PHP Function to Validate IP Address

Simple php function to validate IP address and check whether it is in private network range. Ip validation in php for easy validating of IPv4 address.

function validateIpAddress($ip) {
    if(strtolower($ip)==='unknown' || $ip=="") return false;
    $ip = ip2long($ip); // get ipv4 network address
    if($ip!==false && $ip!==-1) {
        $ip = sprintf('%u', $ip);
        // check private network range
        if ($ip >= 0 && $ip <= 50331647) return false;
        if ($ip >= 167772160 && $ip <= 184549375) return false;
        if ($ip >= 2130706432 && $ip <= 2147483647) return false;
        if ($ip >= 2851995648 && $ip <= 2852061183) return false;
        if ($ip >= 2886729728 && $ip <= 2887778303) return false;
        if ($ip >;= 3221225984 && $ip <= 3221226239) return false;
        if ($ip >;= 3232235520 && $ip <= 3232301055) return false;
        if ($ip >= 4294967040) return false;
    }
    return true;
}