CentOS 7.0 Enable Iptables firewall

CentOS 7.0 uses firewall as a firewall by default, and this is iptables firewall instead.

1. Close firewall:

Systemctl Stop Firewalld.service #停止firewall

Systemctl Disable Firewalld.service #禁止firewall开机启动

2. Install iptables Firewall

Yum Install iptables-services #安装

Vi/etc/sysconfig/iptables #编辑防火墙配置文件

# 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

: wq! #保存退出

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

============, what a wonderful dividing line ============

Iptables is a firewall under Linux, and it is also a service name.
Service iptables Status View Firewall state service iptables start Firewall service iptables stop shutdown firewall Service iptables Restart reboot firewall
Firewall opens specific ports:① file/etc/sysconfig/iptables② Add:-A rh-firewall-1-input-m State--state new-m tcp-p TCP--dport 8080-j ACCEPT ★ The number 8080 represents open 8080 ports, or it can be changed to other ports ★③ reboot the firewall---------------

Save the settings for the firewall serivce iptables save
View iptables rules and numbering iptables-nl--line-number
Closes all input FORWARD (forwarding) output of all ports iptables-p INPUT drop iptables-p FORWARD DROP iptables-p OUTPUT Drop


Open only 22 port iptables-a input-p TCP--dport 22-j ACCEPT iptables-a output-p TCP--sport 22-j
Parameter explanation: –A parameter is to add a rule –p specify what protocol, our common TCP protocol, and of course, UDP, for example, 53 port Dns–dport is the target port, when the data from the outside into the server for the target port –sport data from the server out, Use –J for the data source port is specified as ACCEPT-receive or DROP is not received
Prohibit an IP access iptables-a input-p tcp-s 192.168.1.2-j drop–s parameter is the source (that is, 192.168.1.2) after the rejection is the DROP

Delete rule iptables-d Input 2 Delete the rule for input chain number 2