For whatever reason, sometimes you need to disable the firewall on your CentOS server.
Below is the code necessary that you can run in SSH to disable the firewall.
service iptables save
service iptables stop
chkconfig iptables off
service ip6tables save
service ip6tables stop
chkconfig ip6tables off
Don’t Forget if your server is public facing (Ie, has a direct IP, is in the DMZ of a firewall or has lots of port ranges forwarded to it).
It is strongly recommended not to do the above as your opening your server to the entire world.