centos伺服器永久開啟端口
1.檢視防火牆狀态
systemctl status firewalld.service // 檢視
systemctl start firewalld // 開啟
systemctl stop firewalld // 關閉
2.檢視端口情況
firewall-cmd --list-all
3.打開端口
firewall-cmd --add-port=80/tcp --permanent
4.重新開機防火牆
sudo firewall-cmd --reload