Answer A is incorrect because Layer 2 switches work at the data link layer and look at the MAC address of the packet to determine where it is to be sent.. Answer B is incor-rect becaus
Trang 1Correct answer and explanation: D Layer 5 switch Layer 5 switches
use information from the session layer, allowing it to route packets using Uniform Resource Locators (URLs)
Incorrect answers and explanations: A, B, and C Answer A is incorrect
because an external transceiver is an external device, and thereby isn’t built
onto the NIC Answers C and D are incorrect because neither of these are
types of transceivers They are connectors used for connecting coaxial cable
You are looking into purchasing a new switch for your network You
5
want the switch to be able to route packets of data based on the uniform resource locator included with the packet Which switch type should you buy?
A Layer 2 switch
B Layer 3 switch
C Layer 4 switch
D Layer 5 switch
Correct answer and explanation: D Layer 5 switch Layer 5 switches
use information from the session layer, allowing it to route packets using Uniform Resource Locators (URLs)
Incorrect answers and explanations: A, B, and C Answer A is incorrect
because Layer 2 switches work at the data link layer and look at the MAC
address of the packet to determine where it is to be sent Answer B is
incor-rect because Layer 3 switches work at the network layer of the OSI model and have an integrated router function that allows it to make decisions
as to where the data should be sent Answer D is incorrect because Layer
4 switches use information in the packet that identifies the application it belongs to so that priorities can be set in routing the packets to the destina-tion computer
You have installed new cabling to accommodate a new section of
6
the building that is being networked Once computers are installed, you find that they are unable to connect to the network You believe the problem is that the length of the cabling has exceeded the maximum distance allowed You want to fix the problem with the least amount of cost and work Which of the following will you do?
A Remove the cabling and install cable that supports a longer distance
B Install a passive hub to increase the distance that data can travel along the cable
Trang 2C Install a NIC to increase the distance that data can travel along
the cable
D Install a switch to increase the distance that data can travel
along the cable
Correct answer and explanation: D Install a switch to increase the
dis-tance that data can travel along the cable Switches can perform the same
functions that repeaters used to by regenerating the data so that it is sent out
from the switch at its original strength
Incorrect answers and explanations: A, B, and C Answer A is incorrect
because removing the cabling and replacing it with another kind is not only
costly but a considerable amount of work Answer B is incorrect because
a passive hub won’t regenerate the data when it is sent out from its ports
Answer C is incorrect because a NIC is used as an interface to communicate
on the network It isn’t used as a means of regenerating data so that the
network can be extended
What will happen if we have a routing table with the same route to
7
the same destination network?
A You cannot have the same route listed twice
B You cannot have the same destination listed twice
C The route with the closest router will be used
D The route with the fewest number of hops will be used
Correct answer and explanation: D The route with the fewest number of
hops will be used If a route claims, it can reach the destination in one fewer
hop than another router, then that route will be used
Incorrect answers and explanations: A, B, and C Answer A is incorrect
because fault tolerant routes are a main advantage of routers if one route is
unavailable Answer B is incorrect for the same reason Answer C is
incor-rect because the cable distances aren’t taken into account, only the number
of hops
What will happen if the default gateway is not specified on your
8
computer and you are trying to reach another network?
A The packet will ask every router if they know the path to reach
the destination
B The packet will broadcast for the IP address of the nearest
router
C The packet will be forwarded to the DNS server
D The packet will not be sent
Trang 3Correct answer and explanation: D The packet will not be sent Without that
default gateway, you are stuck on the local network The subnet mask, which you will learn about in the next chapter, is also very important Without a prop-erly configured subnet mask to determine which subnet your computer is on, your computer will be unable to communicate outside of the local network
Incorrect answers and explanations: A, B, and C Answer A is incorrect
because the PC will not know the addresses of the routers to send the data
pack-ets to or even inquire about router addresses or destination addresses Answer B
is incorrect for the same reason Answer C is incorrect because the DNS server
is used for name-to-IP address resolution and not IP addresses of routers
You need to connect two networks that work on two different
9
network protocols Which of the following should be used?
A DMZ
B Firewall
C Gateway
D NAS
Correct answer and explanation: C Gateway If two networks work on
different communication systems, they will not be able to talk to each other
A gateway functions as a translator between two dissimilar networks so that both are able to communicate For example, if your Ethernet network is to be connected to a Token Ring network, you will need to have a gateway so that hosts in the two networks are able to communicate
Incorrect answers and explanations: A, B, and D Answer A is incorrect
because a DMZ is a neutral network segment where systems accessible to the public Internet are housed, which offers some basic levels of protection
against attacks Answer B is incorrect because a firewall provides protection
by filtering traffic from the external network to the internal network, and
vice versa Answer D is incorrect because a NAS is a system of devices that
are dedicated to providing storage of data on the network
You have replaced all the hubs in your network with 10/100 Mbps
10
switches The switch ports are configured to work by automatically sensing the network speed Most of the workstations already had 10/100 Mbps network adapters Which of the following will you need to do to upgrade the speed of the entire network to 100 Mbps?
A Replace all 10 Mbps network adapters to 10/100 Mbps in the remaining workstations
B Reconfigure all the ports on the switch to operate only at 100 Mbps
Trang 4C Reconfigure the 10 Mbps adapters in remaining workstations to
operate only at 100 Mbps
D None of the above
Correct answer and explanation: A Replace all 10 Mbps network
adapt-ers to 10/100 Mbps in the remaining workstations Because the switch
ports are configured to automatically sense the network speed, the
work-stations with 100 Mbps network adapters will communicate with the
switch at 100 Mbps and others at 10 Mbps This will affect the overall
network speed To have a complete 100 Mbps network, you should replace
the 10 Mbps adapters with 10/100 Mbps network adapters in the
remain-ing workstations
Incorrect answers and explanations: B, C, and D Answer B is incorrect
because even if the switch ports are configured to operate at 100 Mbps,
the communication with workstations with 10 Mbps adapters will be at
10 Mbps Answer C is incorrect because 10 Mbps adapters cannot be
con-figured to operate at 100 Mbps Answer D is incorrect because answer A is
a legitimate solution
As a network technician, you are asked to deploy a network load
11
balancer You need to configure a network load balancer on the
10.0.10.0/8 network for the Web development group You need to
configure it appropriately From the list of possible deployment
scenarios, which would you select from as your design?
A You need to distribute the load to a group of SSH servers
B You need to centralize your traffic around your FTP servers
C You need to distribute the load to a pool of Web servers
D You need to redistribute the traffic to a farm of DHCP servers on
your DMZ
Correct answer and explanation: C Load balancers are primarily used
when working with Web servers Although load balancers can be used in
other situations, you would likely not see them used in the other options and
solutions provided for you
Incorrect answers and explanations: A, B, and D Answer A is incorrect
because you would not use a load balancer in that fashion nor would SSH be
used in this way Answer B is incorrect because FTP servers are not in need
of load balancing Answer D is incorrect because you would not use a load
balancer to balance DHCP requests
Trang 5When using a multilayer switch, which layer are you likely
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working on?
A Network
B Application
C Presentation
D Session
Correct answer and explanation: A A multilayer switch operates on the
first three layers of the OSI model Primarily, on Layers 2 and 3 because the multifunction device maintains a list of MAC addresses in its CAM table
as well as a routing table in memory The device can send packets along a routed network just as easily as switching data on a Layer 2 network
Incorrect answers and explanations: B, C, and D Answer B is incorrect
because multilayer switches primarily operate on the first few layers of the
OSI model, not the topmost layers Answer C is incorrect because multilayer
switches primarily operate on the first few layers of the OSI model, not the
topmost layers Answer D is incorrect because multilayer switches primarily
operate on the first few layers of the OSI model, not the topmost layers
A workstation in building A of an office campus network needs to
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obtain IP configuration information from a DHCP server in build-ing B of the same campus What is needed to accomplish this if the packets must traverse a router or a filtering device?
A DNS relay
B DHCP relay
C WINS relay
D Packet Sniffer
Correct answer and explanation: B Answer B is correct because you need
a DHCP relay agent configured on a router or any device configured to filter (and drop) a broadcast typically sent by a DHCP client to a DHCP server
You are the administrator of a small business network You notice
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that as you add workstations to the network over time the speed
of the network decreases, what devices would you replace in your network with what other device to resolve this problem?
A Replace repeaters with hubs
B Replace routers with hubs
C Replace routers with switches
D Replace hubs with switches
Trang 6Correct answer: D.
As a network administrator you need to deploy a VOIP phone You
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are unfamiliar with this technology Which connection type could
you use on a standard IP phone?
A RJ-12
B RJ-13
C RJ-24
D RJ-45
Correct answer: D.
ChApTEr 4: SwITChING
You have purchased a basic switch for your network that can look
1
at information within a packet of data and send it to its
destina-tion address It has no addidestina-tional features What kind of switch is
this?
A Layer 2
B Layer 3
C Layer 4
D Layer 5
Correct answer and explanation: A, Layer 2 This scenario describes a basic
Layer 2 switch, which looks at the packet to determine the MAC address
of the computer where the packet is being sent The MAC address makes
the computer identifiable on a network and allows the switch to determine
which computer the data is meant for
Incorrect answers and explanations: B is incorrect because a Layer 3 switch
has the capabilities of a router A Layer 3 switch uses switching tables and
switching algorithms to determine how to send data via MAC addressing
from host to host, device to device C is incorrect because Layer 4 switches
work at the transport layer of the OSI model and have the added feature
of being able to look at the application protocols being used to send data
D is incorrect because a Layer 5 switch works at the session layer of the OSI
model and looks at the information in a packet provided by this layer for
routing This information includes such information as Uniform Resource
Locators (URLs) that allow the switch to route the packet more effectively to
a destination computer An URL is a method of addressing that is commonly
used on the Internet
Trang 7A broadcast message is sent by a computer onto the network
2
Which of the following will occur when the switch receives the broadcast message?
A The message will be sent to all computers on the network
B The message will be sent to all computers in the same broadcast domain
C The message will not be sent because switches will only send messages between two nodes
D The message will not be sent because switches are designed to always ignore broadcast messages
Correct answer and explanation: B The message will be sent to all
com-puters in the same broadcast domain A broadcast domain is a logical seg-ment of the network Computers that are a part of the same domain can broadcast messages to all the computers in the same domain
Incorrect answers and explanations: A is incorrect because only the com-puters in the broadcast domain will receive the message C is incorrect
because although switches will establish a connection between two comput-ers by passing a message from one port to another, broadcast messages are
sent to all the computers within the same broadcast domain D is incorrect
because switches can pass a broadcast message to all computers within a broadcast domain
You are looking into purchasing a new switch for your network You
3
want the switch to be able to route packets of data based on the uniform resource locator included with the packet Which switch type should you buy?
A Layer 2
B Layer 3
C Layer 4
D Layer 5
Correct answer and explanation: D, Layer 5 switch This type of switch
works at the session layer of the OSI model, and looks at the information in
a packet provided by this layer for routing This information includes such information as Uniform Resource Locators (URLs) that allow the switch
to route the packet more effectively to a destination computer A URL is a method of addressing that is commonly used on the Internet
Incorrect answers and explanations: A is incorrect because a Layer 2 switch
looks at the packet to determine the MAC address of the computer where
Trang 8the packet is being sent The MAC address makes the computer identifiable
on a network and allows the switch to determine which computer the data
is meant for B is incorrect because a Layer 3 switch has the capabilities of a
router A Layer 3 switch uses switching tables and switching algorithms to
determine how to send data via MAC addressing from host to host, device to
device C is incorrect because Layer 4 switches work at the transport layer of
the OSI model and have the added feature of being able to look at the
appli-cation protocols being used to send data
A switch on your network is designed to look at the MAC address
4
of incoming data, and then use switching tables and algorithms to
properly route data to its intended destination What type of switch
is being used?
A Layer 2
B Layer 3
C Layer 4
D Layer 5
Correct answer and explanation: B A Layer 3 switch has the capabilities
of a router A Layer 3 switch works by using switching tables and switching
algorithms to determine how to send data via MAC addressing from host to
host, device to device
Incorrect answers and explanations: A is incorrect because a Layer 2 switch
looks at the packet to determine the MAC address of the computer where
the packet is being sent The MAC address makes the computer identifiable
on a network and allows the switch to determine which computer the data
is meant for C is incorrect because Layer 4 switches work at the transport
layer of the OSI model and have the added feature of being able to look at
the application protocols being used to send data D is incorrect Although a
Layer 5 switch looks at the information in a packet for routing, it uses such
information as Uniform Resource Locators (URLs) that allow the switch
to route the packet more effectively to a destination computer A URL is a
method of addressing that is commonly used on the Internet
Your company has just purchased a smaller rival business and now
5
wants you to connect the two networks together Your company’s
existing network is twice the size of the new network To get these
two networks connected together, which of the following will you do?
A Install a VLAN to connect the two networks together
B Install a switch to connect to the two networks together
Trang 9C Install a bridge to break the larger LAN into two smaller ones, and then connect these to the other LAN using a switch
D Install a switch to break the larger LAN into two smaller ones, and then connect these to the other LAN using a switch
Correct answer and explanation: B Install a switch to connect to the two
net-works together Switches are also called multiport bridges, as it can provide the same functionality as a bridge, which is used to connect two LANs together
Incorrect answers and explanations: A is incorrect because a VLAN is a virtual LAN and wouldn’t be used to connect the two networks together C and D are incorrect because there is no need to segment the existing LAN
before connecting it to the new smaller LAN
A small network consists of three computers named Alpha, Beta,
6
and Omega Alpha sends a message to Omega, and the data is passed through a switch When it reaches the hub, which of the following will occur?
A The message is broadcast to all the computers on the network
B The message is sent out on all the ports Beta will ignore the message because it isn’t intended for that computer
C The message will only be sent out on the port connecting to Beta
D The message will only be sent out on the port connecting to Omega
Correct answer and explanation: D The message will only be sent out on
the port connecting to Omega When the computer named Alpha sends the data to the switch, the switch will then send out the data across the port that connects to its destination, which is the computer named Omega
Incorrect answers and explanations: A is incorrect because the message is being sent to Omega and isn’t a broadcast message B is incorrect because a hub
will send out the data on all ports, whereas a switch will only send out the data
to the port that connects to the destination computer C is incorrect because
the message is intended for the computer named Omega not Beta Therefore, the choice is saying that the data is being sent out over the wrong port
You are the network administrator of a large company that has
7
experienced several hacking attempts in the past You decide to install a new IDS on your network Which of the following will be required so that the IDS can view data going across a switch?
A Port authentication
B Port mirroring
Trang 10D Trunking
Correct answer and explanation: B Port mirroring is used to allow all the
data sent and received on one port or VLAN to be copied to another port In
doing so, a mirror image of the data can be sent to the Intrusion Detection
System so that the network traffic can be analyzed
Incorrect answers and explanations: A is incorrect because port
authentica-tion requires a client authenticating to a server before it is given access to a
port C is incorrect because a VLAN is a virtual LAN, which is used to make
computers in different locations appear to be part of the same local area
net-work In doing so, broadcast messages can be sent to all computers and devices
that are part of the same VLAN because they are part of the same broadcast
domain D is incorrect because trunking is used to allow two or more VLANs
to communicate with one another across a single network link
Your company is looking at replacing all the standard telephones
8
used in its offices with IP telephones The initial analysis shows
that there would be a cost savings to the company using IP
tele-phones, but there is a concern that there would be a high initial
cost of having to install new electrical outlets to power these
devic-es Which of the following could be used to power the IP telephones
without needing to install additional power outlets?
A PoE
B STP
C Trunking
D VLAN
Correct answer and explanation: A PoE is Power over Ethernet, which is
a technology in which power can be transferred over standard twisted-pair
cables without modification to the existing cabling infrastructure The
sce-nario states that the company is seeking to use IP telephones, which would
be a suitable use for PoE
Incorrect answers and explanations: B is incorrect because STP is Spanning
Tree Protocol, which was designed to prevent broadcast storms that result
from looping C is incorrect because a VLAN is a virtual LAN and used so
that broadcast messages can be sent to all computers and devices that are
part of the same VLAN because they are part of the same broadcast domain
D is incorrect because trunking is used to allow two or more VLANs to
com-municate with one another across a single network link