1. VPC Peering

A direct point-to-point connection between two VPCs that enables routing of traffic between them. It can be used in both the same and different regions.

  1. Operates on private IP addresses.
  2. Supports transitive routing only if explicitly set up (e.g., through route tables).
  3. Suitable for small-scale, directly connected networks.
  4. No additional costs beyond data transfer charges between VPCs.

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Use When:

  1. You need simple, direct connections between a few VPCs.
  2. Your architecture doesn't require transitive routing.
  3. Minimal latency and cost are critical.

Example: Connecting two VPCs in the same region for app and database communication.

What is Transitive Routing?

Transitive routing is a specific routing scenario where you connect multiple networks in a topology indirectly through a router/switch. Without transitive routing, networks or devices peered through a hub cannot reach one another.