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L
L2TP (Layer 2 Tunneling
Protocol)
An industry-standard
Internet tunneling protocol. Unlike Point-to-Point Tunneling Protocol
(PPTP), L2TP does not require IP connectivity between the client
workstation and the server. L2TP requires only that the tunnel medium
provide packet-oriented point-to-point connectivity. The protocol can be
used over media such as ATM, Frame Relay, and X.25. L2TP provides the same
functionality as PPTP. Based on Layer 2 Forwarding (L2F) and PPTP
specifications, L2TP allows clients to set up tunnels across intervening
networks.
label
Each part of a full DNS
domain name that represents a node in the domain namespace tree. Domain
names are made up of a sequence of labels, such as the three labels
(example, microsoft, and com) that make up the DNS
domain name example.microsoft.com. Each label used in a DNS name
must be 63 bytes or less in character length.
LAN emulation
(LANE)
A set of protocols that
allow existing Ethernet and Token Ring LAN services to overlie an ATM
network. LANE allows connectivity among LAN- and ATM-attached
stations.
LAN emulation client
(LEC)
The client on an ELAN
that performs data forwarding, address resolution, and other control
functions. The LEC resides on end stations in an
ELAN.
LAN emulation configuration
server
The service that assigns
individual local area network emulation (LANE) clients to particular
emulated local area networks (ELANs) by directing them to the LAN
emulation server (LES).
LAN emulation server
(LES)
The central control point
for an emulated local area network (ELAN). Enables LAN emulation clients
to join the ELAN and resolves LAN addresses to ATM
addresses.
latency
In Active Directory
replication, the delay between the time an update is applied to a given
replica and the time it is applied to some other replica. Latency is
sometimes referred to as propagation delay.
LCD (Liquid Crystal
Display)
LDAP Data Interchange Format
(LDIF)
Files that contain LDAP
instructions that manipulate directory information. Before the LDAP
commands in an LDIF file are carried out, they can be read or modified,
providing an opportunity for fine-tuning.
lease
The length of time for
which a DHCP client can use a dynamically assigned IP address
configuration. Before the lease time expires, the client must either renew
or obtain a new lease with DHCP.
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.
Lightweight Directory Access
Protocol (LDAP)
The primary access
protocol for Active Directory. Lightweight Directory Access Protocol
(LDAP) version 3 is defined by a set of Proposed Standard documents in
Internet Engineering Task Force (IETF) RFC 2251.
Line Printer Daemon
(LPD)
A service on the print
server that receives documents (print jobs) from Line Printer Remote (LPR)
utilities running on client systems.
Line Printer Remote
(LPR)
A connectivity utility
that runs on client systems and is used to print files to a computer
running an LPD server.
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.
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. If you want to edit the
linked information, double-click it. The toolbars and menus from the
original program will appear. If the original document is on your
computer, changes that you make to the linked information will also appear
in the original document.
liquid crystal display
(LCD)
A type of display used in
digital watches and many portable computers. LCD displays utilize two
sheets of polarizing material with a liquid crystal solution between them.
An electric current passed through the liquid causes the crystals to align
so that light cannot pass through them. Each crystal, therefore, is like a
shutter, either allowing light to pass through or blocking the
light.
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 this version of
Windows, the file is stored in the systemroot\System32\Drivers\Etc
folder.
load
balancing
A technique used by
Windows Clustering to scale the performance of a server-based program
(such as a Web server) by distributing its client requests across multiple
servers within the cluster. 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.
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.
local
computer
The computer that you are
currently logged on to as a user. More generally, a local computer is a
computer that you can access directly without using a communications line
or a communications device, such as a network adapter or a
modem.
local
group
For computers running
Windows and member servers, a group that can be granted permissions and
rights from its own computer and (if the computer participates in a
domain) user accounts and global groups both from its own domain and from
trusted domains.
local
printer
A printer that is
directly connected to one of the ports on your
computer.
local user
A person who uses a
computer that is not connected to a network. A local user is most
likely someone using a computer at home.
local user
profile
A computer-based record
about an authorized user that is created automatically on the computer the
first time a user logs on to a workstation or server
computer.
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 plain text (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 on
To begin using a network
by providing a user name and password that identifies a user to the
network.
logical
drive
A volume that you create
within an extended partition on a basic master boot record (MBR) disk.
Logical drives are similar to primary partitions, except that you are
limited to four primary partitions per disk, whereas you can create an
unlimited number of logical drives per disk. A logical drive can be
formatted and assigned a drive letter.
logical
printer
The software interface
between the operating system and the printer in Windows. 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 you
print a document, it is spooled (or stored) on the logical printer before
it is sent to the printer itself.
logon
right
A user right that is
assigned to a user and that specifies the ways in which a user can log on
to a system. An example of a logon right is the right to log on to a
system remotely.
logon
script
Files that can be
assigned to user accounts. Typically a batch file, a logon script runs
automatically every time the user logs on. It can be used to configure a
user's working environment at every logon, and it allows an administrator
to influence a user's environment without managing all aspects of it. A
logon script can be assigned to one or more user
accounts.
logon script
path
A sequence of directory
names that specifies the location of the logon script. When a user logs
on, the authenticating computer locates the specified logon script (if one
has been assigned to that user account) by following that computer's local
logon script path (usually
systemroot\System32\Repl\Import\Scripts).
long distance
operator
Digits dialed before the
area or city code to access a long distance phone service. For example, in
the United States of America, you dial a 1 before the area or city code:
(1) (206) 000-0000. The actual digits depend on the country/region or
phone service. Area codes and long distance operators are not used in all
countries/regions.
long name
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. This version of Windows supports long file names up to
255 characters.
In a Macintosh
environment, users can assign long names to files and folders on the
server and, using AppleTalk network integration, you can assign long names
to Macintosh-accessible volumes when you create them. This version of
Windows automatically translates long names of files and folders to 8.3
names for MS-DOS and Windows 3.x users.
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.
loose name
checking
A form of domain name
checking DNS uses that examines characters in DNS names for valid ANSI
character compliance. However, loose name checking does not check for
compliance with DNS naming requirements and valid character usage for
Internet host names, as specified in RFC 1123, Requirements for
Internet Hosts - Applications and Support.
For RFC compliance, DNS
domain names will use name labels made up only of valid uppercase and
lowercase letters, number characters, and hyphens (A through Z, a through
z, 0 through 9, and -) separated by periods.
luminosity
The brightness of a color
based on a scale from black to white on your
monitor.
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