1. In the administration panel, go to Add-ons > Manage Add-ons.
2. Change the status of the Access restrictions add-on to Active and click on its settings button (the button with the cogwheel icon).
3. In the opened window Settings: Access restrictions, specify the settings for this add-on.
   

   
   
   

4. In the administration panel, go to Add-ons > Access restrictions.
5. On the opened page, add to the IP or Domain sections the IPs or domain names that should be disabled.