ipAddress=$_SERVER['REMOTE_ADDR'];
$macAddr=false;
#run the external command, break output into lines
$arp='arp -a $ipAddress';
$lines=explode("\n", $arp);
#look for the output line describing our IP address
foreach($lines as $line)
{
$cols=preg_split('/\s+/', trim($line));
if ($cols[0]==$ipAddress)
{
$macAddr=$cols[1];
}
}
echo $macAddr;
No está funcionando en el servidor.