Steps to reproduce:
- Add monitoring of a pfSense host using the app/pfsense_snmp template
- Wait for data
- Compare value of system uptime in Zabbix and what's shown in the pfSense GUI
System uptime data in Zabbix shows how long the snmpd on the pfSense host has been running.
System uptime data in Zabbix should show how long it has been since the pfSense host booted.
The solution is to use HOST-RESOURCES-MIB::hrSystemUptime.0 instead of DISMAN-EVENT-MIB::sysUpTimeInstance.
Patch against master is attached.