CIT 130 Final Exam Content Review

ifconfig

A TCP/IP configuration and management utility used with UNIX and Linux systems.

Ring Topology

This network is cheap but the time it takes to communicate with other computers depends on. This ring was a direct competitor with the bus network when computer networks were more expensive

BASH (typically spelled "Bash" or "bash") is a program that runs on multiple operating systems (*nix, Windows in various ways, VMS, etc.) It is a "shell program" meaning that it is a basic command line interface to the computer's basic features and allows scripting of command sequences using a distinct scripting language based on the Bourne Shell syntax. DOS is ambiguous. DOS can mean: IBM's "Disk Operating System" - an early OS for their 360 mainframes back in the 1970s.

How does the DOS scripting language differ from Bash?

http

The hypertext transfer protocol, basis for web browser communication

C Programming Language

A general-purpose, procedural, imperative computer programming language developed in the early 1970s by Dennis Ritchie for use on the Unix operating system.

Star Topology

Two star networks connected together with a "crossover" cable More expensive although does not have to deal with the message contention of the bus.

Public Key Encryption

Used prevalently on the web, it allows for secure messages to be sent between parties without having to agree on, or share, a secret key. It uses an asymmetric encryption scheme in which the encryption key is made public, but the decryption key is kept private.

Switches

Uses network address to pass incoming message onto one destination computer

ADV: Computer networks permit resource sharing, data sharing, easy communication, e-commerce, and telecommuting. DISADV: Networks can be costly, especially with administration and security needs. Also risks of attacks and denial of services/ viruses pose a threat.

What are some advantages/disadvantages of computer networks?

Noisy and incomplete data Distributed Data The data can be complex

What are some challenges of data mining?

Denial of Service IP Spoofing ARP Poisoning Buffer Overflow SQL Injection

What are some common forms of network attack?

Compiled languages execute faster and more efficiently over one interpreter program. Interpreted languages allow for experimentation

What are the advantages of compiled languages over interpreted languages? What are the disadvantages?

High language resembles english with mathematical notation which means that it is easier to understand in some instances.

What are the advantages of high-level languages over assebembly and machine languages?

With assets, vulnerabilities and threats define, we return to the goals. -We prioritize the goals so that we can prioritize the assets and the threats -If we value our people more than our information, we will make sure that the threats to the employees are handled before we tackle hardware threats -If the information is more critical, we must handle threats to confidentiality and integrity

Explain some of the threats and solutions covered in class (business standpoint)

Looks for evidence of illegal access into computer or reconnaissance attacks

Explain what intrusion detection software is...

American computer scientist and entrepeneuar, best known for creating the Morris Worm in 1988 which is considered the first computer worm on the internet

Explain who Robert Morris was, and the significance behind his worth..

Firewall

A program that contains a set of rules and examines incoming and outgoing messages against the set of rules

Syntax Error

Errors in misusing the syntax of language (forgetting a semicolon in C, or misspelling a word)

Machine language is the only language a computer can directly execute Assembly language is easier than machine language but still has simple instructions. It often needs an assembler to translate code from assembly to machine language High level language consists of instructions that are more abstract and deal with concepts like conditions, selections, repetition, etc High level is read more like English with mathematical notation.

Explain the difference between high-level, assembly and machine language?

nslookup

Has the job of performing mapping, along with host and dig.

LISP

LISt processing developed for AI use -Emphasized dynamically allocated memory, lists, recursion, and connected with Interpreted language

Data Warehouse

Organizations collect data (dozens to thousands of databases), known as data warehouses -sum total of data collected by or about the organization -processed data (information), business processes and practices, etc

Hubs

Passes incoming messages to all devices connected to it.

IPV4 is written in decimal as four numbers separated by periods and is a 32 bit numeric address IPV6 is written in hexadecimal and separated by colons and is a 128 bit IP address,

What is the difference between IPV4 and IPV6?

A script may specify #!/bin/bash on the first line, meaning that the script should always be run with bash, rather than another shell. /bin/sh is an executable representing the system shell.

What does #!/bin/bash mean?

CSMA is the Carrier Sense Multiple Access with Collision Detection - Devices sense media for message traffic - If none found, device places message onto media and then the device continues to sense for message traffic -Upon collision detection, sending devices sends out a jam signal to prevent other devices from using network - Devices wait a random amount of time before trying again.

What is CSMA/CD and how does it work? HINT: Colision & Jam Signals

Redundant array of inexpensive (or independent disks) RAID consists of 4 different levels from RAID 0 which is no redundancy, just distribution of files to RAID 3 which is redundancy through parity bits.

What is RAID, and what does it stand for? (From an IT standpoint)

Virtual Private Network -Permitting secure off-site access to LAN -Allows users of network to access network resources remotely

What is a VPN?

In order to combine data from multiple relations, we need some piece of information that is the same in the relations Unique Identifiers is similar to primary keys.

What is a unique identifier

A computer network is a collection of computers and computer resources connected together to permit communication between resources.

What types of components make up a computer network?

This was a big instance where data integrity was threatened. In the 60s and 70s to reduce memory usage, years were stored as 2 digits. The problem was not realized until around 1997 No one knew how many programs might be affected or the results of the affected programs --would missile silos launch their missiles? would planes fall out of the skies? --The US alone spent over $100 billion to fix this problem by working line by line through this old code to update it as necessary

What was Y2K

Smalltalk

A programming language that pioneered object-oriented programming. Not popularly used in Web development.

C++

A programming language; takes C to an object-oriented level.

Message Traffic

A set of messages being sent to different locations across a network

Private Key Encryption

A type of encryption that uses a single key to encrypt and decrypt the file or message.

ARPANET

Advanced Research Projects Agency Network

Interpreted Language

Allows for experimentation -Working in the interpreted environment allows you to define parts of a program and test them out and then redefine them.

Telnet

Allows users to log in to a remote computer with an account Sadlyn, telnet is not secure

Java

An object-oriented programming language designed specifically for programs (particularly multimedia) to be used over the Internet. Java allows programmers to create small programs or applications to enhance websites.

WANs

Wide Area Network -Anything larger, the Internet is the largest WAN

CANs

Campus Area Network -Collection of LANs that make up some organizations site

MODEM

Communications hardware device that facilitates the transmission of data.

Bus

Computers connect via "t" connector to a line that connects all computers.

Gateways

Connects multiple networks of different types together - can translate a message from one protocol to another.

Routers

Connects multiple networks together, uses destination address to pass message onto the next pathway in the network.

DIKW Hierarchy

Data, Information, Knowledge, Wisdom

Run-Time Error

Errors that arise while the program is running causing the program to terminate abnormally

Logical Errors

Errors with the logic of the program so that it runs but not correctly as planned

Physical assets include computers, networks and people Intellectual property which includes ideas, products, business strategies Information which includes data gathered in processed

Explain some of the Information assets discussed in class

FORTRAN

FORmula TRANslater (the earliest high level language developed around 1957 - 1958)

ftp

File transfer protocol, older form of transferring files prior to HTTP

Based on three technologies of the internet -Packet switching - messages are routed while making their way across the Internet -Routers - devices that perform the packet switching, moving messages from one network to another -IP addresses - the method by which we address our messages, along with DNS servers to map aliases to addresses

How does the internet work in regards to packet switching, routers, IP addresses and DNS?

LANs

Local Area Network -Collection of _________ that make up some organization's site

Circuit Switching

Pathway between two devices established at the start of communication and remains that way throughout entire communication (telephone network is circuit switching)

Packet Switching

Pathway established as messages is sent from one location to another (most computer networks are packet switched)

PANs

Personal Area Network -Found in many households, connects no more than a few devices together

Compiled Language

Programming language whose implementations are typically compilers (translators that generate machine code from source code), and not interpreters (step-by-step executors of source code, where no pre-runtime translation takes place.

COBOL

Programs divided into two sections: data definitions, code definition ___________ had many failings: little mathematical capability, all variables are global, no arrays but introduced the idea of defining data structures including character strings.

Semantic Web

Requires converting information into ontologies, better query languages Creation of intelligent agents - bots (software) that can make inferences, each agent has a specific, small role to play, groups of bots work together to solve the problem.

ping

Sends packets to remote machines - it is used to determine if remote machine is accessible and to gage efficiency of a network

ssh

Similar to Telnet but uses encryption

traceroute

Similar to ping but responds with addresses of all interviewing network nodes reached (usually routers)

Bandwidth

The amount of data that can be transmitted over a unit of time, such as bits per second - indicates to some extent network communication efficiency

Databases

The primary form of data storage today -It is an organized collection of data.

Database Management Systems

allows users to create, read, update, and delete data in a relational database

Digital Signature

an encrypted code that a person, website, or organization attaches to an electronic message to verify the identity of the message sender

Cloud Computing

the practice of using a network of remote servers hosted on the Internet to store, manage, and process data, rather than a local server or a personal computer.

Data Mining

the process of analyzing data to extract information not offered by the raw data alone