What is this?

This knowledgebase contains questions and answers about PRTG Network Monitor and network monitoring in general.

Learn more

PRTG Network Monitor

Intuitive to Use. Easy to manage.
More than 500,000 users rely on Paessler PRTG every day. Find out how you can reduce cost, increase QoS and ease planning, as well.

Free Download

Top Tags

View all Tags

Bandwidth Monitoring



I would like to monitor our bandwidth of our links.

We are using SNMP on our firewalls, and we are getting the ifInOctets and ifOutOctets OIDs.

How do I convert these into bandwidth? According to the Cisco website - http://www.cisco.com/c/en/us/support/docs/ip/simple-network-management-protocol-snmp/8141-calculate-bandwidth-snmp.html it statest the following:

Input utilisation = difference betwwen two poll cycles * 8 * 100 / number of seconds in the difference * the interface speed.

I can get the interface speed, the inOctets and outOctets, but how do I do a custom channel that does this calculation?



bandwidth snmp utilisation

Created on Mar 17, 2015 3:29:38 PM

1 Reply



Dear cm2000

As first step, please check your SNMP Traffic Sensor settings. The sensor allows to create more channels for additional data, depending on the SNMP version in use.

If you want to use custom OIDs, please create an SNMP Custom sensor. As value type, please set Delta (Counter) to have PRTG automatically perform the "difference between two poll / time of the difference" calculation.

The SNMP Custom sensor also allows to scale the value by using the field "Multiplication" and "Division".

Created on Mar 18, 2015 3:17:33 PM by  Arne Seifert [Paessler Support]

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.