問題文
An engineer says that an interface is northbound. What does that indicate?
選択肢
- It faces upward from the controller toward the applications, which use it to express what they need from the network.
- It faces downward from the controller toward the forwarding devices, and it is the interface over which the state that determines how each device treats arriving traffic is actually written into that device by the controller.
- It is the interface used by operators to log in to the controller, so an application must drive the network by opening the same session a human operator uses.
- It connects two controllers in a cluster to each other, which makes the direction meaningless in any deployment that runs a single controller.