单项选择题
A. when all switches have the same BID as the root switch
B. when all switches have received the MAC address of each neighboring switch
C. when every enabled switch port has been assigned a unique identifier
D. when every operating switch port is in either the blocking or forwarding state
E. when all switches are in either client, server, or transparent mode
单项选择题 At a branch location, TestKing.com has deployed a non modular router that is equipped with two serial interfaces and two Ethernet interfaces.What additional equipment must be used to allow the branch office to connect to the central office by using an ISDN service?（）
单项选择题 At a branch location, TestKing.com has deployed a non modular router that is equipped with two serial interfaces and two Ethernet interfaces.What additional equipment must be used to allow the branch office to connect to the central office by using an ISDN service?（）
多项选择题 What are two results of entering the Switch(config)# vtp mode client command on a Catalyst switch?（）