SNMP - Configure SNMP service for Linux

Introduction

SNMP configuration on Linux may be complex.

Many documentation exist on Internet but they describe so many different methods it makes it difficult to identify THE best way to do it.

This article will try to identify a kind of procedure to install and configure the service.

Useful links

• SNMP et la supervision.
• snmpusm man page.
• Configure an SNMP daemon and client on Ubuntu 18.04.
• net-snmp documentation on SourceForge.
• Doc UbuntuFr sur le SNMP.
• Configuration de l’agent SNMP V3 Unix.
• ...

Useful tools

• snmpwalk.
• Paessler SNMP Tester.

Install and configure the service

Note: for the moment let's focus on SNMPv3. SNMPv2 should be documented later on.

Ubuntu / Debian

Useful packages:

• snmp
• snmpd
• libsnmp-dev
• snmp-mibs-downloader

Dependencies:

• libsnmp-base
• libsnmp35:amd64

Packages installation:

apt-get install snmp
apt-get install snmpd
apt-get install libsnmp-dev
apt-get install snmp-mibs-downloader

Service stop:

systemctl stop snmpd.service

Service configuration:

vi /etc/snmp/snmpd.conf
...
sysLocation    <location description>
sysContact     <your sysops contact>
...
agentaddress  127.0.0.1,[::1],<IP of your server>
...

net-snmp-config --create-snmpv3-user

Note regarding the use of MIBS downloader: to use it, comment the line in /etc/snmp/snmp.conf:

# mibs :

Note regarding the user creation: not sure this behavior is systematic but you may have to add such a line to /etc/snmp/snmpd.conf for your user to be properly created at service restart. This line may be deleted from /etc/snmp/snmpd.conf after service restart.

createUser username (MD5|SHA|SHA-512|SHA-384|SHA-256|SHA-224) authpassphrase [DES|AES] [privpassphrase]

Service start:

systemctl start snmpd.service

Note: think about allowing flows on the firewall you use on or around the system.