Network Systems Exam 1

In networking, "bandwidth" can be used in multiple contexts. What are they? Choose all that apply.

When discussing frequencies, bandwidth identifies the full range of available frequencies (the width of the band) for a specific application.

When discussing data rates, bandwidth identifies the theoretical maximum number of bits per second.

Given the same maximum frequency, what new technologies offer innovative methods for increasing theoretical bandwidth and effective data throughput? Choose all that apply.

modulation (sending data over an analog signal)

encoding (converting data into a digital signal for transmission)

Why is it important to understand the difference between bits and bytes when describing data quantities versus throughput? Choose all that apply.

Data storage quantities are typically expressed in multiples of bytes and use a capital "B" as in GB for gigabytes.

Data transmission quantities (in other words, throughput) are more commonly expressed in multiples of bits per second with a small "b" as in Gbps, such as 1 Gbps (gigabits per second).

What are the differences between data storage and data throughput measurements? Choose all that apply.

In data throughput, the prefix "kilo" means 10 to the 3rd power (written as 103), or 1000.

In data storage, the prefix "kilo" means 2 to the 10th power (written and 210), or 1024.

What factors can cause signal degradation? Choose all that apply.

attenuation

noise

latency

Noise, or interference, can distort a signal on a network. Signal strength changes are measured to determine signal loss (negative) or gain (positive). How is signal strength measured?

the change in signal strength is measured in dB (decibels)

What are the common sources of noise that can cause interference on a network during transmission? Choose all that apply.

crosstalk

EMI (electromagnetic interference)

What is the transmission flaw that is the loss of a signal's strength as it travels away from its source?

attenuation

Although electrons travel rapidly, they still must travel, and a brief delay takes place between the instant when data leaves the source and when it arrives at its destination. This delay is called latency. What are some of the factors that can cause latency? Choose all that apply.

transmission conversions

processing delays

network traffic congestion

What is the most common way to measure latency on a data network?

calculating a packet's RTT (round trip time)

A network signal may weaken as it travels due to interference. What device strengthens it?

amplifier

What type of crosstalk occurs between two cables?

alien crosstalk

Whitley was watching their favorite show on one of the streaming services when suddenly the image started to jump, and the sound began to cut in and out. What is this problem known as? Choose all that apply.

packet delay variation (PDV)

jitter

Each dB up or down represents a change in power. Typically, a 3 dB loss (i.e., -3 dB) indicates that the signal has lost half its power between the transmitter and receiver. However, it's important to note that dB loss or gain is a relative measure. Which of the following are correct answers for a loss of -3 dB? Choose all that apply.

-3dB on 2000 watts = 1000 watts

-3 dB on 1500 watts = 750 watts

What is the network interface card (NIC) setting that allows signals to travel in both directions over a medium simultaneously?

duplex

What is the network interface card (NIC) setting that allows signals to travel in both directions over a medium but only in one direction at a time?

half-duplex

What network interface card (NIC) setting allows travel in only one direction?

simplex

What is the term used to describe what happens when speed and duplex settings are not supported by a neighboring device and result in a slow or failed transmission?

speed and duplex mismatch

What form of transmission allows many signals to travel simultaneously over one medium?

multiplexing

What is the best way to ensure a strong signal and eliminate, or at least mitigate, noise from signal transmissions? Choose all that apply.

ensure that the strength of the signal exceeds the strength of the noise

proper cable design and installation

What type of crosstalk occurs between wire pairs near the source of a signal?

NEXT

Axel is the network administrator for a mid-sized company that has offices on five nonconsecutive floors in a 50-story building. The company is located on floors 30, 35, 36, 40, and 41, and each floor has a "telecom closet" where all of the switches and routers are located. However, the "telecom closets" on floors 30 and 41 are vacant. The company also has an actual server room situated on the 35th floor. Lately, Axel has been receiving complaints about data errors from the 30th and 41st floors. On the 41st floor, Wi-Fi users have noticed their signal strength dropping to almost zero, and their network connections frequently drop. They must resend emails because they fail to send the first time.On the30th floor, file transfers slow down significantly and sometimes time out. Additionally, employees experience a lot of jitter in the signal when they are streaming live presentations.

add 2 repeaters

Eric is a sales manager at a local TV station. During conference calls with clients, he faces a frustrating problem: he cannot have two-way conversations with them. The communication is one-sided, where he speaks first, and then the client speaks. Unfortunately, this often creates a challenge for Eric, as he sometimes needs to interrupt his clients while they are talking. Since his calls go through his computer, how can this issue be fixed?

change his NIC settings to duplex

What is impedance, and how is it expressed? Choose all that apply.

It is expressed in ohms (Ω).

It refers to the measure of opposition to a current's flow through a cable. It combines resistance, inductance, and capacitance.

Which impedance rating is better for computer networks?

50 ohms

What type of connector is most often used with RG-6 cables?

F-type

Billie is a systems administrator and recently installed new coaxial cable in his office due to issues with jitter with the exiting cable installation. He had some connectors left over from the last installation and ordered new cable. The cable was installed properly, However, after completing the installation, the jitter worsened, and employees were unable to host or participate in video meetings. How could Billie have avoided this situation?

The connectors should have been specific to the cable.

Edsel's electrical engineering firm is collaborating with an architectural firm to create a new twenty-story building. At present, they are in the process of determining where the cable and wire locations will be for the building. What type of cable will Edsel's firm use when running it between floors?

riser-rated

Shielded twisted pair (STP) cable and unshielded twisted pair (UTP) cable can both transmit data at the same speeds up to a point. At what speed does STP surpass UTP?

over 10 Gbps

Electrical signals travel at a speed supported by the conductor material, such as copper, and can approach the speed of light. However, there are other factors that can affect the rate of data transfer. What are some of these factors? Choose all that apply.

data transmission methods

shielding

signal frequency

Fabian was requested to help resolve a wiring issue for one of his clients. It turns out that the new network technician that they hired had manually made the cables, but the company discovered that these cables were not functional with the devices. What's the first thing that should be examined in this scenario?

that the cables were wired to their plugs properly to T568A or T568B standards

A local school district is in the process of installing new ceiling-mounted projectors in each classroom. However, some of the classrooms have drop ceilings, and there is no power outlet in close proximity to where the projectors will be placed. How should the IT department install projectors in these rooms that lack a close proximity to a power outlet?

use PoE (Power over Ethernet)

How is data transmitted through fiber-optic cable? Choose all that apply.

laser

light-emitting diode (LED)

Fiber-optic cable only requires one strand of cable for full-duplex communications.

False

Fiber-optic cable is the industry standard for high-speed networking. What are some of the benefits of fiber-optic cable? Select the benefits from the following list.1. Extremely high throughput2. Power over Ethernet (PoE)3. Very high resistance to noise4. Low latency5. Excellent (though not perfect) security6. Fast repair time7. Ability to carry signals for much longer distances before requiring repeaters8. Low cost

1, 3, 5, 7

Which fiber type consists of a narrow core of 8 to 10 microns in diameter and can accommodate the highest bandwidths and longest distances (without requiring repeaters) of all wired network transmission media?

SMF (single mode fiber)

Jeremy has recently moved to a new office space. During his visit to the network room, he noticed that none of the cables were labeled to indicate which port they were connected to in the wall sockets located around the rooms. Which tool will Jeremy use to find the correct connections?

toner and probe

Madison was summoned to a client's office due to cable connection issues. Upon arrival, Madison identified that one of the cables had been rolled over and had acquired a dent. Therefore, she decided to measure the voltage before proceeding with the troubleshooting process. Which tool will Madison use to measure the voltage on the cable?

multimeter

As a standard procedure, Kim checks cable connections before she plugs anything into her network. As she is checking a cable, she discovers that the wire has a crossed pair. Which is the tool she is using to make this determination?

cable continuity tester

Joel is experiencing problems with a segment of his fiber-optic network. He had some work done on one of the cables recently and the cable had to be spliced. However, he suspects that the splice might be faulty and wants to test it to confirm. Which tool should Joel use to determine if there is a faulty splice or any other issues with his fiber-optic network?

OTDR (optical time domain reflectometers)

The wireless spectrum is defined by the Federal Communication Commission (FCC) as a range of frequencies or bands. What is the range of frequencies?

9 kHz and 300 GHz

When multiple wireless devices transmit a signal at the same time on the same frequency, signals can interfere with one another, which is called a collision. Why do collisions reduce network performance?

the signal must be retransmitted

Which wireless technology transmits short bursts of data on a particular frequency within the band and then moves to the next frequency in the sequence?

FHSS (frequency hopping spread spectrum)

Which wireless technology divides data streams and encodes them into small chunks called chips, which are spread over all available frequencies at the same time?

Omnidirectional sequence

What is the term for the geographic area that can be covered by an antenna or wireless system?

range

Jackson needs to set up a dedicated Wi-Fi signal for his company's conference room using a point-to-point transmission. Which antenna should he use?

unidirectional

RSSI measures the power of the signal on the receiver's end and is displayed as negative dBm values. The scale used for RSSI measurement varies by manufacturer but typically, RSSI is displayed as negative numbers. What would be the best rating of the four numbers below?

-30 dBm

As a wireless signal moves away from the transmission source, it becomes weaker. What is this phenomenon called?

attenuation

As a wave travels into and through a different transmission medium, such as when traveling through glass or other solids, the wave's direction, speed, and wavelength are altered. What is this phenomenon called?

refraction

When the wave encounters an obstacle and reflects, or bounces back, toward its source, a wireless signal will bounce off objects whose surface dimensions are large compared with the signal's average wavelength. What is this phenomena called?

reflection

Jenine was having issues with her home network, i.e., getting one segment of her wireless network to connect to her wired network. One segment worked fine, but the other would not connect, even though the network name on both segments and the wired network were the same. What can be causing this issue? Choose all that apply.

channel mismatch

password is incorrect

In what order were the Wi-Fi standards released?

1. 802.11a

2. 802.11g

3. 802.11b

4. 802.11ac

5. 802.11n

6. 802.11ax

7. 802.11be

3, 1, 2, 5, 4, 6, 7

What are some of the factors that influence the effective range of wireless technology? Choose all that apply.

power of the antenna

physical barriers

interference in the environment

Jason has a problem with his network. He recently switched to Wi-Fi from Ethernet since he thought it would be much easier to manage, as he would add workstations with Wi-Fi NICs as his company grew, instead of adding a cable drop for each new employee that needed a computer. He has a large office space that was not a standard shape and had many out-of-the way offices that needed coverage. As he started adding people, but not nodes, he noticed his network was having many more packet collisions issues than during his original baseline network assessment. What is this problem called, and how can he fix it?

the hidden node problem

What are some examples of IoT devices? Choose all that apply.

garage doors

bathroom scale

In an enterprise setting, configuring wireless access for clients to the network can be a complex process. What is involved in the onboarding process? Choose all that apply.

Users or network technicians install a specific app called an agent on a user's device, which gives the device trusted access to certain portions of the network.

Certain network administrative features might all be controlled by the device's permission levels enabled by on boarding that device.

The agent might also scan the device for any needed OS or security updates, required security settings (such as timeouts or sign-in requirements), and any existing malware.

When setting up a network router, the first step that any networking professional should take is to change the default SSID, username, and password of the device. These are crucial steps that should be followed whether setting up a SOHO network or a corporate network. Why are these steps so crucial?

Default SSIDs and their accompanying usernames and passwords are easily found.

When an employee leaves a company, IT is responsible for offboarding. What is IT's role in offboarding?

revoking access to company data and removing company-related software from the employee's devices

Gavin just lost his company phone and reported the loss to the IT department. Since IT does not have physical access to the device, what will they do to ensure that their data does not fall into the wrong hands?

remote wipe

Why are onboarding and offboarding policies especially critical in a BYOD (bring your own device) environment? Choose all that apply.

It gives the IT department permission to monitor device activity or to wipe data from the device with or without further notice.

The IT staff can ensure the safety of the network while allowing access to a wide range of employee-owned devices using network resources.

It allows for IT staff to monitor company data on personal devices to ensure that personal data is not commingled with the company's sensitive information, and to keep the company's intellectual property safe.

What is the purpose of encryption?

keep information private

What forms of authentication are provided by Wired Equivalent Privacy (WEP)? Choose all that apply.

SKA (Shared Key Authentication)

OSA (Open System Authentication)

Marcelo is aware of the WPA3 Wi-Fi protocol and would like to switch to it. He bought his router in 2020, and the protocol was introduced in 2018, so his router should have it. However, when he tries to turn it on through the router's web interface, he can't find the setting. What could be the reason that WPA3 is not available on Marcelo's router? Choose all that apply.

The router is WPA3 compatible, but the firmware has not been updated.

The mandate to make all routers WPA3 compatible did not apply to the router that Marcelo purchased.

Temporal Key Integrity Protocol (TKIP) was added to address the encryption issues of WEP. What were the significant improvements of adding TKIP? Choose all that apply.

key distribution

encryption

message integrity

In WPA, TKIP aimed for backwards-compatibility, but WPA2's CCMP (Counter Mode with Cipher Block Chaining Message Authentication Code Protocol) ensures future-focused data confidentiality. How does CCMP provide encryption and packet authentication? Choose all that apply.

message encryption

message integrity

What is the essential difference between a block cipher and a stream cipher? Choose all that apply.

A stream cipher encrypts one bit or byte of data at a time.

A block cipher encrypts large chunks or blocks of data at a time.

Randy is setting up security for his home network. Which Wi-Fi security protocol will he use for his home network environment?

WPA2-PSK

Authentication and authorization are two distinct processes. What distinguishes these two processes? Choose all that apply.

Authentication is the sign-in process.

Authorization determines what the entity can do once it gets into the resource.

Shaunda is the owner of a café and wants to provide Internet access for her customers. However, she does not want them to access the company network, go beyond the café's perimeter, or engage in any illegal activities on the network. What security configurations should she make to her Wi-Fi network to ensure that it is set up securely? Choose all that apply.

geofencing

guest network

captive portal

What are some common security threats to Wi-Fi networks? Choose all that apply.

war driving

evil twin

WPS/brute force attack

True story of another ATM scam. This has been reported happening in California and involves a wireless technology called near-field communications (NFC). A customer goes to an ATM to withdraw cash. However, they find that the ATM card slot is jammed. At this point, a outwardly kind individual suggests that they use the tap function on their card to withdraw the money. The customer then uses the tap function to withdraw their money. They successfully complete their transaction and leave the ATM. However, when they receive their bank statement at the end of the month, they discover that an additional $3,000 has been taken from their account. How could that have happened? Choose all that apply.

The tap function requires that the transaction be closed manually.

The customer did not close out the transaction.

The outwardly kind person is really the bad actor.

What type of analyzer can evaluate Wi-Fi network availability as well as help optimize Wi-Fi signal settings or help identify Wi-Fi security threats?

Wi-Fi analyzer

What are some common reasons why a Wi-Fi client cannot connect to the AP? Choose all that apply.

wrong SSID

encryption protocol mismatch

incorrect passphrase

SSIDs are case sensitive. MYCAR does not equal MyCar.

True

Debbie is trying to connect to her router. She has the SSID correct but still cannot log in. What could be the problem?

The passphrase is case sensitive, and she accidentally left her caps lock on.

Marica purchased a new doorbell camera that broadcasts on the 2.4 GHz band. However, the new AP she purchased only broadcasts on the 5 GHz band. What issue will arise from this scenario?

The AP and doorbell camera will not be able to communicate.

Anna has an access point that is compatible with Wi-Fi 1 through Wi-Fi 5. She just bought a new computer that is capable of using Wi-Fi 6, but when she tests the speed from her computer to her AP, she is only able to reach Wi-Fi 5 speeds. What is the reason?

Anna's device is not forward compatible.

What are some of the possible reasons for an AP association to get stuck? Choose all that apply

edge of the network's coverage range

environmental factors

MAC address filtering

Vasyl resides on the first floor of an apartment building just above the garage. Recently, he noticed that whenever he enters the garage from the street or is parked outside his unit, he can easily log in to his home network. He is concerned about the security of his network and wants to know how he can prevent any unauthorized access from outside the apartment or from within the underground garage. How can Vasyl fix this issue? Choose all that apply.

lower the power levels on the router

move APs away from exterior walls

Nathan's wireless network is located in a busy company that employs about 50 people. Every day around noon, when the lunch rush starts, he notices that the wireless signal becomes spotty. Sometimes it drops to barely any signal, and sometimes it drops altogether. However, after the lunch rush, the network works normally again. What might be causing this issue?

interference from electromagnetic interference (EMI)

TCP/IP is a suite of protocols, or standards, that includes TCP, IP (IPv4 and IPv6), UDP, ARP, and many others. Many of these protocols function by adding information at the end of messages transported across the network in fields called footers.

False

If a router that reads and processes the network layer header and leaves alone the transport layer header. At what layer is the router working?

layer 3

Tommy is currently in the process of selecting a firewall to purchase. With several options available, each specializing in different layers of the OSI model, he has decided to opt for a layer 7 firewall over a layer 4 firewall. Why would Tommy choose a layer 7 firewall?

A layer 7 firewall can read through the entire message to check for signs of malware.

At the beginning of a Transmission Control Protocol (TCP) segment, TCP manages several elements by posting data to fields in the TCP headers. What are some of these elements? Choose all that apply.

sequencing

checksum

flow control

Why is the ISN (Initial Sequence Number) of the first SYN message in the three-way handshake considered a security risk?

The ISN is calculated by a predictable clock-based algorithm.

Bianca is live-streaming from her friend's birthday party. What Internet protocol is most likely being used for this service?

UDP

Which OSI layer protocols collaborate with User Datagram Protocol (UDP) to emulate some of the reliability provided Transmission Control Protocol (TCP)?

application layer

What is the protocol that can traverse (internetwork) more than one LAN segment and more than one type of network through a router?

IP

Jeremy was sitting in the network operations center (NOC) watching a live stream from the president of his company. As he was watching the feed, he noticed that the picture was a little "glitchy," occasionally patches of color would be missing from the feed. There was nothing he could do about it because of the way the feed was being transmitted. What protocol could the feed be transmitting in, and why would it look like there were errors in the feed?

UDP. It does not provide error checking or correction mechanisms, so if a packet is lost or corrupted during transmission, it will not be retransmitted, which is why the image had data packets dropping out of it.

Why is there no fragment offset field in an IPv6 packet?

IPv6 hosts adjust their packet sizes to fit the requirements of the network.

Besides IP, what other protocol plays a significant role on both IPv4 and IPv6 networks?

ICMP

What is the reason as to why ARP (Address Resolution Protocol) is sometimes said to function at layer 2.5?

It touches IP and MAC address information at both layers.

What are the multiple types of Address Resolution Protocols (ARP) entries? Choose all that apply.

Dynamic ARP table entries

Static ARP table entries

What is the difference between an Address Resolution Protocol (ARP) table and a Media Access Control (MAC) table? Choose all that apply.

An ARP table maps layer 3 IP addresses to layer 2 MAC addresses.

A MAC address table maps layer 2 MAC addresses to layer 1 physical interfaces on a device.

If Address Resolution Protocol (ARP) is responsible for IPv4 network host discovery through Internet Control Message Protocol (ICMP),, how do IPv6 devices learn about other devices on their networks?

NDP (Neighbor Discovery Protocol)

What is the purpose of the Link Layer Discovery Protocol (LLDP)? Choose all that apply.

discover neighboring networking devices

discover information about neighboring networking devices such as configurations or capabilities

The data link layer is unique because it can be divided into sublayers. What are those sublayers? Choose all that apply.

MAC sublayer

LLC (logical link control) sublayer

What defines the maximum payload size that a layer 2 frame can encapsulate?

MTU (maximum transmission unit)

What is fragmentation and why does it happen?

Fragmentation is the process of dividing packets that are too large for a network's hardware into smaller packets that can safely traverse the network.

In terms of security, data exists generally in three states. In what state is data being moved?

in transit