Which type of dynamic routing is used by default in VPCs?

In Google Cloud's Virtual Private Cloud (VPC), the default dynamic routing mode is regional routing. This means that routes are managed based on specific regions, ensuring that traffic within these regions is routed efficiently. Each region operates its routing independently, allowing for flexibility and optimized routing within the VPC network.

Regional routing supports the use of multiple routes in different regions and enables the use of VPC peering and interconnectivity between regions. This is particularly useful when dealing with hybrid or multi-cloud architectures where applications may span across different geographical locations.

In contrast to regional routing, global routing would allow more extensive routing configurations but is not the default mode in VPCs. Static routing refers to manually defined routes, while default routing typically involves predefined routes for general traffic but does not leverage the dynamic characteristics of regional routing. Thus, regional routing integrates the benefits of dynamic management while providing optimal performance for applications housed within a specific geographical region.