Add 'iptables' To CentOS 7
Install iptables:
yum install -y iptables-services
Gimme my iptables back:
systemctl mask firewalld
systemctl enable iptables
(and if you need ip6tables, add an extra enable line for it
Stop firewalld, start iptables
systemctl stop firewalld
systemctl start iptables
(and start ip6tables if you need it)
Make your iptables modification just like before and save with
iptables-save>/etc/sysconfig/iptables