Please see this article to learn more about IP address ACL.

"Company-level ACL" helps you define a range of authorized IP addresses - and apply it to all users (except Administrator users).

You can manage "Company-level ACL" by following these steps:

1. Login using an account that has 'Administrator' privileges.
2. Click Settings on the top-right, and select Security Controls from the menu.
3. In the resulting page, click  Define allowed IP addresses (Company-level) link.
4. In the page that appears, enter desired IP address ranges using these guidelines.
5. IMPORTANT: To apply this range to all existing users (except Administrator users) - remember to check  Apply now to all current users  checkbox.
6. Click the "Save" button.