Access Control List

A detailed list of permissions granted to users or groups with respect to file and network resource access.

Active Directory Service

A service unique to Microsoft Windows 200x servers that provides a centrally managed directory for management of user identities and computer objects, as well as the permissions each user or computer may be granted to access distributed network resources. ADS uses Kerberos-based authentication and LDAP over Kerberos for directory access.

Common Internet File System

The new name for SMB. Microsoft renamed the SMB protocol to CIFS during the Internet hype in the 1990s. At about the time that the SMB protocol was renamed to CIFS, an additional dialect of the SMB protocol was in development. The need for the deployment of the NetBIOS layer was also removed, thus paving the way for use of the SMB protocol natively over TCP/IP (known as NetBIOS-less SMB or “naked” TCP transport).

Common UNIX Printing System

A recent implementation of a high-capability printing system for UNIX developed by Easy Software Inc.. The design objective of CUPS was to provide a rich print processing system that has built-in intelligence that is capable of correctly rendering (processing) a file that is submitted for printing even if it was formatted for an entirely different printer.

Domain Master Browser

The Domain Master Browser maintains a list of all the servers that have announced their services within a given workgroup or NT domain.

Domain Name Service

A protocol by which computer hostnames may be resolved to the matching IP address/es. DNS is implemented by the Berkeley Internet Name Daemon. There exists a recent version of DNS that allows dynamic name registration by network clients or by a DHCP server. This recent protocol is known as dynamic DNS (DDNS).

Dynamic Host Configuration Protocol

A protocol that was based on the BOOTP protocol that may be used to dynamically assign an IP address, from a reserved pool of addresses, to a network client or device. Additionally, DHCP may assign all network configuration settings and may be used to register a computer name and its address with a dynamic DNS server.


A network analyzer, also known as a network sniffer or a protocol analyzer. Ethereal is freely available for UNIX/Linux and Microsoft Windows systems from the Ethereal Web site.

Group IDentifier

The UNIX system group identifier; on older systems, a 32-bit unsigned integer, and on newer systems, an unsigned 64-bit integer. The GID is used in UNIX-like operating systems for all group-level access control.

Key Distribution Center

The Kerberos authentication protocol makes use of security keys (also called a ticket) by which access to network resources is controlled. The issuing of Kerberos tickets is effected by a KDC.

Lightweight Directory Access Protocol

The Lightweight Directory Access Protocol is a technology that originated from the development of X.500 protocol specifications and implementations. LDAP was designed as a means of rapidly searching through X.500 information. Later LDAP was adapted as an engine that could drive its own directory database. LDAP is not a database per se; rather it is a technology that enables high-volume search and locate activity from clients that wish to obtain simply defined information about a subset of records that are stored in a database. LDAP does not have a particularly efficient mechanism for storing records in the database, and it has no concept of transaction processing nor of mechanisms for preserving data consistency. LDAP is premised around the notion that the search and read activity far outweigh any need to add, delete, or modify records. LDAP does provide a means for replication of the database to keep slave servers up to date with a master. It also has built-in capability to handle external references and deferral.

Local Master Browser

The Local Master Browser maintains a list of all servers that have announced themselves within a given workgroup or NT domain on a particular broadcast isolated subnet.

Media Access Control

The hard-coded address of the physical-layer device that is attached to the network. All network interface controllers must have a hard-coded and unique MAC address. The MAC address is 48 bits long.

NetBIOS Extended User Interface

Very simple network protocol invented by IBM and Microsoft. It is used to do NetBIOS over Ethernet with low overhead. NetBEUI is a non-routable protocol.

Network Address Translation

Network address translation is a form of IP address masquerading. It ensures that internal private (RFC1918) network addresses from packets inside the network are rewritten so that TCP/IP packets that leave the server over a public connection are seen to come only from the external network address.

Network Basic Input/Output System

NetBIOS is a simple application programming interface (API) invented in the 1980s that allows programs to send data to certain network names. NetBIOS is always run over another network protocol such as IPX/SPX, TCP/IP, or Logical Link Control (LLC). NetBIOS run over LLC is best known as NetBEUI (the NetBIOS Extended User Interface a complete misnomer!).


Protocol for transporting NetBIOS frames over TCP/IP. Uses ports 137, 138, and 139. NetBT is a fully routable protocol.

NT/LanManager Security Support Provider

The NTLM Security Support Provider (NTLMSSP) service in Windows NT4/200x/XP is responsible for handling all NTLM authentication requests. It is the front end for protocols such as SPNEGO, Schannel, and other technologies. The generic protocol family supported by NTLMSSP is known as GSSAPI, the Generic Security Service Application Program Interface specified in RFC2078.

Server Message Block

SMB was the original name of the protocol spoken by Samba. It was invented in the 1980s by IBM and adopted and extended further by Microsoft. Microsoft renamed the protocol to CIFS during the Internet hype in the 1990s.

The Simple and Protected GSS-API Negotiation

The purpose of SPNEGO is to allow a client and server to negotiate a security mechanism for authentication. The protocol is specified in RFC2478 and uses tokens as built via ASN.1 DER. DER refers to Distinguished Encoding Rules. These are a set of common rules for creating binary encodings in a platform-independent manner. Samba has support for SPNEGO.

The Official Samba-3 HOWTO and Reference Guide, Second Edition

This book makes repeated reference to “The Official Samba-3 HOWTO and Reference Guide, Second Edition” by John H. Terpstra and Jelmer R. Vernooij. This publication is available from Publisher: Prentice Hall PTR (August 2005), ISBN: 013122282.

User IDentifier

The UNIX system user identifier; on older systems, a 32-bit unsigned integer, and on newer systems, an unsigned 64-bit integer. The UID is used in UNIX-like operating systems for all user-level access control.

Universal Naming Convention

A syntax for specifying the location of network resources (such as file shares). The UNC syntax was developed in the early days of MS DOS 3.x and is used internally by the SMB protocol.