ANS-C01 Network Design Practice Question
A company is designing a multi-VPC architecture in a single AWS Region. The company has three VPCs: Production, Development, and Shared Services. They want to enable transitive routing between all VPCs while minimizing operational overhead. Which TWO solutions meet these requirements?
⚠ Common exam trap
The ANS-C01 exam often tests the misconception that VPC peering can support transitive routing if multiple peering connections are established, but the trap here is that VPC peering is strictly non-transitive, requiring a full mesh for multi-VPC communication, which increases operational overhead.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Use AWS Transit Gateway to connect all VPCs.
AWS Transit Gateway (Option C) serves as a central hub for transitive routing between all connected VPCs, eliminating the need for full-mesh peering. It automatically handles route propagation and attachment management, significantly reducing operational overhead. Option E also uses AWS Transit Gateway as the core, but connects VPCs via VPN attachments to an on-premises router that performs the inter-VPC routing. While this adds some overhead due to the on-premises component, it still provides transitive routing without requiring a full mesh of VPC-to-VPC connections, thus meeting the requirements. Options A and B require full meshes or many point-to-point connections, increasing overhead. Option D introduces an on-premises router but lacks a central hub for VPC-to-VPC routing without additional configuration.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Establish VPC peering connections between each pair of VPCs.
Why it's wrong here
VPC peering is not transitive; each pair must be peered individually, increasing operational overhead.
- ✗
Configure a VPN connection between each VPC.
Why it's wrong here
VPN connections between VPCs would also require full mesh and are not transitive.
- ✓
Use AWS Transit Gateway to connect all VPCs.
Why this is correct
Transit Gateway enables transitive routing between all attached VPCs.
- ✗
Configure AWS Direct Connect connections from each VPC to the same on-premises router.
Why it's wrong here
Direct Connect connections do not provide transitive routing between VPCs without additional routing configuration.
- ✓
Use Transit Gateway with VPN attachments to an on-premises router that performs routing between VPCs.
Why this is correct
This uses Transit Gateway for transitive routing, with on-premises routing as an option.
Go deeper
Related to this question
About these practice questions
One of 1,621 original ANS-C01 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This ANS-C01 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the ANS-C01 exam.