centos7.4 防火墙设置

1.关闭默认的firewall防火墙

1. systemctl stop firewalld.service #停止firewall
    
   systemctl disable firewalld.service #禁止firewall开机启动
    
   firewall-cmd --state #查看默认防火墙状态（关闭后显示notrunning，开启后显示running）
   

   　　

2.  

2.开启iptables

 
yum install iptables （根据centOS7的版本和内核，有些版本已经装过，可以跳过此命令）
 
yum install iptables-services
 
service iptables restart
 
chkconfig iptables on或者systemctl enable iptables.service开机自启</span>
3.编辑防火墙文件（开启了21,22,80,3306端口）
vim /etc/sysconfig/iptables
 

 
<span style="font-size:18px;"># sampleconfiguration for iptables service
 
# # you can edit thismanually or use system-config-firewall
 
# # please do not askus 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 21 -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 80 -j ACCEPT
 
-A INPUT -p tcp -m state --state NEW -m tcp --dport 3306 -j ACCEPT
 
-A INPUT -j REJECT --reject-with icmp-host-prohibited
 
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
 
COMMIT

　　

centos 需要开启此防火墙！