With IPHost Network Monitor you can run simple snmp requests against a Fortinet device in your network.
fgIntfObjectGroup
fg Intf Object Group
1.3.6.1.4.1.12356.101.100.16
Objects pertaining to the inteface table of FortiGate device.
Back to FORTINET-FORTIGATE-MIB MIB page.
IPHost Network monitor allows you to monitor fgIntfObjectGroup 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.