单项选择题
What is the function of the command switchport trunk native vlan 999 on a？（）
A.It designates VLAN 999 for untagged traffic. B.It blocks VLAN 999 traffic from passing on the trunk. C.It creates a VLAN 999 interface. D.It designates VLAN 999 as the default for all unkown tagged traffic.
单项选择题 Refer to the exhibit. What can be determined about the router from the console output?（）
单项选择题 What is the most efficient summarization that R1 can use to advertise its networks to R2（）。
多项选择题 Which two statements describe the Cisco implementation of VLANs? （）
