SNMPd

Install package:

apt-get update; apt-get install snmpd

Edit config file: /etc/snmp/snmpd.conf

At top of file, comment out localhost and uncommon all hosts:

# Listen for connections from the local system only

#agentAddress udp:127.0.0.1:161

# Listen for connections on all interfaces (both IPv4 *and* IPv6)

agentAddress udp:161,udp6:[::1]:161

In the middle of the file, comment out default community strings and add your own

Also allow the network address(s) you want snmp to respond to

# rocommunity public default -V systemonly

# rocommunity6 public default -V systemonly

rocommunity ChangeMe 172.17.0.0/24

Restart Service:

sudo service snmpd restart

Extra Step: Setup Custom SNMP test

Install snmp-mibs-downloader:

Add non-free to end of entries in /etc/apt/sources.list (if not already there):

deb http://ftp.us.debian.org/debian/ stretch main non-free

deb-src http://ftp.us.debian.org/debian/ stretch main non-free

Then install:

apt-get update

apt-get install snmp-mibs-downloader

Install the mibs now:

sudo download-mibs

Update /etc/snmp/snmp.conf:

Change mibs : to #mibs : per the comment at the top of the file

Create script for what you want to monitor:

For example, create a script like this:

vim /usr/sbin/1minloadavg.sh

#!/bin/bash

awk '{print $1}' /proc/loadavg

Update /etc/snmp/snmpd.conf file to extend SNMP:

extend 1minloadavg /usr/sbin/1minloadavg.sh

or

extend updates /bin/cat /usr/local/bin/updates/NumUpdates.txt

Restart Service:

sudo service snmpd restart

Find your OID:

Walk the mibs, you can find your entry by it's proximity to the default hello world ones: