Diagnosing false alert from 1 server?

Help
1

I am new to LibreNMS. I am just assigned to help resolve a false alert that has been found on one particular server. I have tried poking around LibreNMS but I cannot find out what is the problem.

The error from this server is as below:
|2018-11-22 16:11:04 |System|Issued critical alert for rule ‘Devices up/down’ to transport ‘mail’|
|—|---|—|
| 2018-11-22 16:06:04 |System|Issued critical alert for rule ‘Devices up/down’ to transport ‘mail’|
| 2018-11-22 16:01:05 |System|Issued critical alert for rule ‘Devices up/down’ to transport ‘mail’|
| 2018-11-22 15:56:04 |System|Issued critical alert for rule ‘Devices up/down’ to transport ‘mail’|
| 2018-11-22 15:51:04 |System|Issued critical alert for rule ‘Devices up/down’ to transport ‘mail’|
| 2018-11-22 15:46:04 |System|Issued critical alert for rule ‘Devices up/down’ to transport ‘mail’|
| 2018-11-22 15:41:05 |System|Issued critical alert for rule ‘Devices up/down’ to transport ‘mail’|
| 2018-11-22 15:36:04 |System|Issued critical alert for rule ‘Devices up/down’ to transport ‘mail’|
| 2018-11-22 15:31:04 |System|Issued critical alert for rule ‘Devices up/down’ to transport ‘mail’|
| 2018-11-22 15:25:27 |System|Device status changed to Down from snmp check.|

However, the server is up. Can ping to this server manually without issue.

Would appreciate if someone could point me to right direction for this.

2

Here is a screenshot of the processes graph showing no graph recorded during that reported “downtime”.

image

3

In log it shows that snmp stopped responding not icmp. You need check see why snmp stopped working on that server.