vi /etc/sysconfig/iptables 
-A INPUT -m state –state NEW -m tcp -p tcp –dport 80 -j ACCEPT（允許80埠通過防火牆） 
-A INPUT -m state –state NEW -m tcp -p tcp –dport 3306 -j ACCEPT（允許3306埠通過防火牆） 
特別提示：很多網友把這兩條規則新增到防火牆配置的最後一行，導致防火牆啟動失敗，正確的應該是新增到預設的22埠這條規則的下面

新增好之後防火牆規則如下所示：
###################################### 
# Firewall configuration written by system-config-firewall 
# Manual customization of this file is not recommended. 
*filter 
:INPUT ACCEPT [0:0] 
:FORWARD ACCEPT [0:0] 
:OUTPUT ACCEPT [0:0] 
-A
 
 INPUT -m state –state ESTABLISHED,RELATED -j ACCEPT 
-A INPUT -p icmp -j ACCEPT 
-A INPUT -i lo -j ACCEPT 
-A INPUT -m state –state NEW -m tcp -p tcp –dport 22 -j ACCEPT 
-A INPUT -m state –state NEW -m tcp -p tcp –dport 80 -j ACCEPT 
-A INPUT -m state –state NEW -m tcp -p tcp –dport 3306 -j ACCEPT 
 
-A INPUT -j REJECT –reject-with icmp-host-prohibited 
-A FORWARD -j REJECT –reject-with icmp-host-prohibited 
COMMIT 
#####################################
/etc/init.d/iptables restart  
     #最後重啟防火牆使配置生效