistics that are invaluable to network management, planning, and growth. NetFlow analyzes traffic flows, where a flow is defined by such variables as IP address, protocol type, and autonomous system (AS) number. It provides a highly granular analysis, including flow duration, packet size, and many other elements.

For large-scale networks where the core has a heavy traffic load, it is more appropriate to run NetFlow on the edge of the network so that core routers do not have to spend CPU cycles exporting lots of NetFlow data. By distributing this service on each VIP, the Cisco 7500 Series router is able to easily provide NetFlow accounting data for even the largest networks