On an edge router, you want to create a default route with a next hop to an external connection that is only available when you receive routes from the external provider. What type of route should you configure?

The appropriate choice for creating a default route on an edge router with a next hop that depends on received routes from an external provider is a generated route. A generated route is a specific route type that is automatically created by the routing protocol in response to metrics or conditions met, such as the presence of a certain external connection.

When you configure a generated route, the router dynamically adjusts its routing table based on the routes it learns from external sources. This is particularly beneficial in scenarios where an edge router has to rely on accessing an external provider's connectivity; the generated route allows the router to adapt its routing based on available external routes without needing manual adjustments.

Using static routes, in contrast, would mean manually defining the route, which does not allow for dynamic adjustment based on available external connections. Aggregate and primary contributing routes pertain more to summarizing multiple routes or managing route specificity rather than directly creating a default route dependent on external inputs. Hence, the use of a generated route is the suitable choice in this context, enabling the router to operate flexibly with respect to external route dependencies.