Linux配置防火墙，开启80端口、3306端口

防火墙配置有关介绍。

1、编辑防火墙配置

vi /etc/sysconfig/iptables

-A INPUT -m state –state NEW -m tcp -p tcp –dport 80 -j ACCEPT（容许80端口经过防火墙） 
-A INPUT -m state –state NEW -m tcp -p tcp –dport 3306 -j ACCEPT（容许3306端口经过防火墙）

特别提示：不少网友把这两条规则添加到防火墙配置的最后一行，致使防火墙启动失败，正确的应该是添加到默认的22端口这条规则的下面

添加好以后防火墙规则以下所示：

###################################### 
# 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 
#####################################

2、重启

最后重启防火墙使配置生效

/etc/init.d/iptables restart