What is a characteristic of an IPv4 loopback interface on a Cisco IOS router?
- The no shutdown command is required to place this interface in an UP state
- It is a logical interface internal to the router
- Only one loopback interface can be enabled on a router
- It is assigned to a physical port and can be connected to other devices
Explanation: The loopback interface is a logical interface internal to the router and is automatically placed in an UP state, as long as the router is functioning. It is not assigned to a physical port and can therefore never be connected to any other device. Multiple loopback interfaces can be enabled on a router.