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

View past down alarms or whatever is red on the overview graph



Hello, I am sure this is one of the most rudimentary things you can do with PRTG but I'm embarrassingly having trouble figuring it out. I looked online but could not find the solution so I figured I would ask here. How can I view a summary of past down alarms or easily determine what is behind the red on the overview graph?

For instance, when I view the overview graph for 365, I can see all of the outages from the past year (in red.). How can I determine what those were without scrolling through every single sensor graph looking for red? I ran the uptime/downtime report but it did not show everything. (In short, there was some kind of outage or something yesterday, due to red I'm seeing on the summary graph, but I can not determine what it was.) Thanks!

alarm prtg report

Created on Jun 30, 2022 12:57:21 PM

Last change on Jul 5, 2022 2:29:02 PM by  Florian Lesage [Paessler Support]

1 Reply



Hello Dear customer,

Thank you for reaching out to PRTG support.

You can increase this value in the settings of the server (Setup > System Administration > Core & Probes | Historic Data Purging > Log File Records)

You can also use the following URL:


Hopefully this answer your request, feel free to reach out PRTG support for any questions


Created on Jul 5, 2022 2:43:21 PM by  Ricardo Sanchez [Paessler Technical 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.