SNMP not working

[maddin76 (Martin)]

I have added some L2 access switches to check_mk but however only one of 7 (!!!) is being read via SNMP.
All of them are same model, same type, same firmware. The one that is working have been labeled as “cmk/device_type:switch” and SNMP query is woking via CLI.

The other I get SNMP timeout error. If I test this with a SNMP tool, it is working with v1 and v3.

Here the result from the CLI…

OMD[cmk]:~$ cmk -Iv --no-cache SW-ACCS-01
Discovering services and host labels on: SW-ACCS-01
SW-ACCS-01:

• FETCHING DATA
  [SNMPFetcher] Execute data source
  ERROR: SNMP error
  snmpget: Timeout

SNMP scan failed: Cannot fetch system description OID .1.3.6.1.2.1.1.1.0. Please check your SNMP configuration. Possible reason might be: Wrong credentials, wrong SNMP version, Firewall rules, etc.
[PiggybackFetcher] Execute data source
No piggyback files for ‘SW-ACCS-01’. Skip processing.
No piggyback files for ‘192.168.30.231’. Skip processing.

• PARSE FETCHER RESULTS
  Received no piggyback data
• EXECUTING HOST LABEL DISCOVERY
• PERFORM HOST LABEL DISCOVERY
• EXECUTING DISCOVERY PLUGINS (0)
  SUCCESS - Found no new services, no new host labels
  OMD[cmk]:~$

Here the result from the tool…

I use the RAW edition but I also have an older test instance of the Enterprise edition. Here I can add the switches and it is working. I don´t know where the issue is.

[robin.gierse]

Read and understand this.
That should give you a toolkit with which you can tackle SNMP problems.

[maddin76 (Martin)]

Hi Robin,

maybe you did not read my last paragraph. I am able to reach out through SNMP on the Check_mk Enterprise edition I have installed for testing purposes. As I gone deeper into the root cause, the main difference between our RAW instance and the Enterprise is that RAW is installed in a Docker container.

Installed like described in this article https://geekflare.com/checkmk-monitoring/

I checked SNMPGET from the Docker container and this is not working, same check from the Ubuntu instance where the Docker container runs, works perfectly. The weird fact is that SNMP (all versions) is working from OMD/check_mk to other devices like firewall, temperature sensors, printers etc. Even more weird is the fact that switch 192.168.30.233 is being read out via SNMP but all other access switches are not.