I followed these step but taks is failed with error appache service not running, while its was running, screen shot given.
Steps:
sudo yum install iptables-services
sudo systemctl start iptables
sudo systemctl enable iptables
sudo iptables -A INPUT -p tcp --destination-port 6100 -s 172.16.238.14 -j ACCEPT
sudo iptables -A INPUT -p tcp --destination-port 6100 -j DROP
sudo service iptables save