AWS Certified Advanced Networking – Specialty (ANS-C01)Network DesignMedium
A company is deploying a new microservices application across multiple VPCs in different AWS accounts, all within the same region. Each microservice needs to communicate with other microservices without exposing them to the public internet, and the network architecture should minimize the number of direct network connections. The solution must also allow for central network visibility and control. Which AWS service is ideal for connecting these microservices VPCs?
- AAWS PrivateLink
- BAWS VPN CloudHub
- CVPC Peering
- DAWS Transit Gateway
Show answer & explanationAnswer & explanation
Correct answer: D. AWS Transit Gateway
AWS Transit Gateway acts as a central hub for connecting multiple VPCs (even across accounts) in a region, simplifying routing and reducing the number of connections compared to VPC peering. It provides central network visibility and control, meeting the requirements for microservices communication within a private network.
Why the other options are wrong
- A. AWS PrivateLink provides private connectivity to specific *services* (either AWS services or your own service endpoints), not general VPC-to-VPC connectivity for all microservices.
- B. AWS VPN CloudHub is for connecting multiple on-premises VPNs to a single VGW, not for connecting multiple VPCs to each other.
- C. VPC Peering creates 1:1 connections, which doesn't scale well for hundreds of VPCs and complicates central control.
Multi-VPC Connectivity with TGW
Using AWS Transit Gateway as a central network hub to interconnect multiple VPCs across different AWS accounts and organizations, simplifying routing and centralizing network management.
- Provides a hub-and-spoke model for VPC connectivity, reducing N-squared peering connections.
- Supports inter-account and inter-region VPC connections.
- Enables centralized routing, network visibility, and security controls.
- Ideal for complex, distributed applications like microservices across many VPCs.
Memory trick: Transit Gateway is the central traffic controller for all your VPCs.