Which answers list an advantage of controller-based networks versus traditional networks? (Choose two answers.)

Which answers list an advantage of controller-based networks versus traditional networks? (Choose two answers.)

• The ability to configure the features for the network rather than per device
• The ability to have forwarding tables at each device
• Programmatic APIs available per device
• More consistent device configuration

Explanation: Controller-based networks use a controller that communicates with each network device using a southbound interface (an API and protocol). By gathering network information into one central device, the controller can then allow for different operational models. The models often let the operator think in terms of enabling features in the network, rather than thinking about the particulars of each device and command on each device. The controller then configures the specific commands, resulting in more consistent device configuration.

For the incorrect answers, both the old and new models use forwarding tables on each device. Also, controllers do not add to or remove from the programmatic interfaces on each device, some of which existed before controllers, but rather supply useful and powerful northbound APIs.