查看哪些端口被打开 netstat -anp
关闭端口号:
iptables -A OUTPUT -p tcp --dport 端口号 -j DROP
打开端口号:
iptables -A OUTPUT -p tcp --dport 端口号 -j ACCEPT
上面的iptables配置后,只是临时生效,重启iptables后就会被重置。
使iptables配置永久生效,需要修改/etc/sysconfig/iptables
vi /etc/sysconfig/iptables
-A INPUT -m state –state NEW -m tcp -p tcp –dport 80 -j ACCEPT(允许80端口通过防火墙)
-A INPUT -m state –state NEW -m tcp -p tcp –dport 3306 -j ACCEPT(允许3306端口通过防火墙)
特别提示:很多网友把这两条规则添加到防火墙配置的最后一行,导致防火墙启动失败,正确的应该是添加到默认的22端口这条规则的下面
添加好之后防火墙规则如下所示:
######################################
# 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
#最后重启防火墙使配置生效