I need to stop multiple login from same computer even for different user. This is why need client machine's unique identifier or mac address. How can achieve this? I have tried following but not work. Its return NULL
$ip = $_SERVER['REMOTE_ADDR'];
$x = shell_exec('arp -a ' . escapeshellarg($ip));
I need this feature that will work on all browser. Any Idea?
I have seen some solution only work in IE. But how can get solution in all modern browsers?