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

Unusual detection is not helpful



I've got three SNMP Traffic 64bit sensors that all say something like this - "1 hour interval average of 47 kbit/s (Traffic In) is unusually low for this hour of the week"

All three say this in "Last Message". However, they have all said the exact same unchanging message for the last three days. The "interval average" they report is not current.

So I want to know, what time did this happen? When was "this hour of the week"? How can I clear this message?

detection helpful not unusual

Created on Apr 21, 2014 8:01:23 AM

3 Replies



Interesting... I just changed the system Graph Settings, which required a reboot of the PRTG server. After this reboot, the Unusual items mentioned above went away.

Created on Apr 21, 2014 8:24:10 AM




thank you very much for your KB-Post. The Unusual Detection always compares back to the same time of day (and day of the week), into the past. And for this comparison it then uses an hourly average (of this time of day, day of the week). Against this average, the last value is compared, and if the value differs too much, the unusual state is triggered.
You can change the "thresholds" in the System Settings. If the current values show a difference above the threshold, the sensor will probably show the unusual state for at least this one hour (as the base is a hourly average), until either the current values go "back" to normal, or there is another average.
Changing the Graph Settings actually causes a recalculate of the "Graph Cache", during this process the Unusual Detection will be paused.

best regards. best regards.

Created on Apr 21, 2014 12:12:55 PM by  Torsten Lindner [Paessler Support]



Okay, well, something obviously got stuck, because the message remained for three days and the value in the message did not change during those three days even though the traffic varied widely. That is why I was very confused - it kept saying "this hour", but that clearly wasn't true.

This must have been a stuck message leftover from a bug because it cleared immediately upon reset of the PRTG server.

Created on Apr 21, 2014 12:20:12 PM

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.