1.3.3 Networks Flashcards
Describe what is meant by a LAN.(2)
(1) Local Area network
(1) Over a small geographical area
(1) Use of hard-wiring / wireless communication
State two advantages of having a LAN instead of a set of stand-alone machines.(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
TCP/IP uses packet switching. Explain what is meant by packet switching.(2)
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).
What is a node?
A computer in a network.
What is a network?
A collection of collected nodes.
Advantages of Networks
Share files share hardware use any computer
What are the disadvantages of networks?[2]
Expensive(1) Needs specialists.(1)
What is the role of a NIC?[1]
Allows a node to attach to a network.(1)
What is the role of a switch?
Connects several devices in a network.
What is a Wide Area Network? (WAN)
Devices linked across a large geographic area. Often connect via 3rd party channels.
What is malware?
Malicious software designed to steal from or damage a computer.
What is a virus?
Malware designed to self-replicate and spread.
What are the types of malware?
Keyloggers Worms Adware and ransomware.
What is phishing?
Stealing data by tricking users.
What are the methods of defending a network? (4)
Training Antivirus User access levels and strong passwords.
What is a holistic antivirus?
Identifies malware based on predicting behaviour.
What is a signature-Based antivirus
Compares code to libraries of identified malicious behaviour. Liraries have to be maintained.
What is a firewall?
Hardware or software that monitors packets going to and from a network.
What is packet filtering?
Blocking packets based on rules.
Why use a firewall?
Prevent packets from accessing specific devices. Filter packets from a specific location or service. Prevent outgoing packets with sensitive information.
Demilitarised Zone (DMZ)
An area of protected devices between firewalls.
Why use a DMZ?
Offer some external services without comprimising LAN. Additional layer of security if public services are compromised.
What is a gateway?
A hardware device that connects two dissimilar networks. (E.G LAN/Internet)
What is a proxy?
A server that fetches packets on behalf of another device.
Why use a proxy on outgoing traffic?
Layer of security connects on your behalf. May store cached version lightens network load on server. Bypass region locks. Anonymity.
What is a Virtual Private Network (VPN)?
Computers act as if they are on the same LAN. Devices can send requests from a shared router. Data between devices can be encrypted.
