network axamples: Local and Wide Area Networks A system that transmits any combination of voice, video or data between users. network operating system a.k.a NOS Also known as the NOS, software that operates connectivity between client a server computers. network interface card a.k.a. NIC Hardware device used to connect computers to a network. workstation Also known as 'clients' A computer on a Network where users perform a variety of tasks such as word processing, e-mailing or web browsing. In a LAN, these computers connect to a Server. Server Computer A type of computer in a LAN that has functions such as data storage, authentication and processing data. logical addresses Network Software based, easily changed identifiers that are members of a common hiherarchial group. flat network Network This type of network has all its nodes under a single network space. segments Network Groups or nodes per network address that are part of a larger network. segments Network Router switches and bridges can be used to separate these parts of a network. logical names Network User friendly names the identify a network resource. connectionless Network Communications with little overhead, individual packets contain information about the sender and receiver. If some data is not received, the process must start over. connection oriented Routing For data integrity issues. Two nodes establish virtual paths to transmit data through. flow control Network The rules established by two nodes that define how much information whill be sent withing a time interval, how they will signal for data flow to stop and resume (to keep the slower computer for being overwhelmed) and how to acknowledge successful receipt of data. buffering Computer A method by which a receiving node allocates storage area to hold transmission data when data is arriving faster than the node can process it. cyclic redundancy check Computer An error checking method by which the receiving computer performs a set of calculations, agreed upon by the sender and receiver, then compares the calculations with data placed inside a packet. The output determines whether the packet was received successfully or if an error condition occured. Local Area Network Network A network with physical constraints. Typically occupies a single structure such as a bank, office or other department. Wide Area Network Network Service A type of network that interconnects otherwise isolated Local Area Networks. internet Network Services The largest and most common Wide Arean Network campus area network a.k.a. CAN Network Services A network located in a business park, multi-building school or business complex. metropolitan area network a.k.a. MAN Network A network that is a type of WAN, geographically defined to an area such as a city. repeater Network Service Devices on a LAN that amplify the electrical signals and helps overcome distance limitations. hub Network Services A device that connects computers on a LAN. This type of device broadcasts the signals it receives to all computers connected to it. bridge Network Services This device is used to connect two network segments together and can interconnect different tupes of media, such as 10BT, 100BT and Fiber. It also keeps track of MAC addresses and send data directly to the intended segment. switch Network Services A type of Hub or Bridge that keeps a table of MAC addresses and directs data to the specific use. This avoids having to broadcast data to all clients and reduces network congestion. full duplex Computer Services A mode in which ports can send or receive data simultaneously. half duplex Communications A mode in which pors can either send or receive data, not both at the same time. router computer networking An internetworking device that is aware of all other devices on the network. They make forward and drop decisions by examining network addresses. broadcast storm Network A situation in which a broadcast is repeatedly passed between repeaters, bridges or switches until the network is overloaded or incapacitated. router computer networking This device do not pass broadcasts and can effectively prevent broadcast storms. media access control computer networking An address on a network interface card (NIC) that is unique and assigned to them by the manufacturer. router computer networking Which of these devices can apply to a LAN or a WAN: Repeater, Hub, Bridge, Switch, Router? node computer networking Any device connected to a network such as printers, computers, routers, etc. protocol computer networking Defines how communication will take place. An agreed upon standard for communicating. network address computer networking A unique identifier for any node on a network. dynamic address computer networking A network address assigned by and administered by a central server. static address computer networking A scheme where a unique address in manually configured for a node on the network. Ensures that a device on a network is always found at the same address. internetwork operating system IOS computer networking A software program found on Cisco routers used to manage, control or monitor it's performance. open systems interconnect OSI computer networking A standard that defines how communications between various hardware and software devices takes place. Designed to meet interoperability standards between diverse systems. physical address computer networking An address that's hardware encoded to a network device to identify it on the network. logical address computer networking Unique addresses that are software based and can be easily changed on any device. flow control computer networking A function of the Transport layer, it ensures that routed protocols computer networking Layer 3 protocols that a router uses to route traffic across a network from the network addresses these protocols provide. i.e. IPX, IP & Appletalk. routing protocols computer networking Protocols that are tasked with route determination. They keep track of of the status of available routes. hop count computer networking A measure of each internetworking device that a packet muss pass through to get to its destination. metric computer networking A statistical value that determines the performance or availability of a particular hop or path. static routing Network Types of routing protocols that require a network administrator to manually enter routes on a routing device. Devices with this configuration do not update each other and do not accomodate changes in network topology. dynamic routing Network These types of routing protocols that build and maintain their own routing tables by sharing information with neighboring networking devices. distance vector protocols Network Protocols that use a hop count to determine the best route for traffic. distance vecor protocols Network These protocols consider routes with more than 16 hop counts unreachable. routing information protocol Network A distance vector protocol that uses hop count as its only metric. Does not support VLSM and is limited to 16 hops. flapping routes Network Network routes that are going up and down and cause repeated changes to a routing table. triggered updates Network Occurs when there is a change in the metric of a known route. split horizontal/poison reverse Network Amethod used to prevent one router from sending information it received back from another router back to its original sender. RIP v2.0 Network An updated version of RIP that supports VLSM and 128 bit secure authentication. interior gateway routing protocol Network An advanced distance vector routing protocol that has an upper limit hop count of 255 hops. interior gateway routing protocol Network Although this is a distance vector routing protocol, it uses latency, reliability and link capacity to determine the best route. It can also load balance over unequal links. link state protocols Network These protocols build routing tables based on link status (active or inactive) and makes routing decisions based on a virtual network diagram it keeps. As links go up and down, notifications are sent to adjoining routers. open shortest path first Network A link state protocol that supports VLSM and determines routes by the shortest path as well as link state. cost Network A calculation used to determine the best route based on bandwidth. aras network Logical groups of OSPF routers configured to share link state information. enhanced igrp network A link state protocol that supports VLSM, supernetting, load balancing over unequal paths, link state router updating (no periodic updates) and uses 'hello' packets to determine the presence of neighboring routers. Adware Computer Security A type of software program thats installed without a users consent or knowledge while another program is being installed on the computer. Antivirus Computer Security a type of software that is designed to protect your computer and/or network against computer viruses Bitlocker Computer Security A security feature found with Windows Vista and Windows 7 (Ultimate and Enterprise editions only) as well as Windows Server 2008 that enables users to encrypt a full drive using AES encryption. Backdoor Computer Security term used to describe a back way, hidden method, or other type of method of bypassing normal security in order to obtain access to a secure area. Black Hat Computer - Type of Hacker Used to describe a computer hacker or individual who attempts to break into a computer system or computer network with the intent to steal, destroy or otherwise modify data on that computer system without the permission to do so. Brute Force Attack Computer Security A type of password attack that does not attempt to decrypt any information but simply continue to try different passwords. Chain Mail Computer Security a forwarded e-mail sent unbeknown to e-mail contacts containing false information and/or a myth because of sympathy or a scare. Cleartext Computer Security A term used to describe any data that is not encrypted. Companion Virus Computer Security Type of computer virus that stores itself in a file that is named similar to another program file that is commonly executed. When that file is executed, the virus will infect the computer and/or perform malicious steps such as deleting the files on your computer hard disk drive. Cryptography Computer Security The process of manipulating data so that is unreadable and also being able to reverse this process. This is usually used for security reasons for important files so that it can be seen only by people that are supposed to see it. DARPA Network Security Agency and is the central research and development organization for the DoD and is responsible for managing and directing projects for the DoD. DDOS Computer Security a type of DoS attack that uses several computers to attack one victim. DES Computer Security also sometimes referred to as the Data Encryption Algorithm (DEA) and is a type of encryption standard first approved as a US federal standard in November 1976. DOS Computer Security a form of attacking another computer or company by sending millions or more requests every second causing the network to slow down, cause errors or shut down. Dictionary Attack Computer Security A type of password attack that does not attempt to decrypt any information but simply tries each of the words in a dictionary in hopes that the user has used one of the words as his or her password. DNS Hijacking Computer Security change of DNS address that directs users attempting to access a web page to a different web page that looks the same but contains extra content such as advertisements, is a competitor page, a malware page, or third-party search page. Drive-By Download Computer Security Term used to describe when a program and/or advertisement is downloaded to their computer without their consent. This type of action is often done by malware that is infected on your computer as a way for it to get more up-to-date content. Spoof Computer Security a type of hacking or deception technique that imitates another person, software program, hardware device, or computer, with the intentions of bypassing security measures. Evil Twin Computer Security A name given to a fake hotspot, that has been setup to enable other users to intercept the data being sent over the wireless network. Exploit Security a program or set of instructions designed to take advantage of a vulnerability in a program. Firewall Security A software utility and/or hardware device that limits outside network access to a computer or local network by blocking or restricting ports. Phishing Computer Security a term used to describe a malicious individual or group of individuals scamming users by sending e-mails or creating web pages that are designed to collect an individual's bank or credit information. Honeypot Security Term used to describe a computer or network setup with the purpose of attracting a computer hacker. These computers allow a system administrator or security expert to analyze how a computer hacker may attempt to hack a network without risking the threat to their own network. By analyzing this, the system administrator or security expert can then implement the needed security into their network, making it more secure. Intrusion Detection System Security a security measure that helps notify an administrator or company when a device is being opened. Kerberos Computer Security network authentication protocol designed to encrypt and secure data on an insecure network. Keystroke Logger Computer Security a software program or hardware device that is used to monitor and log each of the keys a user types into a computer keyboard. The user who installed the program or hardware device can then view all keys typed in by that user. Because these programs and hardware devices monitor the keys typed in, a user can easily find user passwords and other information a user may not wish others to know about. Man In The Middle Computer Security Man-in-the-middle attack A type of attack where a user gets between the sender and receiver of information and sniffs any information being sent. Security Essentials Computer Security antivirus and malware protection utility released by Microsoft on September 30, 2009 that helps eliminate much of the hassle that comes with many non-free antivirus utilities Policeware Computer Security A term used to describe software that is secretly installed on a suspects computer that allows government and other law enforcements to monitor computer use. Polymorphic Virus Computer A type of computer virus that has the capability of changing its own code, allowing the virus to have hundreds, sometimes thousands, of different variants, making it much more difficult to notice and/or detect. Promiscuous mode Computer Security A network card setting that does not filter incoming packets by MAC it instead receives and accepts all incoming network data. This setting commonly used to sniff all network traffic that may not be intended for it and is used to help diagnose networking issues. However, can also be used to look for any un-encrypted data such as usernames and passwords entered in FTP and Telnet. Ransomware Computer Security Type of malicious program that infects a computer and then locks it preventing the user access to their computer or their data unless a ransom is paid. Resident Virus Computer Security A type of computer virus that stores itself within memory allowing it to infect files instantaneously and does not require the user to run the file to infect files. Shoulder Surfing Computer Security A term used to describe when someone who looks over another person's shoulder as they enter data into a computer or other device. For example, someone might shoulder surf when you're entering your computer password, ATM pin, credit card number, etc. and learn what your password is or other confidential information. Social Engineering Computer Security Term used to describe the act of tricking a person by the act of deception. For example, someone attempting to gain unauthorized access to network may call a business and trick someone into thinking they work for the company and ask for passwords or other company confidential information so they can gain access to the network. SPAM a.k.a. UCE slang commonly used to describe junk e-mail on the Internet. Spyware Computer Security Term used to describe a software program that is intentionally installed on the computer by a user to monitor or spy on what other users of the same computer are doing. Trojan Horse Computer Security A program or utility that falsely appears to be a useful program or utility, such as a screen saver. However, once installed, it performs a function in the background such as allowing other users to have access to your computer or sending information from your computer to other computers. Worm Computer Security code capable of gaining access to computers or networks, and once within the computer or network, causes that computer or network harm by deleting, modifying, distributing, or otherwise manipulating the data. Botnet Computer Security a group of infected computers that are under the control of one or more individuals. The infected computers are used to perform complex tasks that would be hard for one computer and/or a task someone would not want to be caught doing, such as distributing SPAM e-mail and/or a Distributed Denial of Service (DDoS) attack on other computers or networks. Digital Audio Tape DAT Tape Backup DAT was originally developed by Hewlett Packard and Sony as a solution for backing up information on a computer and/or network. Digital Data Storage DDS Tape Backup DDS is the industry standard for digital audio tape or DAT formats Digital Linear Tape DLT Tape Backup DLT is a technology initially developed by Digital who later sold the technology to Quantum. DLT helps address storage capacity and access time when backing up information to tape drives by increasing the total capacity and speed of the tape drive and disks. Basic Input Output System BIOS Computer Service BIOS is a chip located on all computer motherboards that contains instructions and setup for how your system should boot and how it operates. Complimentary Metal Oxide Conductor CMOS Computer Service CMOS is an on-board semiconductor chip powered by a CMOS battery inside computers that stores information such as the system time and system settings for your computer. Integrated Device Electronics Computer Service IDE is more commonly known as ATA and is a standard interface for IBM compatible hard drives. Motherboard Computer Service a printed circuit that is the foundation of a computer and allows the CPU, RAM, and all other computer hardware components to function with each other. Power On Self Test POST Computer Service POST is a test the computer must complete to verify all hardware is working properly before starting the remainder of the boot process. If the computer passes the POST the computer will often return a single beep and if unsuccessful will often beep or several times to indicate the error.. Front Side Bus FSB Computer Service connects the CPU with the main memory and is used to connect to other components within the computer. The FSB can range from speeds of 66 MHz, 133 MHz, 100 MHz, 266 MHz, 400 MHz, and up. The FSB is now another important consideration when looking at purchasing a computer Motherboard or a new computer. Active Directory Computer Service a directory service first provided in Microsoft Windows 2000 that is often managed and controlled through the Microsoft Management Console (MMC) and provides a simplified query for administrators and users to manage resources, services, and users on a network. Blue Screen of Death Computer Repair full blue screen error message generated by Microsoft Windows operating systems. Boot Volume Computer Repair portion of the hard disk drive that contains the operating system, its supporting file system, and what hard disk drive contains the operating system Command Line Computer Service a user interface that is navigated by typing commands at prompts, as opposed to using the mouse to perform a command. Daemon Computer Service Unix term that describes a program that runs automatically without requiring any user interaction. GNOME Computer Service a graphical user interface (GUI) and a set of computer desktop applications for Unix-based operating systems, creating an easier to use Unix environment for end-users. Kernel Computer Repair the first section of the operating system to load into memory. Can be responsible for such things as: disk drive management, interrupt handler, file management, memory management, process management, etc. Linux Computer Service A free and open-source operating system developed by Linus Torvalds Operating System Computer Service a software program that enables the computer hardware to communicate and operate with the computer software. Virtual Machine Computer Service Software program that is capable imitating a physical device, such as a computer.