How to monitor services using snmp

Hi

First up, I’m a newbie to LibreNMS.

Here’s the info you may need to help:

/opt/librenms/validate.php

====================================

Component Version
LibreNMS 1.68-38-gbbf394362
DB Schema 2020_09_24_000500_create_cache_locks_table (176)
PHP 7.3.20
Python 3.6.8
MySQL 10.3.17-MariaDB
RRDTool 1.7.0
SNMP NET-SNMP 5.8

====================================

[OK] Composer Version: 1.10.13
[OK] Dependencies up-to-date.
[OK] Database connection successful
[OK] Database schema correct

Output of:
./discovery.php -h HOSTNAME -d | ./pbin.sh
https://p.libren.ms/view/4ea46997

Output of:
./poller.php -h HOSTNAME -r -f -d | ./pbin.sh
is at the same URL as the discovery results except it ends in 66041c7b

I am successfully getting some stats using SNMP v3 from the CentOS 7 server I’m monitoring.

I see things like cpu, disk space, memory.

If I run this from the librenms server:
snmpwalk -v 3 -l authNoPriv -a SHA -A password -u user 192.168.1.59 .1.3.6.1.4.1.2021.2
I get the output in:
https://p.libren.ms/view/36089678

As you can see, the output contains this for example:
UCD-SNMP-MIB::prNames.1 = STRING: httpd
which I assume means that httpd is being monitored.

However, if I stop httpd on the server being monitored, I don’t see anything in the logs on the librenms server.

How can I get librenms to log the fact that a service like httpd has stopped?

I see references to UCD-SNMP-MIB in the poller and discovery output.

If I can find out how to do that, it’s sufficient for me.

As a secondary question, I do have a custom MIB. Is there an easy way to install that? It’s not essential.

Thanks in advance

Paul

Please don’t bother replying to my question. I only needed LibreNMS to capture SNMP traps and snmptrapd does what I need.