SNMP OID CheckMK ver 2.4

ammari · January 22, 2026, 2:52pm

CMK version: 2.4 RAW
OS version: ubuntu 24.04

Hello,

I have just started using Checkmk and am in the process of setting up my environment.

In my setup, there is equipment with specific OIDs from which I want to retrieve data, but I cannot figure out where to configure this.

Under /lib/nagios/plugins there is only check_pollen; I cannot find “Checkmk extension packages” in the GUI.

I am using the RAW version.

Thanks.

3c2c2ff5 · January 23, 2026, 12:11pm

Hi,

checkmk is shipped with MIB-2 and enterprises OID subtrees and uses the snmp agent to retrieve the data. You can set it in the host configuration view including the credentials for snmpv2/v3.

To monitor specific device data not covered by checkmk default subtrees, you can use the /omd/versions/$version/lib/nagios/plugins/check_snmp

Get the help for the options and you can set it over WATO:
Setup > Services > Other services > Integrate Nagios plug-ins
add a rule and use it as follows:
$USER1$/check_snmp $options

This will check only one oid, not sub-tree, so you need to use it with each oid.

Best regards

andreas-doehler · January 23, 2026, 2:01pm

This menu option is only available in enterprise and cloud edition.
For RAW edition you need to use the “mkp” command line utility.

mike1098 · January 23, 2026, 2:43pm

Not sure with RAW but agents are the same, no?
So you may run the nagios plugin on a remote system via the agent:

@andreas-doehler Can you explain your way via mkp CLI tool? Sounds interesting

andreas-doehler · January 25, 2026, 8:08pm

Yes agents are the same, only you need to do the manual configuration compared to enterprise agent bakery.

For the mkp handling on the CLI you have the “mkp” command that can install, activate, deactivate & remove mkp packages.
I also use this commands often in bigger enterprise environments as the installation via GUI is painfully slow.

mike1098 · January 26, 2026, 8:16am

Thank you for your response. We also use the MKP command-line tool quite frequently; however, I was considering whether it might be helpful to use the SNMP Nagios plugin in the RAW edition. If a community package exists to support a specific device, that would of course be ideal.

I have not previously worked with the RAW edition and was therefore a bit surprised to learn that pure Nagios plugins are not supported in the same way as in the other editions. Apologies for any confusion on my part.

regards

Mike

andreas-doehler · January 26, 2026, 9:00am

Ah ok - the pure Nagios plugins are supported or used the same way in all editions. I have no problem at RAW compared to enterprise systems with classic Nagios checks.

The only difference is the installation of the MKP with the new classic Nagios check if it is not existing already on the system. The included checks are the same in RAW and enterprise.

ammari · January 26, 2026, 12:56pm

Hello and thank you for the responses,

I have now installed and activated two plugins, which are visible in the GUI, but I am still missing the Nagios plugin that everyone is talking about.

I am unable to find it or enable it either via the command line or through the GUI.

The intention is to monitor only network equipment, so no agent on those devices.

andreas-doehler · January 26, 2026, 1:12pm

If booth packages are enabled you should find these two entries under “Setup” –> “HTTP, TCP, email, …” –>

Here you can configure single metrics or some OIDs to fetch with classic check_snmp.

ammari · January 26, 2026, 1:28pm

I have now found them, thank you very much.

Is it possible to manipulate these inputs so that the values retrieved via SNMP can be divided or multiplied?

andreas-doehler · January 26, 2026, 1:50pm

If you want to make a calculation with two values fetched with check_metric then you should use.

Or if it gets more complicated you should consider to write an small SNMP check.
The syntax for check_calculate is not easy for RAW edition users as you cannot fetch the expression from the GUI like in enterprise.

Please have a look here.

A simple SNMP check with 2-3 values is not so hard to build.

Simple SNMP Checks.

github.com/Yogibaer75/Check_MK-Things

check%20plugins%202.3/extreme_vsp_sensors/cmk_addons_plugins/extreme_vsp_sensors/agent_based/extreme_vsp_fans.py

master

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

from typing import Mapping, NamedTuple

from cmk.agent_based.v2 import (
    CheckPlugin,
    CheckResult,
    DiscoveryResult,
    OIDEnd,
    Result,
    Service,
    SimpleSNMPSection,
    SNMPTree,
    State,
    StringTable,
    all_of,
    startswith,
)
from cmk.plugins.lib.netextreme import DETECT_NETEXTREME

This file has been truncated. show original

or

github.com/Checkmk/checkmk

cmk/plugins/collection/agent_based/apc_sts_source.py

master

#!/usr/bin/env python3
# Copyright (C) 2019 Checkmk GmbH - License: GNU General Public License v2
# This file is part of Checkmk (https://checkmk.com). It is subject to the terms and
# conditions defined in the file COPYING, which is part of this source code package.

# .1.3.6.1.4.1.705.2.3.5.0 2 --> MG-SNMP-STS-MIB::stsmgSource1Used.0
# .1.3.6.1.4.1.705.2.4.5.0 1 --> MG-SNMP-STS-MIB::stsmgSource2Used.0


from collections.abc import Mapping
from typing import Any

from cmk.agent_based.v2 import (
    CheckPlugin,
    CheckResult,
    contains,
    DiscoveryResult,
    Result,
    Service,
    SimpleSNMPSection,

This file has been truncated. show original

ammari · January 27, 2026, 6:47am

Thanks for the responses. It seems that I may need to create a custom plugin myself.

The issue I noticed yesterday, after receiving help to activate the plugin, is that certain values are not scaled correctly. For example, temperature values are received as 3750, which requires dividing the value by 100 to obtain a human-readable temperature of 37.5.

andreas-doehler · January 27, 2026, 9:01am

If you only need the division of the value, you can do this with the check_snmp_metric plugin.