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

Enhancing Traffic Monitoring



Good Morning,

I am using the 30 day trial of Network Monitor to test on our corporate network. I am having success with it, but I have some questions.

We are using Dell layer 3 switches (no NetFlow) so I am using SNMP to look at the ports of the switches. On most of the switches I am seeing more sensors than there are physical ports. For example, on a couple of 48 port switches I am seeing sensors for 56 connections. There are 4 fiber uplink ports that if used replace ethernet ports 45 - 48, so I can undersnatd if PRTG lists 52 ports, but 56? As a result I am unsure which sensors are monitoring the uplink ports.

Also, is there a way to see if a particular logged in user is hogging bandwidth without the availability of NetFlow or JFlow, or any other kind of "flow" protocol? I can list the top 100 and take an informed guess as to which port the traffic is moving through, but then I have to trace cables to see which patch panel number is connected to that port, then hunt down the office etc. By that time the offender might be finished with the download and can deny having done it. Will I need a different product on top of this one or is it not possible without NetFlow?

Thank you for the help. I like the product so far.

ports sensors snmp

Created on Mar 24, 2011 1:21:58 PM

1 Reply




without further details, it's hard to say what exactly are the 56 sensor for. Can you maybe send us some screenshots showing the issue to [email protected]?

As for the second issue, I'm afraid without Netflow/Sflow or Packet Sniffing it's nearly impossible to get detailed traffic information.

best regards.

Created on Mar 24, 2011 2:49:55 PM by  Torsten Lindner [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.