Term
| OEM (Original Equipment Manufacturer) |
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Definition
| Contrary to the name, does not create original hardware, but rather purchases components from manufacturers and puts them together in systems under its own brand name. Dell, Inc. and Gateway, Inc., for example, are for the most part OEMs. Apple, Inc., which manufactures most of the components for its own Mac-branded machines, is not an OEM. Also known as value-added resellers (VARs). |
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Term
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Definition
| The process of confirming that mobile devices leaving the control of the organization do not store any proprietary applications or data. |
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Term
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Definition
| A term used to describe resources that are stored and maintained at a location other than the primary office or facility. Examples of resources that can be offsite include servers and data backups. |
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Term
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Definition
| Electronic measurement of a cable’s or an electronic component’s impedance. |
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Term
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Definition
| Technology used in most WAPs that send wireless signals in all directions equally. |
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Term
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Definition
| The process of verifying that new mobile devices appearing in the organization’s infrastructure are secure and safe to use within the organization. |
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Term
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Definition
| Traditionally known as a man-in-the-middle attack. An attacker taps into communications between two systems, covertly intercepting traffic thought to be only between those systems, reading or in some cases even changing the data and then sending the data on. |
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Term
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Definition
| A term used to describe resources that are stored and maintained at the primary office or facility rather than an external location. |
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Term
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Definition
| A port that is currently accepting incoming IP packets and passing them to the application that opened the port. |
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Term
| Open Shortest Path First (OSPF) |
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Definition
| An interior gateway routing protocol developed for IP networks based on the shortest path first or link state algorithm. |
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Term
|
Definition
| Applications and operating systems that offer access to their source code; this enables developers to modify applications and operating systems easily to meet their specific needs. |
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Term
| Open Systems Interconnection (OSI) |
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Definition
| An international standard suite of protocols defined by the International Organization for Standardization (ISO) that implements the OSI seven-layer model for network communications between computers. |
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Term
| Open Systems Interconnection (OSI) seven-layer model |
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Definition
| An architecture model based on the OSI protocol suite, which defines and standardizes the flow of data between computers. |
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Term
Open Systems Interconnection (OSI) seven-layer model
Layer 1 |
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Definition
| The Physical layer defines hardware connections and turns binary into physical pulses (electrical or light). Cables operate at the Physical layer. |
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Term
Open Systems Interconnection (OSI) seven-layer model
Layer 2 |
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Definition
| The Data Link layer identifies devices on the Physical layer. MAC addresses are part of the Data Link layer. Switches operate at the Data Link layer. |
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Term
Open Systems Interconnection (OSI) seven-layer model
Layer 3 |
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Definition
| The Network layer moves packets between computers on different networks. Routers operate at the Network layer. IP operates at the Network layer. |
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Term
Open Systems Interconnection (OSI) seven-layer model
Layer 4 |
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Definition
| The Transport layer breaks data down into manageable chunks with TCP. UDP also operates at the Transport layer. |
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Term
Open Systems Interconnection (OSI) seven-layer model
Layer 5 |
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Definition
| The Session layer manages connections between machines. Sockets operate at the Session layer. |
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Term
Open Systems Interconnection (OSI) seven-layer model
Layer 6 |
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Definition
| The Presentation layer, which can also manage data encryption, hides the differences among various types of computer systems. |
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Term
Open Systems Interconnection (OSI) seven-layer model
Layer 7 |
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Definition
| The Application layer provides tools for programs to use to access the network (and the lower layers). HTTP, SSL/TLS, FTP, SMTP, DNS, DHCP, and IMAP are all examples of protocols that operate at the Application layer. |
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Term
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Definition
| A series of secure programs developed by the OpenBSD organization to fix the limitation of Secure Shell (SSH) of only being able to handle one session per tunnel. |
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Term
|
Definition
| The set of system software that manages a computer’s hardware and software resources and provides an interface between the PC and the user. Examples are Microsoft Windows, Apple macOS, and Manjaro Linux. |
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Term
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Definition
| In a distributed control system, a human who runs the computer-controlled resources through a human–machine interface. See also human–machine interface (HMI). |
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Term
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Definition
| A removable module that enables connectivity between a device and a cable. |
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Term
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Definition
| Specification used to denote the optical data carrying capacity (in Mbps) of fiber-optic cables in networks conforming to the SONET standard. The OC standard is an escalating series of speeds, designed to meet the needs of medium-to-large corporations. SONET establishes OCs from 51.8 Mbps (OC-1) to 39.8 Gbps (OC-768). |
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Term
|
Definition
| Device that measures the intensity of light pulses within or at the terminal ends of fiber-optic cables. |
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Term
| optical time-domain reflectometer (OTDR) |
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Definition
| Tester for fiber-optic cable that determines continuity and reports the location of cable breaks. |
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Term
|
Definition
| A higher level of automation in which smaller automated tasks are composed into longer sequences. These sequences (sometimes called pipelines, processes, or workflows) better represent whatever the organization or its employees are trying to accomplish. Also, arrangement of music for multiple instruments. |
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Term
| organizationally unique identifier (OUI) |
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Definition
| The first 24 bits of a MAC address, assigned to the NIC manufacturer by the IEEE. |
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Term
| orthogonal frequency-division multiplexing (OFDM) |
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Definition
| A spread-spectrum broadcasting method that combines the multiple frequencies of DSSS with FHSS’s hopping capability. |
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Term
|
Definition
| The set of system software that manages a computer’s hardware and software resources and provides an interface between the PC and the user. Examples are Microsoft Windows, Apple macOS, and Manjaro Linux. |
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Term
|
Definition
| A device that gives a graphical/visual representation of signal levels over a period of time. |
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Term
| OSPF (Open Shortest Path First) |
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Definition
| An interior gateway routing protocol developed for IP networks based on the shortest path first or link state algorithm. |
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Term
|
Definition
| Describes the direction of a flow of packets relative to some point of reference. Relative to the entire network, packets leaving the network from within it. |
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Term
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Definition
| Method to connect to and administer a managed device such as a switch or router that does not use a standard network-connected host as the administrative console. A computer connected to the console port of a switch is an example of out-of-band management. |
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Term
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Definition
| Enables two IPv6 networks to connect over an IPv4 network by encapsulating the IPv6 packets within IPv4 headers, transporting them across the IPv4 network, then decapsulating the IPv6 data. |
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Term
|
Definition
| Basic component of communication over a network. A group of bits of fixed maximum size and well-defined format that is switched and transmitted as a complete whole through a network. It contains source and destination address, data, and control information. |
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Term
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Definition
| A program that reads the capture files from packet sniffers and analyzes them based on monitoring needs. |
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Term
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Definition
| A mechanism that blocks any incoming or outgoing packet from a particular IP address or range of IP addresses. Also known as IP filtering. |
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Term
|
Definition
| A tool that intercepts and logs network packets. |
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Term
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Definition
| Extra data added to an Ethernet frame to bring the data up to the minimum required size of 64 bytes. |
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Term
| partially meshed topology |
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Definition
| A mesh topology in which not all of the nodes are directly connected. |
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Term
| passive optical network (PON) |
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Definition
| A fiber architecture that uses a single fiber to the neighborhood switch and then individual fiber runs to each final destination. |
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Term
| Password Authentication Protocol (PAP) |
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Definition
| The oldest and most basic form of authentication and also the least safe because it sends all passwords in cleartext. |
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Term
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Definition
| Flat, plate-shaped antenna that generates a half-sphere beam; used for broadcasting to a select area. |
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Term
|
Definition
| A dedicated block with A/V connections (instead of twisted pair and fiber network connections). |
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Term
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Definition
| Short (2 to 5 foot) UTP cables that connect patch panels to switches. |
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Term
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Definition
| The process of regularly updating operating systems and applications to avoid security threats. |
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Term
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Definition
| A panel containing a row of female connectors (ports) that terminate the horizontal cabling in the equipment room. Patch panels facilitate cabling organization and provide protection to horizontal cabling. See also vertical cross-connect. |
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Term
|
Definition
| Increases availability by ensuring lines out of your network follow diverse paths to other networks. A common method for path diversity in smaller centers, for example, uses a fiber connection for the primary and a very fast cellular connection as a failover. Use of both a fiber ISP and a different cable ISP can also lead to path diversity. |
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Term
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Definition
| A method for determining the highest MTU that can pass through all hops in a route without fragmentation. |
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Term
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Definition
| Routing protocol in which routers maintain path information. This information gets updated dynamically. See Border Gateway Protocol (BGP). |
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Term
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Definition
| Command-line tool that combines the features of the ping command and the tracert/traceroute commands. |
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Term
|
Definition
| The primary data that is encapsulated in a frame or other protocol data unit (PDU) and sent from a source network device to a destination network device. |
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Term
| PBX (private branch exchange) |
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Definition
| A private phone system used within an organization. |
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Term
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Definition
| A network in which each machine can act as either a client or a server. |
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Term
|
Definition
| A wireless networking mode where each node is in direct contact with every other node in a decentralized free-for-all. Ad hoc mode is similar to the mesh topology. |
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Term
| penetration testing (pentesting) |
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Definition
| An authorized, network hacking process that identifies and exploits real-world weaknesses in network security and documents the findings. |
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Term
| Performance Monitor (perfmon.exe) |
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Definition
| The Windows logging utility. |
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Term
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Definition
| Sets of attributes that network administrators assign to users and groups that define what they can do to resources. |
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Term
|
Definition
| In network access control systems, a small scanning program that, once installed on the computer, stays installed and runs every time the computer boots up. Composed of modules that perform a thorough inventory of each security-oriented element in the computer. |
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Term
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Definition
| A connection to a shared folder or drive that the computer immediately reconnects to at logon. |
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Term
| personal area network (PAN) |
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Definition
| The network created among Bluetooth devices such as smartphones, tablets, printers, keyboards, mice, and so on. |
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Term
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Definition
| A social engineering technique where the attacker poses as a trusted source and tries to inspire the victim to act based on a false premise (usually communicated via e-mail, phone, or SMS). A successful attack typically obtains confidential information or introduces malware into the network. |
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Term
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Definition
| An address burned into a ROM chip on a NIC. A MAC address is an example of a physical address. |
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Term
| physical contact (PC) connector |
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Definition
| Family of fiber-optic connectors that enforces direct physical contact between two optical fibers being connected. |
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Term
|
Definition
| defines hardware connections and turns binary into physical pulses (electrical or light). Cables operate at the Physical layer. |
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Term
|
Definition
| A document that shows all of the physical connections on a network. Cabling type, protocol, and speed are also listed for each connection. |
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Term
|
Definition
| The manner in which the physical components of a network are arranged. |
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Term
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Definition
| An authorized person helping an unauthorized person follow them into a secure area |
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Term
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Definition
| A small ICMP message sent to check for the presence and response of another system. Also, a command-line utility that uses these messages to check the “up/down” status of an IP addressed host. See also Internet Control Message Protocol (ICMP). |
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Term
|
Definition
| A command-line utility to check the “up/down” status of an IP addressed host. The –6 switch included on the command line, using the Windows version of ping, specifies that the host under test has an IPv6 address. |
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Term
|
Definition
| Linux command-line utility specifically designed to ping hosts with an IPv6 address. |
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Term
| plain old telephone service (POTS) |
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Definition
| the most common type of phone connection, which takes your sounds, translated into an analog waveform by the microphone, and transmits them to another phone. |
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Term
|
Definition
| Describes the data passed through a cipher (even if it is already encrypted). Running plaintext through a cipher algorithm using a key generates the encrypted ciphertext. |
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Term
|
Definition
| Hardware environment that supports the running of a computer system. |
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Term
| platform as a service (PaaS) |
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Definition
| Cloud service model that provides a complete deployment and management system with all the tools needed to administer and maintain a Web application. See also cloud computing. |
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Term
|
Definition
| Usually a space between a building’s false ceiling and the floor above it. Most of the wiring for networks is located in this space. Plenum is also a fire rating for network cabling. |
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Term
|
Definition
| Network cable type that resists burning and does not give off excessive smoke or noxious fumes when burned. |
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Term
|
Definition
| A group of modules that share the same connection to their distribution switches in a data center. |
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Term
| Point Coordination Function (PCF) |
|
Definition
| A method of collision avoidance defined by the 802.11 standard but has yet to be implemented. |
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Term
| point-to-multipoint topology |
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Definition
| Topology in which one device communicates with more than one other device on a network. |
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Term
| Point-to-Point Protocol (PPP) |
|
Definition
| A protocol that enables two devices to connect, authenticate with a username and password, and negotiate the network protocol the two devices will use. |
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Term
| Point-to-Point Protocol over Ethernet (PPPoE) |
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Definition
| A protocol that was originally designed to encapsulate PPP frames into Ethernet frames. Used by DSL providers to force customers to log into their DSL connections instead of simply connecting automatically. |
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Term
|
Definition
| Network topology in which two computers are directly connected to each other without any other intervening connection components such as hubs or switches. |
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Term
| Point-to-Point Tunneling Protocol (PPTP) |
|
Definition
| A legacy protocol intended to provide a secure data link between computers (a VPN). It has long been included in Windows but has fallen out of favor because it has multiple security vulnerabilities. |
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Term
|
Definition
| A type of DNS record that points IP addresses to hostnames. See also reverse lookup zone. |
|
|
Term
|
Definition
| A material used for the outside insulation and jacketing of most cables. Also a fire rating for a type of cable that has no significant fire protection. |
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Term
| port (logical connection) |
|
Definition
| In TCP/IP, 16-bit numbers between 0 and 65535 assigned to a particular TCP/IP process or application. For example, Web servers use port 443 (HTTPS) to transfer Web pages to clients. The first 1024 ports are called well-known ports. They have been preassigned and generally refer to TCP/IP processes and applications that have been around for a long time. |
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Term
| port (physical connector) |
|
Definition
| In general, the portion of a computer through which a peripheral device may communicate, such as video, USB, serial, and network ports. In the context of networking, the jacks found in computers, switches, routers, and network-enabled peripherals into which network cables are plugged. |
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Term
| port address translation (PAT) |
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Definition
| The most commonly used form of network address translation, where the NAT uses the outgoing IP addresses and port numbers (collectively known as a socket) to map traffic from specific machines in the network. See also network address translation (NAT). |
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Term
|
Definition
| A method for joining two or more switch ports logically to increase bandwidth. |
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Term
|
Definition
| Function of many advanced networking devices that authenticates a connecting device at the point of connection. |
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Term
|
Definition
| Preventing the passage of any TCP segments or UDP datagrams through any ports other than the ones prescribed by the system administrator. |
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Term
|
Definition
| The logical joining of multiple redundant ports and links between two network devices such as a switch and storage array. |
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Term
|
Definition
| Preventing the passage of any TCP segments or UDP datagrams through any ports other than the ones prescribed by the system administrator. |
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Term
|
Definition
| Preventing the passage of any IP packets through any ports other than the ones prescribed by the system administrator. |
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Term
|
Definition
| The capability of many advanced switches to mirror data from any or all physical ports on a switch to a single physical port. Useful for any type of situation where an administrator needs to inspect packets coming to or from certain computers. |
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Term
|
Definition
| Number used to identify the requested service (such as SMTP or FTP) when connecting to a TCP/IP host. Some example server port numbers include 80 (HTTP), 21 (FTP), 25 (SMTP), 53 (DNS), and 67 (DHCP). |
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Term
|
Definition
| A program that probes ports on another system, logging the state of the scanned ports. |
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Term
|
Definition
| The process of querying individual nodes, looking for open or vulnerable ports and creating a report. |
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|
Term
| Post Office Protocol Version 3 (POP3) |
|
Definition
| One of the two protocols that receive e-mail from SMTP servers. POP3 uses TCP port 110. |
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|
Term
| Post Office Protocol Version 3 over SSL (POP3S) |
|
Definition
| Secure version of the POP3 protocol. Uses TLS on port 995. |
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Term
|
Definition
| A language defined by Adobe Systems, Inc., for describing how to create an image on a page. The description is independent of the resolution of the device that will create the image. It includes a technology for defining the shape of a font and creating a raster image at many different resolutions and sizes. |
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Term
|
Definition
| Process by which a client presents its security characteristics via an agent or agent-less interface to an access control server. The server checks the characteristics and decides whether to grant a connection, deny a connection, or redirect the connection depending on the security compliance invoked. |
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Term
|
Definition
| Device that changes AC power to DC power. |
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|
Term
| power distribution unit (PDU) |
|
Definition
| A rack-mounted set of outlets for devices installed in the rack. Connected to the rack’s uninterruptible power supply (UPS). |
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Term
|
Definition
| Backup generator that provides power redundancy by burning petroleum fuel to provide electricity if the main power goes out in a data center or equipment room. |
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|
Term
| Power over Ethernet (PoE) |
|
Definition
| A standard that enables wireless access points (WAPs) to receive their power from the same Ethernet cables that transfer their data. |
|
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Term
|
Definition
| Secondary source of power in the event that primary power fails. The most common redundant power source is an uninterruptible power supply (UPS). |
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|
Term
| PPP (Point-to-Point Protocol) |
|
Definition
| A protocol that enables two devices to connect, authenticate with a username and password, and negotiate the network protocol the two devices will use. |
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|
Term
| PPPoE (PPP over Ethernet) |
|
Definition
| A protocol that was originally designed to encapsulate PPP frames into Ethernet frames. Used by DSL providers to force customers to log into their DSL connections instead of simply connecting automatically. |
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Term
|
Definition
| A 7-byte series of alternating ones and zeroes, followed by a 1-byte start frame delimiter, always precedes a frame. The preamble gives a receiving NIC time to realize a frame is coming and to know exactly where the frame starts. |
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Term
|
Definition
| An IPv6 router configuration that enables it to request an IPv6 address block from an upstream source, then to disseminate it to local clients. |
|
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Term
|
Definition
| The IPv6 term for subnet mask. In all cases, the prefix length is /64. |
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Term
|
Definition
| which can also manage data encryption, hides the differences among various types of computer systems. |
|
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Term
|
Definition
| The name server where records are added, deleted, and modified. The primary name server sends copies of this zone file to secondary name servers in a process known as a zone transfer. |
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Term
|
Definition
| Software, platforms, and infrastructure that an organization owns and operates for internal use. |
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Term
| private direct connections |
|
Definition
| Links between an organization’s network and the cloud provider. The traffic for a private direct connection never goes over the public Internet, but rather over a private line between an organization’s data center and a cloud provider. |
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Term
|
Definition
| Groups of IP addresses set aside for internal networks; Internet routers block these addresses, such as 10.x.x.x /8, 172.(16–31).x.x /16, and 192.168.(0–255).x /24. |
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|
Term
|
Definition
| are the port numbers that are available for use by any application to use in communicating with any other application, using the internet's Transmission Control Protocol (TCP) or the User Datagram Protocol (UDP). |
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|
Term
|
Definition
| A set of actions or instructions that a machine is capable of interpreting and executing. Used as a verb, it means to design, write, and test such instructions. |
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Term
| programmable logic controller (PLC) |
|
Definition
| A computer that controls a machine according to a set of ordered steps. |
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|
Term
|
Definition
| A mode of operation for a NIC in which the NIC processes all frames that it sees on the cable regardless of the frame’s destination address. |
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|
Term
|
Definition
| A character or message provided by an operating system or program to indicate that it is ready to accept input. |
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|
Term
|
Definition
| Term used to describe technology that is unique to, and owned by, a particular vendor. |
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|
Term
| Protected Extensible Authentication Protocol (PEAP) |
|
Definition
| An authentication protocol that uses a password function based on MS-CHAPv2 with the addition of an encrypted TLS tunnel similar to EAP-TLS. |
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|
Term
|
Definition
| An agreement that governs the procedures used to exchange information between cooperating entities; usually includes how much information is to be sent, how often it is sent, how to recover from transmission errors, and who is to receive the information. |
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|
Term
|
Definition
| A tool that monitors the different protocols running at different layers on the network and that can give Application, Session, Network, and Data Link layer information on every frame going through a network. |
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|
Term
|
Definition
| A single unit of information consisting of protocol control information and some form of data. Different layers of the OSI model use different PDUs. For example, a layer 2 PDU would be called a frame, while a layer 3 PDU is known as a packet. |
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Term
|
Definition
| The actual software that implements the protocol suite on a particular operating system. |
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|
Term
|
Definition
| A set of protocols that are commonly used together and operate at different levels of the OSI seven-layer model. |
|
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Term
|
Definition
| Sensor that detects and reads a token that comes within range. The polled information is used to determine the access level of the person carrying the token. |
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|
Term
|
Definition
| The process of making remotely connected computers act as though they are on the same LAN as local computers. |
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|
Term
|
Definition
| A device that fetches Internet resources for a client without exposing that client directly to the Internet. Most proxy servers accept requests for HTTP, FTP, IMAP, and SMTP resources. The proxy server often caches, or stores, a copy of the requested resource for later use. |
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|
Term
| PSTN (public switched telephone network) |
|
Definition
| Also known as plain old telephone service (POTS), the most common type of phone connection, which takes your sounds, translated into an analog waveform by the microphone, and transmits them to another phone. |
|
|
Term
|
Definition
| Software, platforms, and infrastructure delivered through networks that the general public can use. |
|
|
Term
| public switched telephone network (PSTN) |
|
Definition
| Also known as plain old telephone service (POTS), the most common type of phone connection, which takes your sounds, translated into an analog waveform by the microphone, and transmits them to another phone. |
|
|
Term
|
Definition
| A method of encryption and decryption that uses two different keys: a public key for encryption and a private key for decryption. |
|
|
Term
| public-key infrastructure (PKI) |
|
Definition
| The system for creating and distributing digital certificates issued by trusted third parties such as DigiCert, GoDaddy, or Sectigo. |
|
|
Term
|
Definition
| A specialized tool for connecting UTP wires to a 110-block. Also called a 110-punchdown tool. |
|
|
Term
|
Definition
| Type of network cable that offers no special fire protection; burning produces excessive smoke and noxious fumes. |
|
|
Term
| quad small form-factor pluggable (QSFP) |
|
Definition
| Bidirectional (BiDi) fiber-optic connector used in 40GbE networks. |
|
|
Term
|
Definition
| Policies that control how much bandwidth a protocol, PC, user, VLAN, or IP address may use. |
|
|
Term
|
Definition
| Safe network to which are directed stations that either do not require or should not have access to protected resources. |
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