EDB Ark creates and manages clusters that reside on Amazon-hosted virtual private clouds (VPCs). A VPC is similar in structure to a traditional network, but provides the scalability and ease of maintenance offered by cloud computing.A VPC is an isolated network with a unique IP address range and subnet addresses. When deploying a cluster, you can use the Ark console to select the VPC on which the new cluster will reside, or choose to have Ark create a new VPC. Please note that private subnets and IPs are supported only on Amazon hosts.To create a new cluster that resides on a private subnet, log into the Ark console and click the Launch DB Cluster button. Use the Create a new Server Cluster dialog (see Figure 2.5) to provide details about the cluster configuration. Check the box to the left of Use Private IP addresses to display only those VPCs which have a NAT gateway configured to support private subnets in the VPC field. Then, use the VPC drop-down menu to select a VPC. After completing the fields on the Step 1 tab, click Next to continue to the Step 2 tab (see Figure 2.6).The Step 2 tab displays one availability zone/subnet pair for each node of the cluster; you can specify a unique availability zone and subnet for each node. If the SUBNET field specifies Create New Subnet, the EDB Ark console will deploy the node in a new subnet. Click Next to continue to the Step 3 tab (see Figure 2.7).Fields on the Step 3 tab allow you to specify your preferences for cluster backups. After completing the Step 3 tab, click the Launch button to create the new cluster on a virtual machine in the specified VPC network.For detailed information about deploying a cluster, please see the EDB Ark Getting Started Guide, available via the Ark console dashboard.Please note: if you use private IP addresses, the master instance is not assigned an elastic IP address. Should a failover occur, the IP address of the master instance will change.You can deploy the Ark console on a VPC, and use a network address translation (NAT) gateway to provide access to services outside of the VPC. The NAT gateway allows an instance without a public IP address to securely access services and resources such as yum repositories. For more information about using a NAT gateway, visit:When the Ark console is deployed in a private subnet (or without a public IP address), the console can only communicate with private networks in its own VPC or peered VPCs. Clusters are restricted to deploying into VPCs that have a peering connection to the VPC in which the console is deployed, and the console's VPC.A peering connection allows you to route traffic between two virtual private clouds without exposing the clouds to outside connections. For detailed information about using peering, visit:Please note: when the Ark console is deployed in a private subnet, the Use Private IP addresses option is always true.