With IPHost Network Monitor you can run simple snmp requests against a Fortinet device in your network.
fnSysMonCPUUsage
fn Sys Monitor CPU Usage
1.3.6.1.4.1.12356.1.1.6.1
The current CPU usage statistics in percentage
Back to FORTINET-MIB MIB page.
IPHost Network monitor allows you to monitor fnSysMonCPUUsage on Fortinet device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Fortinet firewalls right now.