Docs : https://tecadmin.net/install-and-use-iptables-on-centos-rhel-7 Step 1. STOP And Disable Firewalld # systemctl stop firewalld # systemctl disable firewalld # systemctl is-enabled firewalld disabled Step 2. Install Iptables Service # yum install iptables-services # systemctl enable iptables # systemctl start iptables # systemctl is-enabled iptables enabled # systemctl status iptables