The controller is the core component of SDN. The controller connects to the device through the southbound interface. Which of the following belong to the controller southbound protocol? (Multiple Choice)

As shown in the figure, all four switches run STP, and various parameters adopt default values. If the G0/0/2 port of switch C is blocked and the configuration BPDU cannot be sent through this port, how long will it take for the blocked port in the network to enter the forwarding state?

In the network shown in the figure below, all routers run OSPF protocol, which device is ABR? (Multiple choice)

VRP operating platform, which of the following commands can only view static routes?

Broadly speaking, which of the following does the transmission medium that constitutes the wireless local area network wlan not include?