What routing feature ensures that Cloud Routers only advertise routes to/from their own region?

The feature that ensures Cloud Routers only advertise routes to and from their own region is known as regional routing. In Google Cloud, each Cloud Router operates within a specific region and is responsible for managing routes for virtual private cloud (VPC) networks in that region. This design ensures that route advertisements are contained within the relevant geographic area, which can enhance network efficiency, optimize performance, and simplify routing management within localized environments.

Regional routing is essential in multi-regional setups, where different services might be designed to operate independently within their own regions while still providing a coherent overall architecture. It prevents the unintended propagation of routes across regions, which could lead to traffic being routed inefficiently or incorrectly.

In contrast, global routing involves propagating routes across different regions, which is not applicable when you want to limit route advertisements strictly to a single region. Dynamic and static routing refer to the methods of how routes are learned and advertised but do not specifically address the regional confines of route advertisement that regional routing provides.