Transit Gateway acts as a central hub connecting multiple VPCs. Instead of mesh peering, everything connects to one hub.
Why Transit Gateway:
- VPCs full mesh: connections
- VPCs via Transit Gateway: connections
- Supports transitive routing
Components:
- Attachments: VPCs, VPNs, or Direct Connect
- Route tables: Control traffic flow
- Associations: Link attachments to tables
Segmentation: Use multiple route tables. Production and development in separate tables will not communicate unless you add routes.
Transit Gateway has hourly and data fees. Calculate costs before migrating.