#aws #vpc #transit #transit_gateway

In the case we have multiple VPCs, and peer them each others, so the network topology will be more complicated. So AWS Transit Gateway allows them to connect together.

Some specifications:

  • Transitive peering between thousands of VPC and on-premises, hub and spoke connection.
  • Work cross-region
  • Share Transit Gateway cross account by using RAM (Resource Access Manager) (*)
  • Can peer transit gateways cross accounts
  • Can limit what VPC can talk to what VPC by configuring Route Tables
  • Work with DX gateway, VPN connections
  • It it only service in AWS that supports IP Multicast
![[Drawing 2023-01-21 20.14.15.excalidraw 600x400]]

Use cases

Transit Gateway: Site to Site VPN ECMP

  • ECMP: Equal cost multiple path routing
  • It is routing strategy to allow to forward a package over multiple best path. (Noted)
  • Use case: Create multiple Site to Site VPN connections to increase the bandwidth. ![[Drawing 2023-01-21 20.21.23.excalidraw | 600x400]]

Share DX Connect between multiple accounts

Share a DX connection between multiple account and multiple VPCs

![[Drawing 2023-01-21 20.34.39.excalidraw 600x400]]