This feature blocks specified IP`s from accessing your website. To block a range of IP`s, the part of the IP after the beginning of the range should be left blank. For example, to block all IP`s in the 227.xxx.xxx.xxx range, you would enter 227, for range 227.125.xxx.xxx, the entry would be 227.125.
Please keep in mind that although the blocked IP`s will not be able to view any of your webpages, they will still show up in your Access Log, since a "403 - Forbidden" message is displayed for them by the web server.