Network Protocols & Security - 1.3.2

Question 1

What is a network protocol?

Answer 1

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

Question 2

What is a MAC address (5)?

Answer 2

Assigned to all network enabled devices by the manufacturer
Unique to the device
Cannot be change
48-64 bits long
Mainly used by Ethernet protocol on LAN’s so switches can read them and direct data to the right device

Question 3

What is an IP address (3)?

Answer 3

Internet protocol - well-known set of rules and instructions
Used when sending data between networks
Unique addresses across the internet assigned manually or automatically to a device

Question 4

What are the 2 versions of IP addresses?

Answer 4

IPv4 - uses 32 bits, split into 8 bit chunks and each one is a denary number e.g. 37.153.62.136
IPv6 - uses 128 bit, was created due to the increasing number of devices that needed unique IP addresses

Question 5

What does the TCP/IP do (3)?

Answer 5

Dictates how data is sent between networks
Made up of two protocols:
Transmission Control Protocol - rules for how devices connect on the internet, splits data into packets
Internet Protocol - directs packets to their destination

Question 6

What are the 6 other protocols and their function?

Answer 6

HTTP (hyper text transfer protocol) - transfers webpages from server to client
HTTPS (HTTP secure) - more secure HTTP, uses encryption
FTP (file transfer protocol) - access, edit, move files between devices on a network
POP3 (post office protocol) - retrieves emails from servers, original is deleted
IMAP (internet message access protocol) - retrieves emails, original is not deleted
SMTP (simple mail transfer protocol) - sending emails, transfer from one server to another

Question 7

What is a layer (2)?

Answer 7

A group of protocols with similar functions
Each layer serves the layer above

Question 8

What are the 4 layers of the TCP stack?

Answer 8

Application
Transport
Network
Data

Question 9

What happens in the application layer and with which protocols?

Answer 9

User sends an email or opens a webpage - FTP, POP3, IMAP, SMTP, HTTPS, HTTP

Question 10

What happens in the transport layer and with which protocol?

Answer 10

The email or webpage is split into packets by the OS - TCP

Question 11

What happens in the network layer and with which protocol?

Answer 11

A sender and recipient address is put on the packets - IPv4 or IPv6

Question 12

What happens in the data layer and with which protocol?

Answer 12

Each packet makes its way through the network - Ethernet protocol

Question 13

What is malware (2)?

Answer 13

Malicious software
Installed on someone’s device without their knowledge or consent

Question 14

Actions of malware (4)?

Answer 14

Deleting or modifying files
Scareware
Locking files
Spyware

Question 15

Types of malware (3):

Answer 15

Viruses - attach to certain files, spread when copied, activate by opening
Worms - like viruses but self-replicate, spread very quickly
Trojans - malware disguised as legitimate software, users install them accidentally

Question 16

What is social engineering?

Answer 16

Way of gaining sensitive information or illegal access to networks by influencing people

Question 17

Types of social engineering (2):

Answer 17

Calling employees, pretending to be someone from the company
Phishing - send emails or texts claiming their from well-known businesses, request user to update personal information

Question 18

What is SQL (2)?

Answer 18

Structured query language
Deals with databases
SELECT … FROM … WHERE …

Question 19

What is an SQL injection?

Answer 19

Pieces of SQL typed into a website’s input box which can then reveal sensitive information

Question 20

How to stop security attacks (6)?

Answer 20

Penetration testing - an organisation employ specialist to stimulate attacks on their network to identify possible weaknesses
Physical security - protects the physical parts of a network (fire, flooding, theft), could be locks, cameras
Passwords - prevent unauthorised users from accessing a network
User access levels - controls which part of the network different groups of users can access
Anti-malware - designed to stop malware from damaging a network, e.g. firewalls which examine all data entering and leaving a network
Encryption - data is altered with a specific code so if intercepted can be read but not understood