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PRTG Custom XML Sensor - negative Min Warning Limit or other ideas




I try to monitor our windows DHCP scopes with a custom Powershell script. It collects automatically all scopes as channels and tells PRTG how many leases are in use. I'm giving MaxWarningLimit and MaxErrorLimit and it works well. Now I want to check if scope is enabled and trigger a warning if not. So I changed unit from Percent to Custom and set the value to -1, to set the MinWarningLimit to -1. But it does not work. The value is -1, but there is no warning for the channel. Is it possible to warn at negative values? Does anybody has another idea, how to warn if the scope is disabled?

Thank you for your help. If anyone is interested in script, fee free to ask.

custom-sensor dhcp limit negative-values warning

Created on Feb 14, 2022 9:43:57 AM

2 Replies

Accepted Answer




the lower limits trigger if the value is below them, not below or equal. (For upper limits, they trigger if the value is above).

If you set the lower warning limit for example to -0.5, or -0.9, it should trigger if the sensor has a value of -1.

Created on Feb 15, 2022 10:20:56 AM by  Arne Seifert [Paessler Support]




thank you for your reply and solution. It solved my problem. SOmetimes its so simple. Sry.

Created on Feb 18, 2022 8:27:00 AM

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