Networks

Question 1

What is a LAN?

Answer 1

A local area network is a network over a small geographic area

Question 2

What is a WAN?

Answer 2

A wide area network is a network over a large geographic area to form a network of networks

Question 3

What are the properties of copper wires?

Answer 3

Range: up to 100m
Bandwidth: Up to 10Gbps
Latency: Susceptible to interference
Usage: LAN

Question 4

What are the properties of fibre-optic cables?

Answer 4

Range: Up to 80km
Bandwidth: Up to 100Gbps
Latency: Immune to interference
Usage: Used for long distance data traffic

Question 5

What is a protocol?

Answer 5

A set of rules that governs communication

Question 6

What is the TCP/IP model?

Answer 6

1. Application layer - Provides the interfaces and protocols needed by the user
2. Transport layer - splits data into packets and numbers them
3. Internet layer - Adds the source and destination IP addresses to packets
4. Link layer - Uses network-specific protocols to convert binary data to be transmitted
5. Link layer - Converts incoming signals into binary data
6. Internet layer - Strips address information from incoming packet headers
7. Transport layer - Checks incoming packets and reassembles them in the correct order
8. Application layer - Displays the received information to the user

Question 7

What are the advantages and disadvantages of a bus topology?

Answer 7

1. Easy to set up
2. Relatively cheap to install because only one cable is needed
3. Easy to add extra devices
4. Lots of data collisions occur when multiple devices transmit data at the same time
5. If the main cable fails or gets damaged the whole network will fail
6. The whole network will fail if a terminator is removed

Question 8

What is penetration testing?

Answer 8

Where testers take the role of hackers and try to gain unauthorised access.
In lack box penetration testing the tester is given no information.
In white box penetration testing the tester is given access to relevant network and system information