单项选择题
A.switchport dynamic auto switchport dynamic auto B.switchport access vlan 10 switchport mode dynamic desireable C.switchport mode trunk switchport nonegotiate D.Leave both ports with the default trunk settings
A.By default， native VLAN packets going out this port will be tagged. B.Without an encapsulation command， 802.1Q will be the default encapsulation if DTP fails to negotiate a trunking protocol. C.The interface will support the reception of tagged and untagged traffic. D.If the device connected to this port is not 802.1Q-enabled， it will not be able to handle 802.1Q packets.
A.PortFast， UplinkFast， and BackboneFast specific configurations are ignored in Rapid PVST mode. B.RSTP is enabled globally and uses existing STP configuration. C.Root and alternative ports transition immediately to the forwarding state. D.Convergence is improved by using sub-second timers for the blocking， listening， learning， and forwarding port states.