This image shows two regions, each with one availability domain. The regions are connected by remote peering through dynamic routing gateways. Data Guard connects the Exadata database systems in each region using remote peering.

Region 2 contains 1 availability domain and 1 virtual cloud network (VCN). Exadata infrastructure spans the VCN. The Exadata infrastructure includes a non-production VM cluster and a disaster recovery (DR) VM cluster, each with database instances similar to those in Region 1.

Region 1 contains 1 availability domain and 2 fault domains. The region contains virtual cloud network (VCN) with two subnets. The VCN provides apps in each of the fault domains and Exadata infrastructure that spans the 2 fault domains and 2 subnets. The Exadata infrastructure includes a VM cluster that provides databases in each of the fault domains.

The VCN provides the following gateways:

• A dynamic routing gateway (DRG) provides private communications between the customer data center and the VCN by using site-to-site VPN and for secure communications between VCNs in different regions.
• A network address translation (NAT) gateway enables private resources in a VCN to access hosts on the internet, without exposing those resources to incoming internet connections.
• A remote peering gateway provides communications between subnet resources in different regions using private IP addresses.
• A service gateway provides access to regional services such as object storage
• A static routing connects the VCN and object storage in the Oracle Services Network

The VCN in region 1 provides two private subnets:

• Client private subnet: The on-premises data center communicates with the database in fault domain 1 by using the DRG. The NAT gateway provides access from the Internet to the database. The service gateway provides access from the subnet to cloud services.
• Backup private subnet: Provides a backup database in fault domain 2. The service gateway provides access from the subnet to cloud services and a static route provides access to object storage in the Oracle Services Network.

The Oracle Services network in region 1 provides regional services, object storage for the database in the backup subnet, and an Oracle service tenancy with an admin VCN that communicates with the backup subnet to allow Oracle Cloud operations such as the console operations and REST APIs.