What is AWS RAM?
AWS Resource Access Manager (RAM) helps you securely share your AWS resources across AWS accounts, within your organization, or with specific IAM roles and users. It avoids the need to create duplicate resources in every account.
Key Concepts
1. Resource Sharing
- Share resources like VPC Subnets, Transit Gateways, Route 53 Resolver Rules, and License Configurations.
2. Multi-Account Benefits
- Subnet Sharing: You can create a VPC in a central account and share subnets with other accounts. The other accounts can launch EC2 instances into those subnets, but cannot modify the VPC networking itself.
Exam Tips
[!IMPORTANT] "Share Subnets / Transit Gateways across accounts": The answer is AWS RAM.
[!TIP] It prevents resource duplication and simplifies invoice management (central owner pays for the resource).
Common Use Cases
- Shared VPC: Central IT manages the network (VPC/Subnets), and App Teams deploy instances into shared subnets.
- Centralized Licensing: Managing license quotas across the Org.