After setting up the iptables rules check them!
iptables -S
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
su
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
Reboot the Centos Linux system and check that the iptables rules persist.
