Which components are required for establishing remote peering between two Virtual Cloud Networks (VCNs) in Oracle Cloud Infrastructure (OCI)?

Remote VCN peering connects two Virtual Cloud Networks (VCNs) in different Oracle Cloud Infrastructure (OCI) regions. For this to be successful, several components are mandatory. First, there must be two VCNs, each in a different region, with IP address spaces (CIDR blocks) that do not overlap. Each VCN must have a Dynamic Routing Gateway (DRG) attached. On each DRG, a Remote Peering Connection (RPC) component must be created. Finally, a connection is established between the two RPCs, which enables private traffic flow between the VCNs across regions. This entire setup ensures secure, private communication without traversing the public internet.

A. This is incorrect because it mentions a "single VCN," which is a contradiction. Remote peering requires two distinct VCNs. It also omits the essential Remote Peering Connection (RPC) component.

B. This is incorrect because VCN peering, whether remote or local, strictly requires non-overlapping CIDR blocks. It also incorrectly specifies a VPN gateway, which is used for Site-to-Site VPNs, not VCN peering.

C. This is incorrect because it describes VCNs in the "same region." Peering within the same region is called local peering and uses Local Peering Gateways (LPGs), not DRGs and RPCs.

1. Oracle Cloud Infrastructure Documentation, "Remote VCN Peering (Across Regions)". This document explicitly states the requirements: "The two VCNs in the peering relationship must not have overlapping CIDRs... A remote peering connection (RPC) is a component you create on the DRG attached to your VCN. The RPC's job is to act as a connection point for a remotely peered VCN."

2. Oracle Cloud Infrastructure Documentation, "Dynamic Routing Gateways (DRGs)". This source clarifies the DRG's role: "A DRG is the VCN's gateway for traffic going to... a peered VCN in another region."

3. Oracle Cloud Infrastructure Documentation, "Local VCN Peering (Within Region)". This source confirms why option C is incorrect by defining local peering: "Local VCN peering is the process of connecting two VCNs in the same region... To implement it, you need a local peering gateway (LPG) on each VCN in the peering relationship."