After setting up the iptables rules check them!
At this stage your iptables rules should be showing.
Next iptables needs to be installed as a service and then the iptables service needs to be started on reboot. Then rules need to be saved so that they persist on reboot
Change to root
Install ‘iptables-services’ package
yum install iptables-services
Enable iptables as a system service
systemctl enable iptables
Enable iptables service to start on system startup
systemctl start iptables
Save the iptables rules
service iptables save