With IPHost Network Monitor you can run simple snmp requests against a Fortinet device in your network.
fgIpSessFromPort
fg Ip Sess From Port
1.3.6.1.4.1.12356.101.11.2.1.1.4
Source port number (UDP and TCP only) of the session
Back to FORTINET-FORTIGATE-MIB MIB page.
IPHost Network monitor allows you to monitor fgIpSessFromPort on Fortinet device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Fortinet WAN extenders right now.