關閉firewall：
systemctl stop firewalld.service #停止firewall
systemctl disable firewalld.service #禁止firewall開機啓動
yum install iptables-services #安裝iptables
vi /etc/sysconfig/iptables #編輯防火牆配置文件
# 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 -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
COMMIT
:wq! #保存退出
systemctl start iptables.service #啓動防火牆
systemctl stop iptables.service #停止防火牆
systemctl restart iptables.service #重啓防火牆
systemctl status iptables.service #查看防火牆狀態
systemctl enable iptables.service #設置開機啓動