internet

Parallel and Distributed Computing -Add more computers Benefits:

-Redundant and Fault tolerant -Scalable Challenges: -Complex -Expensive

Steps

1- URL(uniform resource locator) Domain: where we need to look Path: what resource you are requesting 2-HTTP request 3-DNS to get IP address 4- TCP/IP break Request into packets 5-Packets are routed to proper IP address 6- 7-Server creates HTTP response 10-original response is pieced together 11- the page is rendered

An IPv4 address has 32 bits, so there are 232 (over 4 billion) possible IPv4 addresses. Since the Internet is gaining devices quickly, we will soon surpass 232 unique devices on the Internet. In anticipation of all the new Internet devices, we are in the process of switching to IPv6, which uses 128 bits for a single address. That's 96 extra bits to represent one address! Which of the following statements correctly describes how many more addresses will be possible to represent by switching from IPv4 to IPv6? 96 more addresses can be represented with IPv6 296 more addresses can be represented with IPv6 96 times as many addresses can be represented with IPv6 296 times as many addresses can be represented with IPv6

296 times as many addresses can be represented with IPv6

What information is contained in a packet?

A small part of a digital message, and metadata about the message, including where it came from and where it is going

Which of the following best explains what happens when a new device is connected to the Internet? A device driver is assigned to the device. An Internet Protocol (IP) address is assigned to the device. A packet number is assigned to the device. A Web site is assigned to the device.

An Internet Protocol (IP) address is assigned to the device.

What is a Distributed Denial of Service (DDoS) attack? An attempt by a government to deny Internet access to its citizens An attempt to deny access to a website by flooding the website's servers with millions of requests from different computers An attempt by one user to deny service to another user by posting malicious material on a social network An attempt by an Internet user to access private information stored in a private database

An attempt to deny access to a website by flooding the website's servers with millions of requests from different computers

Which of the following is LEAST likely to indicate a phishing attack? An email from a website asks that you click on a link to reset your password. An email from your bank asks you to call the number on your card to verify a transaction. An email from your water utility company asks you to enter your date of birth and social security number for verification purposes. An email indicates you have won money, and asks you to enter your bank account number so the money can be transferred

An email from your bank asks you to call the number on your card to verify a transaction.

How is the bandwidth of a network measured?

Bitrate. Higher bitrate means higher bandwidth.

Routing

Computers send stuff to routers to communicate with each other on network -computer marks with a to and from address -message goes to router with lowest cost

Packet

Data sent over internet is broken down into packets Packets labeled with metadata Once they arrive at destination, pieced together Layout of pockets defined by a protocol

Antivirus software

Detect and delete malicious programs

Cyber warfare

Hacking into government systems

HTTP

Hypertext transfer protocol Hypertext markup language (Html) Request stuff

Which of the following are true statements about digital certificates in Web browsers? I. Digital certificates are used to verify the ownership of encrypted keys used in secure communication.II. Digital certificates are used to verify that the connection to a Web site is fault tolerant. I only II only I and II Neither I nor II

I and II

Each box represents a device connected to the network, each line represents a direct connection between two devices. Which of the following statements are true about this network: I - The network is fault tolerant. If one connection fails, any two devices can still communicate.II - Computers C and E need to first communicate with at least one other device in order to communicate with each other. I only II only I and II Neither I nor II

I only

Parallel and distributed Computin

More than one processor More than one computer Parallel Computing 2x as fast cuz another processor Cons: If there is an error it's harder to find a bug because the need to check both processors gets harder the more processors you add. Architecture is very complex, if it needs to go in a specific order it will low down, could make it more costly

Which of the following activities poses the greatest personal cybersecurity risk? Making a purchase on an online store that uses public key encryption to transmit information Paying a bill using a secure online electronic payment system Purchasing a couch by emailing a credit card number to the couch owner Checking a bank account on a bank's website that uses HTTPS for secure communication

Purchasing a couch by emailing a credit card number to the couch owner

A city government is attempting to reduce the digital divide between groups with differing access to computing and the Internet. Which of the following actions is LEAST likely to be effective in this purpose? Holding basic computer classes at community centers Providing free wireless Internet connections at locations in low-income neighborhoods Putting helpful tips for operating computers on the city government website Requiring that every school and library have assistive devices that allow people with disabilities to access computer resources

Putting helpful tips for operating computers on the city government website

What is the fourth step of viewing a web page as described in the video?

Rendering the Page: Your browser takes the resource and renders it in the browser window

TCP (Transmission Control Protocol)

TCP adds a pocket number to each packet to track order of the packets Missing numbers -- TCP will re-request it

Sequential computing

Take one task at a time and put it through a processor

What is the second step of viewing a web page as described in the video?

The Request: The browser sends a message to a server requesting a resource

What is the third step of viewing a web page as described in the video?

The Response: The server sends a response to the browser with the resource attached

What is the first step of viewing a web page as described in the video?

The URL: You type the URL for the web page into your browser

Which of the following is a benefit of the fault-tolerant nature of Internet routing? The ability to use a hierarchical naming system to avoid naming conflicts The ability to provide data transmission even when some connections between routers have failed The ability to resolve errors in domain name system (DNS) lookups The ability to use multiple protocols such as hypertext transfer protocol (HTTP), Internet protocol (IP), and simple mail transfer protocol (SMTP) to transfer data.

The ability to provide data transmission even when some connections between routers have failed

What is the bitrate of a system?

The amount of data (in bits) that can be sent in a fixed amount of time

Two computers are built by different manufacturers. One is running a Web server and the other is running a Web browser. Which of the following best describes whether these two computers can communicate with each other across the Internet?

The computers can communicate directly because Internet communication uses standard protocols that are used by all computers on the Internet.

A user enters a Web address in a browser, and a request for a file is sent to a Web server. Which of the following best describes how the file is sent back to the user?

The file is broken into packets and sent over a network. The packets must be reassembled by the user's computer when they are received. If any packets are missing, the browser re-requests the missing packets.

latency

The time it takes for a bit to travel from sender to receiver

Which of the following would pose the greatest threat to a user's personal privacy if it were to be leaked to the public? The IP address of the user's computer The user's browser cookies The user's email address The user's public key used for encryption

The user's browser cookies

What is the purpose of the Digital Millennium Copyright Act?

To criminalize the act of circumventing, or getting around, access controls that block access to copyrighted works.

What is the function of the Domain Name System (DNS)

To translate domain names into IP addresses

DNS - domain name system

Translates names to IP addresses sO COMPUTER CAN GO TO WEBSITE WEB REGISTERS DOMAIN DNS MAP DOMAIN TO IP ADDRESS Computer checks cache (memory) for previous website , If does not have it ues DNS 1- ROOT servers only have info about Top level domain 2- Top Level Domain only has info about second level domain 3- Second level domain 4- subdomain

Personally Identifiable Information (PII)

Use strong passwords Don't repeat passwords between websites Install security updates Think twice b4 clicking a link or installing a program

Which of the following is a benefit that online shopping websites provide over brick and mortar stores? Users can try out an item before they buy it Users can easily pay with cash in person Users can easily see product reviews and determine if an item has been satisfactory for a large number of people There is no wait time between purchasing an item and having access to it

Users can easily see product reviews and determine if an item has been satisfactory for a large number of people

Rogue Access point

a wireless access point that gives unauthorized access to secure networks. public networks can be intercepted.

According to the domain name system (DNS), which of the following is a subdomain of the domain example.com?

about.example.com

Fault tolerant:

even if some router are damaged, the others are still up

Phishing

fake website

Is the following statement true, or false: Everyone in the world has internet access.

false

Cybercrime

identity theft, stealing Money

Malware

is software used to perform malicious actions

Redundancy:

multiple paths exist between two points -Improves reliability because even if some individual routers break, there are other paths -Makes system scalable

Cryptography

open standards for encryption SSL/TLS https:// Public key encrypts and private key decrypts Certificate authorities verify the public keys of websites you ue

DNS Spoofing

pretending to be a DNS name revolver, feeds computer wrong IP address, browser now goes so false website

cyber security

protocol for everything / encrypting and decrypting

Which of the following is considered an unethical use of computer resources?

searching online for the answers to CodeHS exercises and quizzes

Distributed Denial of Service attack

spam a web server with so many requests so close together that it crashes