Checkmk discovers only 2 of 4 power supplies on Juniper switch

CMK version:
2.0.0p20 CRE
OS version:
Debian 10.12
Error message:
Output of “cmk --debug -vvn hostname”: (If it is a problem with checks or plugins)

We have.a Juniper qfx10002-72q switch with 4 power supplies, numbered 0 to 3. Power supply number 3 has failed, and checkmk didn’t notice. When I look in checkmk at the services for the switch, checkmk shows that it has discovered power supplies 0 and 1, but doesn’t know about 2 and 3.

What check is it using.

This information is important for troubleshooting, as inside the check is defined what data should be fetched from the device.
Inside the Juniper list of checks is only the “juniper_trpz_power” and “juniper_fru” i think relevant for PSUs.

Can you please provide the output of an SNMPwalk on the OID “.” or “.”

I think the second one is the only working on your device.

It’s using check_mk-juniper_fru

snmpwalk-output.txt (15.0 KB)

As you wrote, the second one is the only one working on our device. Looks like the problem is with the agent on the device, right?

I would also say this is a software problem on the device.
Your snmpwalk only shows two PSUs.

iso. = STRING: "Power Supply 0"
iso. = STRING: "Power Supply 1"
iso. = STRING: "Fan Tray 0 Fan 0"
iso. = STRING: "Fan Tray 0 Fan 1"
iso. = STRING: "Fan Tray 0 Fan 2"

If you have support on this devices it would be a good time to make a support ticket :smiley:

There is a separate MIB for Power supplys (JUNIPER-POWER-SUPPLY-UNIT-MIB) can you check if your device supports this MIB (

Might be the check uses the wrong MIB (FRU → field replaceable unit).

1 Like