All-in-one NetFlow Analyzer PRTG


  • NetFlow Analyzer PRTG analyzes your bandwidth & traffic
  • PRTG supports all different NetFlow versions
  • PRTG analyzes all important Flow protocols
  • The PRTG NetFlow Analyzer saves and processes flows


Free Download
  • Unlimited version of PRTG for 30 days
  • After 30 days, PRTG reverts to a free version
  • Or, you can upgrade to a paid license anytime


Network Monitoring Software - Version (November 25th, 2019)


Download for Windows and hosted version available


English, German, Spanish, French, Portuguese, Dutch, Russian, Japanese, and Simplified Chinese


Up to 100 sensors for free (Price List)

Unified Monitoring

Network devices, bandwidth, servers, applications, virtual environments, remote systems, IoT, and more

Supported Vendors & Applications


Get a holistic view of your network with NetFlow Analyzer


NetFlow Analyzer PRTG lets you check and monitor your bandwidth and determine, for example, the amount of network traffic caused by IP addresses, protocols, or programs. In order to carry out such an analysis, you'll configure your routers such that flow packets are sent to a computer with a PRTG probe. NetFlow technology puts little strain on your CPU and is especially adapted for networks with heavy data traffic and bandwidth.

NetFlow protocol is mainly supported by Cisco routers and switches.

With the PRTG NetFlow Analyzer you can get a holistic view about your network, keep an eye on your network traffic and what your bandwidth is being used for.



i NetFlow is a protocol for collecting, aggregating and recording traffic flow data in a network. NetFlow data provide a more granular view of how bandwidth and network traffic are being used than other monitoring solutions, such as SNMP. NetFlow was developed by Cisco and is embedded in Cisco’s IOS software on the company’s routers and switches and has been supported on almost all Cisco devices since the 11.1 train of Cisco IOS Software. Read more ...

PRTG: A NetFlow analysing software, without any additional costs.





iWhat is a sensor?

In PRTG, “Sensors” are the basic monitoring elements. One sensor usually monitors one measured value in your network, e.g. the traffic of a switch port, the CPU load of a server, the free space of a disk drive. On average you need about 5-10 sensors per device or one sensor per switch port.

View video (3:26 min.)

no need for upgrades

No upgrade necessary

PRTG is an all-in-one tool! The monitoring tool requires no additional upgrade or tool to analyze your bandwidth using Cisco NetFlow. All it takes is a standard PRTG configuration and you’ll be on your way to monitoring the entire traffic which passes via your routers and switches.

all in one

One tool for everything

With PRTG, you get one central software solution for all of your monitoring topics – and a complete overview. The need for a combination of many different tools is a thing of the past. PRTG lets you monitor your bandwidth use, server, CPU, traffic analysis, website, cloud services, and much more. And can be used as a professional NetFlow Analyzer software, as well.

Auto Discovery

Quick configuration

PRTG uses an intelligent Auto Discovery to automatically set up comprehensive monitoring, and creates all the sensors you need. Switching from other NetFlow Analyzer software to PRTG therefore takes no time at all.



By default, Toplists in PRTG always split up the traffic analysis within the sensor among Top Talkers (bandwidth use according to IP address), Top Connections (according to connection), and Top Protocols (according to protocol). With Toplists, you’ll enjoy a categorized overview which makes NetFlow traffic analysis easy.

PRTG sensors for NetFlow analysis



NetFlow version 5 is in widespread use. With PRTG, you get a compatible NetFlow V5 sensor, as well as a NetFlow V5 custom sensor.




NetFlow version 9 is an advanced form of NetFlow technology. PRTG provides you with appropriate sensors for its use: the NetFlow V9 sensor and NetFlow V9 custom sensor.




Internet Protocol Flow Information Export (IPFIX) is an advanced form of Cisco's NetFlow system. PRTG offers two sensors for its use: The IPFIX sensor and IPFX custom sensor, which you can customize to meet your own specific needs.

This is what NetFlow analysing looks like in PRTG

NetFlow Analyzer PRTG - 3 useful applications  

PRTG lets you recognize if your switches are not equipped to handle the quantity of data of your backup solution, before they become completely overloaded.
Should these switches overload during a backup anyway, PRTG NetFlow Analyzer will enable you to quickly find the perpetrator.


Identify bandwidth hogs

Individual sources often use disproportionately high amounts of network bandwidth. These sources may be individual users, but also applications or specific data. With our NetFlow traffic analyzer software, you’ll evaluate IP addresses and get complete traffic analytics.

Spot load peaks early

Many companies experience fluctuations in access to various websites or internally-used applications. Define your own thresholds with PRTG NetFlow Analyzer so you can be informed early: ideally, before the performance of your system takes a hit.


Avoid backup overloads

Thorough backups can lead to problems for the entire network. Such problems are frequently the result of individual routers or switches which overload during the backup and thwart the entire network. Use NetFlow Analyzer PRTG to monitor the complete traffic and bandwidth and find the causes, and thereby optimize your network.


“We can all work with greater peace of mind knowing that our systems are constantly being monitored.”

Markus Puke, Network Administrator at the Schüchtermann-Klinik.


PRTG NetFlow Analyzer simplifies your day!

Let PRTG work for you,
so you can concentrate on your day-to-day tasks with total peace of mind.

PRTG saves time

With PRTG, you get one central monitoring tool with which to monitor your bandwidth and network via NetFlow, SNMP, or Packet Sniffing. Enjoy a quick and easy overview thanks to our dashboards and maps.

PRTG saves worry

Customizing PRTG is a breeze. When it comes to NetFlow analysis, you’ll get all the right sensors in their many different forms. And this will save you time as your get your monitoring up and running.

PRTG saves money

PRTG is worth it. 80 % of our customers report savings in the area of network management. And the respective costs for our PRTG licenses pay for themselves in an average of only a few weeks.

200,000 system administrators worldwide
trust our software. Every day.

We have compiled some reviews for you.




  • Unlimited version of PRTG for 30 days
  • After 30 days, PRTG reverts to a free version
  • Or, you can upgrade to a paid license anytime

Practical tip: “Hey Gerald, what would you tell administrators looking to use PRTG as a NetFlow Analyzer?”

“Cisco has continuously developed the NetFlow technology. Administrators must therefore find out beforehand which NetFlow version is supported by their routers and switches. With the right PRTG sensors, setting up NetFlow monitoring is quick and easy.”

Gerald Schoch works as a technical editor at PAESSLER AG.

NetFlow Analyzer PRTG:
Setup in 3 simple steps!


Configure the router's NetFlow protocol so it sends NetFlow packets to the computer running the PRTG Network Monitor:

Configure PRTG

Configure PRTG. All Flow sensors are even available in the free trial version of PRTG. Choose a suitable license to enjoy comprehensive NetFlow traffic monitoring with over 200 types of sensors. You can do this at a later time.

Configure your router or switch

Configure your Cisco router or switch so that it exports and sends NetFlow data to a computer running a PRTG probe. In the next step, you'll create the NetFlow sensor on this computer. Pay special attention to the Flow version which is exported. A compatible sensor must be used for traffic analysis and bandwidth monitoring via NetFlow in PRTG.

Create sensors

Create NetFlow sensors which are appropriate for the exported Flow version and target address and configure the UDP port and an IP address in the sensor settings where you would like the flows to be received. Another option is to indicate the IP address of a specific Cisco device if you would like the flows to be received by such a device, and turn on sampling mode if you have set this mode on the target device. Enter a value for the Active Flow Timeout which is at least one minute longer than that of the device. Finally, choose which of the sensor's data traffic categories should be displayed in PRTG NetFlow Analyzer, and define an optional filter for the desired data.


Alternative: If you do not require long-term traffic analyses for every single PC and would only like to monitor the network traffic occurring presently and recently on the basis of IP or protocol, then creating a NetFlow sensor and correspondingly analyzing the data traffic in the Toplists based on IP or protocol is sufficient. More information on setup: search answers to user questions in our Knowledge Base. In this article, you'll find additional tips on the configuration of Cisco routers.

Netflow Analyzer for VMware

VMware and NetFlow:
VMware uses NetFlow technology in the "vSphere Distributed Switches (vDS)" product line. In principle, these virtual switches connect the virtual network cards of virtual machines (VMs) to the network by way of the physical network cards of hosts. VMware has incorporated NetFlow for these virtual switches. 

Monitoring with PRTG: Both monitoring and the NetFlow traffic analysis of physical (Cisco) devices are operational here. Set up NetFlow in the VMware vCenter and configure it such that these flows are sent to PRTG NetFlow Analyzer, where a corresponding flow sensor displays and monitors the data. As long as the correct NetFlow version is used, it will make no difference to PRTG where the flows come from.

Further Information:

All you need to know about VMware Monitoring with PRTG.

Over 95% of our customers recommend PRTG


Paessler AG worldwide trialled PRTG in over 600 IT departments.
The aim was to tune the network monitoring software closer to the needs of the administrators.
The result of the survey: over 95% of the participants would recommend PRTG - or already had.

Recommend PRTG

Other Flow sensors

PRTG provides other Flow sensors which allow you to monitor your chat protocols, Citrix, FTP, Email, and other traffic.

sFlow: With an sFlow sensor, only every nth packet will be passed on: this results in even less load on the system. Find our more about the PRTG sFlow sensor here.

jFlow: jFlow lets you monitor Juniper Networks hardware, among others. Here too you can configure devices especially for PRTG. It features a high degree of similarity to NetFlow5. Find out more about our jFlow sensor

Award winning solution

We work hard on making our software as powerful and easy-to-use
as possible for our customers each and every day.
Of course it makes us proud when we get awards for that.



Comparison: Netflow, SNMP, Packet Sniffing


SNMP: SNMP (Simple Network Management Protocol) is extremely popular and an easy way to read device data. It gives you an important first look, e.g. on bandwidth use, CPU, or the temperature of your hardware. More on SNMP monitoring with PRTG

Packet Sniffing: For more detailed information on your bandwidth usage, use Packet Sniffing or NetFlow. You will thus be able to take a closer look at the packets passing through individual routers or switches. More on Packet Sniffing with PRTG.

NetFlow Analysis: NetFlow is a protocol supported in particular by Cisco hardware. You therefore need a monitoring solution which is compatible with NetFlow. Such a solution (Packet Sniffing, e.g.) will enable you to analyze packets in detail. PRTG comes with a set of NetFlow sensors - at no extra charge.


NetFlow collector vs. NetFlow analyzer

What are the best NetFlow tools?

Many tools can collect and analyze flow data. When choosing a NetFlow analyzer tool, you should consider your needs, and the extent to which you would like to analyze your data. It might also make sense to use several different tools concurrently. We have found, for example, that many administrators use Wireshark in addition to PRTG. Thanks to its flow monitoring, PRTG can give you an overall picture while allowing you to rule out possible causes of network problems. Wireshark, on the other hand, offers a detailed look at individual data packets.

What is a NetFlow collector?

A NetFlow collector captures, saves, and processes NetFlow data. Some of these tools are more effective than others at providing in-depth data analysis. Many administrators, however, use one single tool to perform the functions of both NetFlow collectors and NetFlow analyzers.

What is a NetFlow analyzer?

PRTG is a NetFlow collector AND a NetFlow analyzer. It captures and processes all NetFlow data, and presents this data on a dashboard. PRTG takes advantage of the toplists described above to display top talkers, top connections, top protocols, and customizable toplists. You are free to set your own threshold values. If these values are exceeded, PRTG will alert you at once.

What NetFlow analyzers and connectors are available for Windows?

PRTG is a NetFlow Analyzer & collector that runs on Windows. As our focus has always been on Windows systems, we have acquired quite a bit of expertise in the area of NetFlow traffic analysis with Windows. PRTG is your all-in-one Windows monitoring solution. It comes with numerous WMI sensors, as well as Windows Event Log monitoring and security monitoring. It also uses technologies which will enable you to monitor non-Windows operating systems.

NetFlow analyzer download: Free or professional?

Many administrators wonder if there is an effective free NetFlow Analyzer tool, or if they should consider using a professional one. PRTG comes with 100 free sensors which never expire. And if you decide to expand your monitoring in the future, a professional license can be purchased at any time. PRTG licenses let you enjoy all the software’s features: alarm, reports, support, and the full range of sensors.


Also interesting:


Real-Time Monitoring: By monitoring your network in real time, you’ll be sure to always know what is going on inside it. PRTG runs in the background and promptly notifies you if a problem arises.

Printer Monitoring: With PRTG you know the status of every printer. See detailed printer error messages at a glance and get informed if printer replacement is necessary.

WiFi Monitoring: With a WiFi Analyzer you are able to monitor the status of your Wireless Network. PRTG enables you to keep an eye over the device status, load, traffic, speed and signal strength of each router.

VPN Monitoring: PRTG monitors VPN connections and measures traffic, load, and the number of users. Identify connection problems and suspicious traffic.

“Our top priority is to continue to develop PRTG is a constant, practical, and proactive manner. Our hope is that administrators will always be ready for any new standards which arise.”

Dirk Paessler, founder of Paessler AG in Nuremberg

German quality

Free Download
  • Unlimited version of PRTG for 30 days
  • After 30 days, PRTG reverts to a free version
  • Or, you can upgrade to a paid license anytime


Made in Germany: The PRTG Network Monitoring Tool is the fruit of a dedicated, international team. The company was founded by Dirk Paessler. The Paessler AG headquarters are located in the city of Nuremberg, in the heart of Germany.

A quick overview: PRTG provides a quick overview, whether on your desktop or as an app on your smartphone. An individually configurable dashboard features every key stat in the form of an easy-to-understand graph, so you can always make sure your network is running smoothly.

Easy configuration: Our Smart Setup guarantees a quick and easy setup. During configuration, PRTG will ping your network and create appropriate sensors, saving you a great deal of time. Furthermore, switching from other software such as Nagios is relatively quick and easy.

Outstanding support: Our support team strives to resolve inquiries within 24 hours (on business days). Discover a wide selection of videos, webinars, and instructions in our knowledge base. Our manual is also an excellent resource.

Getting started is easy: The trial version is for free, allowing you to evaluate our monitoring tool with no strings attached. To upgrade, simply search for a suitable license. You can modify your license any time you like. 


Network Monitoring Software - Version (November 25th, 2019)


Download for Windows and hosted version available


English, German, Spanish, French, Portuguese, Dutch, Russian, Japanese, and Simplified Chinese


Up to 100 sensors for free (Price List)

Unified Monitoring

Network devices, bandwidth, servers, applications, virtual environments, remote systems, IoT, and more

Supported Vendors & Applications