单项选择题
Which type of cable is used to connect the COM port of a host to the COM port of a router or switch?（）
A. crossover B. straight-through C. rolled D. shielded twisted-pair
单项选择题 Which Cisco Catalyst feature automatically disables the port in an operational PortFast upon receipt of a BPDU?（）
单项选择题 How many bits are contained in each field of an IPv6 address?（）
单项选择题 For which type of connection should a straight-through cable be used?（）
