To make several subnets reachable from outside your enterprise network, which type of route should be configured on the edge device?

Configuring an aggregate route on the edge device allows you to advertise multiple subnets as a single summarized route to external networks. This method reduces the number of routes that need to be managed and propagated to external peers, which not only conserves bandwidth but also simplifies routing tables.

When routes are aggregated, the edge device can represent several detailed subnets with a single entry. For example, instead of advertising individual routes for each subnet, you can configure an aggregate route that encompasses all of them. This is especially beneficial when dealing with large networks, as it enhances efficiency and performance while ensuring that the necessary subnets remain reachable from outside the enterprise.

This choice directly addresses the need to make several subnets accessible without overwhelming external peers with too many specific routes. Other route types such as generated routes or OSPF routes serve different purposes; for instance, generated routes are typically used for internal routing purposes, and OSPF routes relate to dynamic routing protocols rather than the aggregation of subnets for external announcement.