Do Ports 9200 and 9300 Both Open?

Yes. Port 9200 is used by external systems to access CSS clusters, and port 9300 is used for communication between nodes.

The methods for accessing port 9300 are as follows:

• If your client is in the same VPC and subnet with the CSS cluster, you can access it directly.
• If your client is in the same VPC with but different subnet from the CSS cluster, apply for a route separately.
• If your client is in the different VPCs and subnets from the CSS cluster, create a VPC peering connection to enable communication between the two VPCs, and then apply for routes to connect the two subnets.