L

L2TP

See Layer 2 Tunneling Protocol.

L2TP client

A tunnel client using the L2TP tunneling protocol and IPSec.

L2TP server

A tunnel server using the L2TP tunneling protocol and IPSec.

label

See domain name label.

LAN

See local area network.

LAN emulation (LANE)

A set of protocols that allow existing Ethernet and Token Ring LAN services to overlay an ATM network. LANE allows connectivity among LAN- and ATM-attached stations. See also Asynchronous Transfer Mode (ATM).

LAN emulation client (LEC)

The client on an emulated local area network (ELAN) that performs data forwarding, address resolution, and other control functions. The LEC resides on end stations in an emulated local area network (ELAN). See also Asynchronous Transfer Mode (ATM); emulated local area network (ELAN); LAN emulation.

LAN emulation configuration server (LECS)

The service that assigns individual LANE clients to particular emulated local area networks (ELANs) by directing them to the LAN emulation service (LES). See also emulated local area network (ELAN); LAN emulation; LAN emulation server.

LAN emulation server (LES)

The central control point for an emulated local area network (ELAN). Enables LANE clients to join the emulated local area network (ELAN) and resolves LAN addresses to ATM addresses. See also Asynchronous Transfer Mode (ATM); emulated local area network (ELAN); LAN emulation (LANE).

LAN manager replication

The file replication service used under Windows NT. See File Replication service.

large window support

In TCP communications, the largest amount of data that can be transferred without acknowledgment. The window has a fixed size. Large window support dynamically recalculates the window size and allows larger amounts of data to be transferred at one time causing greater throughput.

latency

See replication latency.

layer 2 switch

A switch that operates at the datalink layer of the OSI reference model.

layer 3 switch

A switch that operates at the network layer of the OSI reference model.

Layer two Tunneling Protocol (L2TP)

A tunneling protocol that encapsulates PPP frames to be sent over IP, X.25, Frame Relay, or ATM networks. L2TP is a combination of the Point-to-Point Tunneling Protocol (PPTP) and Layer 2 Forwarding (L2F), a technology proposed by Cisco Systems, Inc.

LDAP

See Lightweight Directory Access Protocol.

LDAP API

See Lightweight Directory Access Protocol Application Programming Interface.

LDAP Data Interchange Format (LDIF)

A draft Internet standard for a file format that can be used to perform batch operations on directories that conform to LDAP standards.

LDAP referral

A reference to another domain controller, returned by an LDAP search when the requested object is not found on the domain controller being searched.

lDAPDisplayName (LDAP-Display-Name)

The name by which LDAP clients identify an attribute. The lDAPDisplayName property must be unique across all lDAPDisplayName attributes for all schemaClass and schemaAttribute objects in the Schema container.

It is recommended that the lDAPDisplayName be the cn with the hyphens removed (except do not remove the hyphen separating your name prefix from the rest of the name) and the first character uses the lower--case. The lDAPDisplayName property must be unique across all lDAPDisplayName attributes for all schemaClass and schemaAttribute objects in the schema container.

It is also recommended that you specify the lDAPDisplayName rather than letting this attribute default.

LDIF Directory Exchange tool

A command--line utility that allows you to import and export objects to and from Active Directory. You can create, modify, and delete directory objects by using this utility. Objects are stored in the LDIF file format. The utility can be run on a Windows 2000 server or copied to a Windows 2000 workstation. For example, LDIFDE can be used to extend the schema, export Active Directory user and group information to other applications or services, and populate Active Directory with data from other directory services.

LDIFDE

See LDIF Directory Exchange tool.

leave latency

The time between when the last host on a subnet has left an IP multicast host group and when no more multicast traffic for that group is forwarded to the subnet.

library

A data-storage system, usually managed by Removable Storage. A library consists of removable media (such as tapes or discs) and a hardware device that can read from or write to the media. There are two major types of libraries: robotic libraries (automated multiple-media, multidrive devices) and stand-alone drive libraries (manually operated, single-drive devices). A robotic library is also called a jukebox or changer. See also Removable Storage.

library request

A request for an online library or stand-alone drive to perform a task. This request can be issued by an application or by Removable Storage.

license service

A server in Terminal Services that stores all client licenses that have been downloaded for a Terminal server and tracks the licenses that have been issued to client computers or terminals.

Lightweight Directory Access Protocol (LDAP)

A directory service protocol that runs directly over TCP/IP and the primary access protocol for Active Directory. LDAP version 3 is defined by a set of Proposed Standard documents in Internet Engineering Task Force (IETF) RFC 2251. See also Lightweight Directory Access Protocol application programming interface (LDAP API).

Lightweight Directory Access Protocol application programming interface (LDAP API)

An API for experienced C programmers who want to enable new or existing applications to connect to, search, and update LDAP servers. You can use the LDAP API to write directory-enabled applications that allow LDAP client applications to search for and retrieve information from an LDAP server. LDAP API enables the modification of directory objects, where such modifications are permitted. There are also functions that provide access control for servers, by allowing clients to authenticate themselves.

The LDAP API is delivered with Windows 2000 and is found in the Wldap32.dll file. The Microsoft LDAP API is compatible with both version 2 and version 3 of the LDAP standard.

limited broadcast address

The broadcast address of 255.255.255.255.

line kill

In UNIX, an assigned key that deletes the entire current line.

Line Printer Daemon (LPD)

A service on the print server that receives documents (print jobs) from line printer remote (LPR) tools running on client systems. See also Line Printer Remote (LPR).

Line Printer Remote (LPR)

A connectivity tool that runs on client systems and is used to print files to a computer running an LPD server. See also Line Printer Daemon (LPD).

Link Control Protocol (LCP)

A PPP control protocol that negotiates link and PPP parameters to dynamically configure the data-link layer of a PPP connection.

Link State Advertisements (LSAs)

A advertisement of an OSPF router that contains its attached networks and their configured costs.

link state database (LSDB)

A map of an area maintained by OSPF routers. It is updated after any change in the network topology. The link state database is used to compute IP routes, which must be computed again after any change in the topology. See also Open Shortest Path First (OSPF).

link station

Hardware and software components within a node that represent a connection to an adjacent node over a specific link.

linked object

An object that is inserted into a document but still exists in the source file. When information is linked, the new document is updated automatically if the information in the original document changes. See also embedded object.

linkID

An integer that indicates that the attribute is a linked attribute. An even integer is a forward link and an odd integer is a back link.

This value must be unique for linkIDs of all attributeSchema objects. A back link must have corresponding forward link.

listening mode

The way that the network adapter analyzes the destination media access control address of incoming frames in order to decide to process them further.

Lmhosts file

A local text file that maps NetBIOS names (commonly used for computer names) to IP addresses for hosts that are not located on the local subnet. In Windows 2000, this file is stored in the SystemRoot\System32\Drivers\Etc folder.

load sharing

See round robin.

load-balancing

Scaling the performance of a server-based program (such as a Web server) by distributing its client requests across multiple servers within the cluster by using Windows Clustering. Each host can specify the load percentage that it will handle, or the load can be equally distributed across all the hosts. If a host fails, Windows Clustering dynamically redistributes the load among the remaining hosts. See also client request; cluster; host; scalability; server.

local area network (LAN)

A communications network connecting a group of computers, printers, and other devices located within a relatively limited area (for example, a building). A LAN allows any connected device to interact with any other on the network. See also wide area network (WAN).

local computer

A computer that can be accessed directly without using a communications line or a communications device, such as a network adapter or a modem. Similarly, running a local program means running the program on your computer, as opposed to running it from a server.

local group

For computers running Windows 2000 Professional and member servers, a group that is granted permissions and rights from its own computer to only those resources on its own computer on which the group resides. See also global group.

local policy module

A Windows 2000 mechanism that provides the QoS Admission Control Service with a means of retrieving policy information from Active Directory. The QoS Admission Control Service invokes the LPM when a policy object with a Windows 2000 Kerberos ticket is detected. The LPM takes the user name from the policy object and the RSVP message, and looks up the user's admission control policy in Active Directory.

local printer

A printer that is directly connected to one of the ports on your computer.

Local Security Authority (LSA)

A protected subsystem that authenticates and logs users onto the local system. In addition, the LSA maintains information about all aspects of local security on a system (collectively known as the local security policy), and provides various services for translation between names and identifiers.

local security policy

Security information about all aspects of local security on a system. The local security policy identifies who is assigned privileges and what security auditing is to be performed.

local storage

For Windows 2000 Server, NTFS disk volumes used as primary data storage. Such disk volumes can be managed by Remote Storage by copying infrequently accessed files to remote, or secondary, storage. See also Remote Storage.

locally administered address (LAA)

Internal network address on a network adapter that is specifically written to accommodate an organization's adapter naming standard.

LocalTalk

The Apple networking hardware built into every Macintosh computer. LocalTalk includes the cables and connector boxes to connect components and network devices that are part of the AppleTalk network system. LocalTalk was formerly known as the AppleTalk Personal Network.

lock

To make a file inaccessible. When more than one user can manipulate a file, that file is locked when a user accesses it in order to prevent more than one user from modifying the file simultaneously.

log file

A file that stores messages generated by an application, service, or operating system. These messages are used to track the operations performed. For example, Web servers maintain log files listing every request made to the server. Log files are usually ASCII files and often have a .log extension. In Backup, a file that contains a record of the date the tapes were created and the names of files and directories successfully backed up and restored. The Performance Logs and Alerts service also creates log files.

log off

To stop using a network, which removes the user name from active use until the user logs on again.

log on

To begin using a network by providing a user name and password that identifies a user to the network.

logical drive

A volume created within an extended partition on a basic disk. You can format and assign a drive letter to a logical drive. Only basic disks can contain logical drives. A logical drive cannot span multiple disks. See also basic disk; basic volume; extended partition.

logical IP subnet (LIS)

A group of IP hosts/members belonging to the same IP subnet and whose host ATMARP server ATM address is the same.

logical link control (LLC)

A protocol standard developed by the IEEE 802 committee, which governs the exchange of transmission frames between data stations independently of how the transmission medium is shared on the local area network.

logical printer

The software interface between the operating system and the printer in Windows 2000. While a printer is the device that does the actual printing, a logical printer is its software interface on the print server. This software interface determines how a print job is processed and how it is routed to its destination (to a local or network port, to a file, or to a remote print share). When a document is printed, it is spooled (or stored) on the logical printer before it is sent to the printer itself. See also spooling.

logical store

See certificate stores.

logical unit (LU)

An IBM Systems Network Architecture protocol that allows end users to communicate with each other and gain access to IBM network resources.

long file name (LFN)

A folder name or file name longer than the 8.3 file name standard (up to eight characters followed by a period and an extension of up to three characters) of the FAT file system. Windows 2000 supports long file names up to the file-name limit of 255 characters. Macintosh users can assign long names to files and folders on the server and, using Services for Macintosh, long names to Macintosh-accessible volumes can be assigned when created. Windows 2000 automatically translates long names of files and folders to 8.3 names for MS-DOS and Windows 3.x users. See also name mapping.

loopback address

The address of the local computer used for routing outgoing packets back to the source computer. This address is used primarily for testing.

loopback option

An option that allows an administrator to apply Group Policy settings based on the computer that the user logs on to, even after the user settings have been processed.

loose consistency

In multimaster directory replication, the tolerance for replication latency. In Active Directory replication, replicas are not guaranteed to be consistent with each other at any particular point in time because changes can be applied to any full replica at any time. Factors that affect replication latency include same or different site, number of hops between domain controllers, whether changes are found via notification or periodic synchronization, bandwidth of links, whether systems are down, and replication load. See also replication convergence.

LPM

See Local Policy Module.

M

m-node

A NetBIOS node type that uses a mix of b-node and p-node communications to register and resolve NetBIOS names. M-node first uses broadcast resolution; then, if necessary, it uses a server query.

Macintosh-accessible volume

Storage space on the server used for folders and files of Macintosh users. A Macintosh-accessible volume is equivalent to a shared folder for personal computer users. Each Macintosh-accessible volume on a computer running Windows 2000 Server will correspond to a folder. Both personal computer users and Macintosh users can be given access to files located in a folder that is designated as both a shared folder and a Macintosh-accessible volume.

Macintosh-style permissions

Folder and volume permissions that are similar to the access privileges used on a Macintosh.

MADCAP

multicast address dynamic client allocation protocol.

Magic Packet

A packet that contains 16 contiguous copies of the receiving network adapter's Ethernet address. A magic packet is used to awaken a computer from a low power state.

Management Information Base (MIB)

A collection of formally described objects, each of which represents a particular type of information, that can be accessed and managed by the Simple Network Management Protocol (SNMP) through a network management system.

mandatory attributes

Object attributes for which values must be specified.

Master Boot Record (MBR)

The first sector on a hard disk, this data structure starts the process of booting the computer. It is the most important area on a hard disk. The MBR contains the partition table for the disk and a small amount of executable code called the master boot code.

master domain

A Windows NT domain that holds user account data. Also known as an account domain.

master file table (MFT)

The database that tracks the contents of an NTFS volume. The MFT is a table whose rows correspond to files on the volume and whose columns correspond to the attributes of each file.

master replica

See full replica.

master server

In a DNS zone transfer, the computer that is the source of the zone. Master servers can vary and are one of two types (either primary or secondary masters), depending on how the server obtains its zone data. See also primary server; secondary server; zone; zone transfer.

maximum password age

The period of time a password can be used before the system requires the user to change it.

maximum receive unit (MRU)

The maximum size of a PPP frame. The MRU is determined during the negotiation of the logical link.

maximum segment size

The maximum size of a TCP segment that can be sent on a TCP connection.

maximum transmission unit (MTU)

The maximum frame size supported by a network technology such as Ethernet or Token Ring.

mayContain

A multivalued property that specifies the attributes that can be present on instances of this class. These are optional attributes that are not mandatory and, therefore, may or may not be present on an instance of this classSchema object. For an existing classSchema object, values can be added to this property but not removed.

Each value is the lDAPDisplayName of an attribute. You must ensure that the attributes exist or will exist when the new class is written to the directory. If one of the attributes does not exist, the classSchema object will fail to be added to the directory.

The full set of optional attributes for this class is the union of the systemMayContain and mayContain on this class as well as the systemMayContain and mayContain properties of all inherited classes.

media access control

A sublayer of the IEEE 802 specifications that defines network access methods and framing.

media access control address

The address used for communication between network adapters on the same subnet. Each network adapter has an associated media access control address.

media label library

A dynamic-link library (DLL) that can interpret the format of a media label written by a Removable Storage application.

member server

A computer that runs Windows 2000 Server but is not a domain controller of a Windows 2000 domain. Member servers participate in a domain, but do not store a copy of the directory database.

memory address

A portion of computer memory that can be allocated to a device or used by a program or the operating system. Devices are usually allocated a range of memory addresses.

memory leak

A condition that occurs when applications allocate memory for use but do not free allocated memory when finished.

message digest

A fixed-size result obtained by applying a one-way mathematical function called a message digest function (sometimes called a "hash function" or "hash algorithm") to an arbitrary amount of data. Given a change in the input data, the resulting value of the message digest will change. Message digest is also called a hash. See message digest function.

message digest function

One-way mathematical algorithm used to produce a message digest (also called a hash). See also message digest.

Messaging API (MAPI)

See Messaging Application Programming Interface.

Messaging Application Programming Interface (MAPI)

A Microsoft API used to support messaging applications.

metacharacter

A character that is assigned a special meaning that is recognized by the shell.

metadata

Stored data that describes and controls the functioning of the Remote Storage system.

metric

A number used to indicate the cost of a route in the IP routing table to enable the selection of the best route among possible multiple routes to the same destination.

Microsoft Challenge Handshake Authentication Protocol version 1 (MS-CHAP v1)

An encrypted authentication mechanism for PPP connections similar to CHAP. The remote access server sends a challenge to the remote access client that consists of a session ID and an arbitrary challenge string. The remote access client must return the user name and a Message Digest 4 (MD4) hash of the challenge string, the session ID, and the MD4-hashed password.

Microsoft Challenge Handshake Authentication Protocol version 2 (MS-CHAP v2)

An encrypted authentication mechanism for PPP connections that provides stronger security than CHAP and MS-CHAP v1. MS-CHAP v2 provides mutual authentication and asymmetric encryption keys.

Microsoft Component Services

A program that runs on an Internet or other server and manages the application and database transaction requests for a client's user. Component Services screens the user and client computer from having to formulate requests for unfamiliar databases and forwards the requests to database servers. It also manages security, connection to other servers, and transaction integrity.

Microsoft Management Console (MMC)

A framework for hosting administrative consoles. A console is defined by the items on its console tree, which might include folders or other containers, World Wide Web pages, and other administrative items. A console has one or more windows that can provide views of the console tree and the administrative properties, services, and events that are acted on by the items in the console tree. The main MMC window provides commands and tools for authoring consoles. The authoring features of MMC and the console tree might be hidden when a console is in User Mode. See also console tree.

migrate

The process of moving files or programs from an older file format or protocol to a more current format or protocol. For example, WINS database entries can be migrated from static WINS database entries to dynamically-registered DHCP entries.

migration

The process of copying an object from local storage to remote storage.

Mini-Setup wizard

A wizard that starts the first time a computer boots from a hard disk that has been duplicated. The wizard gathers any information that is needed for the newly duplicated hard disk.

minimum password length

The fewest characters a password can contain.

minimum TTL

A default Time To Live (TTL) value set in seconds for use with all resource records in a zone. This value is set in the start of authority (SOA) resource record for each zone. By default, the DNS server includes this value in query answers to inform recipients how long it can store and use resource records provided in the query answer before they must expire the stored records data. When TTL values are set for individual resource records, those values will override the minimum TTL. See also Time To Live (TTL).

miniport drivers

A driver that is connected to an intermediate driver and a hardware device.

mirror set

A fully redundant or shadow copy of data. Mirror sets provide an identical twin for a selected disk; all data written to the primary disk is also written to the shadow or mirror disk. This gives you instant access to another disk with a copy of the information. Mirror sets provide fault tolerance. See also stripe set with parity; volume set.

mirrored volume

A fault-tolerant volume that duplicates data on two physical disks. The mirror is always located on a different disk. If one of the physical disks fails, the data on the failed disk becomes unavailable, but the system continues to operate by using the unaffected disk. A mirrored volume is slower than a RAID-5 volume in read operations but faster in write operations. Mirrored volumes can only be created on dynamic disks. In Windows NT 4.0, a mirrored volume was known as a mirror set. See also dynamic disk; dynamic volume; fault tolerance; redundant array of independent disks (RAID); volume.

mixed mode

The default mode setting for domains on Windows 2000 domain controllers. Mixed mode allows Windows 2000 domain controllers and Windows NT backup domain controllers to co-exist in a domain. Mixed mode does not support the universal and nested group enhancements of Windows 2000. You can change the domain mode setting to Windows 2000 native mode after all Windows NT domain controllers are either removed from the domain or upgraded to Windows 2000. See also native mode.

mixed version

Used to describe a server cluster in which different nodes are running different versions of the server cluster software.

mixed-mode domain

A networked set of computers running more than one operating system, for example, both Windows NT and Windows 2000.

MMC

See Microsoft Management Console.

MMC snap-in

A type of management tool that you can add to the console tree of a console supported by Microsoft Management Console (MMC), for example, Device Manager. A snap-in can be either a stand-alone or an extension snap-in. A stand-alone snap-in can be added by itself; an extension snap-in can only be added to extend another snap-in. See also Microsoft Management Console (MMC).

mobile user

A user who travels away from a corporate campus such as a salesperson or field technician.

mobility impairments

The diminished ability to perform certain manual tasks, such as using a mouse or pressing two keys at the same time; having a tendency to hit multiple keys, or bounce fingers off keys; or inability to hold a printed book.

module

A component of the Windows 2000 operating system that has sole responsibility for its functions. An application runs in a separate module in user mode, from which it requests system services. Application processes are transferred to one or more modules in kernel mode (protected), where the actual service is provided.

more fragments flag

A field in the Internet Protocol (IP) header that indicates that more fragments follow this fragment.

MouseKeys

A feature in Microsoft Windows that allows use of the numeric keyboard to move the mouse pointer.

mouthstick

An alternative assistive input device for users with physical impairments.

MS-DOS-based application

An application that is designed to run with MS-DOS and therefore, might not be able to take full advantage of all Windows 2000 features.

multicast

Network traffic destined for a set of hosts that belong to a multicast group. See also multicast group.

multicast address dynamic client allocation protocol (MADCAP)

An extension to the DHCP protocol standard used to support dynamic assignment and configuration of IP multicast addresses on TCP/IP-based networks.

multicast address resolution service (MARS)

A service for resolving multicast IP addresses to the ATM addresses of the clients that have joined that multicast group. The MARS can work in conjunction with the multicast server MCS and clients to distribute multicast data through point-to-multipoint connections.

multicast DHCP (MDHCP)

An extension to the DHCP protocol standard that supports dynamic assignment and configuration of IP multicast addresses on TCP/IP-based networks.

multicast forwarding table

The table used by IP to forward IP multicast traffic. An entry in the IP multicast forwarding table consists of the multicast group address, the source IP address, a list of interfaces to which the traffic is forwarded (next hop interfaces), and the single interface on which the traffic must be received in order to be forwarded (the previous hop interface).

multicast group

A group of member TCP/IP hosts configured to listen and receive datagrams sent to a specified destination IP address. The destination address for the group is a shared IP address in the Class D address range (224.0.0.0 to 2239.255.255.255). See also datagram.

multicast heartbeat

The ability of the Windows 2000 router to listen for a regular multicast notification to a specified group address.

multicast promiscuous mode

A listening mode that passes up for processing all frames that have the IEEE-defined multicast bit set to 1.

multicast routing protocol

Protocols such as Distance Vector Multicast Routing Protocol (DVMRP), Multicast Open Shortest Path First (MOSPF), or Protocol Independent Multicast (PIM) used to exchange IP multicast host membership information. Group membership is either communicated explicitly, by exchanging [group address, subnet] information, or implicitly, by informing upstream routers that there either are or are not group members in the downstream direction from the source of the multicast traffic.

multicast scope

A range of IP multicast addresses in the range of 239.0.0.0 to 239.254.255.255. Multicast addresses in this range can be prevented from propagating in either direction (send or receive) through the use of scope-based multicast boundaries.

multicast static route

A static route used to determine the previous hop interface for IP multicast forwarding table entries and the previous hop neighbor used for multicast diagnostic utilities such as mtrace.

multihomed computer

A computer that has multiple network adapters or that has been configured with multiple IP addresses for a single network adapter.

multilingual APIs

Application programming interfaces used to support multiple languages in Windows 2000.

multilink protocol (MP)

An extension to PPP that is used to aggregate multiple physical links into a single logical link. MP is defined in RFC 1990.

multimaster replication

A system of replication in which all replicas of a given directory partition are writable, allowing updates to be applied to any replica. Active Directory uses a multimaster replication system, and replicates the changes from a given replica to all other replicas automatically and transparently. All replicas are not necessarily fully consistent at all times. This model differs from other replication models in which one computer stores the single modifiable copy of the directory and other computers store backup copies. See also domain controller; replication; loose consistency.

multinetting

The practice of using multiple logical subnets on the same physical network.

multipath routing infrastructure

A routing infrastructure where multiple paths exist between network segments in the internetwork.

multiple provider router (MPR)

A software component that supports Win32 network API requests for redirectors and passes them to the appropriate redirector.

multiple universal naming convention provider (MUP)

A mechanism that chooses the appropriate redirector when an application attempts to resolve a universal naming convention (UNC) name.

multiple-master replication

The process by which Windows 2000 domain controllers replicate domain data. The primary domain controller emulator replicates the domain data to the other domain controllers. See primary domain controller emulator.

Multipurpose Internet Mail Extensions (MIME)

A common method for transmitting non-text data through Internet e-mail. MIME encodes non-text data as ASCII text and then decodes it back to its original format at the receiving end. A MIME header is added to the file which includes the type of data contained and the encoding method used. See also Secure/Multipurpose Internet Mail Extensions (S/MIME).

multithreading

The ability of an operating system to run several processes at the same time to handle multiple tasks.

mustContain

A multi-valued property that specifies the attributes that must be present on instances of this class. These are mandatory attributes that must be present during creation and cannot be cleared after creation. After creation of the class, this attribute cannot be changed.

Each value is the lDAPDisplayName of an attribute. You must ensure that the attributes exist or will exist when the new class is written to the directory. If one of the attributes does not exist, the classSchema object will fail to be added to the directory.

The full set of mandatory attributes for this class is the union of the systemMustContain and mustContain on this class as well as the systemMustContain and mustContain properties of all inherited classes.

mutual authentication

The process when the calling router authenticates itself to the answering router and the answering router authenticates itself to the calling router. Both ends of the connection verify the identity of the other end of the connection. MS-CHAP v2 and EAP-TLS authentication methods provide mutual authentication.