Answer A is incorrect because if a cable broke or failed in some way, it would only remove the computer connected to it from the network.. Thicknet coaxial cable can transfer data over
Trang 1Your network has 10 computers that are networked together using
15
a Star topology Which of the following is a possible point of failure for this topology, which could bring down the entire network?
A Cable
B Network card
C T-connector
D Hub
Correct answer and explanation: D Hub In a Star topology, all computers
are connected through one central hub Computers are cabled to this hub, making it a centralized point where the network is connected If the hub fails, the network would go down
Incorrect answers and explanations: A, B, and C Answer A is incorrect
because if a cable broke or failed in some way, it would only remove the
computer connected to it from the network Answer B is incorrect because
a failed network card in a computer would only prevent that particular
com-puter from being able to access the network Answer C is incorrect because
a T-connector is used to connect computers to a cable in a Bus topology A Star topology is being used in this situation
ChApTEr 2: NETworK MEdIA
You are the network administrator of a 10BaseT network On the
1
weekend, when few people are working, you run 110 m of cable
to a new server that is being used as a file server The cable is installed in a new section of the building, where no cabling cur-rently exists When you attempt to access files on the server, they are experiencing errors and corrupt data Which of the following is most likely the cause of this problem?
A Bandwidth
B Attenuation
C Crosstalk from a neighboring cable
D CSMA/CD issues
Correct answer and explanation: B Attenuation Attenuation occurs when
data transmitted over media weakens over distance The scenario states that the cable length is 110 m, which is 10 m longer than the maximum distance for 10BaseT
Incorrect answers and explanations: A, C, and D Answer A is incorrect
because bandwidth is a measurement of the amount of data that can be
Trang 2passed over a cable in a given amount of time Answer C is incorrect because
the cable is being installed in a section of the building where no other cabling
currently exists Crosstalk occurs when the electromagnetic field of one wire
interferes with the transmission of another Answer D is incorrect because
Carrier Sense Multiple Access with Collision Detection (CSMA/CD) prevents
devices from interfering with one another during transmission by detecting
collisions of data It is not a cause for data to weaken or to corrupted
Your company uses UTP cable for all of its network connections
2
including workstations and servers The users have reported
problems connecting to one of the most important servers on the
network and you have been called in to look at it, due to a possible
physical security breach by a former employee While examining
the server, you find that a small battery-powered motor has been
placed and is running next to the server’s network connection
What is causing the network problem?
A Electromagnetic interference
B Static electricity
C Transceivers
D Unknown, but the motor is probably unrelated
Correct answer and explanation: A Electromagnetic interference (EMI) is a
low voltage, low current, high-frequency signal that can interfere with the
elec-tronic signals transmitted over cabling The motor is powered by electromagnets
whose presence can interfere with the flow of electrons along the UTP cable
Incorrect answers and explanations: B, C, and D Answer B is incorrect
because static electricity may cause damage to network cards and other
elec-tronics but will not interfere with network traffic on a UTP cable Answer C is
incorrect because transceivers are the portion of a network interface that
trans-mits and receives electrical signals across the transmission media It is unlikely
that this is a cause of the problem Answer D is incorrect because the small
motor is most likely to be the source of this interference Anytime a UTP cable
is near electromagnetic interference there will be communications problems
You are designing a new network and are concerned about
interfer-3
ence from other wires Which of the following is most susceptible
to transmission errors due to crosstalk?
A Coaxial
B UTP
C STP
D Fiber optic
Trang 3Correct answer and explanation: B UTP Unshielded twisted-pair is most
vulnerable to crosstalk Crosstalk refers to the unwanted electrical fields induced by neighboring cables These electrical fields generate false signals Because the UTP cable is unshielded, it is more susceptible to transmission errors caused by crosstalk than any other given cable types
Incorrect answers and explanations: A, C, and D Answer A is incorrect
because the coaxial cable is shielded and is less prone to errors cause by
cross-talk Answer C is incorrect because STP (shielded twisted-pair) is shielded, and thereby is also more protected against crosstalk Answer D is incorrect
because the fiber-optic cable works on light signals and is not affected by either electrical or magnetic signals
You are designing a new network for a grocery store Cabling will
4
have to run along the ceiling, where there are a significant num-ber of florescent lights You are concerned about interference from these lights Which of the following cable types could be used, which would not be susceptible to this type of interference?
A Coaxial
B UTP
C STP
D Fiber optic
Correct answer and explanation: D Fiber optic Fiber-optic cabling is the
only type of cabling that is immune to electromagnetic interference Fiber-optic cable carries digital data signals in the form of modulated pulses of light, which isn’t effected by EMI
Incorrect answers and explanations: A, B, and C Answers A, B, and C are
incorrect because each of these use copper wiring that is susceptible to EMI
Your network uses vampire taps and AUI connectors to access data
5
from the network cable Which of the following cabling types is being used?
A Thinnet
B Thicknet
C STP
D Fiber optic
Correct answer and explanation: B Thicknet Thicknet is a term for
cabling used in 10Base5 networks Thicknet coaxial cable can transfer data over longer distances than the 10Base2 Thinnet cable and requires vampire
Trang 4taps to connect to the network interface card with the adapter unit interface
(AUI) connector Thicknet is not a common cabling type and is only used in
backbones
Incorrect answers and explanations: A, C, and D Answer A is incorrect
because the Thinnet is a 10Base2 cable Answer C is incorrect because STP
is a twisted-pair cable that uses an RJ-45 connector and not a vampire tap or
AUI connector Answer D is also incorrect because fiber-optic cable doesn’t
use vampire taps or AUI connectors
You are designing a 10Base2 network In creating this network,
6
what distance limitation will you be facing when installing the
cabling?
A 100 m
B 185 m
C 500 m
D 2 km
Correct answer and explanation: B 185 10Base2 (Thinnet) has a distance
limitation of 185 m 10Base5 (Thicknet) has a distance limitation of 500 m,
and 10BaseT has a distance limitation of 100 m
Incorrect answers and explanations: A, C, and D Answer A is incorrect
because 100 m is a limitation for 10BaseT Answer C is incorrect because
500 m is a distance limitation for 10Base5 networks Answer D is incorrect
because 2 km is a distance limitation for fiber-optic cable
Examine the illustration shown in the following Figure 2.12
7
FIGurE 2.12
Trang 5Your network is a 10Base2 network, and it uses these connectors to attach to the network Which of the following types of connectors is being used?
A RJ-11
B DIX
C BNC Barrel Connector
D BNC T-connector
Correct answer and explanation: D BNC T-connector The connector shown
in the illustration is a BNC T-connector, which is circular and T-shaped It is used to connect workstations to a 10Base2 (Thinnet) network
Incorrect answers and explanations: A, B, and C Answer A is incorrect
because an RJ-11 connector is used to connect devices to a telephone line and is a small square-shaped connector with a locking clip and several wire
places inside the connector itself Answer B is incorrect because a DIX con-nector is D-shaped and has 15 pins Answer D is incorrect because a BNC
barrel connector is round or barrel-shaped
You have been hired by a small company to cable its network The
8
company has offices in two buildings that are 300 m apart Both of the offices have about 15 computers and the numbers are expected
to grow in near future All of the computers are within 90 m of one another You need to decide on the cabling that will be used both
in the individual buildings, and which will be used to connect the buildings LANs together Which of the following will you do?
A Use UTP cabling in each of the buildings, and connect the two buildings together using 10BaseT cabling
B Use fiber-optic cabling in each of the buildings, and connect the two buildings together using 10Base2 cabling
C Use 10BaseT cabling in each of the buildings, and connect the two buildings together using 10Base5 cabling
D Use 100BaseFX cabling in each of the buildings, and connect the two buildings together using 10BaseT cabling
Correct answer and explanation: C Use 10BaseT cabling in each of the
buildings and connect the two buildings together using 10Base5 cabling The two offices can be connected using thick coaxial cable (10Base5), which can transfer data up to 500 m 10BaseT can be used within the buildings because it supports distances of 100 m
Incorrect answers and explanations: A, B, and D Answer A is incorrect
because 10BaseT has a distance limitation of 100 m This means that the
Trang 6two buildings can’t be connected together Answer B is incorrect because
10Base2 has a distance limitation of 185 m, which is too short for the two
buildings Answer D is also incorrect because 10BaseT has a distance
limita-tion of 100 m
Your network uses 100BaseFX so that data can be transferred at
9
higher speeds and up to distances of 400 m During transmission,
data can travel in both directions, but only in one direction at a
given time Which of the following transmission methods is used?
A Simplex
B FireWire
C Half-Duplex
D Full-Duplex
Correct answer and explanation: C Half-Duplex 100BaseFX is an
Ether-net standard that uses fiber optic cabling It can transmit data at speeds of
100 Mbps but if communication is half-duplex, it can transmit data across
cable segments that are up to 400 m in length If full-duplex is used, then it
can transmit data up to 2 km Because data travels both ways on the medium
but in only one direction at a time, half-duplex is being described
Incorrect answers and explanations: A, B, and D Answer A is incorrect
because simplex refers to data moving in a single direction Answer B is
incorrect because FireWire is a proprietary name for IEEE1394, which is
an external bus that supports fast data transfer rates of 400 Mbps and
800 Mbps Answer D is incorrect because full-duplex refers to data traveling
in both directions simultaneously
Examine the illustration shown in the following Figure 2.13
10
Your network uses UTP cabling in a Star topology Which of the
follow-ing types of connectors is befollow-ing used?
FIGurE 2.13
Trang 7B BNC
C ST
D SC
Correct answer and explanation: A RJ-45 The illustration shows an RJ-45
connector This type of connector is used in unshielded twisted-pair (UTP) cabling and commonly used for networks that use a Star topology An RJ-45 cable has eight pins and is rectangular in shape with a plastic lock on one side
Incorrect answers and explanations: B, C, and D Answer B is incorrect
because a BNC Barrel connector is round or barrel-shaped, whereas a BNC T-connector is circular and T-shaped Neither of these types of connectors is
used on with UTP Answers C and D are incorrect because both ST and SC
connectors are used with fiber-optic cabling
You are the Network+ technician assigned to an enterprise
net-11
work looking to install a high-speed backbone You want to imple-ment Gigabit Ethernet Which connectors could you use in such a network? (Choose one)
A RJ-11
B RG 58
C SC
D BNC
Correct answer: C Incorrect answers and explanations: A, B, and D The RJ-11 connector is
used for voice connections RG 58 connectors are used with coaxial cabling, and BNC connectors are used with coaxial cable
As a network technician for 123 LLC, you are asked by your CIO
12
about the access method of Gigabit Ethernet Which of the follow-ing access methods does Gigabit Ethernet use?
A FDDI
B CSMA/CD
C CSMA/CA
D Token passing
Correct answer and explanation: B CSMA/CD Gigabit Ethernet has
evolved from Ethernet that uses the Carrier Sense Multiple Access with Collision Detection (CSMA/CD) access method
Trang 8Incorrect answers and explanations: A, C, and D: FDDI is a technology used
to create high-speed backbone connections and uses token passing – it’s not an
access method CSMA/CA is primarily used for wireless technologies Token
passing is another access method, used with Token Ring networks and FDDI
A new technician for 123 Corp plans out the maximum length of
13
a Gigabit Ethernet segment using MMF optic cable is What is the
correct distance? (Choose only one)
A 100 m
B 125 m
C 550 m
D 10 km
Correct answer and explanation: C Gigabit Ethernet support distances of
550 m for multimode fiber links
Incorrect answers and explanations: A, B, and D – all are of the wrong
length
You are the network engineer assigned to implement a new
14
100 Mbps network connection You need to select the correct
cabling, as well as the correct standard From the selections below,
choose which 100 Mbps networking standard makes use of only
two pairs of a Category 5 UTP cable
A 10BaseT
B 100BaseFL
C 100BaseTX
D 100BroadT4
Correct answer and explanation: C 100BaseTX uses two UTP pairs (four
wires) in a Category 5 UTP cable
Incorrect answers and explanations: A, B, and D Answer A is incorrect
because 10BaseT requires Category 3 UTP and only operates at 10 Mbps
Answer B is incorrect because 100BaseFL doesn’t exist; it’s really 10BaseFL
and it requires 10 Mbps fiber-optic cable Answer D is incorrect because
100BoardT4 is not a legitimate networking standard
You work as a network technician for 123 LLC You need to check
15
the electrical signals being sent from the NIC port out on the cable
Which device would you use to complete this test? (Choose one.)
A A wire map
B A fox and hound
Trang 9C A crossover cable
D A hardware loopback
Correct answer and explanation: D A hardware loopback checks outgoing
signals of a device All other devices are not going to be able to provide that same type of test
ChApTEr 3: NETworK dEvICES
Cables from workstations are connected to a central network
con-1
nectivity device that takes data from one port and resends it to all of the other ports In doing so, the data is regenerated so it is
as strong as when it was originally sent Which of the following devices is being used?
A Active hub
B Passive hub
C Switching hub
D Switch
Correct answer and explanation: A Active hub An active hub will take
data sent to it and resend it to all ports on the hub An active hub also works
as a repeater for all data received on its ports, as the signal is regenerated before it is transmitted on all ports of the hub
Incorrect answers and explanations: B, C, and D Answer B is incorrect
because the function of a passive hub is simply to receive data from one port
of the hub and send it out to the other ports It does not regenerate the data
Answers C and D are incorrect because a switch or switching hub will take
the data sent to it on one port and then send it to a specific port that will send the data only to the destination computer or device
Your network consists of a single large LAN that is in a Star
topol-2
ogy configuration You have found that there are a significant num-ber of collisions occurring on the network and want to segment it into two smaller LANs Which of the following devices will you use
to segment this network, allowing each LAN to communicate with the other?
A NIC
B MAU
C Bridge
D Repeater
Trang 10Correct answer and explanation: C Bridge A bridge is a network
connec-tivity device that connects two different networks and makes them appear to
be one network, and allows a larger LAN to be segmented into two smaller
halves The bridge filters local traffic between the two networks and copies
all other traffic to the other side of the bridge
Incorrect answers and explanations: A, B, and D Answer A is incorrect
because a NIC is simply a network interface card, which is installed on a PC
or other network device, to allow it to communicate on the network Answer
B is incorrect because a MAU is a device that multiple workstations are
connected to communicate on a Token Ring network Answer D is incorrect
because a repeater is used to connect segments of cable and repeat the data
it receives so that it won’t weaken along the cable
You want to get Internet access for a computer that is used by the
3
IT staff to download drivers and updated software from the
Inter-net Because of the amount of data that is going to be downloaded,
you want to use the fastest possible method of downloading data
Which of the following will you use?
A Analog modem with dial-up access to an ISP
B ISDN Digital Subscriber Line
C Consumer Digital Subscriber Line
D Very High Digital Subscriber Line
Correct answer and explanation: D Very High Digital Subscriber Line
A Very High Digital Subscriber Line has a downstream speed of 12.9 to
52.8 Mbps, and an upstream speed of 1.5 to 2.3 Mbps Of the choices offered,
this is the fastest choice for accessing the Internet
Incorrect answers and explanations: A, B, and C Answer A is incorrect
because an analog modem with dial-up access is limited to a maximum
speed of 56 Kbps Answer B is incorrect because an ISDN Digital Subscriber
Line has a maximum speed of 128 Kbps Answer D is incorrect because a
Consumer Digital Subscriber Line has a maximum speed of 1 Mbps
You are fixing a faulty network card and find that it is unable to
4
send or receive data You believe the transceiver has failed Which
type of transceiver is built into the network interface card?
A External
B Onboard
C RG 58
D BNC