How NetFlow Monitoring works
How NetFlow Monitoring works
One option to measure bandwidth usage "by IP address" or "by application" is to use Cisco's NetFlow protocol which is especially suited for high traffic networks. Many routers and switches from Cisco support this protocol.
Cisco devices with NetFlow support track the bandwidth usage of the network internally and then only send pre-aggregated data to the PRTG system for accounting purposes. This way the computing load for PRTG is much lower. This option is recommended for high traffic networks.