This is a simple bit of code you can paste into a PHP file to ban single Ips or Ranges by adding to the blocked_ips Array, it could be adapted for many uses.
PHP:
//// Add full IP or range as shown below. ////
$blocked_ips = array(
"10.20.30",
"11.12.13.14"
);
$sip = isset($_SERVER['HTTP_CLIENT_IP']) ? $_SERVER['HTTP_CLIENT_IP'] : isset($_SERVER['HTTP_X_FORWARDED_FOR']) ? $_SERVER['HTTP_X_FORWARDED_FOR'] : $_SERVER['REMOTE_ADDR'];
if (in_array(substr($sip, 0, strrpos($sip, '.')), $blocked_ips) || in_array($sip , $blocked_ips))
{
//// Add whatever code you want for banned IPs ////
die("Your IP has been banned from this page");
}