Do you want to know which devices, applications or users generate most traffic in your network, or where your network bottlenecks are? Start monitoring your routers today, and you will be amazed how much easier your daily work gets once you have router monitoring in place.

PRTG Network Monitor is a comprehensive network monitoring software with a wide range of router monitoring possibilities. Just choose one of the supported technologies, and you will be able to monitor router traffic and see network usage 24/7. If unusual behavior is detected, the software will alert you right away. This allows you to troubleshoot problems before others are affected.

Free Router Monitoring

The free version of PRTG Network Monitor allows you to monitor up to 30 sensors. The Freeware Edition is completely free for personal and commercial use and may be downloaded at no cost.

We also offer a free 30-Day-Trial-Edition. The Commercial Editions are required if you want to monitor more than 30 sensors. Licenses for our router monitoring software start at $440 / €330.

PRTG offers you the following options for monitoring your router:

Router Monitoring Using SNMP

SNMP is the most basic router monitoring technique. You can set it up with a few clicks:

  • Add a device with the router's IP address, and then add a new SNMP sensor for the device.
  • PRTG will scan the device and list a series of interfaces available for the device
  • Select the interface and save your settings. You will be able to see your bandwidth usage data, split into uploads and downloads, right away.

Visualize Total Network Traffic using NetFlow Router Monitoring

If your routers support NetFlow, sFlow or jFlow (NetFlow is included in most of the more expensive Cisco routers, sFlow and jFlow are standards used by other vendors), you can easily view your traffic data using this protocol.
All PRTG licenses include an unlimited number of NetFlow (and sFlow / jFlow) sensors. They just count against your overall sensor limit.

  • Configure NetFlow protocol on the router to send NetFlow packets to the computer running PRTG (please also see our knowledge base article)
  • Create a new NetFlow Sensor without any filtering to monitor your network's total traffic
  • Note: If you have several switches/routers you may not see all traffic if you only monitor one device

Packet Sniffing: Router Monitoring via the Monitoring Port

  • Using a switch or router that has a "monitoring port" or "port mirroring", it is possible to monitor all the traffic in your network. Most unmanaged switches and routers do not have this feature, many managed switches and routers do.
  • Port mirroring is used on a network switch to send a copy of all network packets seen on one switch port to a monitoring network connection on another switch port. This is commonly used for network applicances that require monitoring of network traffic, such as an intrusion-detection system. Port mirroring on a Cisco Systems switch or router is generally referred to as SPAN.
  • BTW: You can also use an old fashioned hub. Hubs send all network packets to all ports, but they are of course a lot slower than switches
  • Configure the switch(es) and router(s) to send a copy of all network packets to the IP of the machine running PRTG
  • Create a new packet sniffer sensor without any filtering parameters to monitor the network's total traffic
  • Note: If you have several switches/routers you may not see all traffic if you only monitor one device
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