iptables -S
-P INPUT DROP
-P FORWARD DROP
-P OUTPUT ACCEPT
-N DMZ_INET_FORWARD_CHAIN
-N DMZ_INPUT_CHAIN
-N DMZ_LAN_FORWARD_CHAIN
-N EXT_ICMP_FLOOD_CHAIN
-N EXT_INPUT_CHAIN
-N EXT_OUTPUT_CHAIN
-N HOST_BLOCK
-N INET_DMZ_FORWARD_CHAIN
-N LAN_INET_FORWARD_CHAIN
-N LAN_INPUT_CHAIN
-N MAC_FILTER
-N RESERVED_NET_CHK
-N SPOOF_CHK
-N UPNP_FORWARD
-N VALID_CHK
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m state --state RELATED -m tcp --dport 1024:65535 -j ACCEPT
-A INPUT -p udp -m state --state RELATED -m udp --dport 1024:65535 -j ACCEPT
-A INPUT -p icmp -m state --state RELATED -j ACCEPT
-A INPUT -j HOST_BLOCK
-A INPUT -j SPOOF_CHK
-A INPUT -i eth0 -j VALID_CHK
-A INPUT -i eth0 -p ! icmp -m state --state NEW -j EXT_INPUT_CHAIN
-A INPUT -i eth0 -p icmp -m state --state NEW -m limit --limit 60/sec --limit-burst 100 -j EXT_INPUT_CHAIN
-A INPUT -i eth0 -p icmp -m state --state NEW -j EXT_ICMP_FLOOD_CHAIN
-A INPUT -m limit --limit 1/sec -j LOG --log-prefix "Dropped INPUT packet: " --log-level 6
-A INPUT -j DROP
-A FORWARD -i lo -j ACCEPT
-A FORWARD -o eth0 -p tcp -m tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
-A FORWARD -m state --state ESTABLISHED -j ACCEPT
-A FORWARD -p tcp -m state --state RELATED -m tcp --dport 1024:65535 -j ACCEPT
-A FORWARD -p udp -m state --state RELATED -m udp --dport 1024:65535 -j ACCEPT
-A FORWARD -p icmp -m state --state RELATED -j ACCEPT
-A FORWARD -j HOST_BLOCK
-A FORWARD -i eth0 -o ! eth0 -j UPNP_FORWARD
-A FORWARD -j SPOOF_CHK
-A FORWARD -i eth0 -j VALID_CHK
-A FORWARD -m limit --limit 1/min --limit-burst 3 -j LOG --log-prefix "Dropped FORWARD packet: " --log-level 6
-A FORWARD -j DROP
-A OUTPUT -o eth0 -p tcp -m tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
-A OUTPUT -m state --state ESTABLISHED -j ACCEPT
-A OUTPUT -j HOST_BLOCK
-A OUTPUT -f -m limit --limit 3/min -j LOG --log-prefix "FRAGMENTED PACKET (OUT): " --log-level 6
-A OUTPUT -f -j DROP
-A OUTPUT -o eth0 -j EXT_OUTPUT_CHAIN
-A EXT_ICMP_FLOOD_CHAIN -p icmp -m icmp --icmp-type 8 -m limit --limit 12/hour --limit-burst 1 -j LOG --log-prefix "ICMP-request(ping) flood: " --log-level 6
-A EXT_ICMP_FLOOD_CHAIN -p icmp -m icmp --icmp-type 8 -j DROP
-A EXT_ICMP_FLOOD_CHAIN -p icmp -m icmp --icmp-type 3 -m limit --limit 12/hour --limit-burst 1 -j LOG --log-prefix "ICMP-unreachable flood: " --log-level 6
-A EXT_ICMP_FLOOD_CHAIN -p icmp -m icmp --icmp-type 3 -j DROP
-A EXT_ICMP_FLOOD_CHAIN -p icmp -m icmp --icmp-type 4 -m limit --limit 12/hour --limit-burst 1 -j LOG --log-prefix "ICMP-source-quench flood: " --log-level 6
-A EXT_ICMP_FLOOD_CHAIN -p icmp -m icmp --icmp-type 4 -j DROP
-A EXT_ICMP_FLOOD_CHAIN -p icmp -m icmp --icmp-type 11 -m limit --limit 12/hour --limit-burst 1 -j LOG --log-prefix "ICMP-time-exceeded flood: " --log-level 6
-A EXT_ICMP_FLOOD_CHAIN -p icmp -m icmp --icmp-type 11 -j DROP
-A EXT_ICMP_FLOOD_CHAIN -p icmp -m icmp --icmp-type 12 -m limit --limit 12/hour --limit-burst 1 -j LOG --log-prefix "ICMP-param.-problem flood: " --log-level 6
-A EXT_ICMP_FLOOD_CHAIN -p icmp -m icmp --icmp-type 12 -j DROP
-A EXT_ICMP_FLOOD_CHAIN -p icmp -m limit --limit 12/hour --limit-burst 1 -j LOG --log-prefix "ICMP(other) flood: " --log-level 6
-A EXT_ICMP_FLOOD_CHAIN -p icmp -j DROP
-A EXT_INPUT_CHAIN -p tcp -m tcp --dport 0 -m limit --limit 6/hour --limit-burst 1 -j LOG --log-prefix "TCP port 0 OS fingerprint: " --log-level 6
-A EXT_INPUT_CHAIN -p udp -m udp --dport 0 -m limit --limit 6/hour --limit-burst 1 -j LOG --log-prefix "UDP port 0 OS fingerprint: " --log-level 6
-A EXT_INPUT_CHAIN -p tcp -m tcp --dport 0 -j DROP
-A EXT_INPUT_CHAIN -p udp -m udp --dport 0 -j DROP
-A EXT_INPUT_CHAIN -p tcp -m tcp --sport 0 -m limit --limit 6/hour -j LOG --log-prefix "TCP source port 0: " --log-level 6
-A EXT_INPUT_CHAIN -p udp -m udp --sport 0 -m limit --limit 6/hour -j LOG --log-prefix "UDP source port 0: " --log-level 6
-A EXT_INPUT_CHAIN -p tcp -m tcp --sport 0 -j DROP
-A EXT_INPUT_CHAIN -p udp -m udp --sport 0 -j DROP
-A EXT_INPUT_CHAIN -p udp -m udp --sport 67 --dport 68 -j ACCEPT
-A EXT_INPUT_CHAIN -p icmp -m icmp --icmp-type 8 -m limit --limit 3/min --limit-burst 1 -j LOG --log-prefix "ICMP-request: " --log-level 6
-A EXT_INPUT_CHAIN -p icmp -m icmp --icmp-type 3 -m limit --limit 12/hour --limit-burst 1 -j LOG --log-prefix "ICMP-unreachable: " --log-level 6
-A EXT_INPUT_CHAIN -p icmp -m icmp --icmp-type 4 -m limit --limit 12/hour --limit-burst 1 -j LOG --log-prefix "ICMP-source-quench: " --log-level 6
-A EXT_INPUT_CHAIN -p icmp -m icmp --icmp-type 11 -m limit --limit 12/hour --limit-burst 1 -j LOG --log-prefix "ICMP-time-exceeded: " --log-level 6
-A EXT_INPUT_CHAIN -p icmp -m icmp --icmp-type 12 -m limit --limit 12/hour --limit-burst 1 -j LOG --log-prefix "ICMP-param.-problem: " --log-level 6
-A EXT_INPUT_CHAIN -p tcp -m tcp --dport 1024:65535 ! --tcp-flags FIN,SYN,RST,ACK SYN -m limit --limit 3/min -j LOG --log-prefix "Stealth scan (UNPRIV)?: " --log-level 6
-A EXT_INPUT_CHAIN -p tcp -m tcp --dport 0:1023 ! --tcp-flags FIN,SYN,RST,ACK SYN -m limit --limit 3/min -j LOG --log-prefix "Stealth scan (PRIV)?: " --log-level 6
-A EXT_INPUT_CHAIN -p tcp -m tcp ! --tcp-flags FIN,SYN,RST,ACK SYN -j DROP
-A EXT_INPUT_CHAIN -p tcp -m tcp --dport 0:1023 -m limit --limit 6/min --limit-burst 2 -j LOG --log-prefix "Connection attempt (PRIV): " --log-level 6
-A EXT_INPUT_CHAIN -p udp -m udp --dport 0:1023 -m limit --limit 6/min --limit-burst 2 -j LOG --log-prefix "Connection attempt (PRIV): " --log-level 6
-A EXT_INPUT_CHAIN -p tcp -m tcp --dport 1024:65535 -m limit --limit 6/min --limit-burst 2 -j LOG --log-prefix "Connection attempt (UNPRIV): " --log-level 6
-A EXT_INPUT_CHAIN -p udp -m udp --dport 1024:65535 -m limit --limit 6/min --limit-burst 2 -j LOG --log-prefix "Connection attempt (UNPRIV): " --log-level 6
-A EXT_INPUT_CHAIN -p tcp -j DROP
-A EXT_INPUT_CHAIN -p udp -j DROP
-A EXT_INPUT_CHAIN -p icmp -j DROP
-A EXT_INPUT_CHAIN -m limit --limit 1/min -j LOG --log-prefix "Other-IP connection attempt: " --log-level 6
-A EXT_INPUT_CHAIN -j DROP
-A EXT_OUTPUT_CHAIN -j ACCEPT
-A RESERVED_NET_CHK -s 10.0.0.0/8 -m limit --limit 1/min --limit-burst 1 -j LOG --log-prefix "Class A address: " --log-level 6
-A RESERVED_NET_CHK -s 172.16.0.0/12 -m limit --limit 1/min --limit-burst 1 -j LOG --log-prefix "Class B address: " --log-level 6
-A RESERVED_NET_CHK -s 192.168.0.0/16 -m limit --limit 1/min --limit-burst 1 -j LOG --log-prefix "Class C address: " --log-level 6
-A RESERVED_NET_CHK -s 169.254.0.0/16 -m limit --limit 1/min --limit-burst 1 -j LOG --log-prefix "Class M$ address: " --log-level 6
-A RESERVED_NET_CHK -s 10.0.0.0/8 -j DROP
-A RESERVED_NET_CHK -s 172.16.0.0/12 -j DROP
-A RESERVED_NET_CHK -s 192.168.0.0/16 -j DROP
-A RESERVED_NET_CHK -s 169.254.0.0/16 -j DROP
-A SPOOF_CHK -j RETURN
-A VALID_CHK -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG FIN,PSH,URG -m limit --limit 3/min -j LOG --log-prefix "Stealth XMAS scan: " --log-level 6
-A VALID_CHK -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG FIN,SYN,RST,ACK,URG -m limit --limit 3/min -j LOG --log-prefix "Stealth XMAS-PSH scan: " --log-level 6
-A VALID_CHK -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG FIN,SYN,RST,PSH,ACK,URG -m limit --limit 3/min -j LOG --log-prefix "Stealth XMAS-ALL scan: " --log-level 6
-A VALID_CHK -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG FIN -m limit --limit 3/min -j LOG --log-prefix "Stealth FIN scan: " --log-level 6
-A VALID_CHK -p tcp -m tcp --tcp-flags SYN,RST SYN,RST -m limit --limit 3/min -j LOG --log-prefix "Stealth SYN/RST scan: " --log-level 6
-A VALID_CHK -p tcp -m tcp --tcp-flags FIN,SYN FIN,SYN -m limit --limit 3/min -j LOG --log-prefix "Stealth SYN/FIN scan(?): " --log-level 6
-A VALID_CHK -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG NONE -m limit --limit 3/min -j LOG --log-prefix "Stealth Null scan: " --log-level 6
-A VALID_CHK -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG FIN,PSH,URG -j DROP
-A VALID_CHK -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG FIN,SYN,RST,ACK,URG -j DROP
-A VALID_CHK -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG FIN,SYN,RST,PSH,ACK,URG -j DROP
-A VALID_CHK -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG FIN -j DROP
-A VALID_CHK -p tcp -m tcp --tcp-flags SYN,RST SYN,RST -j DROP
-A VALID_CHK -p tcp -m tcp --tcp-flags FIN,SYN FIN,SYN -j DROP
-A VALID_CHK -p tcp -m tcp --tcp-flags FIN,SYN,RST,PSH,ACK,URG NONE -j DROP
-A VALID_CHK -p tcp -m tcp --tcp-option 64 -m limit --limit 3/min --limit-burst 1 -j LOG --log-prefix "Bad TCP flag(64): " --log-level 6
-A VALID_CHK -p tcp -m tcp --tcp-option 128 -m limit --limit 3/min --limit-burst 1 -j LOG --log-prefix "Bad TCP flag(128): " --log-level 6
-A VALID_CHK -p tcp -m tcp --tcp-option 64 -j DROP
-A VALID_CHK -p tcp -m tcp --tcp-option 128 -j DROP
-A VALID_CHK -m state --state INVALID -j DROP
-A VALID_CHK -f -m limit --limit 3/min --limit-burst 1 -j LOG --log-prefix "Fragmented packet: "
-A VALID_CHK -f -j DROP