Term 481
Magic number subnetting
A quick subnetting method that uses the subnet mask's interesting octet to find the network size, often called the magic number (256 minus the mask octet).
Acronym study
Terms 481–510 of 1033 N10-009 acronyms and key terms. Each entry includes a plain-English definition and a link to the full 800-word glossary page with exam context and practice questions.
Term 481
A quick subnetting method that uses the subnet mask's interesting octet to find the network size, often called the magic number (256 minus the mask octet).
Term 482
A Mail Exchange record is a type of DNS record that specifies which mail server is responsible for receiving email messages on behalf of a domain.
Term 483
A Main Distribution Frame is the central point in a building or campus where all external telecommunication cables are terminated and connected to internal network wiring.
Term 484
Malware symptoms are the observable signs on a computer or network that indicate a malicious program may have infected the system, such as slow performance, unexpected pop-ups, or unusual network activity.
Term 485
A Metropolitan Area Network (MAN) is a computer network that spans a geographic area larger than a local area network (LAN) but smaller than a wide area network (WAN), typically covering a city or a large campus.
Term 486
A cyberattack where an attacker secretly intercepts and potentially alters communication between two parties who believe they are directly communicating with each other.
Term 487
Manageability is the ease with which IT administrators can monitor, configure, update, and troubleshoot cloud resources and systems, often through centralized tools and automation.
Term 488
A managed identity is an automatically managed service principal in Azure that allows your code to authenticate to any service that supports Azure AD authentication without storing credentials.
Term 489
A Management Information Base (MIB) is a virtual database that stores information about network devices, organized as a hierarchical tree, which network management tools use to monitor and control those devices.
Term 490
A Management VLAN is a dedicated virtual local area network used to secure and separate administrative access to network devices like switches and routers from regular user data traffic.
Term 491
A mapped drive is a shortcut that assigns a drive letter to a shared folder on a network, making it appear as if it is a local storage device on your computer.
Term 492
The Maximum Transmission Unit (MTU) is the largest size of a data packet that can be sent over a network connection without needing to be broken into smaller pieces.
Term 493
MBR is a 512-byte boot sector that stores partition table and boot code, enabling a computer to load an operating system.
Term 494
MDF (Main Distribution Frame) is the central point where external telecommunication lines enter a building and are connected to internal network wiring.
Term 495
MDIX (Medium Dependent Interface Crossover) is a twisted-pair Ethernet port that internally crosses the transmit and receive pairs for direct device connections.
Term 496
Mean Time To Repair (MTTR) is the average time it takes to fix a failed component or system and restore it to full operation.
Term 497
Measured service is a cloud computing feature where the provider automatically tracks and controls resource usage, and customers pay only for what they consume, like a utility bill.
Term 498
Media Access Control (MAC) is a sublayer of the Data Link Layer in networking that controls how devices on the same network share access to the physical medium and uniquely identifies each device with a hardware address.
Term 499
A media converter is a networking device that connects two different types of network cables, such as changing from copper Ethernet to fiber optic, allowing them to communicate on the same network.
Term 500
A Medium Dependent Interface Crossover (MDIX) is a special Ethernet cable that swaps the transmit and receive wire pairs so two similar devices can connect directly without a switch or hub.
Term 501
A memory leak happens when a program uses up system memory but never releases it, slowly eating away at available memory until the computer slows down or crashes.
Term 502
A network topology where every device is connected to every other device, providing high fault tolerance and redundancy through multiple data paths.
Term 503
A metric is a quantifiable measurement used to assess the performance, health, or status of IT systems, networks, or applications.
Term 504
Metro Ethernet is a service that extends Ethernet networking across a metropolitan area, allowing businesses to connect multiple locations as if they were on the same local network.
Term 505
A Metropolitan Area Network (MAN) is a network that connects multiple locations across a city or large campus, providing high-speed communication like a single large network.
Term 506
A virtual database used by SNMP to organize and store managed device parameters as a structured tree of object identifiers (OIDs).
Term 507
A compact motherboard form factor that offers most of the features of a standard ATX board in a smaller size, making it popular for budget and space-constrained builds.
Term 508
A microphone is an input device that converts sound waves into electrical signals for recording, communication, or voice control in computing systems.
Term 509
MIMO uses multiple antennas at both transmitter and receiver to improve wireless throughput and reliability without extra bandwidth.
Term 510
Mini-ITX is a small form factor motherboard standard designed for compact desktop computers, balancing space savings with essential functionality.