Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

A POE enabled network interface shows ridiculously high usage.
e.g. POE usage (32000W6000W/1800W): : 1777% 333% (warn/crit at 90.0%/95.0%)

...

Some hardware vendors violate the SNMP RFC and output milliwatts instead of watts for pethMainPseConsumptionPower.

Image Added

When looking at an SNMP walk of the affected device, it will become evident, that the value in pethMainPseConsumptionPower (1.3.6.1.2.1.105.1.3.1.1.4.1) is not output in watts:

Code Block
languagebash
themeMidnight
OMD[$SITE]:~$ grep .1.3.6.1.2.1.105.1.3.1.1. ~/var/check_mk/snmpwalks/my_device
.1.3.6.1.2.1.105.1.3.1.1.2.1 1800
.1.3.6.1.2.1.105.1.3.1.1.3.1 1
.1.3.6.1.2.1.105.1.3.1.1.4.1 6000

These values are then used by Checkmk to calculate the percentages:

Code Block
languagebash
themeMidnight
6000/1800 → 333%

There are then off of course, because if your input data is faulty, the result of whatever calculation you do will be faulty as well.

Solution

As the bug lies within SNMP implementation of the affected device, the hardware vendor needs to fix this bug in the firmware.
Please open a ticket with the vendor and ask them to fix the bug.

...