If like me you work in an environment where you have people who are attempting to circumvent your network security it helps to have a banner or disclaimer to warn them about the trouble they will get into if they’re caught. By default when you attempt to login to a FortiGate there is no warning message or login banner.
To enable the banner or disclaimer on a FortiGate (there is both a pre and post login disclaimer you can use) we firstly need to log into the CLI of the FortiGate and enter the following commands to enable the banner. You can substitute pre with post if you wish;
FG621B # config system global FG621B (global) # set pre-login-banner enable FG621B (global) # end
Now log into the web ui of FortiOS and go into System > Config > Replacement Messages once there we need to switch to the extended view and the login banners should be at the top of the list, you can edit the default message if you wish, once done click on Save.
Once you try and get the FortiGate via Terminal or Web Management you should get prompted with the Disclaimer message.