Ctrl + V

$cmd = ssh2_exec($connection, 'iptables -t nat -A PREROUTING -p tcp --dport '.$port.' -j DNAT --to-destination '.$internalip.'; iptables -A FORWARD -s '.$internalip.' -p tcp --dport '.$port.' -j ACCEPT; service iptables save; service iptables reload');
}