Chapter 18 Troubleshooting : ­Verifying FortiGate admin access security : Auditing and Logging
  
Auditing and Logging
Audit web facing administration interfaces. By default, FortiGate logs all deny action, you can check these actions by going to Log & Report > Event Log > System. This default behavior should not be changed. Also secure log files in a central location such as FortiCloud and configure alert email which provides an efficient and direct method of notifying an administrator of events. You can configure log settings by going to Log & Report > Log Config.
An auditing schedule should be established to routinely inspect logs for signs of intrusion and probing.