網上看到一個Linux防火牆規則示例，記錄下來，以備查用
sbin/iptables -P INPUT DROP
/sbin/iptables -I INPUT -p tcp–dport 80 -j ACCEPT
/sbin/iptables -I INPUT -p tcp–dport 22 -j ACCEPT
/sbin/iptables -A INPUT -j DROP
/sbin/iptables -A INPUT -j LOG
/sbin/iptables -A FORWARD -p tcp–syn -m limit–limit 1/s -j ACCEPT
/sbin/iptables -A FORWARD -p tcp –tcp-flags SYN,ACK,FIN,RST RST -m limit –limit 1/s -j ACCEPT
/sbin/iptables -A FORWARD -p icmp–icmp-type echo-request -m limit–limit 1/s -j ACCEPT
/etc/init.d/iptables save /etc/init.d/iptables restart