How to Enable/Disable Firewall on Linux Server

Enable/Disable/Stop/Start Firewall in CentOS/ RHEL or OEL 7 :

To disable firewalld, run the following command as root:

$ systemctl disable firewalld
$ systemctl enable firewalld
$ systemctl status firewalld

To stop firewalld, run the following command as root:

$ systemctl stop firewalld
$ systemctl start firewalld
$ systemctl status firewalld

Enable/Disable/Stop/Start Firewall in Linux:

To Disable / Turn off Linux Firewall, run the following command as root: 
 
$ /etc/init.d/iptables save
$ /etc/init.d/iptables stop
$ /etc/init.d/iptables status

To Enable / Turn on Linux Firewall

$ /etc/init.d/iptables start
$ /etc/init.d/iptables status