AWS Certified Advanced Networking – Specialty (ANS-C00) — Question 293

You have 3 VPCs that need to be able to pass traffic. In what two ways can you achieve this? (Choose two.)

Answer options

• A. Peer each VPC to every other VPC to create a full mesh peering.
• B. Peer them, VPC peering allows transitive peering as of December 2017.
• C. Call AWS to enable transitive peering.
• D. Create VPNs between them and adjust the routing tables accordingly.

Correct answer: A, D

Explanation

AWS VPC peering does not support transitive routing, meaning you cannot route traffic through an intermediate VPC to reach a destination VPC; therefore, a full-mesh peering configuration is required to connect all three. Alternatively, establishing VPN connections between the VPCs and updating the routing tables is another valid method to allow traffic flow. Transitive peering is fundamentally unsupported by AWS, and support cannot enable it manually.