Refer to the exhibit. What is the most appropriate summarization for these routes?（）

单项选择题Refer to the exhibit. Which subnet mask will place all hosts on Network B in the same subnet with the least amount of wasted addresses?（）

A.255.255.255.0
B.255.255.254.0
C.255.255.252.0
D.255.255.248.0

单项选择题What is the first 24 bits in a MAC address called?（）

A. NIC
B. BIA
C. OUI
D. VAI

单项选择题What is known as one-to-nearest addressing in IPv6?（）

A.global unicast
B.anycast
C.multicast
D.unspecified address

多项选择题Refer to the exhibit. A junior network administrator was given the task of configuring port security on SwitchA to allow only PC_A to access the switched network through port fa0 1. If any other device is detected, the port is to drop frames from this device. The administrator configured the interface and tested it with successful pings from PC_A to RouterA, and then observes the output from these two show commands.Which two of these changes are necessary for SwitchA to meet the requirements? （）

A.Port security needs to be globally enabled.
B.Port security needs to be enabled on the interface.
C.Port security needs to be configured to shut down the interface in the event of a violation.
D.Port security needs to be configured to allow only one learned MAC address.
E.Port security interface counters need to be cleared before using the show command.
F.The port security configuration needs to be saved to NVRAM before it can become active.

多项选择题Which two of these statements are true of IPv6 address representation? （）

A.There are four types of IPv6 addresses: unicast, multicast, anycast, and broadcast.
B.A single interface may be assigned multiple IPv6 addresses of any type.
C.Every IPv6 interface contains at least one loopback address.
D.The first 64 bits represent the dynamically created interface ID.
E.Leading zeros in an IPv6 16 bit hexadecimal field are mandatory.