ANS-C01 Question 246
Single answerYour organization has multiple AWS accounts, each with its own Amazon VPCs in different regions. You need to establish connectivity between these VPCs to enable communication for your applications while keeping costs low and ensuring ease of management. Additionally, the solution must support dynamic routing and scalability. Which option would best meet these requirements?
- A
Set up VPC peering between all VPCs across accounts and regions.
- B
Use AWS Transit Gateway to interconnect the VPCs across accounts and regions.
- C
Establish site-to-site VPN connections between the VPCs in all accounts.
- D
Leverage third-party SD-WAN solutions to connect the VPCs across accounts and regions.
Show answer and explanation
Correct answer: B
Explanation
AWS Transit Gateway is the most suitable solution for connecting multiple VPCs across accounts and regions. It simplifies connectivity by acting as a central hub, supports dynamic routing using Border Gateway Protocol (BGP), and scales easily to accommodate growing network requirements. Other options either lack scalability, increase management complexity, or are not cost-effective for this use case.
- A. Incorrect.
Using VPC peering can enable connectivity between VPCs, but it becomes complex and unmanageable at scale due to the need for manual setup and maintenance of peering connections between every pair of VPCs. Additionally, VPC peering does not natively support dynamic routing.
- B. Correct.
AWS Transit Gateway provides a central hub to manage inter-VPC and multi-account connectivity. It supports dynamic routing, scalability, and simplified management, making it the ideal choice for this scenario.
- C. Incorrect.
Site-to-site VPN can provide connectivity between VPCs, but it is not scalable for a large number of VPCs and accounts. It also adds latency and is not cost-effective compared to AWS-native solutions like Transit Gateway.
- D. Incorrect.
Third-party SD-WAN solutions can establish connectivity but require additional configuration, licensing, and management overhead. They are typically used for hybrid cloud scenarios rather than purely inter-VPC connectivity.