Проверка IP В диапазоне

ip check mask

function matchCIDR($addr,$cidr) {
    list($ip,$mask) = explode('/',$cidr);
    return (ip2long($addr) >> (32 - $mask) == ip2long($ip) >> (32 - $mask));
}


function cidr_match($ip, $range)
{
    list ($subnet, $bits) = explode('/', $range);
    $ip = ip2long($ip);
    $subnet = ip2long($subnet);
    $mask = -1 << (32 - $bits);
    $subnet &= $mask; # nb: in case the supplied subnet wasn't correctly aligned
    return ($ip & $mask) == $subnet;
}

matchCIDR ("192.168.1.200", "192.168.1.150/25");