AP Computer Science Chapter 2 Test

How many unique IP addresses could be made in a fixed-length IP address system using 6 bits?

64 users

Internet

A group of computers and servers that are connected to each other.

The Internet Engineering Task Force (IETF) defines the protocols and standards for how the Internet works. The members of the IETF are:

A loosely organized collection of citizens and engineers who communicate mostly by email.

Which of the following is NOT true about packets?

A message sent across the Internet can always be contained in a single packet

IP Address

A number assigned to any item that is connected to the Internet.

Which two of the following statements are true about routing on the Internet.

A packet travelling between two computers on the Internet may be rerouted many times along the way; A packet contains addressing information to allow routers to decide how best to forward along that packet towards its destination.

Protocol

A set of rules governing the exchange or transmission of data between devices.

Router

A type of computer that forwards data across a network

Choose Two: Identify the two true statements about HTTP.

An HTTP request is sent from a client to request access to data stored on a server; Displaying a web page will often require multiple HTTP requests in order to acquire all the necessary data.

URL

An easy-to-remember address for calling a web page (like www.code.org).

HTTP is considered to be a high level protocol because:

HTTP requests make use of abstractions provided by lower level protocols.

What feature of DNS and IP allow the internet to scale?

Hierarchy

HTTP

HyperText Transfer Protocol - the protocol used for transmitting web pages over the Internet

IETF

Internet Engineering Task Force - develops and promotes voluntary Internet standards and protocols, in particular the standards that comprise the Internet protocol suite (TCP/IP).

What is an RFC?

Request For Comments

Packets

Small chunks of information that have been carefully formed from larger chunks of information.

Pick Two: Pick the two statements about packets and routing on the Internet which are true.

TCP ensures messages can be reliably transmitted across the Internet; TCP must account for the fact that packets may not arrive at a destination computer in the intended order

In the Internet Simulator, your router knows to send your message to a different router because:

The first 4 bits of the address specify the router number that your friend is on.

If the post office delivered mail exactly like routers deliver messages on the internet, which 2 of the following statements would be true?

The mailman would sometimes take a different path to deliver each letter to your home; Letters would be written on the outside of envelopes for all to read instead of letters put inside envelopes.

A single central register of IP addresses and names (a DNS style system) is an efficient means of translating human readable names to IP addresses. Which of the following is NOT solved by DNS?

There are too few IP addresses to meet the current demand.

Which of the following information is not necessary in your protocol to play battleship?

Time of Day

TCP

Transmission Control Protocol - provides reliable, ordered, and error-checked delivery of a stream of packets on the internet. TCP is tightly linked with IP and usually seen as TCP/IP in writing.

Why don't we need to know the IP addresses for our favorite sites?

We don't need to know the IP addresses for our favorite sites because the DNS stores them all for us in a directory like database. It would be too difficult for us to remember each IP address for each individual website.

Network Redundancy

having multiple backups to ensure reliability during cases of high usage or failure

Choose the two best answers to complete the sentence: If I understand how the internet works then I will be able to:

make informed choices to support or oppose decisions my government makes about access to the internet; make informed choices about my privacy on the internet

To improve communication in playing battleship on the Internet Simulator your group invented a(n):

protocol

Describe the relative benefits of routing over a broadcast style of communication. Is routed traffic more secure than broadcasting? Justify your answer.

routing messages to a specific address rather than broadcasting the message reduces the number of people who can automatically see the message addressed traffic is more secure than broadcasted, but if the router security is compromised someone other than the intended recipient could read the message.

DNS

short for Domain Name System, this system translates domain names (like example.com) to IP addresses (like 93.184.216.34)

Net Neutrality

the principle that all Internet traffic should be treated equally by Internet Service Providers.

Why do computers need to periodically check the DNS for websites you have already visited?

they need to periodically check the DNS for websites you have already visited because sometimes IP addresses change for a certain website and people could be going to the wrong website. They check it to ensure that the IP address is the same and has not changed.