单项选择题 What is the name of the VTP mode of operation that enables a switch to forward only VTP advertisements while still permitting the editing of local VLAN information?（）

单项选择题 Which command will show the MAC addresses of stations connected to switch ports?（）

单项选择题 QoS policies are applied on the switches of a LAN. Which type of command will show the effects of the policy in real time?（）