1.3.3 Networks

Question 1

Describe what is meant by a LAN.(2)

Answer 1

(1) Local Area network
(1) Over a small geographical area
(1) Use of hard-wiring / wireless communication

Question 2

State two advantages of having a LAN instead of a set of stand-alone machines.(2)

Answer 2

(1) Communication between machines / workers
(1) Any machine can be used
(1) Easier to maintain / add / delete sottware files
(1) Sharing of peripheral devices / software / data
(1) Monitoring of workers
(1) Simplifies backup procedures

Question 3

TCP/IP uses packet switching. Explain what is meant by packet switching.(2)

Answer 3

Data is split into chunks called packets
(1) which have labels (1) including address being sent to
(1 ) and order (1).
Each packet is sent on the most convenient / avoidable route (1) meaning they may arrive in a different order to which they were sent
(1). Once packets arrive at receiver they are reordered (1).

Question 4

What is a node?

Answer 4

A computer in a network.

Question 5

What is a network?

Answer 5

A collection of collected nodes.

Question 6

Advantages of Networks

Answer 6

Share files share hardware use any computer

Question 7

What are the disadvantages of networks?[2]

Answer 7

Expensive(1) Needs specialists.(1)

Question 8

What is the role of a NIC?[1]

Answer 8

Allows a node to attach to a network.(1)

Question 9

What is the role of a switch?

Answer 9

Connects several devices in a network.

Question 10

What is a Wide Area Network? (WAN)

Answer 10

Devices linked across a large geographic area. Often connect via 3rd party channels.

Question 11

What is malware?

Answer 11

Malicious software designed to steal from or damage a computer.

Question 12

What is a virus?

Answer 12

Malware designed to self-replicate and spread.

Question 13

What are the types of malware?

Answer 13

Keyloggers Worms Adware and ransomware.

Question 14

What is phishing?

Answer 14

Stealing data by tricking users.

Question 15

What are the methods of defending a network? (4)

Answer 15

Training Antivirus User access levels and strong passwords.

Question 16

What is a holistic antivirus?

Answer 16

Identifies malware based on predicting behaviour.

Question 17

What is a signature-Based antivirus

Answer 17

Compares code to libraries of identified malicious behaviour. Liraries have to be maintained.

Question 18

What is a firewall?

Answer 18

Hardware or software that monitors packets going to and from a network.

Question 19

What is packet filtering?

Answer 19

Blocking packets based on rules.

Question 20

Why use a firewall?

Answer 20

Prevent packets from accessing specific devices. Filter packets from a specific location or service. Prevent outgoing packets with sensitive information.

Question 21

Demilitarised Zone (DMZ)

Answer 21

An area of protected devices between firewalls.

Question 22

Why use a DMZ?

Answer 22

Offer some external services without comprimising LAN. Additional layer of security if public services are compromised.

Question 23

What is a gateway?

Answer 23

A hardware device that connects two dissimilar networks. (E.G LAN/Internet)

Question 24

What is a proxy?

Answer 24

A server that fetches packets on behalf of another device.

Question 25

Why use a proxy on outgoing traffic?

Answer 25

Layer of security connects on your behalf. May store cached version lightens network load on server. Bypass region locks. Anonymity.

Question 26

What is a Virtual Private Network (VPN)?

Answer 26

Computers act as if they are on the same LAN. Devices can send requests from a shared router. Data between devices can be encrypted.