The Banned IPs module is useful when you want to prevent users with certain IP addresses from accessing or using your website in a certain way. This typically happens when a user posts offensive material on a website (e.g. on a forum), harasses site members or behaves in some other unwanted way. IP banning can also be used to restrict access to your websites from certain areas of the world. These bans can be set either for individual websites or globally for all websites in the system.
To learn how to enable the Banned IPs module, please see the Enabling IP banning topic.
Adding banned IPs can easily be performed by site administrators. The Banning an IP address topic describes how. To find out how to determine which IP a user you want to ban is using, please see the Finding an IP address topic.
The Banned IPs internals and API sub-chapter provides information about the database tables and classes used by the module and examples of how banned IPs can be managed using the API.
IP banning is usually used as a last resort and there are other modules which can help you deal with offensive content and keep your website clean. Please refer to the Modules -> Abuse report and Modules -> Bad words chapters of this guide to read more. If you only wish to temporarily kick a user from a website, the On-line users module provides a way to do so.