Networking Concepts (7)

Question 1

Which of the following are possible reasons why the 5 GHz frequency tends to perform better than the 2.4 GHz frequency on a wireless LAN? (Choose all correct answers.)

The 5 GHz frequency has more channels than the 2.4 GHz frequency.

The 5 GHz frequency supports longer ranges than the 2.4 GHz frequency.

The 5 GHz frequency conflicts with fewer common household devices than the 2.4 GHz frequency.

The 5 GHz frequency transmits at faster speeds than the 2.4 GHz frequency.

Answer 1

The 5 GHz frequency has more channels than the 2.4 GHz frequency.

The 5 GHz frequency conflicts with fewer common household devices than the 2.4 GHz frequency.

The 5 GHz frequency transmits at faster speeds than the 2.4 GHz frequency.

The 5 GHz frequency has 23 channels available in the United States, while the 2.4 GHz frequency has only 11. Many household devices, such as cordless telephones, use the 2.4 GHz frequency band, but relatively few devices use the 5 GHz band. Higher frequencies typically support faster transmission speeds, because with all other conditions equal, they can carry more data in the same amount of time. The 5 GHz frequency typically has a shorter range than 2.4 GHz, because it is less able to penetrate barriers

Question 2

Alice is attempting to deploy an IEEE 802.11b/g wireless LAN on the fifth floor of a ten-story office building that is surrounded on all sides by other office buildings, all of which seem to be running many wireless LANs. Scanning the 2.4 GHz band, she sees literally dozens of networks, spread across all of the available channels. As a result, her wireless devices have trouble connecting to their access point, and when they do, they achieve only low speeds. Choose the two tasks from the following list that Alice should perform to enable the wireless clients to connect to the network most reliably. (Choose two correct answers.)

Upgrade all of the wireless network devices to IEEE 802.11n.

Configure the wireless devices to use the 5 GHz band.

Configure all of the network devices to use WPA2 encryption with AES.

Configure the access point to suppress SSID broadcasts.

Answer 2

Upgrade all of the wireless network devices to IEEE 802.11n.

Configure the wireless devices to use the 5 GHz band.

Upgrading the devices to 802.11n will enable them to use the 5 GHz band and evade the traffic generated by the surrounding networks. Configuring the devices to use the 5 GHz band will provide many more channels to choose from and will avoid the interference from the surrounding 2.4 GHz networks. The type of encryption that a wireless network uses has no bearing on the ability of the devices to avoid the interference generated by surrounding networks. Suppressing SSID broadcasts will not help the devices to connect to the network. Upgrading the firmware on the devices is not likely to have any effect on the connection problems when they are the result of interference from other networks

Question 3

Which of the following is the fastest speed achievable by a wireless LAN using the currently ratified IEEE 802.11 standards?

54 Mbps

600 Mbps

1.3 Gbps

Answer 3

1.3 Gbps

The 802.11ac standard defines a wireless LAN running at a speed of up to 1.3 gigabits per second (Gbps). None of the other 802.11 standards call for speeds beyond 600 Mbps. No currently ratified standard enables speeds of 2.6 Gbps

Question 4

What is the term for the technology implemented in the IEEE 802.11ac standard that enables a wireless device to transmit multiple frames to multiple clients simultaneously?

Channel bonding

CSMA/CA

MU-MIMO

Answer 4

MU-MIMO

The multiple input and multiple output (MIMO) technology introduced in the IEEE 802.11n standard enables wireless devices to transmit and receive signals using multiple antennae simultaneously. The Multiuser MIMO (MU-MIMO) variant defined in the 802.11ac standard advances this technique by enabling wireless devices to transmit multiple frames to different users simultaneously, using multiple antennae. Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) is a media access control mechanism used by all 802.11 networks. Channel bonding is a wireless networking technique that combines channels to increase bandwidth

Question 5

On an IEEE 802.11b/g/n wireless network running at 2.4 GHz with multiple access points, the traditional best practice is to use channels 1, 6, and 11, with no two adjacent access points configured to use the same channel. Which of the following is the real reason why this is a good plan?

Channels 1, 6, and 11 are the only three channels with frequencies that do not overlap.

Channels 1, 6, and 11 have more bandwidth than the other channels.

Channels 1, 6, and 11 have greater ranges than the other channels.

Answer 5

Channels 1, 6, and 11 are the only three channels with frequencies that do not overlap.

The 22 MHz channels in the 2.4 GHz band are spaced 5 MHz apart, which means that they overlap. Channels 1, 6, and 11 are the only three channels that are distant enough from each other not to overlap. Therefore, they do not interfere with each other. Channels 1, 6, and 11 do not differ from the other channels in their bandwidth or their transmission range. Each wireless device can be set to use only one channel. Therefore, channels 1, 6, and 11 cannot all be the default setting

Question 6

Ralph is performing a site survey for a wireless LAN installation in a warehouse with two offices at either end of the building, approximately 300 feet apart. If he installs a single access point in the center of the warehouse, equidistant from the two offices, which of the following standards should he look for when purchasing hardware so that workstations in both offices will be able to connect to the network at the best possible speed?

IEEE 802.11a

IEEE 802.11g

IEEE 802.11n

Answer 6

IEEE 802.11n

Wireless networks using equipment based on the IEEE 802.11n standard can span indoor distances of up to 175 feet at speeds up to 600 Mbps. An 802.11ac network can run at faster speeds—up to 1.3 Gbps—but it is limited to approximately 115-foot distances. Networks using 802.11g equipment can span 150 feet, but they run at only a maximum of 54 Mbps. An 802.11a network cannot span more than 75 feet, and it runs at no more than 54 Mbps

Question 7

Which of the following terms defines a wireless LAN transmission technique in which devices use multiple antennae to increase transmission speeds?

Which of the following terms defines a wireless LAN transmission technique in which devices use multiple antennae to increase transmission speeds?

MIMO

TDMA

PAN

Answer 7

MIMO

Multiple input and multiple output (MIMO) calls for the use of two or more antennae, enabling wireless devices to effectively multiplex signals, hereby increasing their transmission speeds. Time Division Multiple Access (TDMA) is a communication technique that splits a frequency into multiple time slots, enabling it to carry multiple data streams. A personal area network (PAN) provides communication among devices associated with a single person, such as smartphones. Ant+ is a wireless protocol that is typically used to monitor data gathered by sensors, such as those in cardiac pacemakers

Question 8

What is the maximum channel width possible using wireless networking equipment based on the ratified IEEE 802.11 standards?

40 MHz

80 MHz

160 MHz

Answer 8

160 MHz

The 802.11ac standard defines the bonding of up to eight 20 MHz channels, for a total possible channel width of 160 MHz. The 802.11n standard can bond up to two channels, for a 40 MHz width. Earlier standards are limited to a single 20 MHz channel

Question 9

Which of the following wireless networking standards are capable of using only the 5 GHz frequency? (Choose all correct answers.)

IEEE 802.11a

IEEE 802.11b

IEEE 802.11g

IEEE 802.11n

IEEE 802.11ac

Answer 9

IEEE 802.11a

IEEE 802.11ac

The IEEE 802.11a and IEEE 802.11ac standards can use the 5 GHz band only. IEEE 802.11b and IEEE 802.11g can use the 2.4 GHz band only. IEEE 802.11n can use either the 2.4 or 5 GHz band

Question 10

Which of the following IEEE wireless LAN standards provides the greatest possible throughput?

802. 11a
803. 11ac
804. 11b

Answer 10

802.11ac

The IEEE 802.11ac standard provides the greatest possible throughput, at up to 1.3 Gbps. The 802.11n standard runs at speeds up to 600 Mbps. The 802.11a and 802.11g standards run at up to 54 Mbps. The 802.11b standard runs at up to 11 Mbps

Question 11

Which of the following IEEE 802.11 wireless LAN standards are capable of supporting both the 2.4 GHz and 5 GHz frequencies?

802. 11a
803. 11g
804. 11n

Answer 11

802.11n

Only the 802.11n standard defines wireless LAN devices that can support both 2.4 GHz and 5 GHz frequencies. The 802.11a and 802.11ac standards use only 5 GHz, and the 802.11b and 802.11g standards use only 2.4 GHz

Question 12

What is the maximum number of transmit and receive antennae supported by the currently ratified IEEE 802.11 wireless LAN standards?

2

4

8

Answer 12

8

The 802.11ac standard supports multiple input and multiple output (MIMO) through the use of up to eight antennae on a single device. The 802.1n standard is the only standard that supports MIMO, with up to four antennae

Question 13

Which of the following is the term for the network name that you use to connect a client device to an access point on a wireless LAN?

BSS

ESS

SSID

Answer 13

SSID

The Service Set Identifier (SSID) is the name that you use when connecting to a wireless network. A Basic Service Set (BSS) refers to the wireless network itself, consisting of a single access point and a number of clients. An Extended Service Set (ESS) consists of two or more BSSs, using multiple access points. The Basic Service Set Identifier (BSSID) is the MAC address of the access point associated with a BSS

Question 14

Which of the following IEEE wireless LAN standards define devices with a maximum aggregate channel width of 20 MHz? (Choose all correct answers.)

802. 11a
803. 11g
804. 11n
805. 11ac

Answer 14

802. 11a
803. 11g

Devices conforming to the IEEE 802.11a and 802.11g standards can only use a single 20 MHz channel. IEEE 802.n devices can use channel bonding to join two channels together and achieve an aggregate channel width of 40 MHz. IEEE 802.11ac devices can bond up to eight channels, for an aggregate width of 160 MHz

Question 15

Which of the following cloud service models enables you to select the operating system you want to install?

IaaS

PaaS

SaaS

Answer 15

IaaS

The Infrastructure as a Service (IaaS) model provides consumers with processing, storage, and networking resources that they can use to install and run operating systems and other software of their choice. Platform as a Service (PaaS) provides consumers with the ability to install applications of their choice on a server installed by the provider. Software as a Service (SaaS) provides consumers with access to specific applications running on the provider’s servers

Question 16

When you contract with a provider to obtain email services for your company using their servers in the public cloud, which of the following service models are you using?

IaaS

PaaS

SaaS

Answer 16

SaaS

The Software as a Service (SaaS) model provides consumers with access to a specific application running on the provider’s servers. Infrastructure as a Service (IaaS) provides the consumers with processing, storage, and networking resources that they can use to install and run operating systems and other software of their choice. Platform as a Service (PaaS) provides consumers with the ability to install applications of their choice on a server installed by the provider

Question 17

Which of the following cloud service models provides the consumer with the most control over the cloud resources?

IaaS

PaaS

SaaS

Answer 17

IaaS

The Infrastructure as a Service (IaaS) model provides the consumers with the most control, as the provider furnishes processing, storage, and networking resources that the consumer can use as needed. Platform as a Service (PaaS) provides consumers with the ability to install applications of their choice on a server furnished by the provider, but they have only limited control over the server and no control over the underlying resources. Software as a Service (SaaS) provides consumers with access to a specific application running on the provider’s servers, but the consumers have no control over the operating system, the servers, or the underlying resources

Question 18

Alice has just created a new Windows Server 2016 virtual machine using remote controls provided by a cloud service provider on the Internet. Which of the following cloud architectures is she using? (Choose all correct answers.)

IaaS

PaaS

SaaS

Public cloud

Private cloud

Hybrid cloud

Answer 18

IaaS

Public cloud

Infrastructure as a Service (IaaS) provides the consumers like Alice with processing, storage, and networking resources that they can use to install and run operating systems and other software of their choice. In the public cloud model, one organization functions as the provider, and another organization—in this case, Alice—consumes the services of the provider.

Platform as a Service (PaaS) provides consumers with the ability to install applications of their choice on a server furnished by the provider. Software as a Service (SaaS) provides consumers with access to a specific application running on the provider’s servers, but the consumers have no control over the operating system, the servers, or the underlying resources. In a private cloud, the same organization that utilizes the cloud services is also the sole owner of the infrastructure that provides those services. A hybrid cloud is a combination of public and private infrastructure so that the consumer organization is only a partial owner of the infrastructure

Question 19

In which of the following cloud models does a single organization function as both the provider and the consumer of all cloud services?

Public cloud

Private cloud

Hybrid cloud

Answer 19

Private cloud

In a private cloud, the same organization that utilizes the cloud services is also the sole owner of the infrastructure that provides those services. In the public cloud model, one organization functions as the provider, and another organization consumes the services of the provider. A hybrid cloud is a combination of public and private infrastructure so that the consumer organization is only a partial owner of the infrastructure. There is no such thing as an ad hoc cloud model

Question 20

Ed is the overnight manager of his company’s datacenter, and he is responsible for both private and public resources in the company’s hybrid cloud. Due to a new TV commercial shown that night, the company’s website experiences a massive upsurge in traffic. The web server farm on the private cloud is being overwhelmed, so Ed configures some virtual machines in the public cloud to take up the slack. Which of the following is a common term for what Ed has done?

Cloud busting

Cloud bursting

Cloud splitting

Answer 20

Cloud bursting

Cloud bursting is a common term for the offloading of excess traffic from private to public cloud resources when necessary to maintain satisfactory performance levels

Question 21

Microsoft’s Outlook.com email service is an example of which of the following cloud service models?

IaaS

PaaS

SaaS

Answer 21

SaaS

Software as a Service (SaaS) provides consumers with access to a specific application running on the provider’s servers, in this case an email service. Consumers have control over some of their email functions, but they have no control over the operating system, the servers, or the underlying resources. The Infrastructure as a Service (IaaS) model provides the consumers with access to processing, storage, and networking resources that the consumer can use as needed. Platform as a Service (PaaS) provides consumers with the ability to install applications of their choice on a server furnished by the provider

Question 22

Which of the following statements about cloud delivery models is true?

A public cloud is inherently insecure because anyone can access it.

A private cloud consists of hardware that is all located in a single datacenter.

A hybrid cloud enables administrators to migrate services between public and private resources.

Answer 22

A hybrid cloud enables administrators to migrate services between public and private resources.

A hybrid cloud consists of both public and private resources. One of its main advantages is that administrators can move services from private to public cloud servers and back again as needed, depending on the current workload. Public cloud resources require authentication, so while they might be less secure than a private cloud, they are not inherently insecure. The term private cloud refers to hardware resources that are owned and operated by a single organization, regardless of their location. The various cloud delivery models do not impose specific hardware resource requirements

Question 23

Ed has just created a new Windows application for his company, and he wants to deploy it in the public cloud. He is looking for a provider that will furnish his company with a fully installed and configured Windows server on which he can install and run his application. Which of the following service models is he seeking to use?

IaaS

PaaS

SaaS

Answer 23

PaaS

The Platform as a Service (PaaS) model provides consumers with the ability to install applications of their choice on a server furnished by the provider. Infrastructure as a Service (IaaS) provides the consumers with processing, storage, and networking resources that they can use to install and run operating systems and other software of their choice. Software as a Service (SaaS) provides consumers with access to a specific application running on the provider’s servers

Question 24

In which of the following DNS transactions does the querying system generate a recursive query? (Choose all correct answers.)

A DNS client sends the server name www.adatum.com from a URL to its designated DNS server for resolution.

A client’s DNS server sends a request to a root domain server to find the authoritative server for the com top-level domain.

A client’s DNS server sends a request to the com top-level domain server to find the authoritative server for the adatum.com domain.

A client’s DNS server, which has been configured to function as a forwarder, sends the server name www.adatum.com from a URL to its ISP’s DNS server for resolution.

A client’s DNS server sends a request to the adatum.com domain server to find the IP address associated with the server name www.

Answer 24

A DNS client sends the server name www.adatum.com from a URL to its designated DNS server for resolution.

A client’s DNS server, which has been configured to function as a forwarder, sends the server name www.adatum.com from a URL to its ISP’s DNS server for resolution.

When a client sends a name resolution query to its DNS server, it uses a recursive request so that the server will take on the responsibility for resolving the name. The only other use of recursive requests is in the case of a forwarder, which is configured to pass that responsibility on to another server. All of the other queries issued by the client’s server to the various domain authorities are iterative queries

Question 25

Which of the following devices would you most likely configure to function as a Dynamic Host Configuration Protocol (DHCP) server?

A wireless router

An unmanaged switch

A hub

Answer 25

A wireless router

Most wireless routers are designed to provide connecting workstations with IP addresses and other TCP/IP configuration parameters. Switches and bridges are data link layer devices and hubs are physical layer devices, none of which are capable providing clients with network layer IP addresses

Question 26

Which of the following protocols are responsible for assigning IP addresses to hosts? (Choose all correct answers.)

Dynamic Host Configuration Protocol (DHCP)

Address Resolution Protocol (ARP)

Domain Name System (DNS)

File Transfer Protocol (FTP)

Bootstrap Protocol (BOOTP)

Answer 26

Dynamic Host Configuration Protocol (DHCP)

Bootstrap Protocol (BOOTP)

DHCP and BOOTP are both designed to allocate IP addresses to hosts. The primary difference between the two is that DHCP is capable of dynamic allocation and BOOTP is not. DNS resolves hostnames into IP addresses, and ARP resolves IP addresses into data link layer hardware (or MAC) addresses. FTP is designed to transfer files between systems and has no role in IP address allocation