N

name devolution

A process by which a DNS resolver appends one or more domain names to an unqualified domain name, making it a fully qualified domain name, and then submits the fully qualified domain name to a DNS server.

name management

Registering, querying, and releasing NetBIOS names.

name mapping

A Windows 2000 feature that enables file system access by MS-DOS and Windows 3.x users to NTFS and FAT volumes, and enables user account assignments for Kerberos users from non-Windows 2000 Kerberos realms or for external (non-enterprise) users with X.509 certificates. For file system access, Windows 2000 allows share names of up to 255 characters, as opposed to MS-DOS and Windows 3.x, which are restricted to eight characters followed by a period and an extension of up to three characters. Each file or folder with a name that does not conform to the MS-DOS 8.3 standard is automatically given a second name that does. MS-DOS and Windows 3.x users connecting to the file or directory over the network see the name in the 8.3 format; Windows 2000 users see the long name.

name query

A query broadcast to a local network or to a NetBIOS name server in order to resolve the IP address when one NetBIOS application wants to communicate with another NetBIOS application.

name registration

The process of registering a computer name with a name server, such as a DHCP or WINS server, when a client computer joins a computer network. This process of name registration creates a database entry that other network services use to locate that computer.

name registration request

A message sent to a NetBIOS name server when a TCP/IP host begins an attempt to register the domain name.

name release

A message sent to a NetBIOS server to indicate that a domain name has been released and is available for use by another server.

name resolution

The process of having software translate between names that are easy for users to work with, and numerical IP addresses, which are difficult for users but necessary for TCP/IP communications. Name resolution can be provided by software components such as the Domain Name System (DNS) or the Windows Internet Name Service (WINS). In directory service, the phase of LDAP directory operation processing that involves finding a domain controller that holds the target entry for the operation. See also Domain Name System (DNS); Transmission Control Protocol/Internet Protocol (TCP/IP); Windows Internet Name Service (WINS).

name resolution service

A service required by TCP/IP internetworks to convert computer names to IP addresses and IP addresses to computer names. (People use "friendly" names to connect to computers; programs use IP addresses.) See also internetwork; IP address; Transmission Control Protocol/Internet Protocol (TCP/IP).

name server

In the DNS client/server model, a server authoritative for a portion of the DNS database. The server makes computer names and other information available to client resolvers that are querying for name resolution across the Internet or an intranet. See also Domain Name System (DNS).

name server (NS) resource record

A resource record used in a zone to designate the DNS domain names for authoritative DNS servers for the zone. See also resource record.

Named Pipe

A portion of memory that can be used by one process to pass information to another process, so that the output of one process is the input of the other process. The second process can be local (on the same computer as the first) or remote (on a networked computer).

namespace

A set of unique names for resources or items used in a shared computing environment. The names in a namespace can be resolved to the objects they represent. For Microsoft Management Console (MMC), the namespace is represented by the console tree, which displays all of the snap-ins and resources that are accessible to a console. For Domain Name System (DNS), namespace is the vertical or hierarchical structure of the domain name tree. For example, each domain label, such as "host1" or "example," used in a fully qualified domain name, such as "host1.example.microsoft.com," indicates a branch in the domain namespace tree. For Active Directory, namespace corresponds to the DNS namespace in structure, but resolves Active Directory object names.

naming context

See directory partition.

naming service

A service, such as that provided by WINS or DNS, that allows friendly names to be resolved to an address or other specially defined resource data that is used to locate network resources of various types and purposes.

NAT editor

A component of a network address translator that performs additional translation and payload adjustment beyond the IP, TCP, and UDP headers. A NAT editor is an installable component that can properly modify otherwise non-translatable payloads so that they can be forwarded across a NAT.

National Registration Authority (NRA)

An identified body in each nation responsible for issuing object identifiers to enterprises.

native mode

The condition in which all domain controllers within a domain are Windows 2000 domain controllers and an administrator has enabled native mode operation (through Active Directory Users and Computers). See also mixed mode.

negative caching

A situation in which computers that use and query DNS, cache negative responses to a query for a limited period of time. A negative response is obtained when a DNS server directly answers a name query, indicating that no records of the requested DNS domain name were found to exist. The use of this kind of caching can help speed the response for successive queries from other computers for the same name.

negative name registration response

A response to a name registration request from a host or a NetBIOS server indicating that another host or NetBIOS server has already registered the requested name.

negotiation policy

A named collection of security methods in a rule, contained in an Internet Protocol security policy used to establish a security association between the two communicating parties. See also Internet Protocol security policy.

nested groups

A Windows 2000 capability available only in native mode that allows the creation of groups within groups. See also domain local group; forest; global group; trusted forest; universal group.

Net Logon service

A service that runs in the Windows 2000 security subsystem in user mode, and performs the following functions; Replication of Windows NT 3.x and Windows NT 4.0 backup domain controllers with the Windows 2000 PDC emulator; NTLM pass-through authentication; Periodic password updates for computer accounts and interdomain trust relationships; Domain controller discovery using NetBIOS naming for non-directory-aware domain controllers (domain controllers that run Windows NT 3.5 and Windows NT 4.0); Domain controller discovery in closest site using NetBIOS naming or DNS naming for directory-aware domain controllers (Windows 2000 domain controllers).

NetBEUI

See NetBIOS Extended User Interface.

NetBIOS

See network basic input/output system.

NetBIOS Extended User Interface (NetBEUI)

A network protocol native to Microsoft Networking, that is usually used in local area networks of one to 200 clients. NetBEUI uses Token Ring source routing as its only method of routing. It is the Microsoft implementation of the NetBIOS standard.

NetBIOS Frames Control Protocol (NBFCP)

The Network Control Protocol for NetBEUI-based PPP connections. NBFCP negotiates NetBEUI-based parameters to dynamically configure a NetBEUI-based PPP connection across a point-to-point link. NBFCP is documented in RFC 2097.

NetBIOS name

A 16-byte name of a process using NetBIOS. A name recognized by WINS, which maps the name to an IP address.

NetBIOS name query

A packet sent to either a NetBIOS name server, such as a WINS server, or as a broadcast to resolve the IP address of a NetBIOS name.

NetBIOS name resolution

The process of resolving a NetBIOS name to its IP address.

NetBIOS name server

A computer that resolves NetBIOS names to IP addresses. A WINS server is a NetBIOS name server.

NetBIOS Node Type

A designation of the exact mechanisms by which NetBIOS names are resolved to IP addresses.

NetBIOS over TCP/IP (NetBT)

A feature that provides the NetBIOS programming interface over the TCP/IP protocol. It is used for monitoring routed servers that use NetBIOS name resolution.

NetBT

See NetBIOS over TCP/IP.

Netdom

A tool that allows management of Windows 2000 domains and trust relationships from the command line.

netsh

A command-line and scripting utility for Windows 2000 networking components for local or shared computers.

NetWare

Novell's network operating system.

NetWare Core Protocol (NCP)

The file-sharing protocol that governs communications about resource (such as disk and printer), bindery, and NDS operations between server and client computers on a Novell NetWare network. Requests from client computers are transmitted by the IPX protocol. Servers respond according to NCP guidelines. See also bindery; Internetwork Packet Exchange (IPX); Novell Directory Services (NDS).

NetWare Link Services Protocol (NLSP)

A link state routing protocol developed by Novell and used on IPX internetworks.

network access server (NAS)

The device that accepts PPP connections and places clients on the network that the NAS serves. NAS is also called Terminal server.

network adapter

Software or a hardware plug-in board that connects a node or host to a local area network.

network address

See network ID.

network address translation (NAT)

A protocol that allows a network with private addresses to access information on the Internet through an IP translation process. With NAT, you can configure your home network or small office network to share a single connection to the Internet.

network address translator

An IP router defined in RFC 1631 that can translate IP addresses and TCP/UDP port numbers of packets as they are being forwarded.

network administrator

A person responsible for setting up and managing domain controllers or local computers and their user and group accounts, assigning passwords and permissions, and helping users with networking issues. Administrators are members of the Administrators group and have full control over the domain or computer.

network basic input/output system (NetBIOS)

An application programming interface (API) that can be used by applications on a local area network or computers running MS-DOS, OS/2, or some version of UNIX. NetBIOS provides a uniform set of commands for requesting lower level network services.

network bridge

A device that connects networks by using the same communications protocols so that information can be passed from one to the other. Also, a device that connects two local area networks, whether or not they use the same protocols. A bridge operates at the ISO/OSI data-link layer.

Network Control Protocol (NCP)

A protocol within the PPP protocol suite that negotiates the parameters of an individual LAN protocol such as TCP/IP or IPX.

network data stream

The total amount of data transferred over a network at any given time.

Network Driver Interface Specification (NDIS)

A software component that provides Windows 2000 network protocols a common interface for communications with network adapters. NDIS allows more than one transport protocol to be bound and operate simultaneously over a single network adapter card.

network file system (NFS)

A service for distributed computing systems that provides a distributed file system, eliminating the need for keeping multiple copies of files on separate computers.

network gateway

A device that connects networks using different communications protocols so that information can be passed from one to the other. A gateway both transfers information and converts it to a form compatible with the protocols being used by the receiving network.

network ID

A number used to identify the systems that are located on the same physical network bounded by routers. The network ID should be unique to the internetwork.

network interface layer

A layer of the TCP/IP DARPA model that is responsible for placing TCP/IP packets on the network medium and receiving TCP/IP packets off the network medium. The network interface layer is also called the network access layer.

network layer

A layer that addresses messages and translates logical addresses and names into physical addresses. It also determines the route from the source to the destination computer and manages traffic problems, such as switching, routing, and controlling the congestion of data packets.

Network Load Balancing

The Windows Clustering component that distributes incoming Web requests among its cluster of IIS servers.

Network Load Balancing cluster

Up to 32 IIS servers from which Network Load Balancing presents a single IP address to Web clients and among which Network Load Balancing distributes incoming Web requests.

network media

The type of physical wiring and lower-layer protocols used for transmitting and receiving frames. For example, Ethernet, FDDI, and Token Ring.

Network Monitor

A packet capture and analysis tool used to view network traffic. This feature is included with Windows 2000 Server; however, Systems Management Server has a more complete version.

network name

In server clusters, the name through which clients access server cluster resources. A network name is similar to a computer name, and when combined in a resource group with an IP address and the applications clients access, presents a virtual server to clients.

Network News Transfer Protocol (NNTP)

A member of the TCP/IP suite of protocols, used to distribute network news messages to NNTP servers and clients, or news-readers, on the Internet. NNTP is designed so that news articles are stored on a server in a central database, and the user selects specific items to read. See also Transmission Control Protocol/Internet Protocol (TCP/IP).

network number

In the Macintosh environment, the routing address or range of addresses assigned to the physical network that Phase 2 AppleTalk routers use to route information to the appropriate network. Network number is also called network range and cable range. See also routing.

Network Plug and Play

A combination of hardware and software support that enables a computer system to recognize and adapt to hardware configuration changes with little or no user intervention.

network prefix

The number of bits in the IP network ID starting from the high order bit. The network prefix is another way of expressing a subnet mask.

network prefix notation

The practice of expressing a subnet mask as a network prefix rather than a dotted decimal notation.

network range

See network number.

network route

A route to a specific network ID in an internetwork.

NFS

See network file system.

NNTP

See Network News Transfer Protocol.

node

In tree structures, a location on the tree that can have links to one or more items below it. In local area networks (LANs), a device that is connected to the network and is capable of communicating with other network devices. In a server cluster, a server that has Cluster service software installed and is a member of the cluster. See also local area network (LAN).

nonauthoritative restore

The default restore mode when using the Windows 2000 Ntbackup utility. When a domain controller is restored from a backup tape, the domain controller is brought up-to-date with its replica partners using normal Active Directory replication protocols. It is a non-authoritative restore because the objects in the restored directory are not treated as authoritative. The restored objects are replaced with changes held in other replicas of the restored domain.

nonce

A randomly generated value used to defeat replay attacks. See also replay attack.

noncontainer object

An object that cannot logically contain other objects. A file is a noncontainer object. See also container object; object.

noncontiguous namespace

A namespace based on different DNS root domain names, such as that of multiple trees in the same forest. See also namespace; hierarchical namespace; flat namespace.

nonpaged pool

An area of system memory reserved for objects that must remain in physical memory as long as they are active. The alternative is the paged pool.

nonrepudiation

A basic security function of cryptography. Nonrepudiation provides assurance that a party in a communication cannot falsely deny that a part of the communication occurred. Without nonrepudiation, someone can communicate and then later deny the communication or claim that the communication occurred at a different time. See also cryptography; authentication; confidentiality; integrity.

nontransitive trust relationship

A type of trust relationship that is bounded by the two domains in the relationship. For example, if domain A trusts domain B and domain B trusts domain C, there is no trust relationship between domain A and domain C. A nontransitive trust relationship can be a one-way or two-way relationship. It is the only type of trust relationship that can exist between a Windows 2000 domain and a Windows NT domain or between Windows 2000 domains in different forests. See also trust relationship; transitive trust relationship.

notify list

A list maintained by the primary server for a zone of other DNS servers that should be notified when zone changes occur. The notify list is made up of IP addresses for DNS servers configured as secondary servers for the zone. The secondary servers can then check to see if they need to initiate a zone transfer. See also DNS Notify.

Novell Directory Services (NDS)

On networks running Novell NetWare 4.x and NetWare 5.x, a distributed database that maintains information about every resource on the network and provides access to these resources.

NS (name server) resource record

See name server (NS) resource record.

Nslookup

A command-line tool that allows users to make DNS queries for testing and troubleshooting DNS installations.

NTFS file system

A recoverable file system designed for use specifically with Windows NT and Windows 2000. NTFS uses database, transaction-processing, and object paradigms to provide data security, file system reliability, and other advanced features. It supports file system recovery, large storage media, and various features for the POSIX subsystem. It also supports object-oriented applications by treating all files as objects with user-defined and system-defined attributes.

NTLM authentication protocol

A challenge/response authentication protocol. The NTLM authentication protocol was the default for network authentication in Windows NT version 4.0 and earlier. The protocol continues to be supported in Windows 2000 but no longer is the default. See also authentication.

NVRunCmd service

A service that allows commands issued from a host system NetView console to be carried out on the computer running Windows 2000 and SNA Server. The NVRunCmd service also returns the command results to the host NetView console in standard character or number formats.

NWLink

An implementation of the Internetwork Packet Exchange (IPX), Sequenced Packet Exchange (SPX), and NetBIOS protocols used in Novell networks. NWLink is a standard network protocol that supports routing and can support NetWare client/server applications, where NetWare-aware Sockets-based applications communicate with IPX/SPX Sockets-based applications. See also Internetwork Packet Exchange (IPX); network basic input/output system (NetBIOS).

O

object

An entity, such as a file, folder, shared folder, printer, or Active Directory object, described by a distinct, named set of attributes. For example, the attributes of a File object include its name, location, and size; the attributes of an Active Directory User object might include the user's first name, last name, and e-mail address. For OLE and ActiveX objects, an object can also be any piece of information that can be linked to, or embedded into, another object. See also attribute; child object; container object; noncontainer object; parent object.

object class

The object class is the formal definition of a specific kind of object that can be stored in the directory. An object class is a distinct, named set of attributes that represents something concrete, such as a user, a printer, or an application. The attributes hold data describing the thing that is identified by the directory object. Attributes of a user might include the user's first name, last name, and e-mail address. The terms object class and class are used interchangeably. The attributes that can be used to describe an object are determined by the content rules.

object linking and embedding (OLE)

A method for sharing information among applications. Linking an object, such as a graphic, from one document to another inserts a reference to the object into the second document. Any changes you make in the object in the first document will also be made in the second document. Embedding an object inserts a copy of an object from one document into another document. Changes you make in the object in the first document will not be updated in the second unless the embedded object is explicitly updated. See also ActiveX.

objectClassCategory

An integer value that specifies the category of the class. The category can be Structural, Abstract, or Auxiliary.

octet

In programming, an octet refers to eight bits or one byte. IP addresses, for example, are typically represented in dotted-decimal notation; that is, with the decimal value of each octet of the address separated by a period. See also IP address.

off-subnet addressing

The allocation of IP addresses from remote access servers to remote access clients that are not in a range defined by a subnet to which the remote access server is attached.

offline

In a server cluster, the state of a resource, group, or node when it is unavailable to the cluster. Resources and groups also have an offline state. See also group; node; online, paused; resource.

offline media

Media that are not connected to the computer and require external assistance to be accessed.

offset

When defining a pattern match within a filter using Network Monitor, the number of bytes from the beginning of the frame where the pattern occurs in a frame.

OLE

See object linking and embedding.

oMObjectClass

For object-syntaxed attributes (OM-syntax = 127), a binary value that describes the type of object.

oMSyntax

The OM syntax of an attribute. Syntax of this attribute as defined by the XAPIA X/Open Object Model (XOM) specification.

on-demand connection

A demand-dial connection made over dial-up links when the cost of using the communications link is time-sensitive. For example, long distance analog phone calls are charged on a per-minute basis. With on-demand connections, the connection is made when traffic is forwarded, and the connection is terminated after a configured amount of idle time.

on-demand installation

An installation option that gives Windows 2000-compatible software the ability to install new features on first use rather than when the application is first installed.

on-demand router-to-router VPN connection

A router-to-router VPN connection that is made by a calling router who has a dial-up connection to the Internet.

on-media identifier (OMID)

A label that is electronically recorded on each medium in a Removable Storage system. Removable Storage uses on-media identifiers to track media in the Removable Storage database. An application on-media identifier is a subset of the media label.

on-screen keyboard

A utility that displays a virtual keyboard on a computer screen and allows users with mobility impairments to type using a pointing device or joystick.

on-subnet addressing

The allocation of IP addresses from a remote access server to remote access clients that are in a range defined by a subnet to which the remote access server is attached.

one-level search

See search scope.

online

In a server cluster, the state of a resource, group, or node when it is available to the cluster. See also heartbeat; node; offline; paused; resource.

online library

A robotic library unit, sometimes referred to as a jukebox.

OnNow Power Initiative

A system-wide approach to power management. All components can be instantly on or off and work in conjunction with hardware and software components to alter their power state as system use requires.

open database connectivity (ODBC)

An application programming interface (API) that enables database applications to access data from a variety of existing data sources.

Open Shortest Path First (OSPF)

A routing protocol used in medium-sized and large-sized networks. This protocol is more complex than RIP, but allows better control and is more efficient in propagating routing information.

open systems interconnection reference model

A networking model introduced by the International Organization for Standardization (ISO) to promote multi-vendor interoperability. Open Systems Interconnection (OSI) is a seven-layered conceptual model consisting of the application, presentation, session, transport, network, data-link, and physical layers.

operational attribute

An attribute that is used only for administering the directory database. It is an artifact attribute that is never defined in the schema and does not require any storage. Generally, when you set the operational attribute, you trigger some immediate action on the server.

operations master

A domain controller that has been assigned one or more special roles in an Active Directory domain. The domain controllers assigned these roles perform operations that are single-master (not permitted to occur at different places in the network at the same time). Examples of these operations include resource identifier allocation, schema modification, primary domain controller election and certain infrastructure changes. The domain controller that controls the particular operation owns the operations master role for that operation. The ownership of these operations master roles can be transferred to other domain controllers. See also Active Directory; domain naming master; infrastructure master; multimaster replication; relative ID master; replication; schema master.

operator request

A request for the operator to perform a task. This request can be issued by an application or by Removable Storage.

option types

Client configuration parameters that a DHCP server can assign when offering an IP address lease to a client. Typically, these option types are enabled and configured for each scope. Most options are predefined through RFC 2132, but DHCP Manager can be used to define and add custom option types if needed.

organizational domain

A type of domain signified by a three-character code that indicates the primary function or activity of the organizations contained within the domain, such as .org, .edu, or .gov.

organizational unit (OU)

An Active Directory container object used within domains. An organizational unit is a logical container into which users, groups, computers, and other organizational units are placed. It can contain objects only from its parent domain. An organizational unit is the smallest scope to which a Group Policy object can be linked, or over which administrative authority can be delegated.

original equipment manufacturer (OEM)

The maker of a piece of equipment. In making computers and computer-related equipment, manufacturers of original equipment typically purchase components from other manufacturers of original equipment and then integrate them into their own products.

originating update

In Active Directory replication, a write to a property at the system initiating the change, as opposed to a write to a property that is caused by replication. For example, a change to attribute A on object O on server S1 is the originating write. When S2 receives the change from S1, the local database update on S2 for object O, attribute A is the corresponding replicated write. See also replicated update.

OSChooser Markup Language (OSCML)

The markup language used to modify the Client Installation Wizard (CIW) .osc files for the screens presented when using Remote Installation Service.

OSI

See open systems interconnection reference model.

OSPF

See Open Shortest Path First.

output filters

Filters which define the traffic that is allowed to be sent from that interface.

overclocking

Setting a microprocessor to run at speeds above the rated specification.

owner

In Windows 2000, the person who controls how permissions are set on objects and can grant permissions to others. In the Macintosh environment, an owner is the user responsible for setting permissions for a folder on a server. A Macintosh user who creates a folder on the server automatically becomes the owner of the folder. The owner can transfer ownership to someone else. Each Macintosh-accessible volume on the server also has an owner.