Networks

Question 1

What is a network?

Answer 1

two or more connected computing devices that can share data and resources

Question 2

true or false? the internet is a giant LAN

Answer 2

false - the internet is a giant WAN

Question 3

What does WAN stand for?

Answer 3

wide area network

Question 4

The ‘CGP School of Science’ building has 10 classrooms with computers. All of the computers are connected to one central network. Is this a LAN or a WAN?

Answer 4

LAN - all computers are in the same ‘local area’ as they are in the same building

Question 5

Why do companies usually hire infrastructure when setting up a WAN?

Answer 5

WANs are expensive to set up, so hiring infrastructure can be cheaper and more practical

Question 6

Devices on a LAN can share hardware like printers, scanners and speakers. Give 2 other benefits of connecting devices on a LAN (there’s actually 4 in the list)

Answer 6

• Internet connection can be shared btw. devices
• files can be shared easily, and can be worked on by multiple users at the same time
• software can be installed and updated on all network machines at the same time
• users can log in from any device on the network

Question 7

An international complany has an office in NY and London. Explain how they can use LANs and WANs to connect all their computers in one network.

Answer 7

each office sets up a LAN connecting all devices at that site, the 2 LANs connected via WAN, so both offices are connected

Question 8

What does WAP stand for?

Answer 8

Wireless access point

Question 9

Which piece of hardware manages the transfer of data between devices on a LAN?

Answer 9

switch (or hub)

Question 10

Which of these is a type of network cable?
Connector, coaxial, covalent

Answer 10

coaxial

Question 11

Describe the purpose of a network interface controller

Answer 11

piece of hardware inside a computer that allows it to connect to a network, also has a unique identifier called a MAC address

Question 12

Fibre optic cables are high-performance and do not suffer much from outside interference. However, Ethernet cables, which have lower performance, are still very popular. Suggest one reason why this is the case

Answer 12

Ethernet are much cheaper and don’t suffer too badly from outside interference over short distances

Question 13

Casta networks are developing the HubBanjo, which is a router, a switch and a WAP all in one. During testing, computers could connect wirelessly and share files, but could not connect to the Internet. Explain which parts of the HubBanjo are faulty

Answer 13

the router is faulty as computers cannot connect to the Internet
(switch and WAP must be working as the computers can connect wirelessly and share files)

Question 14

What is Ethernet?

Answer 14

family of network protocols used for wired connections between devices on a LAN

Question 15

What is the bandwidth of a network?

Answer 15

the amount of data that can be transferred over a network in a given time

Question 16

In general, which type of wireless technology has a larger connection range; Bluetooth or WiFi?

Answer 16

Wi-Fi

Question 17

Give 2 factors that can affect the bandwidth available to a device on a wired network (there’s actually 5)

Answer 17

• types of cables used
• types of hardware used
• network topology
• number of other devices accessing the network
• the activity of other devices on the network

Question 18

What are the advantages of using a wired network rather than a wireless network?

Answer 18

wired networks are generally more reliable, have higher bandwidth and are more secure than wireless networks

Question 19

Tamal is deciding whether to have a wired or wireless LAN in his office. The office is a small open room made up of lots of scattered desks. Suggest 2 reasons for having a wireless LAN (there’s 3, sorry pookie, I hate to lie to u)

Answer 19

• open room means there’s little risk of interference from physical obstructions
• wired LAN requires lots of cables, which could be unsafe/expensive
• over small distance, the wireless signal should be strong enough

Question 20

Describe the roles of the clients and the server in a C-S network

Answer 20

clients send requests for resources or services to the server
server processes the requests and responds to the clients

Question 21

T/F; in a P2P network, files are stored on individual devices

Answer 21

true - devices on a P2P network can store and share files without a server

Question 22

Describe 1 security measure that could be used to manage network security on a client-server network

Answer 22

they only gave 2 examples but literally use ur common sense, it’s computer science
- user access levels
- passwords
both to restrict or prevent access to info stored on server

Question 23

A group of 4 anti-celery activists are deciding which type of network to install in their new office, give 2 (i mean 3) benefits of the activists installing a P2P network

Answer 23

• a P2P will be easier to maintain
• may be cheaper, won’t need to buy expensive server
• network won’t be dependent on any one device (like a server)

Question 24

Explain why it is easier to carry out backups on a C-S network than on a P2P network

Answer 24

in C-S, all data is stored on the server, so backing up all data requires backup of the server
in P2P, data is stored on the machines themselves, so to backup all data, you need to do a backup of every machine

Question 25

How are devices connected in a star topology?

Answer 25

every device is directly connected to a central device that controls that network

Question 26

Dodgy Dan has lots of old computers that he wants to connect in a network, though each computer has a high chance of randomly exploding. Suggest why a full mesh may be appropriate for Dan's network

Answer 26

a full mesh means if a computer explodes, there would always be a different route that data could be sent along to reach the destination device

Question 27

Explain the benefits of using wireless connections for a mesh network

Answer 27

using wireless connections may be cheaper, as you wouldn't need to buy cables to connect all of the devices also, any new devices could connect to the network easily without needing to set up any wiring

Question 28

Give one advantage and one disadvantage of using a star topology rather than a mesh topology for a wired network

Answer 28

advantages: - can be easier to add more devices to the network - devices do not have to waste processing power transmitting data for other devices disadvantages: - if a wire is damaged/broken, a computer could lose access to the network, whereas there could be another route for the data on a mesh network - if there's a problem with the switch/server, the entire network goes down

Question 29

What are network protocols?

Answer 29

sets of rules for how devices communicate and how data is transmitted across a network

Question 30

Network protocols are grouped int layers, what is a layer?

Answer 30

a group of protocols that have similar network functionality

Question 31

When a government website is accessed, all info sent and received is encrypted, which protocol is being used?

Answer 31

HTTPS

Question 32

POP3 and IMAP are both protocols that are used to retrieve emails from a server, explain the difference between how the 2 protocols work

Answer 32

POP3 deletes email from server as soon as you download it, IMAP keeps email on server until you delete it

Question 33

Give 2 advantages of using layers in network protocols

Answer 33

- network communication is broken into more manageable pieces - having rules for each layer encourages people to make universal hardware and software - each layer is self-contained, so a layer can be changed without affecting any others

Question 34

Alex downloads a PDF from his company's server that directs him to a useful website. After viewing the website, he sends an email to his colleagues to tell them about it, suggest 3 network protocols Alex may have used and explain how each was used

Answer 34

FTP to download PDF, HTTP(S) to access website, SMTP to send email may have used TCP and IP to send across network

Question 35

What are URLs?

Answer 35

web addresses used to access web servers and the resources stored on them

Question 36

What does file hosting mean?

Answer 36

when a business uses its servers to store another organisation's files

Question 37

T/F; the cloud can provide increased computing power

Answer 37

true - the could can also offer data storage and access to applications

Question 38

Explain the role of a DNS

Answer 38

a domain name server turns a website's domain name into an IP address, allowing users to access the website using the domain name, rather than having to know the IP address

Question 39

Give a benefit of using cloud applications

Answer 39

cloud applications are run on powerful servers, so users can access demanding applications with a computer that has low spec hardware

Question 40

A blogger is thinking about using the cloud to store the photos that she takes while travelling around the world. Give a benefit and a drawback of using cloud storage to save her photos

Answer 40

cloud storage can provide lots of storage space at a low cost, and she won't have to carry around any extra hardware but, if she visits places with poor internet access, it might be difficult for her to upload her photos to the cloud storage

Question 41

What is meant by an active attack?

Answer 41

when someone uses malware or other direct methods to attack a network

Question 42

An employee exploits their security clearance to steal information from the company, which type of attack is this an example of?

Answer 42

insider attack

Question 43

Suggest how to protect a network from data interception

Answer 43

encrypt the data sent over the networks

Question 44

Describe how a denial of service attack works

Answer 44

a network (or website) is flooded with useless traffic, making the network extremely slow or inaccessible to users

Question 45

A hacker has written a program called "madhax.exe" that can automatically input data into a website. Describe how this program could be used to carry out a brute force attack on a website that requires user to log into their private accounts

Answer 45

the program could be used to try lots of potential username and password combinations very quickly. sooner or later, this could come across a valid combination, giving the hacker access to that user account

Question 46

A company develops a new piece of software that can monitor and record data packets being sent across a network, explain an ethical issue with developing this type of technology

Answer 46

- software could be used by the government to intercept information about illegal activities, though the public may see this as an invasion of privacy - creating the software means its possible that criminals could use it to access sensitive information as it is being sent across a network

Question 47

viruses, worms and trojans are all types of malware. What is malware?

Answer 47

harmful software that's installed on someone's device without their knowledge

Question 48

What is meant by the term 'social engineering'?

Answer 48

gaining sensitive information or illegal access to networks by influencing people

Question 49

What is phishing?

Answer 49

sending emails pretending to be from well-known businesses, asking for personal details

Question 50

Outline how SQL injections can be used to gain unauthorised access to a database

Answer 50

weak input validation is exploited by entering something that changes the SQL statement

Question 51

How can a business reduce the risks of phishing?

Answer 51

filtering suspicious emails, blocking links to untrusted websites and educating staff about phishing scams

Question 52

Suggest how malware cold be used to exploit a user into giving money to a hacker

Answer 52

- using malware to encrypt the user's files and demanding money in exchange for a decryption key to be sent - using malware to redirect a user to a fake version of a website they trust, then trick them into sending money to the hacker

Question 53

Identify 2 weaknesses in the following network security rules: - update the firewall every five years - give admin privileges to all users so they can fix themselves

Answer 53

the firewall should be updated more frequently that once every five years admin access shouldn't be given to everyone as it allows access to sensitive information

Question 54

Give 2 examples of software that can improve network security

Answer 54

anti-malware, spam filter, encryption utilities, firewalls

Question 55

What is needed to turn encrypted cipher text back into plain text?

Answer 55

the decryption key

Question 56

How can a company limit the number of staff with access to sensitive information?

Answer 56

create user access levels that restrict access to information

Question 57

What is the benefit of performing penetration testing?

Answer 57

potential weakness can be identified while there isn't an actual threat, and fixed before a real attack takes place

Question 58

Siobhan uses the password 'cat', suggest how she could make it more secure

Answer 58

use more characters, a mixture of letters, numbers and symbols, user uppercase and lowercase letters

Question 59

Suggest 2 physical security measures that can improve network security

Answer 59

- locks and passcodes can restrict access to certain areas like server rooms - surveillance equipment like cameras or motion sensors can deter intruders

Question 60

A company is having issues with people sneaking onto staff computers while they're on their lunch, they decide to implement a procedure where users will need to enter their password every 5 minutes evaluate this new procedure

Answer 60

the procedure will make it much harder for people to gain unauthorised access to staff computers, as computers that have been left unattended will only be useable for 5 minutes before the password is required, however re-entering the password so frequently will waste a lot of the staff's time, and they will likely find it very annoying