Once you install CentOS 7, you will understand there are many differences between CentOS 6 and 7, but however, some technical and people want to use old programs like “iptables” on CentOS 7. One of the programs which are not common on CentOS 7 is “iptables”. CentOS 7 comes with another firewall installed in it called “firewalld” which is known by any customer.
You are able to disable this new firewall and enable old known iptables on CentOS 7 again. Here I will show you how to do this.
We have to stop and disable firewalld service.
[root@test-lab ~]# systemctl stop firewalld
[root@test-lab ~]# systemctl mask firewalld
Then we should install iptables again on CentOS 7.
yum install -y iptables iptables-services
Once it is done, we have to enable and start it
systemctl enable iptables
systemctl start iptables
Now you are able to use old known iptables on CentOS 7 again, however, firewalld will give you more ability and better firewall options if you want to go professional.