Centos7关闭默认防火墙firewall和启用iptables操作

1.关闭防火墙：sudo systemctl stop firewalld.service
2. 关闭开机启动：sudo systemctl disable firewalld.service
3.安装iptables防火墙
sudo yum install iptables-services
4. 设置iptables防火墙开机启动：sudo systemctl enable iptables
或者systemctl enable iptables.service

5.禁用22端口添加指定ip访问指定端口

vim  /etc/sysconfig/iptables

-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j DROP
-A INPUT -s 192.168.255.13 -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT
6.重启防火墙：systemctl restart iptables