With IPHost Network Monitor you can run simple snmp requests against a Fortinet device in your network.
fnVpnIKEStatus
fn Vpn IKE Status
1.3.6.1.4.1.12356.4.1.2.1.21
The status of the tunnel
Back to FORTINET-MIB MIB page.
IPHost Network monitor allows you to monitor fnVpnIKEStatus on Fortinet device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Fortinet access points right now.