Unit 5 Flashcards
Which component is required to access the internet?
Network interface card (NIC)
What are IP addresses and why are they needed?
Each address has a 32-bit number
It is usually written in denary with a dot separating each byte
The address allows data to be sent to the correct computer
Why are data packets needed?
When data is sent through the Internet
or a TCP/IP network, it is split up
into much smaller quantities
known as data packets.
What are routers used for?
The home router will route packets. It also:
Contains a wireless access point for Wi-Fi connections
Connects the local network to the internet using a modem
Assigns IP addresses to each computer that connects to it
What is used for IP address assignment?
When a new device connects to the network it is assigned
an IP address by the DHCP server
What are MAC addresses needed for?
The MAC address is given to the NIC when it is manufactured.
Every network hardware device has a unique MAC address
MAC addresses are used
to send data between two
items of hardware on a
network – such as
a computer
and router.
What do different parts of the MAC address represent?
The first three bytes (24 bits) of the MAC address contains a number that represents the manufacturer
The second part of the number is the serial code which is given to the hardware device by the manufacturer
What are some internet protocol issues?
IP version 4 (IPv4) addresses are made from
four bytes.
The problem with 32-bit IP addresses is that there aren’t enough of them
As more and more devices are added to the Internet we need an IP address system that can address all of them.
We therefore need to use a larger binary number than a 16-bit address.
What are differences between the address sizes of IPV4 and IPV6?
IPV4: 32-bit
IPV6: 128-bit
What is the different numbers of unique addresses for IPV4 and IPV6.
IPV4: 4.3 billion
IPv6: 340 trillion trillion trillion
What are the seperators in IPV4 and IPV6?
IPV4: Dots
IPV6: Colons
What are the security differences between the 2 internet protocols.
IPV6 has better security.
What assigns IP addresses as IPV4?
IPV4: DHCP server
IPV6: They configure themselves;autoconfiguration or use DHCPv6 as well
What is a dynamic IP address?
Sometimes the ISP will give a different IP address each time the router connects – this is known as a dynamic IP address
What is a static IP address?
If the IP address is always the same, it is known as a
static IP address
What are some features of a browser?
Storing bookmarks and favourites
Recording user history
Allowing use of multiple tabs
Storing cookies
Providing navigation tools
Providing an address bar
What is the address bar needed for?
The address bar allows the user to enter a
web address.
browsers also allow navigation such as previous page, next page and refresh page
What are bookmarks used for in a browser?
Users are able to store a list of bookmarks of sites they want to visit again
Folders allow these to be organised easily
What is user browsing history?
Web browsers store a history of visited web pages, including timestamps, enabling users to easily revisit and search recent sites.
What are tabs?
Tabs are a user interface feature that allow many web pages to remain open at the same time
What is the router?
The router is responsible for routing data packets between different networks. Assigning IP addresses to devices on the network.
What is the router responsible for?
Send and Receive packets of data
Connect a local network to the internet
Assign IP addresses to devices
Converts packets from one protocol to another
What is the internet?
The Internet is a global network of networks
What is the world wide web?
a collection of websites and web pages that are accessed using the internet
What does HTTP do?
Hypertext Transfer Protocol (HTTP) allows communication between clients and servers for website viewing
HTTP & HTTPS are protocols, a set of rules governing communication between devices on a network
HTTP allows clients to receive data from the sever (fetching a webpage) and send data to the server (submitting a form, uploading a file)
What is HTTPs?
HTTPS works in the same way as HTTP but with an added layer of security
All data sent and received using HTTPS is encrypted
HTTPS is used to protect sensitive information such as passwords, financial information and personal data
What is a web browser?
A web browser is a piece of software used to access and display information on the internet
Functions of Web browser
- Render HTML
-Provide navigation tools - Storing bookmarks
- Storing cookies
- Record user history
- Provide address bar
- Multiple tabs
How is a web page loaded?
Web pages are held on web servers (1), known as ‘hosting’
To access a web page on a web server, a web browser is used
In the browser, a user enters a web page URL (2)
The browser sends the domain name to a DNS (3)
The browser connects to the web server and requests to access the page
HTML (4) is transferred and rendered by the browser, displaying the web page
What is a web server?
A web server is a remote computer that stores the files needed to display a web page on the Internet
- Multiple people can access at the same time
- available 24/7
What is a URL?
A Uniform Resource Locator (URL) is a unique identifier for a web page, known as the website address
What are the parts of a URL?
Protocol
Domain name
Web page/file name
Split https://www.savemyexams.com/igcse/computer-science/cie/23/revision-notes/ into 3 parts
Protocol: https
Domain name: www.savemyexams.com
Web page/file name: /igcse/computer-science/cie/23/revision-notes/
What is meant by cookies?
A cookie is a tiny data file stored on a computer by browser software that holds information relating to your browsing activity
What are the 2 types of cookies and how do they work?
Session - Created and replaced every time a user visits a website
Persistent - Created and saved the first time a user visits a website, retained until they expire
What are the functions of a cookie?
Browsing history - what websites you have visited
Login information - usernames & passwords
Preferences - language/font size/themes
Shopping cart
What is a brute-force attack?
A brute force attack works by an attacker repeatedly trying multiple combinations of a user’s password to try and gain unauthorised access to their accounts or devices
What is data interception?
Data interception and theft is when thieves or hackers can compromise usernames and passwords as well as other sensitive data
This is done by using devices such as a packet sniffer
A packet sniffer will be able to collect the data that is being transferred on a network
A thief can use this data to gain unauthorised access to websites, companies and more
What is a DDoS attack?
A Distributed Denial of Service Attack (DDoS attack) is a large scale, coordinated attack designed to slow down a server to the point of it becoming unusable
A server is continually flooded with requests from multiple distributed devices preventing genuine users from accessing or using a service
What is hacking?
Hacking is the process of identifying and exploiting weaknesses in a computer system or network to gain unauthorised access
What is malware?
Malware (malicious software) is the term used for any software that has been created with malicious intent to cause harm to a computer system
Types of malware?
Virus
Worm
Trojan horse
Ransomware
Spyware
Adware
What is pharming?
Pharming is typing a website address into a browser and it being redirected to a ‘fake’ website in order to trick a user into typing in sensitive information such as passwords
What is phishing?
Phishing is the process of sending fraudulent emails/SMS to a large number of people, claiming to be from a reputable company or trusted source
What is social engineering?
Social engineering is exploiting weaknesses in a computer system by targeting the people that use or have access to them
There are many forms of social engineering, some examples include
Fraudulent phone calls: pretending to be someone else to gain access to their account or their details
Pretexting: A scammer will send a fake text message, pretending to be from the government or human resources of a company, this scam is used to trick an individual into giving out confidential data
What are access levels?
Access levels ensure users of a network can access what they need to access and do not have access to information/resources they shouldn’t
Users can have designated roles on a network
What is anti-malware software?
Anti-malware software is a term used to describe a combination of different software to prevent computers from being susceptible to viruses and other malicious software
How does ant-malware work?
Anti-malware scans through email attachments, websites and downloaded files to search for issues
Anti-malware software has a list of known malware signatures to block immediately if they try to access your device in any way
What is authentication?
Authentication is the process of ensuring that a system is secure by asking the user to complete tasks to prove they are an authorised user of the system
What are biometrics?
Biometrics use biological data for authentication by identifying unique physical characteristics of a human such as fingerprints, facial recognition, or iris scans
What are automatic software updates?
Automatic software updates take away the need for a user to remember to keep software updated and reduce the risk of software flaws/vulnerabilities being targeted in out of date software
What is communication?
One way of protecting data is by monitoring digital communication to check for errors in the spelling and grammar or tone of the communication
How to check a URL?
Checking the URL attached to a link is another way to prevent phishing attacks
What is a firewall?
A firewall monitors incoming and outgoing network traffic and uses a set of rules to determine which traffic to allow
A firewall prevents unwanted traffic from entering a network by filtering requests to ensure they are legitimate
What are privacy settings?
Privacy settings are used to control the amount of personal information that is shared online
What is a proxy server?
A proxy-server is used to hide a user’s IP address and location, making it more difficult for hackers to track them
What is SSL?
Secure Socket Layer (SSL) is a security protocol which is used to encrypt data transmitted over the internet
This helps to prevent eavesdropping and other forms of interception
