Need to install firewalld in your system, run the following command as root access,


# yum install firewalld

Also install this graphical user interface tool firewall-config, 
# yum install firewall-config

Enable / Disable :

To enable a firewalld service to be started on bootup:
# systemctl enable firewalld.service

ln -s '/usr/lib/systemd/system/firewalld.service'
ln -s '/usr/lib/systemd/system/firewalld.service'

To disable a firewalld service to be started on bootup:
# systemctl disable firewalld.service

rm '/etc/systemd/system/dbus-org.fedoraproject.FirewallD1.service'
rm '/etc/systemd/system/'

Start/Stop  firewalld :

Start or stop or check the status of firewalld run the following commands,
# systemctl start firewalld

# systemctl status firewalld

# systemctl stop firewalld

firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled)
   Active: active (running) since Thu 2015-02-26 11:05:44 IST; 1s ago
 Main PID: 5741 (firewalld)
   CGroup: /system.slice/firewalld.service
           ├─5741 /usr/bin/python /usr/sbin/firewalld --nofork --nopid
           └─6012 /usr/bin/python /usr/sbin/firewalld --nofork --nopid

Another command is firewall-cmd to connect to the daemon
# firewall-cmd --state

To know the interface assigned to a zone,
# firewall-cmd --zone=public --list-interfaces

Also we can view the network zones currently active, 
# firewall-cmd --get-service

amanda-client bacula bacula-client dhcp dhcpv6 dhcpv6-client dns ftp
high-availability http https imaps ipp ipp-client ipsec kerberos kpasswd ldap
ldaps libvirt libvirt-tls mdns mountd ms-wbt mysql nfs ntp openvpn pmcd
pmproxy pmwebapi pmwebapis pop3s postgresql proxy-dhcp radius rpc-bind samba
samba-client smtp ssh telnet tftp tftp-client transmission-client vnc-server

To reload the firewall with out interrupting user connections run below command,
# firewall-cmd --reload

To Check firewalld version :
#  firewall-cmd --version
# firewall-cmd -V

Help :

Do you know more information about firewall,
#  firewall-cmd --help