Login banners are a great way of explicitly asking users if they are authorized to log in, show your legal terms, or just leave a message for users when they log in such as ‘don’t forget to backup the configuration’ .. etc.
In Fortigate login banners are very easy to write and enable. Just a few options need to be tweaked.
The banner can be modified by going to – system – config – replacement messages. Select the extended view at the top right, and then you will see the login banner, both pre and post. Pre is show before you login, post is shown after. The messages can differ. After you modify the message, remember to save.
Switch to extended:
Now we need to enable the banner to show in CLI – to do this modify the global settings .
Now the banner will prompt.
If Pre-login-banner is enabled the banner will show as soon as you go to the page to login – before you even get prompted to log in. Post will prompt after login. This is what the banner looks like: