CentOS7中使用iptables

1、关闭firewall：

systemctl stop firewalld.service #停止firewall
systemctl disable firewalld.service #禁止firewall开机启动

2、安装iptables防火墙

#安装
yum install iptables-services

3、编辑防火墙配置文件

vi /etc/sysconfig/iptables
# sample configuration for iptables service
# you can edit this manually or use system-config-firewall
# please do not ask us to add additional ports/services to this default configuration
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
 
-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 21 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 20 -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    

4、重启iptables并设置开机启动

systemctl restart iptables.service #最后重启防火墙使配置生效
 
systemctl enable iptables.service #设置防火墙开机启动

5、关闭SELINUX

#SELINUX=enforcing #注释掉
#SELINUXTYPE=targeted #注释掉
SELINUX=disabled #增加

6、如果是立即生效则是：

setenforce 0 #使配置立即生效