You can use Rpm-qa | grep iptables to view, centos7 default firewall is firewalld,iptables should not be installed, you can use Yum install iptables-y to install.
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
3
The next thing is the same as using iptables, to open a port, (for example, 80 ports, red is the added rule) (
In a sequential order .):
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
############################## after adding firewall rules as shown below ##############################
# 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-j REJECT--reject-with icmp-host-prohibited
-A forward-j REJECT--reject-with icmp-host-prohibited
COMMIT
Restart Service
Systemctl Restart Iptables
Systemctl Enable Iptables.service #设置防火墙开机启动