单项选择题 What speeds must be disabled in a mixed 802.11b/g WLAN to allow only 802.11g clients to connect?（）

单项选择题 Which port state is introduced by Rapid-PVST?（）

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?（）