firewall-cmd - is the command line client of the firewalld daemon
To verify the status of the firewall service
$ sudo firewall-cmd --state
To check all the available zones in firewalld
$ sudo firewall-cmd --get-zones
To find out which is the default zone
$ sudo firewall-cmd --get-default-zone
To find a list of active zones and associated network interfaces
$ sudo firewall-cmd --get-active-zones
To find out if there are any rules listed in the active public zone
$ sudo firewall-cmd --list-all --zone="public"
To check the list of all available zones
$ sudo firewall-cmd --list-all-zones
To list all the available services in firewalld
$ sudo firewall-cmd --get-services
To add an existing service to the default zone
$ sudo firewall-cmd --add-service=https
To add a service permanently
$ sudo firewall-cmd --permanent --add-service=https
To reload the firewall
$ sudo firewall-cmd --reload
To migrate runtime settings to permanent
$ sudo firewall-cmd --runtime-to-permanent
To open a port in the public zone
$ sudo firewall-cmd --zone=public --add-port=<port_number>/udp
$ sudo firewall-cmd --zone=public --add-port=<port_number>/tcp
$ sudo firewall-cmd --zone=public --add-port=53/udp
$ sudo firewall-cmd --zone=public --add-port=53/tcp
To list open ports in firewalld
$ sudo firewall-cmd --list-ports
To display help options
$ firewall-cmd --help
To close or remove a port
$ sudo firewall-cmd --remove-port=5432/tcp
$ sudo firewall-cmd --reload
To list all rules
$ sudo firewall-cmd --list-all
To allow access to port 5432 only from IP 192.168.122.200
$ sudo firewall-cmd --permanent --zone=public --add-rich-rule 'rule
family="ipv4" source address="192.168.122.200" port port=5432 protocol=tcp
accept'
regards,
T.Dhanasekar
