Chapter 10 Install and System Administration for FortiOS 5.0 : Basic Administration : Administrators : Security Precautions : Idle time-out
  
Idle time-out
To avoid the possibility of an administrator walking away from the management computer and leaving it exposed to unauthorized personnel, you can add an idle time-out that will automatically log the user out if the web-based manager is not used for a specified amount of time. This will cause the administrator to log in to the device again in order to continue their work.
The time-out can be set as high as 480 minutes, or eight hours, although this is not recommend.
To set the idle time out - web-based manager
1. Go to System > Admin > Settings.
2. In the Administration Settings, enter the amount of time the Administrator login can remain idol in the Idle Timeout field.
3. Select Apply.
To set the idle time out - CLI
config system global
set admintimeout <minutes>
end
See Also
Security Precautions
Passwords
 
Disable admin services
Disable the console interface
Disable interfaces
SSH login time out
Administrator lockout
Idle time-out
Administrative ports
Segregated administrative roles