pfSense is shipped with bsnmpd that does not have support to SNMPv3. We do no want our messages moving around without encryption and to enable SNMPv3 we need to install an extra package and add extra configuration as well.
1) Installing Net-SNMP
System > Package Manager and install the below package.
2) SNMPv3 Configuration
Services > SNMP (NET-SNMP) > General enable the service and bind it to an IP address and port.
In the host information tab set the General Information as desired and leave the rest as default.
Users tab and click on the +Add button to create a new user.
Our user will have read only rights.
Next step we will set the user authentication.
Click on the save button to add the user.
3) Enabling SNMPv3 Service
pfSense is shipped with bsnmpd as its default SNMP agent server and to have net-snmpd running we need to stop the default SNMP agent server.
Services > SNMP disable it.
4) Adding to LibreNMS
Under the SNMP settings of your device set as the picture below.
With the steps above we have succesfully configured our firewall to transmit SNMP messages with encryption and privacy. In the next article we will learn how to send our firewall's log to a syslog server.