This post will show you how to use iptables on centos7. Centos7 has moved its firewall service to firewalld, away from iptables, but if you have been running centos for a while (I’ve been running iptables since I moved from ipchains), you will no doubt have a big list of iptables rules that you have crafted over time and rather than re-write all your rules its easy enough to keep using your existing rules from iptables on centos7 for now (you’ll have to re-write your firewall rules at some point in the future though)