1. Check the firewall status
systemctl list-unit-files|grep firewalld.service 或 systemctl status firewalld.service
2. Open
systemctl start firewalld.service
3. Stop
systemctl stop firewalld.service
4. Restart
systemctl restart firewalld.service
5. boot
systemctl enable firewalld.service
6. Never start the boot
systemctl disable firewalld.service
7. Check whether the boot from Kai
systemctl is-enabled firewalld.service;echo $?
8. enumerate all the boot from Kai Services
systemctl list-unit-files|grep enabled
9. Review the port has been opened
firewall-cmd --list-ports
10. Add the open port (firewall restart to take effect)
firewall-cmd --zone=public --add-port=80/tcp --permanent
--zone Scope
--add - port add a port number
--permanent permanent, then restart the machine without fail
11. Restart the firewall
firewall-cmd --reload
12. Firewall running state
firewall-cmd --state