Difference between direct connect gateway and transit gateway

A Direct Connect gateway (DX gateway) and a Transit Gateway (TGW) are two different AWS services that are used to connect networks in different regions and VPCs (Virtual Private Clouds).

Here are some key differences between Direct Connect gateway and Transit Gateway:

1. Purpose: The Direct Connect gateway is used to establish a dedicated, private network connection between an on-premises data center and a VPC in a specific region. In contrast, the Transit Gateway is used to connect multiple VPCs and remote networks across multiple regions in a hub-and-spoke architecture.
2. Scale: Direct Connect gateway is typically used for a smaller number of VPCs and network connections, whereas Transit Gateway is designed to scale for larger, more complex networks with many VPCs and connections.
3. Routing: Direct Connect gateway provides a simple, static routing solution for a single VPC, while Transit Gateway provides dynamic routing between multiple VPCs and remote networks.
4. Connectivity: Direct Connect gateway provides a dedicated, private network connection between an on-premises data center and a single VPC, while Transit Gateway enables connections between multiple VPCs, remote networks, and other Transit Gateways.

In summary, Direct Connect gateway is used for point-to-point connections between an on-premises data center and a single VPC, while Transit Gateway is used for connecting multiple VPCs and remote networks in a hub-and-spoke architecture.

Transit Gateway supports connecting on-premises networks to VPCs in AWS. You can establish connectivity between your on-premises network and a Transit Gateway using a VPN connection or AWS Direct Connect.

To establish a VPN connection between your on-premises network and Transit Gateway, you can use an Amazon Web Services (AWS) Site-to-Site VPN connection. You can configure a Site-to-Site VPN connection to create an IPsec VPN tunnel between your on-premises network and a Transit Gateway. Once the VPN connection is established, traffic can flow between your on-premises network and the VPCs connected to the Transit Gateway.

Alternatively, you can use AWS Direct Connect to establish a dedicated network connection between your on-premises network and AWS. You can then use Transit Gateway to connect the on-premises network to the VPCs. This provides a faster, more reliable connection compared to VPN, and allows you to transfer large amounts of data between your on-premises network and the VPCs.

In summary, Transit Gateway supports connecting on-premises networks to VPCs in AWS using VPN or Direct Connect.