Adding a new node

I am trying to add a new node to the existing cluster of elasticsearch (v 2.3.4). I have public ip as well as private ip for the new virtual machine I have created.
In yml file, below changes are done myclustername I have tried both ip's along with port 9200 and 9300.
The new node is not getting added to the cluster. Is there any other setting I need to do?

You need to set on both nodes. Otherwise they can't communicate as they are only listening on by default.