Oracle Cloud Infrastructure 2022 Architect Professional — Question 6
You have two Virtual Cloud Networks (VCN) that need to be peered. The set up is as follows:
The VCNs are in different tenancies.
Peering has to be via Local Peering Gateway (LPG) because one of the VCNs needs to be added to an existing Hub and Spoke configuration that consists of a hub and two spokes.
There is a CIDR overlap. The VCN that serves as the Hub VCN has a 172.19.0.0/16 CIDR prefix. The other VCN to be added as a Spoke VCN has a 172.19.128.0/17 CIDR prefix.
The other two spokes have 10.0.0.0/16 and 192.168.0.0/16 prefixes, respectively.
What is a possible solution to this problem?
Answer options
- A. Use Dynamic Routing Gateway (DRG) instead.
- B. Add another CIDR prefix to the VCN that is integrating with the Hub and Spoke and does not overlap. Use that CIDR for the LPG connection.
- C. Review the subnets in the hub VCN. If they all have the third octet under 128, change the VCN prefix to /17.
- D. Review the subnets in the hub VCN. If they all have the third octet above 128, change the VCN prefix to /17.
- E. Review all subnets in the hub VCN. If one of them has the third octet at 128, change the VCN prefix to /17.
Correct answer: B
Explanation
The correct answer is B because adding a non-overlapping CIDR prefix allows the VCN to establish peering without address conflicts. Option A is incorrect as using a DRG does not resolve the CIDR overlap issue. Options C, D, and E suggest modifying the VCN prefix based on subnet conditions, which does not address the need for a new, non-overlapping CIDR for successful peering.