/sbin/iptables -N DROP_UDP_SUSPICIOUS /sbin/iptables -A DROP_UDP_SUSPICIOUS -p udp --sport 0:21 -j DROP /sbin/iptables -A DROP_UDP_SUSPICIOUS -p udp --dport 0:21 -j DROP /sbin/iptables -A INPUT -i ! lo+ -p udp -j DROP_UDP_SUSPICIOUS /sbin/iptables -A FORWARD -p udp -j DROP_UDP_SUSPICIOUS /sbin/iptables -A OUTPUT -p udp -j DROP_UDP_SUSPICIOUS