To successfully peer two Oracle Cloud Infrastructure (OCI) VCNs across different regions for disaster recovery purposes, what CIDR ranges should not overlap?

For successful peering of two Oracle Cloud Infrastructure (OCI) Virtual Cloud Networks (VCNs) across different regions, it is crucial that their CIDR ranges do not overlap. In the correct answer, VCN1 uses the CIDR block of 10.0.0.0/16, while VCN2 is assigned the CIDR block of 172.16.0.0/16. These two CIDR ranges are from distinct address spaces, meaning that they do not share any IP addresses.

The range 10.0.0.0/16 represents IP addresses from 10.0.0.0 to 10.0.255.255, while the range 172.16.0.0/16 encompasses addresses from 172.16.0.0 to 172.16.255.255. Since there are no overlapping IPs within these two ranges, they can be successfully peered without conflict. This is especially important in disaster recovery scenarios, where having distinct, non-overlapping IP addresses helps ensure seamless communication and data replication between the two VCNs.

In contrast, other choices illustrate potential overlapping or shared address ranges. For example, in option A, VCN1 and VCN