>>firewall 防火墙
# 查看firewall防火墙状态
firewall-cmd --state
# 或者
systemctl status firewalld
# 打开防火墙
systemctl start firewalld
# 重启防火墙
firewall-cmd --reload
# 或者
systemctl reload firewalld
# 关闭防火墙
systemctl stop firewalld
# 开机自启动防火墙
systemctl enable firewalld
# 禁止开机启动防火墙
systemctl disable firewalld
# 查看已打开的端口
firewall-cmd --list-ports
# 打开端口
firewall-cmd --permanent --zone=public --add-port=80/tcp
# 关闭端口
firewall-cmd --permanent --zone=public --remove-port=80/tcp
# 重启防火墙
firewall-cmd --reload