选择

计算机网络选择题题库（PDY 整理）
第一章测试
A NETWORK ADMINISTRATOR IS IMPLEMENTING A POLICY THAT REQUIRES STRONG, COMPLEX
PASSWORDS. WHICH DATA PROTECTION GOAL DOES THIS POLICY SUPPORT?
A、data quality
B、data redundancy
C、data integrity
D、data confidentiality
正确答案： D
WHICH DEVICE PERFORMS THE FUNCTION OF DETERMINING THE PATH THAT MESSAGES
SHOULD TAKE THROUGH INTERNETWORKS?
A、a router
B、 a web server
C、a DSL modem
D、a firewall
正确答案： A
WHICH STATEMENT DESCRIBES THE USE OF POWERLINE NETWORKING TECHNOLOGY?
A、A home LAN is installed without the use of physical cabling
B、New “smart” electrical cabling is used to extend an existing home LAN. C、Wireless access points use powerline adapters to distribute data through the home LAN. D、A device connects to an existing home LAN using an adapter and an existing electrical outlet. 正确答案： D
AN EMPLOYEE AT A BRANCH OFFICE IS CREATING A QUOTE FOR A CUSTOMER. IN ORDER TO DO
THIS, THE EMPLOYEE NEEDS TO ACCESS CONFIDENTIAL PRICING INFORMATION FROM INTERNAL
SERVERS AT THE HEAD OFFICE. WHAT TYPE OF NETWORK WOULD THE EMPLOYEE ACCESS?
A、an intranet
B、the Internet
C、a local area network
D、an extranet
正确答案： A
WHAT TYPE OF NETWORK TRAFFIC REQUIRES QOS?
A、wiki
B、email
C、video conferencing
D、on-line purchasing
正确答案： C
WHAT SECURITY VIOLATION WOULD CAUSE THE MOST AMOUNT OF DAMAGE TO THE LIFE OF A
HOME USER?
A、capturing of personal data that leads to identity theft
B、denial of service to your email server
C、replication of worms and viruses in your computer
D、spyware that leads to spam emails
正确答案： A
WHICH TERM DESCRIBES THE STATE OF A NETWORK WHEN THE DEMAND ON THE NETWORK
RESOURCES EXCEEDS THE AVAILABLE CAPACITY?
A、optimization
B、convergence
C、synchronization
D、congestion
正确答案： D
WHICH AREA OF THE NETWORK WOULD A COLLEGE IT STAFF MOST LIKELY HAVE TO REDESIGN AS
A DIRECT RESULT OF MANY STUDENTS BRINGING THEIR OWN TABLETS AND SMARTPHONES TO
SCHOOL TO ACCESS SCHOOL RESOURCES?
A、wireless WAN
B、wireless LAN
C、intranet
D、wired LAN
E、extranet
正确答案： B
WHAT TYPE OF NETWORK MUST A HOME USER ACCESS IN ORDER TO DO ONLINE SHOPPING?
A、an intranet
B、a local area network
C、an extranet
D、the Internet
正确答案： D
WHICH STATEMENT DESCRIBES A CHARACTERISTIC OF CLOUD COMPUTING?
A、Investment in new infrastructure is required in order to access the cloud. B、Applications can be accessed over the Internet by individual users or businesses using any
device, anywhere in the world. C、Devices can connect to the Internet through existing electrical wiring.
D、A business can connect directly to the Internet without the use of an ISP. 正确答案： B
WHAT IS THE INTERNET?
A、It provides connections through interconnected global networks. B、It is a private network for an organization with LAN and WAN connections. C、It provides network access for mobile devices. D、It is a network based on Ethernet technology. 正确答案： A
WHICH EXPRESSION ACCURATELY DEFINES THE TERM BANDWIDTH?
A、a method of limiting the impact of a hardware or software failure on the network
B、a set of techniques to manage the utilization of network resources
C、a measure of the data carrying capacity of the media
D、a state where the demand on the network resources exceeds the available capacity
正确答案： C
二.多选题（共 7 题,28.7 分）
A USER IS IMPLEMENTING SECURITY ON A SMALL OFFICE NETWORK. WHICH TWO ACTIONS
WOULD PROVIDE THE MINIMUM SECURITY REQUIREMENTS FOR THIS NETWORK? (CHOOSE
TWO.)
A、adding a dedicated intrusion prevention device
B、installing antivirus software
C、implementing an intrusion detection system
D、implementing a firewall
E、installing a wireless network
正确答案： BD
WHICH TWO STATEMENTS DESCRIBE INTERMEDIARY DEVICES? (CHOOSE TWO.)
A、Intermediary devices connect individual hosts to the network. B、Intermediary devices alter data content. C、Intermediary devices generate data content. D、Intermediary devices direct the path of the data. E、Intermediary devices initiate the encapsulation process. 正确答案： AD
WHAT ARE TWO FUNCTIONS OF END DEVICES ON A NETWORK?
A、They provide the channel over which the network message travels. B、They are the interface between humans and the communication network. C、They originate the data that flows through the network. D、They direct data over alternate paths in the event of link failures. E、They filter the flow of data to enhance security. 正确答案： BC
WHICH TWO CONNECTION OPTIONS PROVIDE AN ALWAYS-ON, HIGH-BANDWIDTH INTERNET
CONNECTION TO COMPUTERS IN A HOME OFFICE? (CHOOSE TWO.)
A、satellite
B、cellular
C、dial-up telephone
D、DSL
E、cable
正确答案： DE
A COMPANY IS CONTEMPLATING WHETHER TO USE A CLIENT/SERVER OR A PEER-TO-PEER
NETWORK. WHAT ARE THREE CHARACTERISTICS OF A PEER-TO-PEER NETWORK? (CHOOSE
THREE.)
A、lacks centralized administration
B、easy to create
C、scalable
D、less cost to implement
E、better device performance when acting as both client and server
F、better security
正确答案： ABD
WHAT TWO CRITERIA ARE USED TO HELP SELECT A NETWORK MEDIUM FROM VARIOUS
NETWORK MEDIA? (CHOOSE TWO.)
A、the distance the selected medium can successfully carry a signal
B、the cost of the end devices utilized in the network
C、the types of data that need to be prioritized
D、the environment where the selected medium is to be installed
E、the number of intermediary devices installed in the network
正确答案： AD
WHICH TWO INTERNET CONNECTION OPTIONS DO NOT REQUIRE THAT PHYSICAL CABLES BE RUN
TO THE BUILDING? (CHOOSE TWO.)
A、DSL
B、Satellite
C、Dedicated leased Line
D、Dialup
E、cellular
正确答案： BE
三.填空题（共 2 题,8.2 分）
FILL IN THE BLANK. THE ACRONYM ___ REFERS TO THE POLICY THAT ALLOWS EMPLOYEES TO USE THEIR PERSONAL
DEVICES IN THE BUSINESS OFFICE TO ACCESS THE NETWORK AND OTHER RESOURCES. 正确答案：
第一空：
BYOD
FILL IN THE BLANK. A __ NETWORK IS CAPABLE OF DELIVERING VOICE, VIDEO, TEXT, AND GRAPHICS OVER THE SAME
COMMUNICATION CHANNELS. 正确答案：
第一空：
converged
四.连线题（共 3 题,13.9 分）
MATCH EACH CHARACTERISTIC TO ITS CORRESPONDING INTERNET CONNECTIVITY TYPE. (NOT
ALL OPTIONS ARE USED.)
第一组数据
1、satellite
2、dialup telephone
3、DSL
4、cable
第二组数据
A、typically has very low bandwidth
B、Not suited for heavily wooded areas
C、uses coaxial cable as a medium
D、splits the access line into three signals
正确答案
1.------------ B
2.------------ A
3.------------ D
4.------------ C
MATCH THE DESCRIPTION TO THE FORM OF NETWORK COMMUNICATION. (NOT ALL OPTIONS
ARE USED.)
第一组数据
1、Web pages that groups of people can edit and view together
2、Interactive websites where people created and share user-generated content with friends and
family
3、real-time communication of between two or more people
4、an audio-based medium that allows people to deliver their recordings to a wide audience
第二组数据
A、Social media
B、wiki
C、podcast
D、instant messaging
正确答案
1.------------ B
2.------------ A
3.------------ D
4.------------ C
MATCH THE DEFINITION TO THE SECURITY GOAL. (NOT ALL OPTIONS ARE USED.)
第一组数据
1、maintaining integrity
2、ensuring confidentiality
3、ensuring availability
第二组数据
A、the assurance that the information has not been altered during transmission
B、the assurance of timely and reliable access to data
C、only the intended recipients can access and read the data
正确答案
1.------------ A
2.------------ C
3.------------ B
第二章测试
1
WHY WOULD A LAYER 2 SWITCH NEED AN IP ADDRESS?
A、
to enable the switch to be managed remotely。
B、
to enable the switch to receive frames from attached PCs
C、
to enable the switch to function as a default gateway
D、
D: to enable the switch to send broadcast frames to attached PCs
正确答案： A 我的答案：A 得分： 4.1 分
答案解析：
A switch, as a Layer 2 device, does not need an IP address to transmit frames to attached devices. However, when a switch is accessed remotely through the network, it must have a Layer 3
address. The IP address must be applied to a virtual interface rather than to a physical interface. Routers, not switches, function as default gateways. 2
WHILE TRYING TO SOLVE A NETWORK ISSUE, A TECHNICIAN MADE MULTIPLE CHANGES TO THE
CURRENT ROUTER CONFIGURATION FILE. THE CHANGES DID NOT SOLVE THE PROBLEM AND
WERE NOT SAVED. WHAT ACTION CAN THE TECHNICIAN TAKE TO DISCARD THE CHANGES AND
WORK WITH THE FILE IN NVRAM?
A、
Delete the vlan.dat file and reboot the device.
B、
Issue the copy startup-config running-config command. C、
Issue the reload command without saving the running configuration. D、
Close and reopen the terminal emulation software. 正确答案： C 我的答案：C 得分： 4.1 分
答案解析：
The technician does not want to make any mistakes trying to remove all the changes that were
done to the running configuration file. The solution is to reboot the router without saving the
running configuration. The copy startup-config running-config command does not overwrite the
running configuration file with the configuration file stored in NVRAM, but rather it just has an
additive effect. 3
WHICH COMMAND OR KEY COMBINATION ALLOWS A USER TO RETURN TO THE PREVIOUS LEVEL
IN THE COMMAND HIERARCHY?
A、
exit
B、
Ctrl-C
C、
Ctrl-Z
D、
end
正确答案： A 我的答案：A 得分： 4.1 分
答案解析：
End and CTRL-Z return the user to the privileged EXEC mode. Ctrl-C ends a command in process. The exit command returns the user to the previous level.
4
WHICH PROCEDURE IS USED TO ACCESS A CISCO 2960 SWITCH WHEN PERFORMING AN INITIAL
CONFIGURATION IN A SECURE ENVIRONMENT?
A、
Use the console port to locally access the switch from a serial or USB interface of the PC. B、
Use the AUX port to locally access the switch from a serial or USB interface of the PC. C、
Use Secure Shell to remotely access the switch through the network. D、
Use Telnet to remotely access the switch through the network. 正确答案： A 我的答案：A 得分： 4.1 分
答案解析：
Telnet and SSH require active networking services to be configured on a Cisco device before they
become functional. Cisco switches do not contain AUX ports. 5
REFER TO THE EXHIBIT. A NETWORK ADMINISTRATOR IS CONFIGURING THE MOTD ON SWITCH
SW1. WHAT IS THE PURPOSE OF THIS COMMAND?
2.png
A、
to configure switch SW1 so that the message will display when a user enters the enable
command
B、
to force users of the Admin group to enter a password for authentication
C、
to display a message when a user accesses the switch
D、
to configure switch SW1 so that only the users in the Admin group can telnet into SW1
正确答案： C 我的答案：C 得分： 4.1 分
答案解析：
A banner message can be an important part of the legal process in the event that someone is
prosecuted for breaking into a device. A banner message should make it clear that only
authorized personnel should attempt to access the device. However, the banner command does
not prevent unauthorized entry. 6
WHY IS IT IMPORTANT TO CONFIGURE A HOSTNAME ON A DEVICE?
A、
a Cisco router or switch only begins to operate when its hostname is set
B、
a hostname must be configured before any other parameters
C、
to allow local access to the device through the console port
D、
to identify the device during remote access (SSH or telnet)
正确答案： D 我的答案：D 得分： 4.1 分
答案解析：
It is important to configure a hostname because various authentication processes use the device
hostname. Hostnames are helpful for documentation, and they identify the device during remote
access.
7
A TECHNICIAN IS ADDING A NEW PC TO A LAN. AFTER UNPACKING THE COMPONENTS AND
MAKING ALL THE CONNECTIONS, THE TECHNICIAN STARTS THE PC. AFTER THE OS LOADS, THE
TECHNICIAN OPENS A BROWSER, AND VERIFIES THAT THE PC CAN REACH THE INTERNET. WHY
WAS THE PC ABLE TO CONNECT TO THE NETWORK WITH NO ADDITIONAL CONFIGURATION?
A、
The PC came preconfigured with IP addressing information from the factory. B、
The PC was preconfigured to use DHCP. C、
The PC does not require any additional information to function on the network. D、
The PC virtual interface is compatible with any network. E、
The PC used DNS to automatically receive IP addressing information from a server. 正确答案： B 我的答案：B 得分： 4.1 分
答案解析：
The new PC was preconfigured to use DHCP. When the PC is connected to a network that uses
DHCP, it gets the IP address settings from the DHCP server that will allow it to function on the
network. All devices require at least an IP address and subnet mask to function on a LAN. DNS
does not automatically configure addresses on hosts. PC virtual interfaces are not universally
compatible with LANs and do not necessarily provide a host with an IP address. At this place in
the course, virtual interfaces are used on network switches. 8
WHICH INTERFACE IS THE DEFAULT SVI ON A CISCO SWITCH?
A、
VLAN 1
B、
VLAN 99
C、
GigabitEthernet 0/1
D、
FastEthernet 0/1
正确答案： A 我的答案：A 得分： 4.1 分
答案解析：
An SVI is a virtual interface and VLAN 1 is enabled by default on Cisco switches. VLAN 99 must be
configured to be used. FastEthernet 0/1 and GigabitEthernet 0/1 are physical interfaces. 9
WHAT COMMAND CAN BE USED ON A WINDOWS PC TO SEE THE IP CONFIGURATION OF THAT
COMPUTER?
A、
ping
B、
show interfaces
C、
ipconfig
D、
show ip interface brief
正确答案： C 我的答案：C 得分： 4.1 分
答案解析：
On a Windows PC, the ipconfig command can be used to verify the current IP configuration. The
ping command can be used to verify connectivity to other network devices. The show interfaces
and show ip interface brief commands are both Cisco IOS commands that are used to see the
status of router and switch interfaces. 10
HOW DOES THE SERVICE PASSWORD-ENCRYPTION COMMAND ENHANCE PASSWORD SECURITY
ON CISCO ROUTERS AND SWITCHES?
A、
It encrypts passwords that are stored in router or switch configuration files. B、
It requires that a user type encrypted passwords to gain console access to a router or switch. C、
It encrypts passwords as they are sent across the network. D、
It requires encrypted passwords to be used when connecting remotely to a router or switch with
Telnet. 正确答案： A 我的答案：A 得分： 4.1 分
答案解析：
The service password-encryption command encrypts plaintext passwords in the configuration file
so that they cannot be viewed by unauthorized users. 11
WHAT IS A USER TRYING TO DETERMINE WHEN ISSUING A PING 10.1.1.1 COMMAND ON A PC?
A、
what type of device is at the destination
B、
the path that traffic will take to reach the destination
C、
if the TCP/IP stack is functioning on the PC without putting traffic on the wire
D、
if there is connectivity with the destination device
正确答案： D 我的答案：D 得分： 4.1 分
答案解析：
The ping destination command can be used to test connectivity. 12
WHAT IS THE FUNCTION OF THE KERNEL OF AN OPERATING SOFTWARE?
A、
The kernel provisions hardware resources to meet software requirements. B、
It provides a user interface that allows users to request a specific task. C、
The kernel links the hardware drivers with the underlying electronics of a computer. D、
It is an application that allows the initial configuration of a Cisco device. 正确答案： A 我的答案：A 得分： 4.1 分
答案解析：
Operating systems function with a shell, a kernel, and the hardware. The shell interfaces with the
users, allowing them to request specific tasks from the device. The kernel provisions resources
from the hardware to meet software requirements. The hardware functions by using drivers and
their underlying electronics. The hardware represents the physical components of the device.
13
WHICH STATEMENT IS TRUE ABOUT THE RUNNING CONFIGURATION FILE IN A CISCO IOS DEVICE?
A、
It is automatically saved when the router reboots. B、
It should be deleted using the erase running-config command. C、
It affects the operation of the device immediately when modified. D、
It is stored in NVRAM. 正确答案： C 我的答案：C 得分： 4.1 分
答案解析：
As soon as configuration commands are entered into a router, they modify the device
immediately. Running configuration files can not be deleted nor are they saved automatically. 14
WHICH INTERFACE ALLOWS REMOTE MANAGEMENT OF A LAYER 2 SWITCH?
A、
the AUX interface
B、
the first Ethernet port interface
C、
the console port interface
D、
the switch virtual interface
正确答案： D 我的答案：D 得分： 4.1 分
答案解析：
In a Layer 2 switch, there is a switch virtual interface (SVI) that provides a means for remotely
managing the device. 15
WHICH INFORMATION DOES THE SHOW STARTUP-CONFIG COMMAND DISPLAY?
A、
the bootstrap program in the ROM
B、
the contents of the current running configuration file in the RAM
C、
the contents of the saved configuration file in the NVRAM
D、
the IOS image copied into RAM
正确答案： C 我的答案：C 得分： 4.1 分
答案解析：
The show startup-config command displays the saved configuration located in NVRAM. The show
running-config command displays the contents of the currently running configuration file located
in RAM. 16
A NETWORK ADMINISTRATOR NEEDS TO KEEP THE USER ID, PASSWORD, AND SESSION CONTENTS
PRIVATE WHEN ESTABLISHING REMOTE CLI CONNECTIVITY WITH A SWITCH TO MANAGE IT. WHICH ACCESS METHOD SHOULD BE CHOSEN?
A、
Telnet
B、
AUX
C、
Console
D、
SSH
正确答案： D 我的答案：D 得分： 4.1 分
17
A ROUTER HAS A VALID OPERATING SYSTEM AND A CONFIGURATION FILE STORED IN NVRAM. THE CONFIGURATION FILE CONTAINS AN ENABLE SECRET PASSWORD BUT NO CONSOLE
PASSWORD. WHEN THE ROUTER BOOTS UP, WHICH MODE WILL DISPLAY?
A、
user EXEC mode
B、
global configuration mode
C、
privileged EXEC mode
D、
setup mode
正确答案： A 我的答案：A 得分： 4.1 分
答案解析：
If a Cisco IOS device has a valid IOS and a valid configuration file, it will boot into user EXEC mode. A password will be required to enter privileged EXEC mode. 二.多选题（共 5 题,20.5 分）
1
WHICH TWO HOST NAMES FOLLOW THE GUIDELINES FOR NAMING CONVENTIONS ON CISCO IOS
DEVICES? (CHOOSE TWO.)
A、
SwBranch799
B、
Branch2!
C、
Floor(15)
D、
RM-3-Switch-2A4
E、
HO Floor 17
正确答案： AD 我的答案：AD 得分： 4.1 分
答案解析：
Some guidelines for naming conventions are that names should:
Start with a letter
Contain no spaces
End with a letter or digit
Use only letters, digits, and dashes
Be less than 64 characters in length
2
WHICH TWO FUNCTIONS ARE PROVIDED TO USERS BY THE CONTEXT-SENSITIVE HELP FEATURE
OF THE CISCO IOS CLI? (CHOOSE TWO.)
A、
determining which option, keyword, or argument is available for the entered command
B、
providing an error message when a wrong command is submitted
C、
selecting the best command to accomplish a task
D、
allowing the user to complete the remainder of an abbreviated command with the TAB key
E、
displaying a list of all available commands within the current mode
正确答案： AE 我的答案：AE 得分： 4.1 分
答案解析：
Context-sensitive help provides the user with a list of commands and the arguments associated
with those commands within the current mode of a networking device. A syntax checker provides
error checks on submitted commands and the TAB key can be used for command completion if a
partial command is entered. 3
REFER TO THE EXHIBIT. WHAT THREE FACTS CAN BE DETERMINED FROM THE VIEWABLE OUTPUT
OF THE SHOW IP INTERFACE BRIEF COMMAND? (CHOOSE THREE.)
1.png
A、
One device is attached to a physical interface. B、
Passwords have been configured on the switch. C、
The default SVI has been configured. D、
The switch can be remotely managed. E、
Two devices are attached to the switch. F、
Two physical interfaces have been configured. 正确答案： ACD 我的答案：ACD 得分： 4.1 分
答案解析：
Vlan1 is the default SVI. Because an SVI has been configured, the switch can be configured and
managed remotely. FastEthernet0/0 is showing up and up, so a device is connected. 4
REFER TO THE EXHIBIT. A NETWORK TECHNICIAN IS TESTING CONNECTIVITY IN A NEW NETWORK. BASED ON THE TEST RESULTS SHOWN IN THE EXHIBIT, WHICH DEVICE DOES THE TECHNICIAN
HAVE CONNECTIVITY WITH AND WHICH DEVICE DOES THE TECHNICIAN NOT HAVE CONNECTIVITY
WITH? (CHOOSE TWO.)
3.png
A、
no connectivity: switch 2
B、
no connectivity: switch 1
C、
connectivity: PC-D
D、
no connectivity: PC-C
E、
connectivity: switch 2
F、
connectivity: PC-B
正确答案： DE 我的答案：DE 得分： 4.1 分
答案解析：
The exhibit shows ping tests to two devices. One device has the IP address of 192.168.1.2, which
is switch 2. The other test is to the IP address of 192.168.1.21, which is host PC-C. For the first
test, to switch 2, the results are successful, with four reply messages received. This means that
connectivity exists to switch 2. For the second test, all four messages timed out. This indicates
that connectivity does not exist to PC-C. 5
WHAT ARE TWO CHARACTERISTICS OF RAM ON A CISCO DEVICE? (CHOOSE TWO.)
A、
RAM is a component in Cisco switches but not in Cisco routers. B、
RAM is able to store multiple versions of IOS and configuration files. C、
The configuration that is actively running on the device is stored in RAM. D、
The contents of RAM are lost during a power cycle. E、
RAM provides nonvolatile storage. 正确答案： CD 我的答案：CD 得分： 4.1 分
答案解析：
RAM stores data that is used by the device to support network operations. The running
configuration is stored in RAM. This type of memory is considered volatile memory because data
is lost during a power cycle. Flash memory stores the IOS and delivers a copy of the IOS into RAM
when a device is powered on. Flash memory is nonvolatile since it retains stored contents during
a loss of power. 三.连线题（共 2 题,9.8 分）
1
AN ADMINISTRATOR IS CONFIGURING A SWITCH CONSOLE PORT WITH A PASSWORD. IN WHAT
ORDER WILL THE ADMINISTRATOR TRAVEL THROUGH THE IOS MODES OF OPERATION IN ORDER
TO REACH THE MODE IN WHICH THE CONFIGURATION COMMANDS WILL BE ENTERED? (NOT ALL
OPTIONS ARE USED.)
第一组数据
1、
privileged EXEC mode
2、
line configuration mode
3、
global configuration mode
4、
user EXEC mode
第二组数据
A、
third mode
B、
second mode
C、
final mode
D、
first mode
正确答案
1.------------ B
2.------------ C
3.------------ A
4.------------ D
我的答案
1.------------ B
2.------------ C
3.------------ A
4.------------ D
得分： 4.1 分
2
MATCH THE DEFINITIONS TO THEIR RESPECTIVE CLI HOT KEYS AND SHORTCUTS. (NOT ALL
OPTIONS ARE USED.)
第一组数据
1、
tab
2、
space bar
3、
Up Arrow
4、
?
5、
Ctrl-Shift-6
第二组数据
A、
completes abbreviated commands and parameters
B、
displays the next screen
C、
scrolls backwards through previously entered commands
D、
provides context-sensitive help
E、
aborts commands such as trace and ping
正确答案
1.------------ A
2.------------ B
3.------------ C
4.------------ D
5.------------ E
我的答案
1.------------ A
2.------------ B
3.------------ C
4.------------ D
5.------------ E
第三章测试

1. (单选题)
   WHAT IS AN ADVANTAGE OF NETWORK DEVICES USING OPEN STANDARD PROTOCOLS?
   A. A client host and a server running different operating systems can successfully exchange
   data. B. Internet access can be controlled by a single ISP in each market
   C. Competition and innovation are limited to specific types of products. D. Network communications is confined to data transfers between devices from the same vendor. 我的答案: A 正确答案: A
   4.5 分
   答案解析：An advantage of network devices implementing open standard protocols, such as
   from the TCP/IP suite, is that clients and servers running different operating systems can
   communicate with each other. Open standard protocols facilitate innovation and competition
   between vendors and across markets, and can reduce the occurrence of monopolies in
   networking markets. 2. (单选题)
   REFER TO THE EXHIBIT. IF HOST1 WERE TO TRANSFER A FILE TO THE SERVER, WHAT LAYERS OF
   THE TCP/IP MODEL WOULD BE USED?
   1.png
   A. only application and Internet layers
   B. application, transport, Internet, and network access layers
   C. only Internet and network access layers
   D. application, session, transport, network, data link, and physical layers
   E. only application, transport, network, data link, and physical layers
   F. only application, Internet, and network access layers
   我的答案: B 正确答案: B
   4.5 分
   答案解析：The TCP/IP model contains the application, transport, internet, and network access
   layers. A file transfer uses the FTP application layer protocol. The data would move from the
   application layer through all of the layers of the model and across the network to the file server. 3. (单选题)
   WHICH STATEMENT IS TRUE ABOUT THE TCP/IP AND OSI MODELS?
   A. The first three OSI layers describe general services that are also provided by the TCP/IP
   internet layer. B. The TCP/IP network access layer has similar functions to the OSI network layer. C. The TCP/IP transport layer and OSI Layer 4 provide similar services and functions. D. The OSI Layer 7 and the TCP/IP application layer provide identical functions. 我的答案: C 正确答案: C
   4.5 分
   答案解析：The TCP/IP internet layer provides the same function as the OSI network layer. The
   transport layer of both the TCP/IP and OSI models provides the same function. The TCP/IP
   application layer includes the same functions as OSI Layers 5, 6, and 7. 4. (单选题)
   WHICH STATEMENT IS CORRECT ABOUT NETWORK PROTOCOLS?
   A. Network protocols define the type of hardware that is used and how it is mounted in racks. B. They define how messages are exchanged between the source and the destination. C. They are only required for exchange of messages between devices on remote networks. D. They all function in the network access layer of TCP/IP. 我的答案: B 正确答案: B
   4.5 分
   答案解析：Network protocols are implemented in hardware, or software, or both. They interact
   with each other within different layers of a protocol stack. Protocols have nothing to do with the
   installation of the network equipment. Network protocols are required to exchange information
   between source and destination devices in both local and remote networks. 5. (单选题)
   A WEB CLIENT IS SENDING A REQUEST FOR A WEBPAGE TO A WEB SERVER. FROM THE
   PERSPECTIVE OF THE CLIENT, WHAT IS THE CORRECT ORDER OF THE PROTOCOL STACK THAT IS
   USED TO PREPARE THE REQUEST FOR TRANSMISSION?
   A. HTTP, TCP, IP, Ethernet
   B. Ethernet, TCP, IP, HTTP
   C. HTTP, IP, TCP, Ethern
   D. Ethernet, IP, TCP, HTTP
   我的答案: A 正确答案: A
   4.5 分
   答案解析：1. HTTP governs the way that a web server and client interact. 2. TCP manages individual conversations between web servers and clients. 3. IP is responsible for delivery across the best path to the destination. 4. Ethernet takes the packet from IP and formats it for transmission. 6. (单选题)
   WHICH PDU FORMAT IS USED WHEN BITS ARE RECEIVED FROM THE NETWORK MEDIUM BY THE
   NIC OF A HOST?
   A. frame
   B. file
   C. packet
   D. segment
   我的答案: A 正确答案: A
   4.5 分
   答案解析：When received at the physical layer of a host, the bits are formatted into a frame at
   the data link layer. A packet is the PDU at the network layer. A segment is the PDU at the
   transport layer. A file is a data structure that may be used at the application layer. 7. (单选题)
   WHAT TYPE OF COMMUNICATION WILL SEND A MESSAGE TO ALL DEVICES ON A LOCAL AREA
   NETWORK?
   A. allcast
   B. multicast
   C. broadcast
   D. unicast
   我的答案: C 正确答案: C
   4.5 分
   答案解析：Broadcast communication is a one-to-all communication. A unicast communication is
   a one-to-one communication. Multicast is a one-to-many communication where the message is
   delivered to a specific group of hosts. Allcast is not a standard term to describe message delivery. 8. (单选题)
   WHAT WILL HAPPEN IF THE DEFAULT GATEWAY ADDRESS IS INCORRECTLY CONFIGURED ON A
   HOST?
   A. The host cannot communicate with other hosts in the local network. B. A ping from the host to 127.0.0.1 would not be successful. C. The switch will not forward packets initiated by the host.
   D. The host cannot communicate with hosts in other networks. E. The host will have to use ARP to determine the correct address of the default gateway. 我的答案: D 正确答案: D
   4.5 分
   答案解析：When a host needs to send a message to another host located on the same network,
   it can forward the message directly. However, when a host needs to send a message to a remote
   network, it must use the router, also known as the default gateway. This is because the data link
   frame address of the remote destination host cannot be used directly. Instead, the IP packet has
   to be sent to the router (default gateway) and the router will forward the packet toward its
   destination. Therefore, if the default gateway is incorrectly configured, the host can communicate
   with other hosts on the same network, but not with hosts on remote networks. 9. (单选题)
   WHICH CHARACTERISTIC DESCRIBES THE DEFAULT GATEWAY OF A HOST COMPUTER?
   A. the logical address assigned to the switch interface connected to the router
   B. the physical address of the router interface on the same network as the host computer
   C. the physical address of the switch interface connected to the host computer
   D. the logical address of the router interface on the same network as the host computer
   我的答案: D 正确答案: D
   4.5 分
   答案解析：The default gateway is the IP address of an interface on the router on the same
   network as the sending host. 10. (单选题)
   WHAT METHOD CAN BE USED BY TWO COMPUTERS TO ENSURE THAT PACKETS ARE NOT
   DROPPED BECAUSE TOO MUCH DATA IS BEING SENT TOO QUICKLY?
   A. flow control
   B. encapsulation
   C. response timeout
   D. access method
   我的答案: A 正确答案: A
   4.5 分
   答案解析：In order for two computers to be able to communicate effectively, there must be a
   mechanism that allows both the source and destination to set the timing of the transmission and
   receipt of data. Flow control allows for this by ensuring that data is not sent too fast for it to be
   received properly.
2. (单选题)
   WHAT ARE PROPRIETARY PROTOCOLS?
   A. protocols developed by private organizations to operate on any vendor hardware
   B. protocols developed by organizations who have control over their definition and operation
   C. a collection of protocols known as the TCP/IP protocol suite
   D. protocols that can be freely used by any organization or vendor
   我的答案: B 正确答案: B
   4.5 分
   答案解析：Proprietary protocols have their definition and operation controlled by one company
   or vendor. Some of them can be used by different organizations with permission from the owner. The TCP/IP protocol suite is an open standard, not a proprietary protocol. 12. (单选题)
   WHAT PROCESS IS USED TO PLACE ONE MESSAGE INSIDE ANOTHER MESSAGE FOR TRANSFER
   FROM THE SOURCE TO THE DESTINATION?
   A. access control
   B. decoding
   C. flow control
   D. encapsulation
   我的答案: D 正确答案: D
   4.5 分
   答案解析：Encapsulation is the process of placing one message format into another message
   format. An example is how a packet is placed in its entirety into the data field as it is
   encapsulated into a frame. 13. (单选题)
   WHICH ADDRESS DOES A NIC USE WHEN DECIDING WHETHER TO ACCEPT A FRAME?
   A. source MAC address
   B. destination MAC address
   C. source IP address
   D. source Ethernet address
   E. destination IP address
   我的答案: B 正确答案: B
   4.5 分
3. (单选题)
   WHICH PDU IS PROCESSED WHEN A HOST COMPUTER IS DE-ENCAPSULATING A MESSAGE AT THE
   TRANSPORT LAYER OF THE TCP/IP MODEL?
   A. bits
   B. frame
   C. packet
   D. segment
   我的答案: D 正确答案: D
   4.5 分
   答案解析：At the transport layer, a host computer will de-encapsulate a segment to reassemble
   data to an acceptable format by the application layer protocol of the TCP/IP model. 15. (单选题)
   WHAT IS AN ADVANTAGE OF USING STANDARDS TO DEVELOP AND IMPLEMENT PROTOCOLS?
   A. Different manufacturers are free to apply different requirements when implementing a
   protocol. B. Products from different manufacturers can interoperate successfully. C. A particular protocol can only be implemented by one manufacturer. D. Standards provide flexibility for manufacturers to create devices that comply with unique
   requirements. 我的答案: B 正确答案: B
   4.5 分
   答 案 解 析 ： Standards-based protocols enable products from different manufacturers to
   interoperate successfully. Standards-based protocols enable many manufacturers to implement
   that protocol. If different manufacturers implement different requirements within the same
   protocol, then their products will not be interoperable. 16. (单选题)
   AT WHICH LAYER OF THE OSI MODEL WOULD A LOGICAL ADDRESS BE ENCAPSULATED?
   A. transport layer
   B. network layer
   C. data link layer
   D. physical layer
   我的答案: B 正确答案: B
   4.5 分
   答案解析：Logical addresses, also known as IP addresses, are encapsulated at the network layer. Physical addresses are encapsulated at the data link layer. Port addresses are encapsulated at the
   transport layer. No addresses are encapsulated at the physical layer. 二. 多选题（共 3 题，13.5 分）
4. (多选题)
   WHAT THREE APPLICATION LAYER PROTOCOLS ARE PART OF THE TCP/IP PROTOCOL SUITE?
   (CHOOSE THREE.)
   A. NAT
   B. ARP
   C. DNS
   D. DHCP
   E. FTP
   F. PPP
   我的答案: CDE 正确答案: CDE
   4.5 分
   答案解析：DNS, DHCP, and FTP are all application layer protocols in the TCP/IP protocol suite. ARP and PPP are network access layer protocols, and NAT is an internet layer protocol in the
   TCP/IP protocol suite. 18. (多选题)
   REFER TO THE EXHIBIT. HOSTA IS ATTEMPTING TO CONTACT SERVERB. WHICH TWO STATEMENTS
   CORRECTLY DESCRIBE THE ADDRESSING THAT HOSTA WILL GENERATE IN THE PROCESS? (CHOOSE
   TWO.)
   1.png
   A. A packet with the destination IP address of RouterA. B. A frame with the destination MAC address of SwitchA. C. A packet with the destination IP address of ServerB. D. A frame with the destination MAC address of ServerB. E. A frame with the destination MAC address of RouterA. F. A packet with the destination IP address of RouterB. 我的答案: CE 正确答案: CE
   4.5 分
   答案解析：In order to send data to ServerB, HostA will generate a packet that contains the IP
   address of the destination device on the remote network and a frame that contains the MAC
   address of the default gateway device on the local network. 19. (多选题)
   WHICH THREE LAYERS OF THE OSI MODEL ARE COMPARABLE IN FUNCTION TO THE APPLICATION
   LAYER OF THE TCP/IP MODEL? (CHOOSE THREE.)
   A. network
   B. presentation
   C. physical
   D. session
   E. application
   F. transport
   G. data link
   我的答案: BDE 正确答案: BDE
   4.5 分
   答案解析：The TCP/IP model consists of four layers: application, transport, internet, and network
   access. The OSI model consists of seven layers: application, presentation, session, transport, network, data link, and physical. The top three layers of the OSI model: application, presentation, and session map to the application layer of the TCP/IP model. 三. 连线题（共 3 题，14.5 分）
5. ( 连 线 题 )MATCH THE PROTOCOL FUNCTION TO THE DESCRIPTION WHILE TAKING INTO
   CONSIDERATION THAT A NETWORK CLIENT IS VISITING A WEB SITE. (NOT ALL OPTIONS ARE
   USED.)
   第 1 组
6. governing the way a web server and a web client interact
7. talking the segments from the transport protocol, encapsulating them into packets, and
   assigning them with appropriate addresses
8. preparing packets to be transmitted over the network media
9. managing the individual conversation between web servers and web clients
   第 2 组
   A. transport protocol
   B. network access protocol
   C. internet protocol
   D. application protocol
   我的答案：
   1
   D
   2
   C
   3
   B
   4
   A
   正确答案：
   1
   D
   2
   C
   3
   B
   4
   A
   4.5 分
10. (连线题)
    MATCH THE DESCRIPTION TO THE ORGANIZATION. (NOT ALL OPTIONS ARE USED.)
    第 1 组
11. ISOC
12. ISO
13. IANA
    第 2 组
    A. This organization is responsible for overseeing and managing IP address allocation, domain
    name management, and protocol identifiers
    B. This organization is the largest developer of international standars in the world for a wide
    variety of products and services. It is know for its Open System Interconection (OSI) reference
    model. C. The organization promotes the open development, evolution, and use of the internet
    throughout the world
    我的答案：
    1
    C
    2
    B
    3
    A
    正确答案：
    1
    C
    2
    B
    3
    A
    4.5 分
14. (连线题)
    MATCH EACH DESCRIPTION TO ITS CORRESPONDING TERM. (NOT ALL OPTIONS ARE USED.)
    第 1 组
15. message encoding
16. message encapsulation
17. message sizing
    第 2 组
    A. the process of converting information from one format into another acceptable for
    transmission
    B. the process of breaking up a long message into individual pieces before being sent over the
    network
    C. the process of placing one message format inside another message format
    我的答案：
    1
    A
    2
    C
    3
    B
    正确答案：
    1
    A
    2
    C
    3
    B
    第四章测试
18. (单选题)
    WHY ARE TWO STRANDS OF FIBER USED FOR A SINGLE FIBER OPTIC CONNECTION?
    A. They increase the speed at which the data can travel. B. They allow for full-duplex connectivity. C. The two strands allow the data to travel for longer distances without degrading. D. hey prevent crosstalk from causing interference on the connection. 我的答案: B 正确答案: B
    4.1 分
    答案解析：Light can only travel in one direction down a single strand of fiber. In order to allow for
    full-duplex communication two strands of fiber must be connected between each device. 2. (单选题)
    WHICH STATEMENT DESCRIBES AN EXTENDED STAR TOPOLOGY?
    A. End devices connect to a central intermediate device, which in turn connects to other central
    intermediate devices. B. All end and intermediate devices are connected in a chain to each other. C. Each end system is connected to its respective neighbor via an intermediate device. D. End devices are connected together by a bus and each bus connects to a central intermediate
    device. 我的答案: A 正确答案: A
    4.1 分
    答案解析：In an extended star topology, central intermediate devices interconnect other star
    topologies. 3. (单选题)
    WHICH TYPE OF CONNECTOR DOES A NETWORK INTERFACE CARD USE?
    A. DIN
    B. RJ-11
    C. RJ-45
    D. PS-2
    我的答案: C 正确答案: C
    4.1 分
19. (单选题)
    WHAT IS CONTAINED IN THE TRAILER OF A DATA-LINK FRAME?
    A. data
    B. logical address
    C. error detection
    D. physical address
    我的答案: C 正确答案: C
    4.1 分
    答案解析：The trailer in a data-link frame contains error detection information that is pertinent
    to the frame included in the FCS field. The header contains control information, such as the
    addressing, while the area that is indicated by the word “data” includes the data, transport layer
    PDU, and the IP header. 5. (单选题)
    WHAT TECHNIQUE IS USED WITH UTP CABLE TO HELP PROTECT AGAINST SIGNAL INTERFERENCE
    FROM CROSSTALK?
    A. terminating the cable with special grounded connectors
    B. wrapping a foil shield around the wire pairs
    C. twisting the wires together into pairs
    D. encasing the cables within a flexible plastic sheath
    我的答案: C 正确答案: C
    4.1 分
    答案解析：To help prevent the effects of crosstalk, UTP cable wires are twisted together into pairs. Twisting the wires together causes the magnetic fields of each wire to cancel each other out. 6. (单选题)
    WHICH METHOD OF DATA TRANSFER ALLOWS INFORMATION TO BE SENT AND RECEIVED AT THE
    SAME TIME?
    A. multiplex
    B. half duplex
    C. full duplex
    D. simplex
    我的答案: C 正确答案: C
    4.1 分
20. (单选题)
    REFER TO THE EXHIBIT. WHAT IS WRONG WITH THE DISPLAYED TERMINATION?
    1.png
    A. The wires are too thick for the connector that is used. B. The untwisted length of each wire is too long. C. The woven copper braid should not have been removed. D. The wrong type of connector is being used. 我的答案: B 正确答案: B
    4.1 分
    答案解析：When a cable to an RJ-45 connector is terminated, it is important to ensure that the
    untwisted wires are not too long and that the flexible plastic sheath surrounding the wires is
    crimped down and not the bare wires. None of the colored wires should be visible from the
    bottom of the jack. 8. (单选题)
    REFER TO THE EXHIBIT. WHICH STATEMENT DESCRIBES THE MEDIA ACCESS CONTROL METHODS
    THAT ARE USED BY THE NETWORKS IN THE EXHIBIT?
    1.png
    A. None of the networks require media access control. B. Network 1 uses CSMA/CA and Network 2 uses CSMA/CD. C. Network 2 uses CSMA/CA and Network 3 uses CSMA/CD. D. All three networks use CSMA/CA
    E. Network 1 uses CSMA/CD and Network 3 uses CSMA/CA. 我的答案: E 正确答案: E
    4.1 分
    答案解析：Network 1 represents an Ethernet LAN. Data on the wired LAN accesses the media
    using CSMA/CD. Network 2 represents a point-to-point WAN connection so no media access
    method is required. Network 3 represents a WLAN and data accesses the network using
    CSMA/CA. 9. (单选题)
    REFER TO THE EXHIBIT. THE PC IS CONNECTED TO THE CONSOLE PORT OF THE SWITCH. ALL THE
    OTHER CONNECTIONS ARE MADE THROUGH FASTETHERNET LINKS. WHICH TYPES OF UTP CABLES
    CAN BE USED TO CONNECT THE DEVICES?
    1.png
    A. 1 – crossover, 2 – rollover, 3 – straight-through
    B. 1 – rollover, 2 – crossover, 3 – straight-through
    C. 1 – rollover, 2 – straight-through, 3 – crossover
    D. 1 – crossover, 2 – straight-through, 3 – rollover
    我的答案: C 正确答案: C
    4.1 分
    答案解析：A straight-through cable is commonly used to interconnect a host to a switch and a
    switch to a router. A crossover cable is used to interconnect similar devices together like switch to
    a switch, a host to a host, or a router to a router. If a switch has the MDIX capability, a crossover
    could be used to connect the switch to the router; however, that option is not available. A
    rollover cable is used to connect to a router or switch console port. 10. (单选题)
    WHAT IS THE FUNCTION OF THE CRC VALUE THAT IS FOUND IN THE FCS FIELD OF A FRAME?
    A. to verify the physical address in the frame
    B. to compute the checksum header for the data field in the frame
    C. to verify the logical address in the frame
    D. to verify the integrity of the received frame
    我的答案: D 正确答案: D
    4.1 分
    答案解析：The CRC value in the FCS field of the received frame is compared to the computed CRC
    value of that frame, in order to verify the integrity of the frame. If the two values do not match, then the frame is discarded. 11. (单选题)
    WHICH LAYER OF THE OSI MODEL IS RESPONSIBLE FOR SPECIFYING THE ENCAPSULATION
    METHOD USED FOR SPECIFIC TYPES OF MEDIA?
    A. application
    B. data link
    C. transport
    D. physical
    我的答案: B 正确答案: B
    4.1 分
    答 案 解 析 ：Encapsulation is a function of the data link layer. Different media types require
    different data link layer encapsulation. 12. (单选题)
    WHAT IS ONE ADVANTAGE OF USING FIBER OPTIC CABLING RATHER THAN COPPER CABLING?
    A. It is easier to terminate and install than copper cabling. B. It is able to carry signals much farther than copper cabling. C. It is usually cheaper than copper cabling. D. It is able to be installed around sharp bends. 我的答案: B 正确答案: B
    4.1 分
    答 案 解 析 ： Copper cabling is usually cheaper and easier to install than fiber optic cabling. However, fiber cables generally have a much greater signaling range than copper. 13. (单选题)
    WHICH CHARACTERISTIC DESCRIBES CROSSTALK?
    A. the distortion of the transmitted messages from signals carried in adjacent wires
    B. the weakening of the network signal over long cable lengths
    C. the loss of wireless signal over excessive distance from the access point
    D. the distortion of the network signal from fluorescent lighting
    我的答案: A 正确答案: A
    4.1 分
    答案解析：EMI and RFI can distort network signals because of interference from fluorescent
    lights or electric motors. Attenuation results in deterioration of the network signal as it travels
    along copper cabling. Wireless devices can experience loss of signals because of excessive
    distances from a access point, but this is not crosstalk. Crosstalk is the disturbance caused by the
    electric or magnetic fields of the signal carried on an adjacent wire within the same cable. 14. (单选题)
    WHAT IS TRUE CONCERNING PHYSICAL AND LOGICAL TOPOLOGIES?
    A. Logical topologies refer to how a network transfers data between devices. B. Physical topologies display the IP addressing scheme of each network. C. The logical topology is always the same as the physical topology. D. Physical topologies are concerned with how a network transfers frames.
    我的答案: A 正确答案: A
    4.1 分
    答案解析：Physical topologies show the physical interconnection of devices. Logical topologies
    show the way the network will transfer data between connected nodes. 15. (单选题)
    WHAT IS INDICATED BY THE TERM THROUGHPUT?
    A. the measure of the bits transferred across the media over a given period of time
    B. the guaranteed data transfer rate offered by an ISP
    C. the time it takes for a message to get from sender to receiver
    D. the measure of the usable data transferred across the media
    E. the capacity of a particular medium to carry data
    我的答案: A 正确答案: A
    4.1 分
    答案解析：Throughput is the measure of the transfer of bits across the media over a given period
    of time. Throughput is affected by a number of factors such as, EMI and latency, so it rarely
    matches the specified bandwidth for a network medium. The throughput measurement includes
    user data bits and other data bits, such as overhead, acknowledging, and encapsulation. The
    measure of the usable data transferred across the media is called goodput. 16. (单选题)
    AS DATA TRAVELS ON THE MEDIA IN A STREAM OF 1S AND 0S HOW DOES A RECEIVING NODE
    IDENTIFY THE BEGINNING AND END OF A FRAME?
    A. The receiving node identifies the beginning of a frame by seeing a physical address. B. The transmitting node sends a beacon to notify that a data frame is attached. C. The transmitting node sends an out-of-band signal to the receiver about the beginning of the
    frame. D. The transmitting node inserts start and stop bits into the frame. 我的答案: D 正确答案: D
    4.1 分
    答案解析：When data travels on the media, it is converted into a stream of 1s and 0s. The
    framing process inserts into the frame start and stop indicator flags so that the destination can
    detect the beginning and end of the frame. 二. 多选题（共 4 题，16.4 分）
21. (多选题)
    WHAT ARE TWO SERVICES PERFORMED BY THE DATA LINK LAYER OF THE OSI MODEL? (CHOOSE
    TWO.)
    A. It monitors the Layer 2 communication by building a MAC address table. B. It provides media access control and performs error detection. C. It determines the path to forward packets. D. It encrypts data packets. E. It accepts Layer 3 packets and encapsulates them into frames. 我的答案: BE 正确答案: BE
    4.1 分
    答案解析：The data link layer is responsible for the exchange of frames between nodes over a
    physical network media. Specifically the data link layer performs two basic services:
    It accepts Layer 3 packets and encapsulates them into frames.
    It provides media access control and performs error detection. Path determination is a service provided at Layer 3. A Layer 2 switch builds a MAC address table
    as part of its operation, but path determination is not the service that is provided by the data link
    layer. 18. (多选题)
    A NETWORK ADMINISTRATOR IS DESIGNING THE LAYOUT OF A NEW WIRELESS NETWORK. WHICH THREE AREAS OF CONCERN SHOULD BE ACCOUNTED FOR WHEN BUILDING A WIRELESS
    NETWORK? (CHOOSE THREE.)
    A. extensive cabling
    B. interference
    C. mobility options
    D. packet collision
    E. coverage area
    F. security
    我的答案: BEF 正确答案: BEF
    4.1 分
    答案解析：The three areas of concern for wireless networks focus on the size of the coverage
    area, any nearby interference, and providing network security. Extensive cabling is not a concern
    for wireless networks, as a wireless network will require minimal cabling for providing wireless
    access to hosts. Mobility options are not a component of the areas of concern for wireless
    networks.
22. (多选题)
    WHAT ARE TWO REASONS FOR PHYSICAL LAYER PROTOCOLS TO USE FRAME ENCODING
    TECHNIQUES? (CHOOSE TWO.)
    A. to identify where the frame starts and ends
    B. to distinguish data bits from control bits
    C. to reduce the number of collisions on the media
    D. to provide better media error correction
    E. to increase the media throughput
    我的答案: AB 正确答案: AB
    4.1 分
    答案解析：An encoding technique converts a stream of data bits in a predefined code that can be
    recognized by both the transmitter and the receiver. Using predefined patterns helps to
    differentiate data bits from control bits and provide better media error detection. 20. (多选题)
    A NETWORK ADMINISTRATOR NOTICES THAT SOME NEWLY INSTALLED ETHERNET CABLING IS
    CARRYING CORRUPT AND DISTORTED DATA SIGNALS. THE NEW CABLING WAS INSTALLED IN THE
    CEILING CLOSE TO FLUORESCENT LIGHTS AND ELECTRICAL EQUIPMENT. WHICH TWO FACTORS
    MAY INTERFERE WITH THE COPPER CABLING AND RESULT IN SIGNAL DISTORTION AND DATA
    CORRUPTION? (CHOOSE TWO.)
    A. crosstalk
    B. extended length of cabling
    C. signal attenuation
    D. RFI
    E. EMI
    我的答案: DE 正确答案: DE
    4.1 分
    答案解析：EMI and RFI signals can distort and corrupt data signals that are carried by copper
    media. These distortions usually come from radio waves and electromagnetic devices such as
    motors and florescent lights. Crosstalk is a disturbance that is caused by adjacent wires bundled
    too close together with the magnetic field of one wire affecting another. Signal attenuation is
    caused when an electrical signal begins to deteriorate over the length of a copper cable. 三. 填空题（共 3 题，12.3 分）
23. (填空题)
    THE TERM __ INDICATES THE CAPACITY OF A MEDIUM TO CARRY DATA AND IT IS TYPICALLY
    MEASURED IN KILOBITS PER SECOND (KB/S) OR MEGABITS PER SECOND (MB/S). 我的答案：
    4.1 分
    (1) Bandwidth
    正确答案：
    (1) Bandwidth
    答案解析：Bandwidth is the capacity of a medium to carry data in a given amount of time. It is
    typically measured in kilobits per second (kb/s) or megabits per second (Mb/s). 22. (填空题)WHAT ACRONYM IS USED TO REFERENCE THE DATA LINK SUBLAYER THAT IDENTIFIES
    THE NETWORK LAYER PROTOCOL ENCAPSULATED IN THE FRAME? __ 我的答案：
    4.1 分
    (1) LLC
    正确答案：
    (1) LLC
    答案解析：Logical Link Control (LLC) is the data link sublayer that defines the software processes
    that provide services to the network layer protocols. LLC places information in the frame and that
    information identifies the network layer protocol that is encapsulated in the frame. 23. (填空题)
    A PHYSICAL TOPOLOGY THAT IS A VARIATION OR COMBINATION OF A POINT-TO-POINT, HUB AND
    SPOKE, OR MESH TOPOLOGY IS COMMONLY KNOWN AS A __ TOPOLOGY. 我的答案：
    4.1 分
    (1) Hybrid
    正确答案：
    (1) Hybrid
    答案解析：A hybrid topology is a variation or combination of a point-to-point, hub and spoke, or
    mesh topology. This may include a partial mesh or extended star topology. 四. 连线题（共 1 题，5.7 分）
24. (连线题)MATCH THE CHARACTERISTICS TO THE CORRECT TYPE OF FIBER. (NOT ALL OPTIONS
    ARE USED.)
    第 1 组
25. Multimode Fiber
26. Single-mode Fiber
    第 2 组
    A. LED as light source
    several paths of light into the fiber
    generally used with LANs
    B. only one ray of light into the fiber
    generally used for campus backbone
    laser as light source
    我的答案：
    1
    A
    2
    B
    正确答案：
    1
    A
    2
    B
    第五章测试
27. (单选题)
    WHAT STATEMENT DESCRIBES A CHARACTERISTIC OF MAC ADDRESSES?
    A. They have a 32-bit binary value. B. They are added as part of a Layer 3 PDU. C. They must be globally unique. D. They are only routable within the private network. 我的答案: C 正确答案: C
    4.7 分
    答案解析：Any vendor selling Ethernet devices must register with the IEEE to ensure the vendor
    is assigned a unique 24-bit code, which becomes the first 24 bits of the MAC address. The last 24
    bits of the MAC address are generated per hardware device. This helps to ensure globally unique
    addresses for each Ethernet device. 2. (单选题)
    WHAT IS AUTO-MDIX?
    A. a type of Cisco switch
    B. a feature that detects Ethernet cable type
    C. an Ethernet connector type
    D. a type of port on a Cisco switch
    我的答案: B 正确答案: B
    4.7 分
    答案解析：Auto-MDIX is a feature that is enabled on the latest Cisco switches and that allows the
    switch to detect and use whatever type of cable is attached to a specific port. 3. (单选题)
    THE ARP TABLE IN A SWITCH MAPS WHICH TWO TYPES OF ADDRESS TOGETHER?
    A. Layer 3 address to a Layer 4 address
    B. Layer 4 address to a Layer 2 address
    C. Layer 2 address to a Layer 4 address
    D. Layer 3 address to a Layer 2 address
    我的答案: D 正确答案: D
    4.7 分
    答案 解析 ：The switch ARP table keeps a mapping of Layer 2 MAC addresses to Layer 3 IP
    addresses. These mappings can be learned by the switch dynamically through ARP or statically
    through manual configuration. 4. (单选题)
    REFER TO THE EXHIBIT. THE EXHIBIT SHOWS A SMALL SWITCHED NETWORK AND THE CONTENTS
    OF THE MAC ADDRESS TABLE OF THE SWITCH. PC1 HAS SENT A FRAME ADDRESSED TO PC3. WHAT WILL THE SWITCH DO WITH THE FRAME?
    1.png
    A. The switch will forward the frame to all ports except port 4. B. The switch will forward the frame to all ports. C. The switch will forward the frame only to ports 1 and 3.
    D. The switch will forward the frame only to port 2. E. The switch will discard the frame. 我的答案: A 正确答案: A
    4.7 分
    答案解析：The MAC address of PC3 is not present in the MAC table of the switch. Because the
    switch does not know where to send the frame that is addressed to PC3, it will forward the frame
    to all the switch ports, except for port 4, which is the incoming port. 5. (单选题)
    WHAT STATEMENT DESCRIBES ETHERNET?
    A. It defines a standard model used to describe how networking works. B. It connects multiple sites such as routers located in different countries. C. It defines the most common LAN type in the world. D. It is the required Layer 1 and 2 standard for Internet communication. 我的答案: C 正确答案: C
    4.7 分
    答案解析：Ethernet is the most common LAN protocol in the world. It operates at Layer 1 and 2, but is not required for Internet communication. The OSI model is used to describe how networks
    operate. A WAN connects multiple sites located in different countries. 6. (单选题)
    WHICH DESTINATION ADDRESS IS USED IN AN ARP REQUEST FRAME?
    A. 255.255.255.255
    B. 0.0.0.0
    C. 01-00-5E-00-AA-23
    D. 127.0.0.1
    E. FFFF.FFFF.FFFF
    我的答案: E 正确答案: E
    4.7 分
    答案解析：The purpose of an ARP request is to find the MAC address of the destination host on
    an Ethernet LAN. The ARP process sends a Layer 2 broadcast to all devices on the Ethernet LAN. The frame contains the IP address of the destination and the broadcast MAC address, FFFF.FFFF.FFFF.
28. (单选题)
    WHICH STATEMENT IS TRUE ABOUT MAC ADDRESSES?
    A. The first three bytes are used by the vendor assigned OUI. B. A NIC only needs a MAC address if connected to a WAN. C. MAC addresses are implemented by software. D. The ISO is responsible for MAC addresses regulations. 我的答案: A 正确答案: A
    4.7 分
    答 案 解 析 ： A MAC address is composed of 6 bytes. The first 3 bytes are used for vendor
    identification and the last 3 bytes must be assigned a unique value within the same OUI. MAC
    addresses are implemented in hardware. A NIC needs a MAC address to communicate over the
    LAN. The IEEE regulates the MAC addresses. 8. (单选题)
    WHICH SWITCHING METHOD USES THE CRC VALUE IN A FRAME?
    A. fragment-free
    B. fast-forward
    C. cut-through
    D. store-and-forward
    我的答案: D 正确答案: D
    4.7 分
    答 案 解 析 ： When the store-and-forward switching method is used, the switch receives the
    complete frame before forwarding it on to the destination. The cyclic redundancy check (CRC)
    part of the trailer is used to determine if the frame has been modified during transit. In contrast, a cut-through switch forwards the frame once the destination Layer 2 address is read. Two types
    of cut-through switching methods are fast-forward and fragment-free. 9. (单选题)
    REFER TO THE EXHIBIT. THE SWITCHES ARE IN THEIR DEFAULT CONFIGURATION. HOST A NEEDS
    TO COMMUNICATE WITH HOST D, BUT HOST A DOES NOT HAVE THE MAC ADDRESS FOR ITS
    DEFAULT GATEWAY. WHICH NETWORK HOSTS WILL RECEIVE THE ARP REQUEST SENT BY HOST A?
    1.png
    A. only hosts B and C
    B. only hosts B, C, and router R1
    C. only hosts A, B, and C
    D. only host D
    E. only hosts A, B, C, and D
    F. only router R1
    我的答案: B 正确答案: B
    4.7 分
    答案解析：Since host A does not have the MAC address of the default gateway in its ARP table, host A sends an ARP broadcast. The ARP broadcast would be sent to every device on the local
    network. Hosts B, C, and router R1 would receive the broadcast. Router R1 would not forward the
    message. 10. (单选题)
    REFER TO THE EXHIBIT. A SWITCH WITH A DEFAULT CONFIGURATION CONNECTS FOUR HOSTS. THE ARP TABLE FOR HOST A IS SHOWN. WHAT HAPPENS WHEN HOST A WANTS TO SEND AN IP
    PACKET TO HOST D?
    1.png
    A. Host A sends out a broadcast of FF:FF:FF:FF:FF:FF. Every other host connected to the switch
    receives the broadcast and host D responds with its MAC address. B. Host D sends an ARP request to host A. C. Host A sends out the packet to the switch. The switch sends the packet only to the host D, which in turn responds. D. Host A sends an ARP request to the MAC address of host D. 我的答案: A 正确答案: A
    4.7 分
    答案解析：Whenever the destination MAC address is not contained within the ARP table of the
    originating host, the host (host A in this example) will send a Layer 2 broadcast that has a
    destination MAC address of FF:FF:FF:FF:FF:FF. All devices on the same network receive this
    broadcast. Host D will respond to this broadcast. 11. (单选题)
    WHICH STATEMENT DESCRIBES THE TREATMENT OF ARP REQUESTS ON THE LOCAL LINK?
    A. They are dropped by all switches on the local network. B. They are received and processed only by the target device. C. They must be forwarded by all routers on the local network. D. They are received and processed by every device on the local network. 我的答案: D 正确答案: D
    4.7 分
29. (单选题)
    REFER TO THE EXHIBIT.
    PC1 ISSUES AN ARP REQUEST BECAUSE IT NEEDS TO SEND A PACKET TO PC2. IN THIS SCENARIO, WHAT WILL HAPPEN NEXT?
    A. SW1 will send an ARP reply with its Fa0/1 MAC address
    B. PC2 will send an ARP reply with its MAC address
    C. RT1 will send an ARP reply with the PC2 MAC address. D. RT1 will send an ARP reply with its Fa0/0 MAC address. E. SW1 will send an ARP reply with the PC2 MAC address. 我的答案: B 正确答案: B
    4.7 分
    答案解析：When a network device wants to communicate with another device on the same
    network, it sends a broadcast ARP request. In this case, the request will contain the IP address of
    PC2. The destination device (PC2) sends an ARP reply with its MAC address. 13. (单选题)
    WHAT ADDRESSING INFORMATION IS RECORDED BY A SWITCH TO BUILD ITS MAC ADDRESS
    TABLE?
    A. the source Layer 2 address of incoming frames
    B. the destination Layer 2 address of outgoing frames
    C. the destination Layer 3 address of incoming packets
    D. the source Layer 3 address of outgoing packets
    我的答案: A 正确答案: A
    4.7 分
    答案解析：A switch builds a MAC address table by inspecting incoming Layer 2 frames and
    recording the source MAC address found in the frame header. The discovered and recorded MAC
    address is then associated with the port used to receive the frame. 14. (单选题)
    WHAT HAPPENS TO RUNT FRAMES RECEIVED BY A CISCO ETHERNET SWITCH?
    A. The frame is dropped. B. The frame is sent to the default gateway
    C. The frame is returned to the originating network device. D. The frame is broadcast to all other devices on the same network. 我的答案: A 正确答案: A
    4.7 分
    答案解析：
    In an attempt to conserve bandwidth and not forward useless frames, Ethernet devices drop
    frames that are considered to be runt (less than 64 bytes) or jumbo (greater than 1500 bytes)
    frames. 二. 多选题（共 3 题，14.1 分）
30. (多选题)
    WHICH TWO STATEMENTS DESCRIBE FEATURES OR FUNCTIONS OF THE LOGICAL LINK CONTROL
    SUBLAYER IN ETHERNET STANDARDS? (CHOOSE TWO.)
    A. The data link layer uses LLC to communicate with the upper layers of the protocol suite. B. Logical link control is specified in the IEEE 802.3 standard. C. The LLC sublayer is responsible for the placement and retrieval of frames on and off the media. D. Logical link control is implemented in software. E. The LLC sublayer adds a header and a trailer to the data. 我的答案: AD 正确答案: AD
    4.7 分
    答案解析：Logical link control is implemented in software and enables the data link layer to
    communicate with the upper layers of the protocol suite. Logical link control is specified in the
    IEEE 802.2 standard. IEEE 802.3 is a suite of standards that define the different Ethernet types. The MAC (Media Access Control) sublayer is responsible for the placement and retrieval of
    frames on and off the media. The MAC sublayer is also responsible for adding a header and a
    trailer to the network layer protocol data unit (PDU). 16. (多选题)
    WHAT ARE TWO POTENTIAL NETWORK PROBLEMS THAT CAN RESULT FROM ARP OPERATION?
    (CHOOSE TWO.)
    A. On large networks with low bandwidth, multiple ARP broadcasts could cause data
    communication delays. B. Large numbers of ARP request broadcasts could cause the host MAC address table to overflow
    and prevent the host from communicating on the network. C. Manually configuring static ARP associations could facilitate ARP poisoning or MAC address
    spoofing. D. Network attackers could manipulate MAC address and IP address mappings in ARP messages
    with the intent of intercepting network traffic. E. Multiple ARP replies result in the switch MAC address table containing entries that match the
    MAC addresses of hosts that are connected to the relevant switch port. 我的答案: AD 正确答案: AD
    4.7 分
    答 案 解 析 ： Large numbers of ARP broadcast messages could cause momentary data
    communications delays. Network attackers could manipulate MAC address and IP address
    mappings in ARP messages with the intent to intercept network traffic. ARP requests and replies
    cause entries to be made into the ARP table, not the MAC address table. ARP table overflows are
    very unlikely. Manually configuring static ARP associations is a way to prevent, not facilitate, ARP
    poisoning and MAC address spoofing. Multiple ARP replies resulting in the switch MAC address
    table containing entries that match the MAC addresses of connected nodes and are associated
    with the relevant switch port are required for normal switch frame forwarding operations. It is
    not an ARP caused network problem. 17. (多选题)
    WHAT ARE THE TWO SIZES (MINIMUM AND MAXIMUM) OF AN ETHERNET FRAME? (CHOOSE
    TWO.)
    A. 1518 bytes
    B. 56 bytes
    C. 1024 bytes
    D. 64 bytes
    E. 128 bytes
    我的答案: AD 正确答案: AD
    4.7 分
    答案解析：The minimum Ethernet frame is 64 bytes. The maximum Ethernet frame is 1518 bytes. A network technician must know the minimum and maximum frame size in order to recognize
    runt and jumbo frames. 三. 填空题（共 3 题，14.1 分）
31. (填空题)
    FILL IN THE BLANK. A COLLISION FRAGMENT, ALSO KNOWN AS A _ _ FRAME, IS A FRAME OF FEWER THAN 64
    BYTES IN LENGTH. 我的答案：
    4.7 分
    (1) RUNT
    正确答案：
    (1) RUNT
    答案解析：A runt frame is a frame of fewer than 64 bytes, usually generated by a collision or a
    network interface failure. 19. (填空题)
    ARP __ IS A TECHNIQUE THAT IS USED TO SEND FAKE ARP MESSAGES TO OTHER HOSTS IN THE
    LAN. THE AIM IS TO ASSOCIATE IP ADDRESSES TO THE WRONG MAC ADDRESSES. 我的答案：
    4.7 分
    (1) Spoofing
    正确答案：
    (1) Spoofing
32. (填空题)
    ON A CISCO SWITCH, __ MEMORY BUFFERING IS USED TO BUFFER FRAMES IN QUEUES LINKED
    TO SPECIFIC INCOMING AND OUTGOING PORTS. 我的答案：
    4.7 分
    (1) port-based
    正确答案：
    (1) port-based
    四. 判断题（共 1 题，6 分）
33. (判断题)WHEN A DEVICE IS SENDING DATA TO ANOTHER DEVICE ON A REMOTE NETWORK, THE ETHERNET FRAME IS SENT TO THE MAC ADDRESS OF THE DEFAULT GATEWAY.
    A. 对
    B. 错
    我的答案: 对正确答案: 对
    第六章测试
34. (单选题)
    WHAT TYPE OF ROUTE IS INDICATED BY THE CODE C IN AN IPV4 ROUTING TABLE ON A CISCO
    ROUTER?
    A. dynamic route that is learned through EIGRP
    B. static route
    C. directly connected route
    D. default route
    我的答案: C 正确答案: C
    5 分
    答案解析：Some of the IPv4 routing table codes include the following:
    C – directly connected
    S – static
    D – EIGRP

• – candidate default

2. (单选题)
   WHICH CHARACTERISTIC DESCRIBES AN IPV6 ENHANCEMENT OVER IPV4?
   A. Both IPv4 and IPv6 support authentication, but only IPv6 supports privacy capabilities. B. IPv6 addresses are based on 128-bit flat addressing as opposed to IPv4 which is based on
   32-bit hierarchical addressing. C. The IPv6 header is simpler than the IPv4 header is, which improves packet handling. D. The IPv6 address space is four times bigger than the IPv4 address space. 我的答案: C 正确答案: C
   5 分
   答案解析：IPv6 addresses are based on 128-bit hierarchical addressing, and the IPv6 header has
   been simplified with fewer fields, improving packet handling. IPv6 natively supports
   authentication and privacy capabilities as opposed to IPv4 that needs additional features to
   support those. The IPv6 address space is many times bigger than IPv4 address space. 3. (单选题)
   FOLLOWING DEFAULT SETTINGS, WHAT IS THE NEXT STEP IN THE ROUTER BOOT SEQUENCE
   AFTER THE IOS LOADS FROM FLASH?
   A. Load the running-config file from RAM. B. Perform the POST routine. C. Load the bootstrap program from ROM. D. Locate and load the startup-config file from NVRAM. 我的答案: D 正确答案: D
   5 分
   答案解析：There are three major steps to the router boot sequence:
   Perform Power-On-Self-Test (POST)
   Load the IOS from Flash or TFTP server
   Load the startup configuration file from NVRAM
3. ( 单 选 题 )REFER TO THE EXHIBIT. R1 RECEIVES A PACKET DESTINED FOR THE IP ADDRESS
   192.168.2.10. OUT WHICH INTERFACE WILL R1 FORWARD THE PACKET?
   1.png
   A. FastEthernet0/1
   B. Serial0/0/1
   C. FastEthernet0/0
   D. Serial0/0/0
   我的答案: B 正确答案: B
   5 分
   答案解析：If a route in the routing table points to a next hop address, the router will perform a
   second lookup to determine out which interface the next hop is located. 5. (单选题)
   WHAT IS THE PURPOSE OF THE STARTUP CONFIGURATION FILE ON A CISCO ROUTER?
   A. to contain the commands that are used to initially configure a router on startup
   B. to contain the configuration commands that the router IOS is currently using
   C. to provide a limited backup version of the IOS, in case the router cannot load the full featured
   IOS
   D. to facilitate the basic operation of the hardware components of a device
   我的答案: A 正确答案: A
   5 分
   答案解析：The startup configuration file is stored in NVRAM and contains the commands needed
   to initially configure a router. It also creates the running configuration file that is stored in in
   RAM. 6. (单选题) WHAT ADDRESSES ARE MAPPED BY ARP?
   A. destination MAC address to the source IPv4 address
   B. destination IPv4 address to the source MAC address
   C. destination IPv4 address to the destination host name
   D. destination MAC address to a destination IPv4 address
   我的答案: D 正确答案: D
   5 分
4. (单选题)
   WHEN A CONNECTIONLESS PROTOCOL IS IN USE AT A LOWER LAYER OF THE OSI MODEL, HOW IS
   MISSING DATA DETECTED AND RETRANSMITTED IF NECESSARY?
   A. Network layer IP protocols manage the communication sessions if connection-oriented
   transport services are not available.
   B. Connectionless acknowledgements are used to request retransmission. C. The best-effort delivery process guarantees that all packets that are sent are received. D. Upper-layer connection-oriented protocols keep track of the data received and can request
   retransmission from the upper-level protocols on the sending host. 我的答案: D 正确答案: D
   5 分
   答 案 解 析 ： When connectionless protocols are in use at a lower layer of the OSI model, upper-level protocols may need to work together on the sending and receiving hosts to account
   for and retransmit lost data. In some cases, this is not necessary, because for some applications a
   certain amount of data loss is tolerable. 8. (单选题)
   WHAT IPV4 HEADER FIELD IDENTIFIES THE UPPER LAYER PROTOCOL CARRIED IN THE PACKET?
   A. Differentiated Services
   B. Protocol
   C. Identification
   D. Version
   我的答案: B 正确答案: B
   5 分
   答案解析：It is the Protocol field in the IP header that identifies the upper-layer protocol the
   packet is carrying. The Version field identifies the IP version. The Differential Services field is used
   for setting packet priority. The Identification field is used to reorder fragmented packets. 9. (单选题)
   WHICH FIELD IN THE IPV4 HEADER IS USED TO PREVENT A PACKET FROM TRAVERSING A
   NETWORK ENDLESSLY?
   A. Differentiated Services
   B. Acknowledgment Number
   C. Sequence Number
   D. Time-to-Live
   我的答案: D 正确答案: D
   5 分
   答案解析：The value of the Time-to-Live (TTL) field in the IPv4 header is used to limit the lifetime
   of a packet. The sending host sets the initial TTL value; which is decreased by one each time the
   packet is processed by a router. If the TTL field decrements to zero, the router discards the packet
   and sends an Internet Control Message Protocol (ICMP) Time Exceeded message to the source IP
   address. The Differentiated Services (DS) field is used to determine the priority of each packet. Sequence Number and Acknowledgment Number are two fields in the TCP header.
5. (单选题)
   A ROUTER BOOTS AND ENTERS SETUP MODE. WHAT IS THE REASON FOR THIS?
   A. Cisco IOS is missing from flash memory. B. The POST process has detected hardware failure. C. The configuration file is missing from NVRAM. D. The IOS image is corrupt. 我的答案: C 正确答案: C
   5 分
6. (单选题)
   WHAT ROUTING TABLE ENTRY HAS A NEXT HOP ADDRESS ASSOCIATED WITH A DESTINATION
   NETWORK?
   A. directly-connected routes
   B. remote routes
   C. C and L source routes
   D. local routes
   我的答案: B 正确答案: B
   5 分
   答案解析：Routing table entries for remote routes will have a next hop IP address. The next hop
   IP address is the address of the router interface of the next device to be used to reach the
   destination network. Directly-connected and local routes have no next hop, because they do not
   require going through another router to be reached. 12. (单选题)
   WHICH STATEMENT DESCRIBES A HARDWARE FEATURE OF A CISCO 1941 ROUTER THAT HAS THE
   DEFAULT HARDWARE CONFIGURATION?
   A. It has two types of ports that can be used to access the console. B. It does not have an AUX port. C. It has three FastEthernet interfaces for LAN access. D. It does not require a CPU because it relies on Compact Flash to run the IOS.
   我的答案: A 正确答案: A
   5 分
   答案解析：The connections in a Cisco 1941 router include two types of ports that are used for
   initial configuration and command-line interface management access. The two ports are the
   regular RJ-45 port and a new USB Type-B (mini-B USB) connector. In addition, the router has an
   AUX port for remote management access, and two Gigabit Ethernet interfaces for LAN access. Compact Flash can be used increase device storage, but it does not perform the functions of the
   CPU, which is required for operation of the device. 13. (单选题)
   WHAT IS ONE ADVANTAGE THAT THE IPV6 SIMPLIFIED HEADER OFFERS OVER IPV4?
   A. little requirement for processing checksums
   B. smaller-sized source and destination IP addresses
   C. efficient packet handling
   D. smaller-sized header
   我的答案: C 正确答案: C
   5 分
   答案解析：The IPv6 simplified header offers several advantages over IPv4:
   · Better routing efficiency and efficient packet handling for performance and forwarding-rate
   scalability
   · No requirement for processing checksums
   · Simplified and more efficient extension header mechanisms (as opposed to the IPv4 Options
   field)
   · A Flow Label field for per-flow processing with no need to open the transport inner packet to
   identify the various traffic flows
7. (单选题)REFER TO THE EXHIBIT. WHICH ROUTE FROM THE PC1 ROUTING TABLE WILL BE USED
   TO REACH PC2?
   1.png
   A. Network destination: 192.168.10.0
   Netmask: 255.255.255.0
   Gateway: On-link
   Interface: 192.168.10.10
   Metric: 281
   B. Network destination: 192.168.10.10
   Netmask: 255.255.255.255
   Gateway: On-link
   Interface: 192.168.10.10
   Metric: 281
   C. Network destination: 0.0.0.0
   Netmask: 0.0.0.0
   Gateway: 192.168.10.1
   Interface: 192.168.10.10
   Metric: 25
   D. Network destination: 127.0.0.1
   Netmask: 255.255.255.255
   Gateway: On-link
   Interface: 127.0.0.1
   Metric: 306
   我的答案: A 正确答案: A
   5 分
   答案解析：PC1 and PC2 are both on network 192.168.10.0 with mask 255.255.255.0, so there is
   no need to access the default gateway (entry 0.0.0.0 0.0.0.0). Entry 127.0.0.1 255.255.255.255 is
   the loopback interface and entry 192.168.10.10 255.255.255.255 identifies the PC1 address
   interface. 15. (单选题)
   WHICH CHARACTERISTIC OF THE NETWORK LAYER IN THE OSI MODEL ALLOWS CARRYING
   PACKETS FOR MULTIPLE TYPES OF COMMUNICATIONS AMONG MANY HOSTS?
   A. the ability to operate without regard to the data that is carried in each packet
   B. the selection of paths for and direct packets toward the destination
   C. the de-encapsulation of headers from lower layers
   D. the ability to manage the data transport between processes running on hosts
   我的答案: A 正确答案: A
   5 分
   答 案 解 析 ： The function of the network layer protocols specifies the packet structure and
   processing used to carry the data from one host to another host. The actual communication data
   is encapsulated in the network layer PDU. The feature of its operation without regard to the data
   carried in each packet allows the network layer to carry packets for multiple types of
   communications.
   二. 多选题（共 4 题，20 分）
8. (多选题)
   WHAT ARE TWO TYPES OF ROUTER INTERFACES? (CHOOSE TWO.)
   A. Telnet
   B. LAN
   C. SVI
   D. DHCP
   E. WAN
   我的答案: BE 正确答案: BE
   5 分
   答案解析：LAN interfaces – Used for connecting cables that terminate with LAN devices, such as
   computers and switches. This interface can also be used to connect routers to each other. WAN interfaces – Used for connecting routers to external networks, usually over a larger
   geographical distance. 17. (多选题)
   WHICH TWO PIECES OF INFORMATION ARE IN THE RAM OF A CISCO ROUTER DURING NORMAL
   OPERATION? (CHOOSE TWO.)
   A. startup configuration file
   B. basic diagnostic software
   C. backup IOS file
   D. Cisco IOS
   E. IP routing table
   我的答案: DE 正确答案: DE
   5 分
   答案解析：The Cisco IOS file is stored in flash memory and copied into RAM during the boot up. The IP routing table is also stored in RAM. The basic diagnostic software is stored in ROM and the
   startup configuration file is stored in NVRAM. 18. (多选题)
   WHICH THREE COMMANDS ARE USED TO SET UP SECURE ACCESS TO A ROUTER THROUGH A
   CONNECTION TO THE CONSOLE INTERFACE? (CHOOSE THREE.)
   A. line vty 0 4
   B. login
   C. enable secret cisco
   D. line console 0
   E. interface fastethernet 0/0
   F. password cisco
   我的答案: BDF 正确答案: BDF
   5 分
   答案解析：The three commands needed to password protect the console port are as follows:
   line console 0
   password cisco
   login
9. (多选题)
   WHAT ARE TWO CHARACTERISTICS OF IP? (CHOOSE TWO.)
   A. does not require a dedicated end-to-end connection
   B. operates independently of the network media
   C. re-assembles out of order packets into the correct order at the receiver end
   D. guarantees delivery of packets
   E. retransmits packets if errors occur
   我的答案: AB 正确答案: AB
   5 分
   答案解析：The Internet Protocol (IP) is a connectionless, best effort protocol. This means that IP
   requires no end-to-end connection nor does it guarantee delivery of packets. IP is also media
   independent, which means it operates independently of the network media carrying the packets. 三. 连线题（共 1 题，5 分）
10. (连线题)MATCH THE COMMAND WITH THE DEVICE MODE AT WHICH THE COMMAND IS
    ENTERED. (NOT ALL OPTIONS ARE USED.)
    第 1 组
11. service password-encrytion
12. enable
13. copy running-config startup-config
14. login
15. ip address 192.168.4.4 255.255.255.0
    第 2 组
    A. R1(config)#
    B. R1>
    C. R1#
    D. R1(config-line)
    E. R1(config-if)#
    我的答案：
    1
    A
    2
    B
    3
    C
    4
    D
    5
    E
    正确答案：
    1
    A
    2
    B
    3
    C
    4
    D
    5
    E
    第七章测试
16. (单选题)
    WHAT SUBNET MASK IS REPRESENTED BY THE SLASH NOTATION /20?
    A. 255.255.240.0
    B. 255.255.255.248
    C. 255.255.255.192
    D. 255.255.255.0
    E. 255.255.224.0
    我的答案: A 正确答案: A
    4.1 分
    答案解析：The slash notation /20 represents a subnet mask with 20 1s. This would translate to:
    11111111.11111111.11110000.0000, which in turn would convert into 255.255.240.0. 2. (单选题)
    A MESSAGE IS SENT TO ALL HOSTS ON A REMOTE NETWORK. WHICH TYPE OF MESSAGE IS IT?
    A. unicast
    B. directed broadcast
    C. limited broadcast
    D. multicast
    我的答案: B 正确答案: B
    4.1 分
    答案解析：A directed broadcast is a message sent to all hosts on a specific network. It is useful
    for sending a broadcast to all hosts on a nonlocal network. A multicast message is a message sent
    to a selected group of hosts that are part of a subscribing multicast group. A limited broadcast is
    used for a communication that is limited to the hosts on the local network. A unicast message is a
    message sent from one host to another. 3. (单选题)
    WHAT TYPE OF ADDRESS IS AUTOMATICALLY ASSIGNED TO AN INTERFACE WHEN IPV6 IS
    ENABLED ON THAT INTERFACE?
    A. global unicast
    B. link-local
    C. unique local
    D. loopback
    我的答案: B 正确答案: B
    4.1 分
17. (单选题)
    WHAT DOES THE IP ADDRESS 172.17.4.250/24 REPRESENT?
    A. host address
    B. broadcast address
    C. multicast address
    D. network address
    我的答案: A 正确答案: A
    4.1 分
18. (单选题)
    WHAT FIELD CONTENT IS USED BY ICMPV6 TO DETERMINE THAT A PACKET HAS EXPIRED?
    A. CRC field
    B. Hop Limit field
    C. TTL field
    D. Time Exceeded field
    我的答案: B 正确答案: B
    4.1 分
    答案解析：ICMPv6 sends a Time Exceeded message if the router cannot forward an IPv6 packet
    because the packet expired. The router uses a hop limit field to determine if the packet has
    expired, and does not have a TTL field. 6. (单选题)
    HOW MANY BITS ARE IN AN IPV4 ADDRESS?
    A. 256
    B. 128
    C. 32
    D. 64
    我的答案: C 正确答案: C
    4.1 分
19. (单选题)
    WHICH PROTOCOL SUPPORTS STATELESS ADDRESS AUTOCONFIGURATION (SLAAC) FOR DYNAMIC
    ASSIGNMENT OF IPV6 ADDRESSES TO A HOST?
    A. ICMPv6
    B. UDP
    C. ARPv6
    D. DHCPv6
    我的答案: A 正确答案: A
    4.1 分
20. (单选题)
    WHAT IS THE PURPOSE OF THE SUBNET MASK IN CONJUNCTION WITH AN IP ADDRESS?
    A. to determine the subnet to which the host belongs
    B. to mask the IP address to outsiders
    C. to identify whether the address is public or private
    D. to uniquely identify a host on a network
    我的答案: A 正确答案: A
    4.1 分
21. (单选题)
    WHAT IS INDICATED BY A SUCCESSFUL PING TO THE ::1 IPV6 ADDRESS?
    A. All hosts on the local link are available. B. The link-local address is correctly configured. C. The default gateway address is correctly configured. D. IP is properly installed on the host
    E. The host is cabled properly. 我的答案: D 正确答案: D
    4.1 分
    答案解析：The IPv6 address ::1 is the loopback address. A successful ping to this address means
    that the TCP/IP stack is correctly installed. It does not mean that any addresses are correctly
    configured. 10. (单选题)
    WHAT IS THE PURPOSE OF ICMP MESSAGES?
    A. to provide feedback of IP packet transmissions
    B. to inform routers about network topology changes
    C. to ensure the delivery of an IP packet
    D. to monitor the process of a domain name to IP address resolution
    我的答案: A 正确答案: A
    4.1 分
22. (单选题)
    WHICH OF THESE ADDRESSES IS THE SHORTEST ABBREVIATION FOR THE IP ADDRESS:
    3FFE:1044:0000:0000:00AB:0000:0000:0057?
    A. 3FFE:1044:0000:0000:00AB::57
    B. 3FFE:1044::AB::57
    C. 3FFE:1044:0:0:00AB::0057
    D. 3FFE:1044:0:0:AB::57
    E. 3FFE:1044::00AB::0057
    F. 3FFE:1044:0000:0000:00AB::0057
    我的答案: D 正确答案: D
    4.1 分
23. (单选题)
    AN ADMINISTRATOR WANTS TO CONFIGURE HOSTS TO AUTOMATICALLY ASSIGN IPV6 ADDRESSES
    TO THEMSELVES BY THE USE OF ROUTER ADVERTISEMENT MESSAGES, BUT ALSO TO OBTAIN THE
    DNS SERVER ADDRESS FROM A DHCPV6 SERVER. WHICH ADDRESS ASSIGNMENT METHOD
    SHOULD BE CONFIGURED?
    A. SLAAC
    B. RA and EUI-64
    C. stateless DHCPv6
    D. stateful DHCPv6
    我的答案: C 正确答案: C
    4.1 分
24. (单选题)
    A USER IS EXECUTING A TRACERT TO A REMOTE DEVICE. AT WHAT POINT WOULD A ROUTER, WHICH IS IN THE PATH TO THE DESTINATION DEVICE, STOP FORWARDING THE PACKET?
    A. when the value in the TTL field reaches zero
    B. when the RTT value reaches zero
    C. when the values of both the Echo Request and Echo Reply messages reach zero
    D. when the host responds with an ICMP Echo Reply message
    E. when the router receives an ICMP Time Exceeded message
    我的答案: A 正确答案: A
    4.1 分
    二. 多选题（共 7 题，28.7 分）
25. (多选题)
    WHICH TWO PARTS ARE COMPONENTS OF AN IPV4 ADDRESS? (CHOOSE TWO.)
    A. subnet portion
    B. logical portion
    C. physical portion
    D. broadcast portion
    E. host portion
    F. network portion
    我的答案: EF 正确答案: EF
    4.1 分
26. (多选题)
    WHAT ARE THREE PARTS OF AN IPV6 GLOBAL UNICAST ADDRESS? (CHOOSE THREE.)
    A. a subnet ID that is used to identify networks inside of the local enterprise site
    B. a global routing prefix that is used to identify the network portion of the address that has been
    provided by an ISP
    C. an interface ID that is used to identify the local host on the network
    D. a global routing prefix that is used to identify the portion of the network address provided by a
    local administrator
    E. an interface ID that is used to identify the local network for a particular host
    我的答案: ABC 正确答案: ABC
    4.1 分
27. (多选题)
    WHAT ARE TWO TYPES OF IPV6 UNICAST ADDRESSES? (CHOOSE TWO.)
    A. anycast
    B. link-local
    C. multicast
    D. loopback
    E. broadcast
    我的答案: BD 正确答案: BD
    4.1 分
28. (多选题)
    WHICH TWO THINGS CAN BE DETERMINED BY USING THE PING COMMAND? (CHOOSE TWO.)
    A. the average time it takes each router in the path between source and destination to respond
    B. the average time it takes a packet to reach the destination and for the response to return to
    the source
    C. the IP address of the router nearest the destination device
    D. the number of routers between the source and destination device
    E. the destination device is reachable through the network
    我的答案: BE 正确答案: BE
    4.1 分
29. (多选题)
    WHICH TWO IPV4 TO IPV6 TRANSITION TECHNIQUES MANAGE THE INTERCONNECTION OF IPV6
    DOMAINS? (CHOOSE TWO.)
    A. multiplexing
    B. tunneling
    C. encapsulation
    D. trunking
    E. dual stack
    我的答案: BE 正确答案: BE
    4.1 分
30. (多选题)
    WHICH THREE IP ADDRESSES ARE PRIVATE ? (CHOOSE THREE.)
    A. 10.1.1.1
    B.224.6.6.6
    C.192.168.5.5
    D.172.32.5.2
    E. 172.16.4.4
    F.192.167.10.10
    我的答案: ACE 正确答案: ACE
    4.1 分
31. (多选题)
    WHAT ARE THREE CHARACTERISTICS OF MULTICAST TRANSMISSION? (CHOOSE THREE.)
    A. Multicast messages map lower layer addresses to upper layer addresses. B. A single packet can be sent to a group of hosts. C. The source address of a multicast transmission is in the range of 224.0.0.0 to 224.0.0.255. D. Multicast transmission can be used by routers to exchange routing information. E. The range of 224.0.0.0 to 224.0.0.255 is reserved to reach multicast groups on a local
    network. 我的答案: BDE 正确答案: BDE
    4.1 分
    三. 填空题（共 3 题，12.3 分）
32. (填空题)
    THE DECIMAL EQUIVALENT OF THE BINARY NUMBER 10010101 IS __ 我的答案：
    4.1 分
    (1) 149
    正确答案：
    (1) 149
33. (填空题)
    WHAT IS THE DECIMAL EQUIVALENT OF THE HEX NUMBER 0X3F? __ 我的答案：
    4.1 分
    (1) 63
    正确答案：
    (1) 63
34. (填空题)
    THE BINARY EQUIVALENT OF THE DECIMAL NUMBER 232 IS __ 我的答案：
    4.1 分
    (1) 11101000
    正确答案：
    (1) 11101000
    四. 连线题（共 1 题，5.7 分）
35. (连线题)
    MATCH EACH DESCRIPTION WITH AN APPROPRIATE IP ADDRESS. (NOT ALL OPTIONS ARE USED.)
    第 1 组
36. 169.254.1.5
37. 192.0.2.123
38. 240.2.6.255
39. 172.19.20.5
40. 127.0.0.1
    第 2 组
    A. a link-local address
    B. a TEST-NET address
    C. an experimental address
    D. a private address
    E. a loopback address
    我的答案：
    1
    A
    2
    B
    3
    C
    4
    D
    5
    E
    正确答案：
    1
    A
    2
    B
    3
    C
    4
    D
    5
    E
    第八章测试
41. (单选题)
    WHAT IS A RESULT OF CONNECTING TWO OR MORE SWITCHES TOGETHER?
    A. The size of the broadcast domain is increased. B. The number of broadcast domains is increased. C. The size of the collision domain is increased. D. The number of collision domains is reduced. 我的答案: A 正确答案: A
    4.5 分
42. (单选题)
    HOW MANY BITS MUST BE BORROWED FROM THE HOST PORTION OF AN ADDRESS TO
    ACCOMMODATE A ROUTER WITH FIVE CONNECTED NETWORKS?
    A. two
    B. four
    C. three
    D. five
    我的答案: C 正确答案: C
    4.5 分
43. (单选题)
    REFER TO THE EXHIBIT. HOW MANY BROADCAST DOMAINS ARE THERE?
    1.png
    A. 1
    B. 2
    C. 3
    D. 4
    我的答案: D 正确答案: D
    4.5 分
44. (单选题)
    A NETWORK ADMINISTRATOR WANTS TO HAVE THE SAME NETWORK MASK FOR ALL NETWORKS
    AT A PARTICULAR SMALL SITE. THE SITE HAS THE FOLLOWING NETWORKS AND NUMBER OF
    DEVICES:
    IP PHONES – 22 ADDRESSES
    PCS – 20 ADDRESSES NEEDED
    PRINTERS – 2 ADDRESSES NEEDED
    SCANNERS – 2 ADDRESSES NEEDED
    THE NETWORK ADMINISTRATOR HAS DEEMED THAT 192.168.10.0/24 IS TO BE THE NETWORK
    USED AT THIS SITE. WHICH SINGLE SUBNET MASK WOULD MAKE THE MOST EFFICIENT USE OF
    THE AVAILABLE ADDRESSES TO USE FOR THE FOUR SUBNETWORKS?
    A. 255.255.255.248
    B. 255.255.255.240
    C. 255.255.255.0
    D. 255.255.255.192
    E. 255.255.255.224
    F. 255.255.255.252
    我的答案: E 正确答案: E
    4.5 分
45. (单选题)
    A DHCP SERVER IS USED TO ASSIGN IP ADDRESSES DYNAMICALLY TO THE HOSTS ON A NETWORK. THE ADDRESS POOL IS CONFIGURED WITH 192.168.10.0/24. THERE ARE 3 PRINTERS ON THIS
    NETWORK THAT NEED TO USE RESERVED STATIC IP ADDRESSES FROM THE POOL. HOW MANY IP
    ADDRESSES IN THE POOL ARE LEFT TO BE ASSIGNED TO OTHER HOSTS?
    A. 253
    B. 254
    C. 251
    D. 252
    我的答案: C 正确答案: C
    4.5 分
46. (单选题)REFER TO THE EXHIBIT. CONSIDERING THE ADDRESSES ALREADY USED AND HAVING
    TO REMAIN WITHIN THE 10.16.10.0/24 NETWORK RANGE, WHICH SUBNET ADDRESS COULD BE
    ASSIGNED TO THE NETWORK CONTAINING 25 HOSTS?
    1.png
    A. 10.16.10.224/26
    B. 10.16.10.240/28
    C. 10.16.10.160/26
    D. 10.16.10.64/27
    E. 10.16.10.240/27
    F. 10.16.10.128/28
    我的答案: D 正确答案: D
    4.5 分
47. (单选题)REFER TO THE EXHIBIT. A COMPANY USES THE ADDRESS BLOCK OF 128.107.0.0/16
    FOR ITS NETWORK. WHAT SUBNET MASK WOULD PROVIDE THE MAXIMUM NUMBER OF EQUAL
    SIZE SUBNETS WHILE PROVIDING ENOUGH HOST ADDRESSES FOR EACH SUBNET IN THE EXHIBIT?
    1.png
    A. 255.255.255.240
    B. 255.255.255.192
    C. 255.255.255.224
    D. 255.255.255.0
    E. 255.255.255.128
    我的答案: E 正确答案: E
    4.5 分
48. (单选题)
    WHICH SUBNET MASK WOULD BE USED IF 5 HOST BITS ARE AVAILABLE?
    A. 255.255.255.240
    B. 255.255.255.224
    C. 255.255.255.128
    D. 255.255.255.0
    我的答案: B 正确答案: B
    4.5 分
49. (单选题)
    HOW MANY HOST ADDRESSES ARE AVAILABLE ON THE NETWORK 172.16.128.0 WITH A SUBNET
    MASK OF 255.255.252.0?
    A. 2046
    B. 510
    C. 2048
    D. 512
    E. 1022
    F. 1024
    我的答案: E 正确答案: E
    4.5 分
50. (单选题)
    WHAT IS THE PREFIX FOR THE HOST ADDRESS 2001:DB8:BC15:A:12AB::1/64?
    A. 2001:DB8:BC15:A
    B. 2001:DB8:BC15:A:1
    C. 2001:DB8:BC15:A:12
    D. 2001:DB8:BC15
    我的答案: A 正确答案: A
    4.5 分
51. (单选题)REFER TO THE EXHIBIT. A COMPANY IS DEPLOYING AN IPV6 ADDRESSING SCHEME
    FOR ITS NETWORK. THE COMPANY DESIGN DOCUMENT INDICATES THAT THE SUBNET PORTION
    OF THE IPV6 ADDRESSES IS USED FOR THE NEW HIERARCHICAL NETWORK DESIGN, WITH THE
    SITE SUBSECTION TO REPRESENT MULTIPLE GEOGRAPHICAL SITES OF THE COMPANY, THE
    SUB-SITE SECTION TO REPRESENT MULTIPLE CAMPUSES AT EACH SITE, AND THE SUBNET SECTION
    TO INDICATE EACH NETWORK SEGMENT SEPARATED BY ROUTERS. WITH SUCH A SCHEME, WHAT
    IS THE MAXIMUM NUMBER OF SUBNETS ACHIEVED PER SUB-SITE?
    1.png
    A. 4
    B. 0
    C. 256
    D. 16
    我的答案: D 正确答案: D
    4.5 分
52. (单选题)REFER TO THE EXHIBIT. THE NETWORK ADMINISTRATOR HAS ASSIGNED THE LAN OF
    LBMISS AN ADDRESS RANGE OF 192.168.10.0. THIS ADDRESS RANGE HAS BEEN SUBNETTED
    USING A /29 PREFIX. IN ORDER TO ACCOMMODATE A NEW BUILDING, THE TECHNICIAN HAS
    DECIDED TO USE THE FIFTH SUBNET FOR CONFIGURING THE NEW NETWORK (SUBNET ZERO IS
    THE FIRST SUBNET). BY COMPANY POLICIES, THE ROUTER INTERFACE IS ALWAYS ASSIGNED THE
    FIRST USABLE HOST ADDRESS AND THE WORKGROUP SERVER IS GIVEN THE LAST USABLE HOST
    ADDRESS. WHICH CONFIGURATION SHOULD BE ENTERED INTO THE PROPERTIES OF THE
    WORKGROUP SERVER TO ALLOW CONNECTIVITY TO THE INTERNET?
    1.png
    A. IP address: 192.168.10.65 subnet mask: 255.255.255.240, default gateway: 192.168.10.76
    B. IP address: 192.168.10.254 subnet mask: 255.255.255.0, default gateway: 192.168.10.1
    C. IP address: 192.168.10.41 subnet mask: 255.255.255.248, default gateway: 192.168.10.46
    D. IP address: 192.168.10.38 subnet mask: 255.255.255.248, default gateway: 192.168.10.33
    E. IP address: 192.168.10.38 subnet mask: 255.255.255.240, default gateway: 192.168.10.33
    我的答案: D 正确答案: D
    4.5 分
53. (单选题)
    A NETWORK ADMINISTRATOR IS VARIABLY SUBNETTING A NETWORK. THE SMALLEST SUBNET
    HAS A MASK OF 255.255.255.248. HOW MANY USABLE HOST ADDRESSES WILL THIS SUBNET
    PROVIDE?
    A. 8
    B. 6
    C. 4
    D. 12
    E. 10
    我的答案: B 正确答案: B
    4.5 分
54. (单选题)REFER TO THE EXHIBIT. GIVEN THE NETWORK ADDRESS OF 192.168.5.0 AND A SUBNET MASK OF 255.255.255.224, HOW
    MANY TOTAL HOST ADDRESSES ARE UNUSED IN THE ASSIGNED SUBNETS?
    1.png
    A. 68
    B. 60
    C. 56
    D. 72
    E. 64
    我的答案: D 正确答案: D
    4.5 分
55. (单选题)
    IF A NETWORK DEVICE HAS A MASK OF /28, HOW MANY IP ADDRESSES ARE AVAILABLE FOR
    HOSTS ON THIS NETWORK?
    A. 14
    B. 62
    C. 254
    D. 16
    E. 256
    F. 32
    我的答案: A 正确答案: A
    4.5 分
56. (单选题)
    A NETWORK ADMINISTRATOR NEEDS TO MONITOR NETWORK TRAFFIC TO AND FROM SERVERS
    IN A DATA CENTER. WHICH FEATURES OF AN IP ADDRESSING SCHEME SHOULD BE APPLIED TO
    THESE DEVICES?
    A. addresses from different subnets for redundancy
    B. predictable static IP addresses for easier identification
    C. dynamic addresses to reduce the probability of duplicate addresses
    D. random static addresses to improve security
    我的答案: B 正确答案: B
    4.5 分
    二. 多选题（共 3 题，13.5 分）
57. (多选题)
    A COMPANY HAS A NETWORK ADDRESS OF 192.168.1.64 WITH A SUBNET MASK OF
    255.255.255.192. THE COMPANY WANTS TO CREATE TWO SUBNETWORKS THAT WOULD
    CONTAIN 10 HOSTS AND 18 HOSTS RESPECTIVELY. WHICH TWO NETWORKS WOULD ACHIEVE
    THAT? (CHOOSE TWO.)
    A. 192.168.1.64/27
    B. 192.168.1.96/28
    C. 192.168.1.192/28
    D. 192.168.1.128/27
    E. 192.168.1.16/28
    我的答案: AB 正确答案: AB
    4.5 分
58. (多选题)
    WHICH TWO REASONS GENERALLY MAKE DHCP THE PREFERRED METHOD OF ASSIGNING IP
    ADDRESSES TO HOSTS ON LARGE NETWORKS? (CHOOSE TWO.)
    A. It reduces the burden on network support staff. B. It eliminates most address configuration errors. C. It guarantees that every device that needs an address will get one. D. It provides an address only to devices that are authorized to be connected to the network. E. It ensures that addresses are only applied to devices that require a permanent address. 我的答案: AB 正确答案: AB
    4.5 分
59. (多选题)
    WHAT ARE TWO REASONS A NETWORK ADMINISTRATOR MIGHT WANT TO CREATE SUBNETS?
    (CHOOSE TWO.)
    A. improves network performance
    B. easier to implement security policies
    C. reduction in number of switches needed
    D. simplifies network design
    E. reduction in number of routers needed
    我的答案: AB 正确答案: AB
    4.5 分
    三. 填空题（共 1 题，4.5 分）
60. (填空题)
    CONSIDER THE FOLLOWING RANGE OF ADDRESSES:
    2001:0DB8:BC15:00A0:0000::
    2001:0DB8:BC15:00A1:0000::
    2001:0DB8:BC15:00A2:0000:: …
    2001:0DB8:BC15:00AF:0000::
    THE PREFIX-LENGTH FOR THE RANGE OF ADDRESSES IS_______ 我的答案：
    4.5 分
    (1) /60
    正确答案：
    (1) /60
    四. 连线题（共 2 题，10 分）
61. (连线题)REFER TO THE EXHIBIT. MATCH THE NETWORK WITH THE CORRECT IP ADDRESS AND
    PREFIX THAT WILL SATISFY THE USABLE HOST ADDRESSING REQUIREMENTS FOR EACH NETWORK. (NOT ALL OPTIONS ARE USED.)
    1.png
    第 1 组
62. Network A
63. Network B
64. Network C
65. Network D
    第 2 组
    A. 192.168.0.0 /25
    B. 192.168.0.128 /26
    C. 192.168.0.192 /27
    D. 192.168.0.224 /30
    我的答案：
    1
    A
    2
    B
    3
    C
    4
    D
    正确答案：
    1
    A
    2
    B
    3
    C
    4
    D
    4.5 分
66. (连线题)MATCH THE SUBNETWORK TO A HOST ADDRESS THAT WOULD BE INCLUDED WITHIN
    THE SUBNETWORK. (NOT ALL OPTIONS ARE USED.)
    1.png
    第 1 组
67. 192.168.1.64/27
68. 192.168.1.32/27
69. 192.168.1.96/27
    第 2 组
    A. 192.168.1.68
    B. 192.168.1.48
    C. 192.168.1.121
    我的答案：
    1
    A
    2
    B
    3
    C
    正确答案：
    1
    A
    2
    B
    3
    C
    第九章测试
70. (单选题)
    WHAT DOES A CLIENT DO WHEN IT HAS UDP DATAGRAMS TO SEND?
    A. It sends a simplified three-way handshake to the server. B. It sends to the server a segment with the SYN flag set to synchronize the conversation. C. It queries the server to see if it is ready to receive data. D. It just sends the datagrams. 我的答案: D 正确答案: D
    4.3 分
    答案解析：When a client has UDP datagrams to send, it just sends the datagrams. 2. (单选题)
    A PC IS DOWNLOADING A LARGE FILE FROM A SERVER. THE TCP WINDOW IS 1000 BYTES. THE
    SERVER IS SENDING THE FILE USING 100-BYTE SEGMENTS. HOW MANY SEGMENTS WILL THE
    SERVER SEND BEFORE IT REQUIRES AN ACKNOWLEDGMENT FROM THE PC?
    A. A: 100 segments
    B. B: 1 segment
    C. C: 10 segments
    D. D: 1000 segments
    我的答案: C 正确答案: C
    4.3 分
71. (单选题)
    WHEN IS UDP PREFERRED TO TCP?
    A. when an application can tolerate some loss of data during transmission
    B. when all the data must be fully received before any part of it is considered useful
    C. when a client sends a segment to a server
    D. when segments must arrive in a very specific sequence to be processed successfully
    我的答案: A 正确答案: A
    4.3 分
    答 案 解 析 ： UDP can be used when an application can tolerate some data loss. UDP is the
    preferred protocol for applications that provide voice or video that cannot tolerate delay. 4. (单选题)
    WHY DOES HTTP USE TCP AS THE TRANSPORT LAYER PROTOCOL?
    A. because transmission errors can be tolerated easily
    B. to ensure the fastest possible download speed
    C. because HTTP requires reliable delivery
    D. because HTTP is a best-effort protocol
    我的答案: C 正确答案: C
    4.3 分
    答案解析：When a host requests a web page, transmission reliability and completeness must be
    guaranteed. Therefore, HTTP uses TCP as its transport layer protocol. 5. (单选题)
    WHAT IS THE COMPLETE RANGE OF TCP AND UDP WELL-KNOWN PORTS?
    A. 0 to 255
    B. 1024 – 49151
    C. 256 – 1023
    D. 0 to 1023
    我的答案: D 正确答案: D
    4.3 分
72. (单选题)
    WHAT HAPPENS IF PART OF AN FTP MESSAGE IS NOT DELIVERED TO THE DESTINATION?
    A. The FTP source host sends a query to the destination host.
    B. The part of the FTP message that was lost is re-sent. C. The message is lost because FTP does not use a reliable delivery method. D. The entire FTP message is re-sent. 我的答案: B 正确答案: B
    4.3 分
73. (单选题)
    WHAT IS A CHARACTERISTIC OF UDP?
    A. UDP only passes data to the network when the destination is ready to receive the data. B. UDP datagrams take the same path and arrive in the correct order at the destination. C. Applications that use UDP are always considered unreliable. D. UDP reassembles the received datagrams in the order they were received. 我的答案: D 正确答案: D
    4.3 分
74. (单选题)
    WHAT TYPE OF INFORMATION IS INCLUDED IN THE TRANSPORT HEADER?
    A. destination and source physical addresses
    B. encoded application data
    C. destination and source port numbers
    D. destination and source logical addresses
    我的答案: C 正确答案: C
    4.3 分
75. (单选题)
    DURING A TCP SESSION, A DESTINATION DEVICE SENDS AN ACKNOWLEDGMENT NUMBER TO
    THE SOURCE DEVICE. WHAT DOES THE ACKNOWLEDGMENT NUMBER REPRESENT?
    A. one number more than the sequence number
    B. the total number of bytes that have been received
    C. the next byte that the destination expects to receive
    D. the last sequence number that was sent by the source
    我的答案: C 正确答案: C
    4.3 分
76. (单选题)
    WHAT HAPPENS IF THE FIRST PACKET OF A TFTP TRANSFER IS LOST?
    A. The client will wait indefinitely for the reply. B. The TFTP application will retry the request if a reply is not received. C. The next-hop router or the default gateway will provide a reply with an error code. D. The transport layer will retry the query if a reply is not received. 我的答案: B 正确答案: B
    4.3 分
77. (单选题)
    WHAT INFORMATION IS USED BY TCP TO REASSEMBLE AND REORDER RECEIVED SEGMENTS?
    A. sequence numbers
    B. fragment numbers
    C. acknowledgment numbers
    D. port numbers
    我的答案: A 正确答案: A
    4.3 分
78. (单选题)
    WHAT DOES TCP DO IF THE SENDING SOURCE DETECTS NETWORK CONGESTION ON THE PATH TO
    THE DESTINATION?
    A. The source host will send a request for more frequent acknowledgments to the destination. B. The destination will request retransmission of the entire message. C. The source will acknowledge the last segment that is sent and include a request for a smaller
    window size in the message. D. The source will decrease the amount of data that it sends before it must receive
    acknowledgements from the destination. 我的答案: D 正确答案: D
    4.3 分
79. (单选题)
    WHAT IS A SOCKET?
    A. the combination of the source and destination IP address and source and destination Ethernet
    address
    B. the combination of the source and destination sequence and acknowledgment numbers
    C. the combination of the source and destination sequence numbers and port numbers
    D. the combination of a source IP address and port number or a destination IP address and port
    number
    我的答案: D 正确答案: D
    4.3 分
80. (单选题)
    A HOST DEVICE IS RECEIVING LIVE STREAMING VIDEO. HOW DOES THE DEVICE ACCOUNT FOR
    VIDEO DATA THAT IS LOST DURING TRANSMISSION?
    A. The device will use sequence numbers to pause the video stream until the correct data arrives. B. The device will continue receiving the streaming video, but there may be a momentary
    disruption
    C. The device will delay the streaming video until the entire video stream is received. D. The device will immediately request a retransmission of the missing data. 我的答案: B 正确答案: B
    4.3 分
81. (单选题)A HOST DEVICE NEEDS TO SEND A LARGE VIDEO FILE ACROSS THE NETWORK WHILE
    PROVIDING DATA COMMUNICATION TO OTHER USERS. WHICH FEATURE WILL ALLOW DIFFERENT
    COMMUNICATION STREAMS TO OCCUR AT THE SAME TIME, WITHOUT HAVING A SINGLE DATA
    STREAM USING ALL AVAILABLE BANDWIDTH?
    A. acknowledgments
    B. port numbers
    C. window size
    D. multiplexing
    我的答案: D 正确答案: D
    4.3 分
82. (单选题)
    WHICH FACTOR DETERMINES TCP WINDOW SIZE?
    A. the number of services included in the TCP segment
    B. the amount of data to be transmitted
    C. the amount of data the destination can process at one time
    D. the amount of data the source is capable of sending at one time
    我的答案: C 正确答案: C
    4.3 分
83. (单选题)
    WHAT KIND OF PORT MUST BE REQUESTED FROM IANA IN ORDER TO BE USED WITH A SPECIFIC
    APPLICATION?
    A. private port
    B. dynamic port
    C. registered port
    D. source port
    我的答案: C 正确答案: C
    4.3 分
84. (单选题)
    WHAT IS A CHARACTERISTIC OF A TCP SERVER PROCESS?
    A. There can be many ports open simultaneously on a server, one for each active server
    application. B. Every application process running on the server has to be configured to use a dynamic port
    number. C. A host running two different applications can have both configured to use the same server
    port. D. An individual server can have two services assigned to the same port number within the same
    transport layer services. 我的答案: A 正确答案: A
    4.3 分
85. (单选题)
    WHICH FLAG IN THE TCP HEADER IS USED IN RESPONSE TO A RECEIVED FIN IN ORDER TO
    TERMINATE CONNECTIVITY BETWEEN TWO NETWORK DEVICES?
    A. RST
    B. ACK
    C. SYN
    D. FIN
    我的答案: B 正确答案: B
    4.3 分
    二. 多选题（共 3 题，12.9 分）
86. (多选题)
    WHICH TWO CHARACTERISTICS ARE ASSOCIATED WITH UDP SESSIONS? (CHOOSE TWO.)
    A. Destination devices receive traffic with minimal delay. B. Destination devices reassemble messages and pass them to an application. C. Received data is unacknowledged. D. Unacknowledged data packets are retransmitted. E. Transmitted data segments are tracked. 我的答案: AC 正确答案: AC
    4.3 分
87. (多选题)
    WHICH TWO FLAGS IN THE TCP HEADER ARE USED IN A TCP THREE-WAY HANDSHAKE TO
    ESTABLISH CONNECTIVITY BETWEEN TWO NETWORK DEVICES? (CHOOSE TWO.)
    A. FIN
    B. PSH
    C. ACK
    D. URG
    E. RST
    F. SYN
    我的答案: CF 正确答案: CF
    4.3 分
88. (多选题)
    WHICH THREE APPLICATION LAYER PROTOCOLS USE TCP? (CHOOSE THREE.)
    A. SNMP
    B. DHCP
    C. TFTP
    D. SMTP
    E. HTTP
    F. FTP
    我的答案: DEF 正确答案: DEF
    4.3 分
    三. 连线题（共 1 题，5.4 分）
89. (连线题)REFER TO THE EXHIBIT. CONSIDER A DATAGRAM THAT ORIGINATES ON THE PC AND
    THAT IS DESTINED FOR THE WEB SERVER. MATCH THE IP ADDRESSES AND PORT NUMBERS THAT
    ARE IN THAT DATAGRAM TO THE DESCRIPTION. (NOT ALL OPTIONS ARE USED.)
    1.png1.png
    第 1 组
90. destination IP address
91. destination port number
92. source IP address
93. source port number
    第 2 组
    A. 192.168.2.2
    B. 80
    C. 192.168.1.2
    D. 2578
    我的答案：
    1
    A
    2
    B
    3
    C
    4
    D
    正确答案：
    1
    A
    2
    B
    3
    C
    4
    D
    第十章测试
94. ( 单 选 题 )WHAT IS AN EXAMPLE OF NETWORK COMMUNICATION THAT USES THE
    CLIENT-SERVER MODEL?
    A. A workstation initiates a DNS request when the user types www.cisco.com in the address bar
    of a web browser. B. A user uses eMule to download a file that is shared by a friend after the file location is
    determined. C. A workstation initiates an ARP to find the MAC address of a receiving host. D. A user prints a document by using a printer that is attached to a workstation of a coworker. 我的答案: A 正确答案: A
    4.3 分
95. (单选题)
    WHAT DO THE CLIENT/SERVER AND PEER-TO-PEER NETWORK MODELS HAVE IN COMMON?
    A. Both models require the use of TCP/IP-based protocols. B. Both models have dedicated servers
    C. Both models are used only in the wired network environment. D. Both models support devices in server and client roles.
    我的答案: D 正确答案: D
    4.3 分
96. (单选题)
    WHICH STATEMENT IS TRUE ABOUT FTP?
    A. The client can download data from or upload data to the server. B. The client can choose if FTP is going to establish one or two connections with the server. C. FTP does not provide reliability during data transmission. D. FTP is a peer-to-peer application. 我的答案: A 正确答案: A
    4.3 分
97. (单选题)
    WHICH PHRASE DESCRIBES AN FTP DAEMON?
    A. a diagnostic FTP program
    B. a program that is running on an FTP server
    C. a program that is running on an FTP client
    D. an application that is used to request data from an FTP server
    我的答案: B 正确答案: B
    4.3 分
98. (单选题)
    WHICH APPLICATION LAYER PROTOCOL IS USED TO PROVIDE FILE-SHARING AND PRINT SERVICES
    TO MICROSOFT APPLICATIONS?
    A. SMB
    B. DHCP
    C. SMTP
    D. HTTP
    我的答案: A 正确答案: A
    4.3 分
99. (单选题)
    WHEN RETRIEVING EMAIL MESSAGES, WHICH PROTOCOL ALLOWS FOR EASY, CENTRALIZED
    STORAGE AND BACKUP OF EMAILS THAT WOULD BE DESIRABLE FOR A SMALL- TO MEDIUM-SIZED
    BUSINESS?
    A. SMTP
    B. POP
    C. IMAP
    D. HTTPS
    我的答案: C 正确答案: C
    4.3 分
100. (单选题)OPEN THE PT ACTIVITY. PERFORM THE TASKS IN THE ACTIVITY INSTRUCTIONS AND
     THEN ANSWER THE QUESTION. 1.png
     A. PC_1 and PC_3
     B. PC_3
     C. PC_1
     D. PC_2
     我的答案: D 正确答案: D
     4.3 分
101. (单选题)
     WHICH APPLICATION LAYER PROTOCOL USES MESSAGE TYPES SUCH AS GET, PUT, AND POST?
     A. SMTP
     B. DNS
     C. DHCP
     D. POP3
     E. HTTP
     我的答案: E 正确答案: E
     4.3 分
102. (单选题)
     WHAT PART OF THE URL, HTTP://WWW.CISCO.COM/INDEX.HTML, REPRESENTS THE TOP-LEVEL
     DNS DOMAIN?
     A. www
     B. http
     C. index
     D. .com
     我的答案: D 正确答案: D
     4.3 分
103. (单选题)
     WHAT IS AN ADVANTAGE FOR SMALL ORGANIZATIONS OF ADOPTING IMAP INSTEAD OF POP?
     A. When the user connects to a POP server, copies of the messages are kept in the mail server
     for a short time, but IMAP keeps them for a long time. B. IMAP sends and retrieves email, but POP only retrieves email.
     C. Messages are kept in the mail servers until they are manually deleted from the email client. D. POP only allows the client to store messages in a centralized way, while IMAP allows
     distributed storage. 我的答案: C 正确答案: C
     4.3 分
104. (单选题)
     WHICH LAYER IN THE TCP/IP MODEL IS USED FOR FORMATTING, COMPRESSING, AND
     ENCRYPTING DATA?
     A. application
     B. internetwork
     C. presentation
     D. network access
     我的答案: A 正确答案: A
     4.3 分
105. (单选题)
     WHAT IS TRUE ABOUT THE SERVER MESSAGE BLOCK PROTOCOL?
     A. Different SMB message types have a different format. B. SMB uses the FTP protocol for communication. C. Clients establish a long term connection to servers. D. SMB messages cannot authenticate a session. 我的答案: C 正确答案: C
     4.3 分
106. (单选题)
     TWO STUDENTS ARE WORKING ON A NETWORK DESIGN PROJECT. ONE STUDENT IS DOING THE
     DRAWING, WHILE THE OTHER STUDENT IS WRITING THE PROPOSAL. THE DRAWING IS FINISHED
     AND THE STUDENT WANTS TO SHARE THE FOLDER THAT CONTAINS THE DRAWING SO THAT THE
     OTHER STUDENT CAN ACCESS THE FILE AND COPY IT TO A USB DRIVE. WHICH NETWORKING
     MODEL IS BEING USED?
     A. peer-to-peer
     B. master-slave
     C. point-to-point
     D. client-based
     我的答案: A 正确答案: A
     4.3 分
     二. 多选题（共 6 题，25.8 分）
107. (多选题)
     WHICH THREE STATEMENTS DESCRIBE A DHCP DISCOVER MESSAGE? (CHOOSE THREE.)
     A. The message comes from a client seeking an IP address. B. The message comes from a server offering an IP address. C. The source MAC address is 48 ones (FF-FF-FF-FF-FF-FF). D. Only the DHCP server receives the message. E. The destination IP address is 255.255.255.255. F. All hosts receive the message, but only a DHCP server replies. 我的答案: AEF 正确答案: AEF
     4.3 分
108. (多选题)
     THE APPLICATION LAYER OF THE TCP/IP MODEL PERFORMS THE FUNCTIONS OF WHAT THREE
     LAYERS OF THE OSI MODEL? (CHOOSE THREE.)
     A. application
     B. transport
     C. network
     D. data link
     E. physical
     F. session
     G. presentation
     我的答案: AFG 正确答案: AFG
     4.3 分
109. (多选题)
     A MANUFACTURING COMPANY SUBSCRIBES TO CERTAIN HOSTED SERVICES FROM ITS ISP. THE
     SERVICES THAT ARE REQUIRED INCLUDE HOSTED WORLD WIDE WEB, FILE TRANSFER, AND
     E-MAIL. WHICH PROTOCOLS REPRESENT THESE THREE KEY APPLICATIONS? (CHOOSE THREE.)
     A. HTTP
     B. DHCP
     C. DNS
     D. FTP
     E. SMTP
     F. SNMP
     我的答案: ADE 正确答案: ADE
     4.3 分
110. (多选题)
     WHICH TWO TASKS CAN BE PERFORMED BY A LOCAL DNS SERVER? (CHOOSE TWO.)
     A. mapping name-to-IP addresses for internal hosts
     B. forwarding name resolution requests between servers
     C. allowing data transfer between two network devices
     D. providing IP addresses to local hosts
     E. retrieving email messages
     我的答案: AB 正确答案: AB
     4.3 分
111. (多选题)
     WHICH TWO DEFINITIONS ACCURATELY DESCRIBE THE ASSOCIATED APPLICATION LAYER
     PROTOCOL? (CHOOSE TWO.)
     A. HTTP – enables devices on a network to obtain IP addresses
     B. FTP – transfers email messages and attachments
     C. Telnet – provides remote access to servers and networking devices
     D. SMTP – transfers web pages from web servers to clients
     E. DNS – resolves Internet names to IP addresses
     我的答案: CE 正确答案: CE
     4.3 分
112. (多选题)
     WHAT ARE TWO CHARACTERISTICS OF THE APPLICATION LAYER OF THE TCP/IP MODEL? (CHOOSE
     TWO.)
     A. closest to the end user
     B. responsibility for physical addressing
     C. the creation and maintenance of dialogue between source and destination applications
     D. responsibility for logical addressing
     E. the establishing of window size
     我的答案: AC 正确答案: AC
     4.3 分
     三. 填空题（共 3 题，12.9 分）
113. (填空题)FILL IN THE BLANK. THE HTTP MESSAGE TYPE USED BY THE CLIENT TO REQUEST DATA FROM THE WEB SERVER IS THE __ MESSAGE. 我的答案：
     4.3 分
     (1) GET
     正确答案：
     (1) GET
114. (填空题)FILL IN THE BLANK. REFER TO THE EXHIBIT. WHAT COMMAND WAS USED TO RESOLVE A GIVEN HOST NAME BY
     QUERYING THE NAME SERVERS?
     1.png
     我的答案：
     4.3 分
     (1) NSLOOKUP
     正确答案：
     (1) NSLOOKUP
115. (填空题)FILL IN THE BLANK. WHAT IS THE ACRONYM FOR THE PROTOCOL THAT IS USED WHEN SECURELY COMMUNICATING
     WITH A WEB SERVER?
     我的答案：
     4.3 分
     (1) HTTPS
     正确答案：
     (1) HTTPS
     四. 连线题（共 1 题，5.4 分）
116. (连线题)MATCH THE FUNCTION TO THE NAME OF THE APPLICATION. (NOT ALL OPTIONS ARE
     USED.)
     1.png
     第 1 组
117. dynamically assigns IP address to clients
118. maps URLs to numerical addresses
119. allows viewing of messages on email clients
120. displays web pages
121. sends email messages
     第 2 组
     A. DHCP
     B. DNS
     C. IMAP
     D. HTTP
     E. SMTP
     我的答案：
     1
     A
     2
     B
     3
     C
     4
     D
     5
     E
     正确答案：
     1
     A
     2
     B
     3
     C
     4
     D
     5
     E
     第十一章测试
122. (单选题)
     WHICH NETWORK DESIGN CONSIDERATION WOULD BE MORE IMPORTANT TO A LARGE
     CORPORATION THAN TO A SMALL BUSINESS?
     A. low port density switch
     B. redundancy
     C. Internet router
     D. firewall
     我的答案: B 正确答案: B
     3.7 分
123. (单选题)
     WHAT IS THE PURPOSE OF USING SSH TO CONNECT TO A ROUTER?
     A. It allows secure transfer of the IOS software image from an unsecure workstation or server. B. It allows a secure remote connection to the router command line interface. C. It allows the router to be monitored through a network management application. D. It allows a router to be configured using a graphical interface. 我的答案: B 正确答案: B
     3.7 分
124. (单选题)
     WHICH COMMAND SHOULD BE USED ON A CISCO ROUTER OR SWITCH TO ALLOW LOG
     MESSAGES TO BE DISPLAYED ON REMOTELY CONNECTED SESSIONS USING TELNET OR SSH?
     A. show running-config
     B. terminal monitor
     C. debug all
     D. logging synchronous
     我的答案: B 正确答案: B
     3.7 分
125. (单选题)
     A NETWORK TECHNICIAN ISSUES THE C:> TRACERT -6 WWW.CISCO.COM COMMAND ON A
     WINDOWS PC. WHAT IS THE PURPOSE OF THE -6 COMMAND OPTION?
     A. It sends 6 probes within each TTL time period. B. It sets a 6 milliseconds timeout for each replay. C. It limits the trace to only 6 hops. D. It forces the trace to use IPv6. 我的答案: D 正确答案: D
     3.7 分
126. (单选题)
     A NETWORK TECHNICIAN ISSUES THE ARP -D * COMMAND ON A PC AFTER THE ROUTER THAT IS
     CONNECTED TO THE LAN IS RECONFIGURED. WHAT IS THE RESULT AFTER THIS COMMAND IS
     ISSUED?
     A. The detailed information of the ARP cache is displayed. B. The ARP cache is synchronized with the router interface. C. The ARP cache is cleared.
     D. The current content of the ARP cache is displayed. 我的答案: C 正确答案: C
     3.7 分
127. (单选题)
     A NETWORK ADMINISTRATOR IS ISSUING THE LOGIN BLOCK-FOR 180 ATTEMPTS 2 WITHIN 30
     COMMAND ON A ROUTER. WHICH THREAT IS THE NETWORK ADMINISTRATOR TRYING TO
     PREVENT?
     A. a device that is trying to inspect the traffic on a link
     B. an unidentified individual who is trying to access the network equipment room
     C. a worm that is attempting to access another part of the network
     D. a user who is trying to guess a password to access the router
     我的答案: D 正确答案: D
     3.7 分
128. (单选题)
     WHICH STATEMENT IS TRUE ABOUT CDP ON A CISCO DEVICE?
     A. Because it runs at the data link layer, the CDP protocol can only be implemented in switches. B. CDP can be disabled globally or on a specific interface. C. The show cdp neighbor detail command will reveal the IP address of a neighbor only if there
     is Layer 3 connectivity. D. To disable CDP globally, the no cdp enable command in interface configuration mode must be
     used. 我的答案: B 正确答案: B
     3.7 分
129. (单选题)REFER TO THE EXHIBIT. BASELINE DOCUMENTATION FOR A SMALL COMPANY HAD
     PING ROUND TRIP TIME STATISTICS OF 36/97/132 BETWEEN HOSTS H1 AND H3. TODAY THE
     NETWORK ADMINISTRATOR CHECKED CONNECTIVITY BY PINGING BETWEEN HOSTS H1 AND H3
     THAT RESULTED IN A ROUND TRIP TIME OF 1458/2390/6066. WHAT DOES THIS INDICATE TO THE
     NETWORK ADMINISTRATOR?
     1.png
     A. H3 is not connected properly to the network. B. Connectivity between H1 and H3 is fine. C. Performance between the networks is within expected parameters. D. Something is causing a time delay between the networks. E. Something is causing interference between H1 and R1. 我的答案: D 正确答案: D
     3.7 分
130. (单选题)
     SOME ROUTERS AND SWITCHES IN A WIRING CLOSET MALFUNCTIONED AFTER AN AIR
     CONDITIONING UNIT FAILED. WHAT TYPE OF THREAT DOES THIS SITUATION DESCRIBE?
     A. maintenance
     B. electrical
     C. environmental
     D. configuration
     我的答案: C 正确答案: C
     3.7 分
131. (单选题)
     A NEWLY HIRED NETWORK TECHNICIAN IS GIVEN THE TASK OF ORDERING NEW HARDWARE FOR
     A SMALL BUSINESS WITH A LARGE GROWTH FORECAST. WHICH PRIMARY FACTOR SHOULD THE
     TECHNICIAN BE CONCERNED WITH WHEN CHOOSING THE NEW DEVICES?
     A. devices with support for modularity
     B. devices that have support for network monitoring
     C. redundant devices
     D. devices with a fixed number and type of interfaces
     我的答案: A 正确答案: A
     3.7 分
132. (单选题)
     A NETWORK ADMINISTRATOR FOR A SMALL CAMPUS NETWORK HAS ISSUED THE SHOW IP
     INTERFACE BRIEF COMMAND ON A SWITCH. WHAT IS THE ADMINISTRATOR VERIFYING WITH
     THIS COMMAND?
     A. that a specific host on another network can be reached
     B. the status of the switch interfaces and the address configured on interface vlan 1
     C. the path that is used to reach a specific host on another network
     D. the default gateway that is used by the switch
     我的答案: B 正确答案: B
     3.7 分
133. (单选题)
     WHAT IS THE PURPOSE OF ISSUING THE COMMANDS CD NVRAM: THEN DIR AT THE PRIVILEGE
     EXEC MODE OF A ROUTER?
     A. to direct all new files to the NVRAM
     B. to list the content of the NVRAM
     C. to clear the content of the NVRAM
     D. to copy the directories from the NVRAM
     我的答案: B 正确答案: B
     3.7 分
134. ( 单 选 题 )REFER TO THE EXHIBIT. AN ADMINISTRATOR IS TRYING TO TROUBLESHOOT
     CONNECTIVITY BETWEEN PC1 AND PC2 AND USES THE TRACERT COMMAND FROM PC1 TO DO IT. BASED ON THE DISPLAYED OUTPUT, WHERE SHOULD THE ADMINISTRATOR BEGIN
     TROUBLESHOOTING?
     1.png
     A. SW1
     B. PC2
     C. SW2
     D. R1
     E. R2
     我的答案: D 正确答案: D
     3.7 分
135. (单选题)
     WHICH TYPE OF NETWORK THREAT IS INTENDED TO PREVENT AUTHORIZED USERS FROM
     ACCESSING RESOURCES?
     A. DoS attacks
     B. reconnaissance attacks
     C. trust exploitation
     D. access attacks
     我的答案: A 正确答案: A
     3.7 分
136. (单选题)
     WHEN SHOULD AN ADMINISTRATOR ESTABLISH A NETWORK BASELINE?
     A. when there is a sudden drop in traffic
     B. at regular intervals over a period of time
     C. at the lowest point of traffic in the network
     D. when the traffic is at peak in the network
     我的答案: B 正确答案: B
     3.7 分
137. (单选题)
     WHICH COMMAND WILL BACKUP THE CONFIGURATION THAT IS STORED IN NVRAM TO A TFTP
     SERVER?
     A. copy tftp startup-config
     B. copy startup-config tftp
     C. copy running-config tftp
     D. copy tftp running-config
     我的答案: B 正确答案: B
     3.7 分
138. (单选题)
     WHICH FIREWALL FEATURE IS USED TO ENSURE THAT PACKETS COMING INTO A NETWORK ARE
     LEGITIMATE RESPONSES INITIATED FROM INTERNAL HOSTS?
     A. stateful packet inspection
     B. URL filtering
     C. packet filtering
     D. application filtering
     我的答案: A 正确答案: A
     3.7 分
139. (单选题)
     WHAT IS THE PURPOSE OF THE NETWORK SECURITY AUTHENTICATION FUNCTION?
     A. to provide challenge and response questions
     B. to keep track of the actions of a user
     C. to require users to prove who they are
     D. to determine which resources a user can access
     我的答案: C 正确答案: C
     3.7 分
     二. 多选题（共 5 题，18.5 分）
140. (多选题)
     WHICH TWO ACTIONS CAN BE TAKEN TO PREVENT A SUCCESSFUL NETWORK ATTACK ON AN
     EMAIL SERVER ACCOUNT? (CHOOSE TWO.)
     A. Use servers from different vendors. B. Never send the password through the network in a clear text. C. Limit the number of unsuccessful attempts to log in to the server. D. Never use passwords that need the Shift key. E. Distribute servers throughout the building, placing them close to the stakeholders. 我的答案: BC 正确答案: BC
     3.7 分
141. (多选题)
     WHICH TWO TRAFFIC TYPES REQUIRE DELAY SENSITIVE DELIVERY? (CHOOSE TWO.)
     A. FTP
     B. web
     C. email
     D. voice
     E. video
     我的答案: DE 正确答案: DE
     3.7 分
142. (多选题)
     WHICH TWO STATEMENTS DESCRIBE HOW TO ASSESS TRAFFIC FLOW PATTERNS AND NETWORK
     TRAFFIC TYPES USING A PROTOCOL ANALYZER? (CHOOSE TWO.)
     A. Only capture WAN traffic because traffic to the web is responsible for the largest amount of
     traffic on a network. B. Capture traffic during peak utilization times to get a good representation of the different
     traffic types. C. Capture traffic on the weekends when most employees are off work. D. Perform the capture on different network segments. E. Only capture traffic in the areas of the network that receive most of the traffic such as the data
     center. 我的答案: BD 正确答案: BD
     3.7 分
143. (多选题)
     WHICH TWO STEPS ARE REQUIRED BEFORE SSH CAN BE ENABLED ON A CISCO ROUTER? (CHOOSE
     TWO.)
     A. Generate a set of secret keys to be used for encryption and decryption. B. Give the router a host name and domain name. C. Create a banner that will be displayed to users when they connect. D. Set up an authentication server to handle incoming connection requests.
     E. Enable SSH on the physical interfaces where the incoming connection requests will be
     received. 我的答案: AB 正确答案: AB
     3.7 分
144. (多选题)A NETWORK ADMINISTRATOR FOR A SMALL COMPANY IS CONTEMPLATING HOW TO
     SCALE THE NETWORK OVER THE NEXT THREE YEARS TO ACCOMMODATE PROJECTED GROWTH. WHICH THREE TYPES OF INFORMATION SHOULD BE USED TO PLAN FOR NETWORK GROWTH?
     (CHOOSE THREE.)
     A. listing of the current employees and their role in the company
     B. documentation of the current physical and logical topologies
     C. human resource policies and procedures for all employees in the company
     D. analysis of the network traffic based on protocols, applications, and services used on the
     network
     E. inventory of the devices that are currently used on the network
     F. history and mission statement of the company
     我的答案: BDE 正确答案: BDE
     3.7 分
     三. 填空题（共 3 题，11.1 分）
145. ( 填 空 题 )_ _DEFINES THE PROTOCOLS AND TECHNOLOGIES THAT IMPLEMENT THE
     TRANSMISSION OF VOICE DATA OVER AN IP NETWORK
     我的答案：
     3.7 分
     (1) VoIP
     正确答案：
     (1) VoIP
146. (填空题)
     FILL IN THE BLANK. DO NOT USE ABBREVIATIONS. THE SHOW __ COMMAND PROVIDES INFORMATION ABOUT THE AMOUNT OF FREE NVRAM AND
     FLASH MEMORY WITH THE PERMISSIONS FOR READING OR WRITING DATA. 我的答案：
     3.7 分
     (1) file systems
     正确答案：
     (1) file systems
147. (填空题)
     FILL IN THE BLANK. DO NOT USE ABBREVIATIONS. THE __ COMMAND THAT IS ISSUED ON A ROUTER IS USED TO VERIFY THE VALUE OF THE
     SOFTWARE CONFIGURATION REGISTER. 我的答案：
     3.7 分
     (1) show version
     正确答案：
     (1) show version
     四. 连线题（共 1 题，3.8 分）
148. (连线题)MATCH THE TYPE OF INFORMATION SECURITY THREAT TO THE SCENARIO. (NOT ALL
     OPTIONS ARE USED.)
     1.png
     第 1 组
149. data loss
150. identity theft
151. disruption of service
152. information theft
     第 2 组
     A. installing virus code to destroy surveillance recordings for certain days
     B. pretending to be someone else by using stolen personal information to apply for a credit card
     C. preventing userd from accessing a website by sending a large number of link requests in a
     short period
     D. obtaining trade secret documents illegally
     我的答案：
     1
     A
     2
     B
     3
     C
     4
     D
     正确答案：
     1
     A
     2
     B
     3
     C
     4
     D

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