1.3.3 network

Question 1

standalone machine

Answer 1

computer that is not connected to anything

stopping the spread of a virus on hardwares(unknown memory sticks)

Question 2

network

Answer 2

a group of devices connected to each other and can communicate with each other

Question 3

internet

Answer 3

inter connected networks- global network of computers connected together (network of networks)

Question 4

www

Answer 4

collection of webpages

Question 5

protocol

Answer 5

RULES that govern how devices COMMUNICATION with each other(standard)

Question 6

use of protocol layering

Answer 6

(the concept of having the different layers)

DECOMPOSITION-Reducing a complex problem into smaller sub-problems.

ABSTRACTION FOR SPECIFIC FUNCTION-Devices can be manufactured to operate at a particular layer.

COMPATABILITY-Products from different vendors will work together.

Question 7

TCP/IP Stack

Answer 7

used in the routing of packets through networks

how it works:
Data is split into chunks called packets by TCP(1 – AO1.1)
which have labels by IP(1 –AO1.1)
including their destination address and order (2 – AO1.1).
Each packet is sent on the most convenient / avoidable route (1 –AO1.2)
meaning they may arrive in a different order to which they were sent(1 – AO1.2).
Once packets arrive at receiver they are reordered (1 - AO1.2).

Question 8

TCP

Answer 8

Transmission Control Protocol – used with IP to ensure ERROR FREE transmission and package switching

• establish an end-to-end connection between the source and recipient computer
• splits the data packets and add a sequence of numbers to them
• check the number of packets and resemble the data packets at the other end ends
• acknowledgement of success transmission (hence error free)

Question 9

IP

Answer 9

Internet Protocol – used to transfer all packets across the internet between routers

add IP address, check IP address, remove IP address

Question 10

IP address

Answer 10

A numerical address made of 4 numbers each between 0 and 255 / 32
hexadecimal digits (1)
That uniquely identifies a device on a
network. (1)
It is a logical identifier (i.e. can change
on a physical device) (1)

Question 11

DNS

Answer 11

use of system: name and organise internet resources

TLD: org/uk/com
SLD: google/edgbarrow

Question 12

DNS server

Answer 12

stores a list of domain names and translate them into associated IP addresses (ISP)

how it works:
-domain name entered and sent to dns servers
-dns servers map the domain to an ip address
-if the domain name cannot be fetched, a request is sent to another dns server
-dns server sends the ip address to the browser
-the ip address than retrieved the website from the web server

Question 13

LAN

Answer 13

group of computers
in a small geographical area
network and hardware owned by the organisation/network owner

link: UTP cable, fiber optic , wifi

Question 14

WAN

Answer 14

size of area: larger geographical area (>1 sq mile)

ownership of hardware: connect to LANs, telecommunication companies who own and manage it.

link: telephone lines, fiber optics cables, satellite links

Question 15

UTP

Answer 15

link layer- one less layer of shield

Question 16

STP

Answer 16

twisted pair-link layer
- one more layer of shield than UTP
- low bandwidth
- used for telephones networks, data networks
- relatively affordable

Question 17

packet switching

Answer 17

Splitting data into packets that can be sends individually across different routes across a network
(the routes can be most convenient/ to avoid traffic)
Once all packets are received, they are reordered

Question 18

circuit switching

Answer 18

Reserving a particular network route to transfer data between two devices

Question 19

SMTP

Answer 19

outbound:
simple mail transfer protocol-
FORWARD the mail to the appropriate mail server

(the SMTP server has the database of email address)for the recipient’s email address

Question 20

IMAP

Answer 20

inbound:
internet message access protocol - keep emails on mail server

(allow flagging and searching, can sync devices, less privacy )

Question 21

POP

Answer 21

inbound:
post office protocol- deletes email from mail server once it is downloaded

(removes the mail from other devices, cannot do complex searches and flagging mail)

Question 22

switch

Answer 22

Network device that connects multiple devices together, sending the data that it receives to the intended recipient device only

Question 23

hub

Answer 23

Network device that connects multiple devices together, sending the data that it receives to all connected devices

Question 24

router

Answer 24

Network device that directs data from one network to another

Question 25

MAC vs IP address

Answer 25

MAC: individual device (in link layer, changed at each server hop) IP: the location/general area for destination

Question 26

TLD

Answer 26

top level domain - e.g. .org, .uk, .com, .edu, .gov

Question 27

SLD

Answer 27

second level domain - e.g. google

Question 28

FTP

Answer 28

file transmission protocol- handles file uploads and downloads (works at the back end), normally on WAN

Question 29

HTTP, HTTPS

Answer 29

hypertext transfer protocol (secure) for client and server to send and receive requests and deliver HTML web pages (s): secure - encryption and authentication

Question 30

UDP

Answer 30

user datagram protocol- simple connectionless transmission model

Question 31

protocol layering

Answer 31

application transport network link

Question 32

the area/purposes of protocol

Answer 32

email(SMTP,IMAP,POP) webpage request(HTTP,HTTPS) file transfer (FTP) LAN/WAN (TCP/IP, UDP)

Question 33

client to server model

Answer 33

one device (the client) requests services from another device (the server).

Question 34

peer to peer model

Answer 34

all terminals have equal status and there is no powerful central server, each computer acts as both a client and a server.

Question 35

switch(vs hub) vs router

Answer 35

a switch connects multiple devices to create a network, a router connects multiple switches, and their respective networks, to form an even larger network

Question 36

(links) Fibre Optic Cables

Answer 36

newer, faster and high-capacity

Question 37

firewall

Answer 37

Security measure that controls incoming and outgoing network traffic using a set of rules (ports) act as filter mechanism of firewall: -proxy -inspection and packet filtering

Question 38

proxies

Answer 38

A proxy ensures there is no direct physical connection between a single user and a remote source.

Question 39

encryption

Answer 39

A method of transforming data into an unintelligible way so that it cannot be read by unauthorised individuals.

Question 40

malware

Answer 40

malicious software - software that annoys users or damages their data. For example, Worms, Viruses, Trojans and Spyware.

Question 41

worm

Answer 41

standalone copies itself

Question 42

virus

Answer 42

copies itself by attaching itself to another program

Question 43

trojan

Answer 43

looks innocent but has ill intent open up back doors

Question 44

social engineering

Answer 44

involves with “social” and human interaction -smishing : fake text messages -vishing: fake voice call -pharming : fake websites

Question 45

phishing

Answer 45

use of email to take the user to a fake website to take their personal information

Question 46

SQL injections

Answer 46

code enter to input text boxes prevention: sanitisation and by blocking certain characters

Question 47

ransomeware

Answer 47

blackmail(scare users) into making a payment

Question 48

most vulnerable with social engineering

Answer 48

the elderly the youngs people not familiar with technology

Question 49

spyware

Answer 49

designed to collect information about what you are doing on the computer e.g. keylogger there are also hackers that hack cameras and mics

Question 50

anti-malware vs anti-virus

Answer 50

COVERAGE anti-malware: designed to log keys(keylogger) and target adverts(adware) + virus anti-virus: ‘quarantine’ the file so it cannot be used to spread the virus; does not cover malware

Question 51

hackers

Answer 51

black hat grey hat white hat

Question 52

DOS and DDOS

Answer 52

sending requests after requests to affect server performance denial of service- one attacker using one/ more devices distributed denial of service- uses botnet

Question 53

network security methods

Answer 53

-username and password -acceptance usage policy -penetration testing -physical security -user access levels cards included: -firewalls -encryption