Frequently Used Linux
iptables Rules Examples
sources: wikipedia, geekstuff
by Patrick O'Connor
(Block all from IP)
-m limit: This uses the limit iptables extension
–limit 25/minute: This limits only maximum of 25 connection per minute.
–limit-burst 100: This value indicates that the limit/minute will be enforced only after the total number of connection have reached the limitburst level.
*filter :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [0:0] -A INPUT -i lo -j ACCEPT -A INPUT -d 127.0.0.0/8 ! -i lo -j REJECT --reject-with icmp-port-unreachable -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A INPUT -p tcp -m tcp --dport 80 -j ACCEPT -A INPUT -p tcp -m tcp --dport 443 -j ACCEPT -A INPUT -s 172.0.0.0/16 -p tcp -m tcp --dport 636 -j ACCEPT -A INPUT -s 192.168.1.0/24 -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT -A INPUT -s 192.168.2.10/32 -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT -A INPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT -A INPUT -m limit --limit 5/min -j LOG --log-prefix "iptables denied: " --log-level 7 -A INPUT -j REJECT --reject-with icmp-port-unreachable -A FORWARD -j REJECT --reject-with icmp-port-unreachable -A OUTPUT -j ACCEPT COMMIT