31.3. Utilizing an Elastic IP Address

While each node in the cluster is able to discover other nodes in the cluster using the S3_PING protocol, all network traffic is over the internal private network. It is recommended to configure an Elastic IP, or static IP, for a single node, so that a consistent address is available for configuring the cluster, such as through the Administration Console, across restarts. If no Elastic IP is configured each instance will contain a randomized IP address on its public network whenever it is started.

Full instructions for configuring an Elastic IP address may be found in Amazon's Getting Started Guide.