L

label

In DNS, each part of a DNS domain name that represents a node in the domain namespace tree. For example, the three labels example , microsoft , and com make up the DNS domain name example.microsoft.com . Each label used in a DNS name cannot exceed 63 octets, 255 bytes including the terminating dot, for the fully qualified domain name (FQDN). See also domain name; Domain Name System (DNS); fully qualified domain name (FQDN).

Layer Two Tunneling Protocol (L2TP)

An industry-standard Internet tunneling protocol that provides encapsulation for sending Point-to-Point Protocol (PPP) frames across packet-oriented media. For IP networks, L2TP traffic is sent as User Datagram Protocol (UDP) messages. In Microsoft operating systems, L2TP is used in conjunction with Internet Protocol security (IPSec) as a virtual private network (VPN) technology to provide remote access or router-to-router VPN connections. L2TP is described in RFC 2661. See also Internet Protocol security (IPSec); Point-to- Point Protocol (PPP); tunnel.

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. See also Dynamic Host Configuration Protocol (DHCP); IP address.

Lightweight Directory Access Protocol (LDAP)

The primary access protocol for Active Directory. LDAP is an industry-standard protocol, established by the Internet Engineering Task Force (IETF), that allows users to query and update information in a directory service. Active Directory supports both LDAP version 2 and LDAP version 3. See also Active Directory; Internet Engineering Task Force (IETF); protocol.

Lmhosts file

A local text file that maps network basic input/output (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, this file is stored in the systemroot \System32\Drivers\Etc folder. See also host; IP address; network basic input/output system (NetBIOS); systemroot.

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 enables any connected device to interact with any other on the network. See also network basic input/output system (NetBIOS); virtual local area network (VLAN).

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

A security group that can be granted rights and permissions on only resources on the computer on which the group is created. Local groups can have any user accounts that are local to the computer as members , as well as users, groups, and computers from a domain to which the computer belongs. See also global group; member server; user account.

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.

See also service.

logon script

A file, typically a batch file, that runs automatically every time a user logs on to a computer or network. It can be used to configure a user s working environment whenever a user logs on, 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. See also user account.

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 file allocation table (FAT) file system. This version of Windows supports file names up to 255 characters and automatically translates long names of files and folders to 8.3 names for MS-DOS and Windows 3. x users. In a Macintosh environment, users can assign names up to 31 characters, excluding colons, to files and folders. See also file allocation table (FAT).