What type of static route specifies only the exit interface?

A static route that specifies only the exit interface is known as a directly attached route. This type of route allows the router to forward packets out of a specific interface without needing to specify a next-hop IP address. When a static route is configured in this manner, the router uses the interface to determine how to handle outgoing packets.

The router assumes that packets destined for a network reachable through that exit interface can be sent directly. This is particularly useful for routes within directly connected networks, where the exit interface provides a simple and efficient way to direct traffic without involving the next-hop addressing.

In contrast, other types of static routes require additional information, such as the next-hop IP address or explicitly defined networks. Recursive routes point to the next hop and rely on routing tables to determine the exit interface, while fully specified routes include both a next-hop IP address and an exit interface, thus providing complete route information. Next-hop routes focus on the IP address of the next device to forward packets to rather than an interface. Therefore, the distinction of a directly attached route being unique in specifying only an exit interface is what makes it the correct choice.