NetFlow Analyzer
PRTG is an Advanced NetFlow Analyzer
The Cisco NetFlow protocol internally tracks the bandwidth usage of the network, giving administrators useful information on bandwidth usage, type of traffic, or traffic volume. NetFlow monitoring based on Cisco's NetFlow protocol is supported by most Cisco routers and certain Cisco switches. These devices can be configured to send pre-aggregated data to the computer running a NetFlow analyzer such as PRTG Network Monitor.
The NetFlow analyzer can give you information similiar to a packet sniffer on where, how and by whom specific applications are being used and how the usage might affect the network. The advantage of using NetFlow is that it only requires little CPU load on the router itself and also on the machine running PRTG, especially when compared to packet sniffers. This network monitoring utility is therefore essential for network troubleshooting, especially for administrators who need to find bottlenecks and analyze net bandwidth usage.
The PRTG NetFlow Analyzer
PRTG Network Monitor is the powerful network and internet monitoring software by Paessler. It ensures the availability of network components while also measuring traffic and usage. It saves costs by avoiding outages, optimizing connections, saving time and controlling service level agreements (SLAs). PRTG has been tested and certified "Cisco Compatible" as it's a market leading NetFlow Analyzer.
The NetFlow Analyzer is available in two editions. For basic, free availability and bandwidth monitoring, the Freeware Edition of the network port monitor may be downloaded and used for personal and commercial use completely free of charge. For more advanced needs, including the NetFlow analyzer functionality, licenses for the Commercial Editions start at $400 / €300.
Every PRTG license, even the freeware, includes NetFlow sensors. They just count as normal sensors against your overall sensor count.