Chapter 10 Install and System Administration for FortiOS 5.0 : Monitoring : SNMP : SNMP configuration settings
  
SNMP configuration settings
Before a remote SNMP manager can connect to the FortiGate agent, you must configure one or more FortiGate interfaces to accept SNMP connections by going to System > Network > Interface. Select the interface and, in the Administrative Access, select SNMP.
For VDOMS, SNMP traps can only be sent on interfaces in the management VDOM. Traps cannot be sent over other interfaces outside the management VDOM.
To configure SNMP settings, go to System > Config > SNMP.
See Also
Gigabit interfaces
SNMP agent
SNMP community
Enabling on the interface
Fortinet MIBs
SNMP get command syntax