Centos7 View the open port corresponding to the firewall 
 View open ports 
 firewall-cmd --list-ports
 Open port 
 firewall-cmd --zone=public --add-port=80/tcp --permanent
  Command meaning :
 –zone # Scope 
 –add-port=80/tcp # Add port , The format is : port / Communication protocol 
 –permanent # Permanent effect , Failure after restart without this parameter 
 Remember to restart after opening the port 
 start-up :
 systemctl start firewalld
  stop it :
 systemctl stop firewalld
  restart :
 systemctl restart firewalld.service
  View status :
 systemctl status firewalld
  Boot up :
 systemctl enable firewalld.service
  Boot disabled :
 systemctl disable firewalld
  Check whether the service is started :
 systemctl is-enabled firewalld.service
  View the list of started services :
 systemctl list-unit-files|grep enabled
  View the list of services that failed to start :
 systemctl --failed
  View version :
 firewall-cmd --version
  view help :
 firewall-cmd --help
  Display status :
 firewall-cmd --state
  View all open ports :
 firewall-cmd --zone=public --list-ports
  Update firewall rules :
 firewall-cmd --reload
  View area information :
 firewall-cmd --get-active-zones
  View the area of the specified interface :
 firewall-cmd --get-zone-of-interface=eth0
  Reject all packages :
 firewall-cmd --panic-on
  Cancel reject status :
 firewall-cmd --panic-off
  Check whether to reject :
 firewall-cmd --query-panic
  to open up 80 port :
 firewall-cmd --zone=public --add-port=80/tcp --permanent 
(–permanent Permanent effect , Failure after restart without this parameter )
  see 80 port :
 firewall-cmd --zone=public --query-port=80/tcp
  delete 80 port :
 firewall-cmd --zone=public --remove-port=80/tcp --permanent
  Open port range :
 firewall-cmd --permanent --zone=public --add-port=8080-9999/tcp // permanent 
  Reload makes the configuration take effect immediately :
 firewall-cmd --reload
Technology