Transit Gateway
Transit Gateway is an AWS service that simplifies and centralizes network connectivity between multiple VPCs, VPN connections, and on-premises networks. It acts as a hub that connects various VPCs and remote networks. Supports both inbound and outbound traffics.

1. Common Use Case
- You need a scalable, fully managed solution to connect many VPCs and on-premises networks.
- Your architecture requires transitive routing between VPCs and hybrid environments.
- Simplicity and centralized control without the overhead of managing third-party appliances are desired.
Example
Centralized hub for an organization with multiple VPCs across different accounts and regions.
2. Transit Gateway vs Transit VPC
- Transit Gateway: Preferred for modern cloud architectures due to its AWS-managed nature, scalability, and ease of use.
- Transit VPC: Still a valid option when specific third-party VPN or networking tools are needed but comes with higher maintenance and complexity.
3. Advantages of AWS Transit Gateway over Transit VPC
- Simplified Management: Eliminates the complexity of managing VPN connections for hundreds of VPCs.
- No EC2 Dependency: Removes the need for EC2-based VPN appliances, as AWS manages the routing infrastructure.
- High Availability: Provides built-in Multi-AZ redundancy and high availability without user intervention.
- High Performance: Offers inter-VPC communication with burst speeds of up to 50 Gbps per Availability Zone.
- Cost-Efficient Pricing: Streamlines costs with a straightforward per hour and per GB transferred pricing model.
- Reduced Latency: Avoids EC2 proxies and VPN encapsulation, reducing overhead and latency.
4. List of Gateways in AWS
- Networking Gateways
- Storage Gateways
7. AWS Storage Gateway - Application Integration Gateways
7. Amazon API Gateway - Hybrid and Edge Gateways
8. Direct Connect Gateway