Router Monitoring
Setting up Router Monitoring With PRTG Network Monitor
Router Monitoring with PRTG Network Monitor allows administrators to discern actual bandwidth usage based on multiple parameters, such as IP addresses, port numbers, protocols, etc., using either SNMP, packet sniffing or NetFlow Sensors. Packet sniffing sensors generally use the host machine's network card, but can be configured to use router monitoring ports found on some networking devices using port mirroring / forwarding in order to monitor the overall network bandwidth utilization. NetFlow Collectors receive data forwarded by NetFlow-capable Cisco devices using NetFlow Sensors (included in all PRTG licenses, including the freeware).
The configuration and implementation for such router monitoring methods are outlined below. With PRTG's three data acquisition technologies and the various infrastructure options in use today, it can sometimes become complicated to decide which router monitoring technology is right for your configuration. The easiest setup would be to monitor the local traffic of one PC by installing PRTG directly on it. This scenario is used to monitor a single PC in a LAN or to monitor a PC connected to the Internet via DSL, modem, or cable.
Router Monitoring Using SNMP From a Single PC
SNMP is the most basic router monitoring technique. It is easy to set up:
- Add a device with the router's IP address, then add a new SNMP sensor for the device
- The software will scan the device and list a series of interfaces available for the device
- Select the interface and save your settings. The software will start monitoring right away
Router Monitoring For Total Network Traffic With NetFlow
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 (see corresponding knowledge base article)
- Create a new NetFlow Sensor without any filtering to monitor network's total traffic
- Note: If you have several switches/routers you may not see all traffic if you only monitor one device
Router Monitoring Using a Switch or Router With 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
Further information on setting up router monitoring can be found here.
Router Monitoring For Free
You can set up router monitoring with PRTG Network Monitor for free, or test the capabilities of router monitoring with the 30-Day-Trial-Edition. The Freeware Edition is completely free for personal and commercial use and may be downloaded at no cost. The Commercial Editions are required if you want to monitor more than ten sensors. Licenses for our router monitoring software start at $400 / €300.
