Fortinet fortigate-100a Benutzerhandbuch

Whenever the IPS detects or prevents an attack, it generates an attack message. You 
can configure the FortiGate unit to add the message to the attack log and to send an 
alert email to administrators. You can configure how often the FortiGate unit sends 
alert email. You can also reduce the number of log messages and alerts by disabling 
signatures for attacks that your system is not vulnerable to (for example, web attacks 
when you are not running a web server). For more information on FortiGate logging 
and alert email, see 

If for any reason the IPS should cease to function, it will fail open by default. This 
means that crucial network traffic will not be blocked and the Firewall will continue to 
operate while the problem is resolved.

You can change the default fail open setting using the CLI:

config sys global

set ips-open [enable | disable]

end

Enable ips_open to cause the IPS to fail open and disable ips_open to cause the 

IPS to fail closed.