防火墙相关

# 开启防火墙
systemctl start firewalld
# 关闭防火墙
systemctl stop firewalld
# 查看端口开放情况
firewall-cmd --list-ports
# 开放某个特定的端口
firewall-cmd --zone=public --add-port=81/tcp --permanent
# 关闭某个特定的端口
firewall-cmd --remove-port=80/tcp --permanent
# 更改配置后重启防火墙
systemctl reload firewalld