Your EC2 has a Public and Private IP. Use the Private IP and create the applicable rule in your Security Group's Inbound settings.
Log-in to the AWS Management Console and navigate to EC2.
To get your Private IP, navigate to Instances. Select the EC2 instance and go to the Description tab. You will find the Private IP there.
To create a Security Group rule, go to Network and Security > Security Groups. Select the applicable security settings and add port 9200 using the Private IP.
EDIT: I suggest you just edit your existing Security Group instead of creating a new one. Each EC2 comes with a Security Group when it is created.
- Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/
- In the navigation pane, choose Security Groups.
- Select the security group used by the EC2 instance that you want to allow inbound port 9200.
- Once selected, in the Inbound Tab, choose Edit.
- Once the Edit inbound rule page opens, choose Add Rule. Here your can add port 9200 using the Private IP of the other EC2 instances.
Sample vaues when adding new security rule:
- Type: Custom TCP Rule
- Protocol: TCP
- Port Range: 9200
- Source: Custom IP 172.25.25.25/32