/* Get the IP Address */
$iptosave = "1.2.3.4";
$iptosavefiltered = preg_replace('[^a-zA-Z0-9\.:]', '', $iptosave);

/* Save IPv4 / IPv6 address to the database.  In this example a varbinary(16) column called "ip" */
INSERT INTO ip_address (ip) VALUES ('" . inet_pton($iptosavefiltered) . "');

/* Read the IPv4 / IPv6 address from the database.  The question mark is the unique id of the row. */
SELECT ipa.ip FROM ip_address ipa WHERE ipa.id = ?;

/* Convert the ip address that was saved in the database */
$iptoread = ipv46presentationFromBinary($row["ip"]);

/* Show the human-readable ip address */
print $iptoread;

/* This function takes a binary encoded IPv4 or IPv6 address (stored in mySQL as varbinary(16)) and converts it into human readable form. */
function ipv46presentationFromBinary($binvalue) {
	/* For IPv6, avoid use of PHP's default inet_ntop behavior which is to convert an IPv4/IPv6 down to an approximate IPv4 address. */
	$assembledippresentation = "";
	$tmpconversion = inet_ntop($binvalue);
	/* IPv6 Address; special handling to avoid automatic down-conversion to an IPv4. */
	if (preg_match("/^:/", $tmpconversion)) {
		$frombinhex = bin2hex($binvalue);
		/* Add ":" notation */
		$charcount = 0; $segment = "";
		for ($a = 0; $a <= strlen($frombinhex); $a++) {
			$segment = $segment . substr($frombinhex, $a, 1);
			$charcount = $charcount + 1;
			if ($charcount == 4) {
				if (strlen($assembledippresentation) == 0) { $assembledippresentation = $segment; }
				else { $assembledippresentation = $assembledippresentation . ":" . $segment; }
				$charcount = 0; $segment = "";
			}
		}
		/* Replace "0000" with "0" */
		$assembledippresentation = str_replace("0000", "0", $assembledippresentation);
	}
	else {
		/* Assume IPv4 and use PHP's inet_ntop */
		$assembledippresentation = $tmpconversion;
	}
	return $assembledippresentation;
}