This article applies to PRTG Network Monitor 12 or later

Graphs in PRTG

The normal Data view of PRTG offers up to four different graphs which can be displayed simultaneously. By default, these are

• Live graph (last 2 hours)
• 2 days graph
• 30 days graph
• 365 days graph

If monitoring data is available for the defined timespan each graph will display the respective data. However, in the event that a sensor’s live graph is not displaying any data, while all other graphs are, there are a couple of methods of solving this issue.

If All Sensor Graphs are Affected

Perform a cache recalculation. This will delete and re-calculate the graph cache used for the display in the web interface and the Enterprise Console.

For detailed instructions, please see: My PRTG has stopped graphing

If Individual Graphs are Affected

If you see unexpected high or incredibly low values in your graphs this may be the result of wrong data reported by your devices. A spike filter can remove these false peaks.

For detailed instructions, please see: Why do I see huge peaks or spikes in graphs for SNMP sensors?

Other

If none of these procedures provides a solution please check your PRTG log files for any error messages, such as read / write errors or sensor counter changes which could account for the problem.