When CentOS 7 was released, it was quickly obvious that CentOS and Red Hat had switched over to firewalld for its firewall control. Although its syntax is a bit easier to work with than iptables, some software out there has issues with it, such as Docker. Some just prefer to stick with the standard iptables syntax because it is what they know and what they are comfortable with. So, if you have CentOS 7 or RHEL 7 installed and want the old iptables back, this guide is for you.
First thing’s first, disable firewalld
# systemctl mask firewalld
Now, lets stop firewalld
# systemctl stop firewalld
It would be a good idea to go ahead and make sure that firewalld is masked and inactive, so lets do just that.
# systemctl status firewalld firewalld.service Loaded: masked (/dev/null) Active: inactive (dead)