Topic 3) Networks

Question 1

What is a Server?

Answer 1

A computer system or a software application that provides a service to other computer systems on the same network

Question 2

What is a client?

Answer 2

Computer system or software application that requests a service from a server, connected to the same network

Question 3

What are Computer Networks?

Answer 3

A computer network is formed when 2 or more computers are linked together
Every computer or device on a network can send and recieve data from any other computer/device on the same network

Question 4

What devices are used to connect computers to a network?

Answer 4

Hubs
Switches
Routers

Question 5

What is a Hub? How do they work?

Answer 5

A connection point for devices on a single network.
When a network device wishes to send data across the network, it copies the data and sends it to all devices connected to its ports
–> very unecessary traffic, slows the network down

Question 6

What is a Switch?

Answer 6

It identifies which device is connected to each port. Data is only sent to the computer that needs it.
–> Much faster than a Hub

Question 7

What is a Router?

Answer 7

Connects multiple networks and serves as an intermediary between them ie. home network and the internet

Question 8

What is the Internet?

Answer 8

A globally connected network system
Uses TCP/IP Protocols to transmit data
Not centrally governed
Hosts web pages on the World Wide Web (www.____________)

Question 9

How does the Internet work?

Answer 9

Every file/data you send over the internet gets split into packets
The packets all take different routes but ultimately reach the same destination.

Question 10

What is a Router?

Answer 10

Used to manage traffic
Controls the data flow of packets
Checks address on data packets
Puts the packets on the correct path through a secure transmission

Question 11

What are the types of network?
Briefly describe each one

Answer 11

LAN- Covers a single building or collection of buildings
WAN- Covers larger areas (1km radius), or several LAN’s
VLAN- 1 or more physical LANS’s, divides a network into numerous networks
SAN- Network of storage devices, purpose specific
WLAN- Takes requests and responses from the internet.
Intranet- private network, only accessible from within one network
Extranet- an accessible network via an online portal.
VPN- private internet access
PAN- Personal Area Network
P2P- Sharing resources with 2 or more computers

Question 12

What is a VPN?

Answer 12

all requests are sent to the VPN server, the server then makes the request on the users behalf, returning the reponse to the user via the VPN client.
All connections are encrypted, connecting between user and client is tunnelling and the encryption is usually (SSL, TLS or IPSec)

Question 13

What are the advantages to VPN’s?

Answer 13

Authentication: Encryption cannot be changed by an outsider
Encryption: Data cannot be accessed or altered
Tunnelling: Data can be secured using proprietary protocols
Multiple Exit Nodes: Origin of initial data packets is unclear, and data can appear to originate from multiple IP Addresses

Question 14

What is a Protocol?

Answer 14

A set of rules for data transmission
ie. TCP/IP, HTTPS, SFTP

Question 15

What are the roles of protocols?
- and what do they do?

Answer 15

Maintain Data Integrity- same data that is sent is received
Flow Control- data is sent and received at the same rate
Prevent Deadlock- two packets don’t “block each other”
Prevent Errors- makes sure no errors are introduced in transmit

Question 16

What is the OSI model?

Answer 16

Open Systems Interconnection
It models network connection in layers

Question 17

What are the 7 OSI Layers? (minimum of 3)

Answer 17

“All People Seem To Need Data Processing”
Application
Presentation
Session
Transport
Network
Data Link
Physical

Question 18

What is Transmission Media?
Describe it

Answer 18

Physical media by which data packets are transmitted
Two types: Wired and Wireless

Question 19

What are some examples of Wired Transmission Media?

Answer 19

Ethernet, Fiber Optic, Coaxial

Question 20

What are some examples of Wireless Transmission Media?

Answer 20

Radio Waves (WLAN), Microwaves

Question 21

What 4 factors need to be considered with Transmission Media?

Answer 21

Security
Reliability
Cost
Speed

Question 22

What are the differences between Wifi and Ethernet?

Answer 22

Ethernet is faster, more consistent speed, lower latency of data transfer
Wifi is easier to install and deploy, and is cheaper
Ethernet is more secure, can only be tapped through physical access

Question 23

Whats’s the difference between Fiber Optic and Copper Cabling?

Answer 23

Fiber is faster, more expensive, lighter and almost impossible to tap, immune to interference, and has a longer range
Copper is succeptible to electromagnetic interference, shorer range, heavier and thicker

Question 24

What are the types of transmission factors?
- and what are they?

Answer 24

Primary Factors: Traffic
Secondary Factors: Time of Day, Distance, Infrastructure
Tertiary Factor: Environmental Issues (Temperature, Interference), Financial Factors (Cheaper equipment, etc.), Type of Data (Size, Streaming, etc.)

Question 25

What are the two types of Compression?

Answer 25

Lossy
Lossless

Question 26

What is Lossy Compression?

Answer 26

Removes Data
Smaller File Size
Irreversible
Used when some data can be lost

Question 27

What is Lossless Compression?

Answer 27

Uses algorithm to reduce file size
Larger than lossy, but smaller than normal
Reversible
Used when no data can be lost (text, software, etc.)

Question 28

What are the types of Authentication, and what are some examples?

Answer 28

One Factor: One way, (Something you know)
ie. passwords, security question or pin code
Two Factor: Two ways, (Something you know, and something you have)
ie. smartphone, smart code, hardware token, in addition to first factor
Three Factor: Three ways, (Something you know, something you have and something you are)
ie. fingerprint, retinal scans, facial recognition

Question 29

What is Encryption?

Answer 29

Encoding data, which can only be read by the sender and reciever who also have access to the “key” which decodes the data

Question 30

What is a MAC Address?

Answer 30

Media Access Control
Used to identify network-enabled devices in networks
“Hard-coded” by the manufactorer
Unique, 6 pairs of 2 hex digits
Can get checked against a list and is prodominntly used by the authorities.

Question 31

What are Firewalls?

Answer 31

Hardware or Software based
Analyzes data packets, controls incoming and outgoing traffic according to predetermined rules, can filter based on MAC Addresses.

Question 32

What are some types of Physical Security?

Answer 32

Locked Doors
Cages
Security Guards
Secure Rooms
Hurricane/Earthquake Proof
EMP-insulated