Filter Access by IP Address

This is a code snippet to keep unwanted visitors out while a site is under construction or being updated. The associative array helps to keep record of the identity of the user’s IP instead of just a collection of numbers with no semantic association. The $filter_ips value makes it easy to toggle the filtering on/off.

// ---	Filter vitsitor's IP address and bounce those not in the list.
$bounce_url 	= '/maintenance.php';
$filter_ips 	= true;
$allow_ips 	= array (
	'ORG: Firstname Lastname' 	=> ''
if ( $filter_ips && !in_array ( $_SERVER[ 'REMOTE_ADDR' ], $allow_ips ) ) {
	header ( "location: $bounce_url" );
	exit ();

It’s also helpful to output the user’s IP address on your bounce page so user’s trying to gain access can easily copy/paste their IP to send to you:

<?php echo $_SERVER[ 'REMOTE_ADDR' ]; ?>