开启防火墙

systemctl start firewalld.service

防火墙开机启动

systemctl enable firewalld.service

关闭防火墙

systemctl stop firewalld.service

查看防火墙状态

firewall-cmd --state

查看现有的规则

iptables -nL
firewall-cmd --zone=public --list-ports

重载防火墙配置

firewall-cmd --reload

添加单个单端口

firewall-cmd --permanent --zone=public --add-port=81/tcp
firewall-cmd --permanent --zone=public --add-port=2020/tcp

添加多个端口

firewall-cmd --permanent --zone=public --add-port=8080-8083/tcp

删除某个端口

firewall-cmd --permanent --zone=public --remove-port=81/tcp

针对某个 IP开放端口

firewall-cmd --permanent --add-rich-rule="rule family="ipv4" source address="192.168.142.166" port protocol="tcp" port="6379" accept"
firewall-cmd --permanent --add-rich-rule="rule family="ipv4" source address="192.168.0.233" accept"

删除某个IP

firewall-cmd --permanent --remove-rich-rule="rule family="ipv4" source address="192.168.1.51" accept"

针对一个ip段访问

firewall-cmd --permanent --add-rich-rule="rule family="ipv4" source address="192.168.0.0/16" accept"
firewall-cmd --permanent --add-rich-rule="rule family="ipv4" source address="192.168.1.0/24" port protocol="tcp" port="9200" accept"

添加操作后别忘了执行重载

firewall-cmd --reload

关闭邮件服务（禁用25端口）

sudo systemctl stop dovecot
sudo systemctl stop postfix
sudo systemctl disable dovecot
sudo systemctl disable postfix

systemctl status postfix
lsof -i:25