- SA
- See Security Association.
- SAP table
- The service and IPX internetwork address information is collected in a database called a SAP table by IPX routers and Novell NetWare servers.
- scalability
- A measure of how well a computer, service, or application can expand to meet increasing performance demands. For server clusters, the ability to incrementally add one or more systems to an existing cluster when the overall load of the cluster exceeds its capabilities.
- scaling
- The process of adding processors to a system to achieve higher throughput.
- scavenging
- The process of cleaning and removing extinct or outdated name data from the WINS database.
- schema
- The universe of objects that can be stored in the directory is defined in the schema. For each object class, the schema defines what attributes an instance of the class must have, what additional attributes it may have, and what object class can be a parent of the current object class.
The Active Directory schema is implemented as a set of object class instances stored in the directory. This is very different than many directories which have a schema but store it as a text file read at startup. Storing the schema in the directory has many advantages. For example, user applications can read it to discover what objects and properties are available.
The Active Directory schema can be updated dynamically. That is, an application can extend the schema with new attributes and classes and use the extensions immediately. Schema updates are accomplished by creating or modifying the schema objects stored in the directory. Like every object in the Active Directory, schema objects are protected by ACLs, so only authorized users may alter the schema.
- schema cache
- All changes made to Active Directory are validated first against the schema. For performance reasons, this validation takes place against a version of the schema that is held in memory on the domain controllers. This "in-memory version," called the schema cache, is updated automatically after the on-disk version has been updated. The schema cache provides mapping between attribute identifiers, such as a database column identifier or a MAPI identifier, and the in-memory structures that describe those attributes. The schema cache also provides lookups for class identifiers to get in-memory structures describing those classes.
- schema master role
- The domain controller that holds the schema master role is the only domain controller that can perform write operations to the directory schema. Those schema updates are replicated from the schema master to all other domain controllers in the forest.
- schemaIDGUID
- A GUID that uniquely identifies the attribute. It is recommended that you generate your own GUID for each attribute so that all installations of your schema extension use the same schemaIDGUID to refer to the attribute. If no value is specified, Active Directory generates a GUID.
- script
- A type of program consisting of a set of instructions to an application or utility program. A script usually expresses instructions by using the application's or utility's rules and syntax, combined with simple control structures such as loops and if/then expressions. "Batch program" is often used interchangeably with "script" in the Windows environment.
- search base
- In an LDAP search, the distinguished name of the search base object, which defines the location in the directory from which to begin searching.
- search filter
- An argument in an LDAP search that allows certain entries in the subtree and excludes others. Filters allow you to define search criteria and give you better control to achieve more effective and efficient searches.
- search scope
- Defines how deep to search within the search base. Base, or zero levels, searches the base object only (a read of that object). One level searches objects immediately subordinate to the base object, but not including the base object itself. Subtree searches the entire subtree of which the base distinguished name is the topmost object, including that base object. Also called a deep search.
- searchFlags
- An integer value that contains bit flags. The attribute is indexed if the least significant bit is set to 1, or non-indexed if the bit is zero. The searchFlags property of each property's attributeSchema object defines whether a property is indexed (indexed has a value of 1; nonindexed is 0).
The four currently defined bits for this attribute are as follows:
1 = Index over attribute only;
2 = Index over container and attribute;
4 = Add this attribute to the Ambiguous Name Resolution (ANR) set (should be used in conjunction with 1);
8 = Preserve this attribute on logical deletion (that is, make this attribute available on tombstones).
- second-level domain
- A domain in the Domain Name System (DNS) that is immediately under a top--level domain.
- secondary server
- An authoritative DNS server for a zone that is used as a source for replication of the zone to other servers. Secondary masters only update their zone data by transferring zone data from other DNS servers and do not have the ability to perform zone updates. See also master server; zone transfer.
- secondary storage
- A storage device used to store data that has been migrated from managed volumes. Secondary storage includes the part of the hard disk that is used for a migration staging area.
- secondary zone
- A copy of the zone that must be replicated from a server containing the primary zone.
- secret key
- An encryption key that two parties share with each other and with no one else. See also symmetric key encryption.
- secure dynamic update
- The process by which a secure dynamic update client submits a dynamic update request to a DNS server, and the server attempts the update only if the client can prove its identity and has the proper credentials to make the update. See also dynamic update.
- secure electronic transaction (SET)
- A standard protocol that is used for securing online credit card payments that are made over the Internet.
- Secure Sockets Layer (SSL)
- A proposed open standard developed by Netscape Communications for establishing a secure communications channel to prevent the interception of critical information, such as credit card numbers. Primarily, it enables secure electronic financial transactions on the World Wide Web, although it is designed to work on other Internet services as well.
- Secure/Multipurpose Internet Mail Extensions (S/MIME)
- An extension of MIME to support secure mail. It enables message originators to digitally sign e-mail messages to provide proof of message origin and data integrity. It also enables messages to be transmitted in encrypted format to provide confidential communications. See also Multipurpose Internet Mail Extensions (MIME).
- Security Accounts Manager (SAM)
- A protected subsystem that manages user and group account information. In Windows NT 4.0, both local and domain security principals are stored by SAM in the registry. In Windows 2000, workstation security accounts are stored by SAM in the local computer registry, and domain controller security accounts are stored in Active Directory.
- security administrator
- A user who has been assigned the right to manage auditing and the security log. By default, this user right is granted to the Administrators group. See also auditing; system access control list (SACL); user rights.
- security association (SA)
- A set of parameters that defines the services and mechanisms necessary to protect Internet Protocol security communications. See also Internet Protocol security (IPSec).
- security context
- The security attributes or rules that are currently in effect. For example, the rules that govern what a user can do to a protected object are determined by security information in the user's access token and in the object's security descriptor. Together, the access token and the security descriptor form a security context for the user's actions on the object. See also access token; security descriptor.
- security descriptor
- A data structure that contains security information associated with a protected object. Security descriptors include information about who owns the object, who may access it and in what way, and what types of access will be audited. See also access control list; object.
- security groups
- Groups that can be used to administer permissions for users and other domain objects.
- security ID (SID)
- A data structure of variable length that uniquely identifies user, group, service, and computer accounts within an enterprise. Every account is issued a SID when the account is first created. Access control mechanisms in Windows 2000 identify security principals by SID rather than by name. See also relative ID; security principal.
- security method
- A process that determines the Internet Protocol security services, key settings, and algorithms that will be used to protect the data during the communication.
- Security Parameters Index (SPI)
- A unique, identifying value in the SA used to distinguish among multiple security associations existing at the receiving computer.
- security principal
- An account-holder, such as a user, computer, or service. Each security principal within a Windows 2000 domain is identified by a unique security ID (SID). When a security principal logs on to a computer running Windows 2000, the Local Security Authority (LSA) authenticates the security principal's account name and password. If the logon is successful, the system creates an access token. Every process executed on behalf of this security principal will have a copy of its access token. See also access token; security ID; security principal name.
- security principal name
- A name that uniquely identifies a user, group, or computer within a single domain. This name is not guaranteed to be unique across domains. See also security principal.
- Security Reference Monitor
- A subsystem that is the primary authority for enforcing access control on a computer running Windows 2000 or Windows NT.
- security subsystem
- See Local Security Authority (LSA).
- security template
- A physical file representation of a security configuration that can be applied to a local computer or imported to a Group Policy object in Active Directory. When you import a security template to a Group Policy object, Group Policy processes the template and makes the corresponding changes to the members of that Group Policy object, which can be users or computers.
- seed router
- In the Macintosh environment, a router which initializes and broadcasts routing information about one or more physical networks. This information tells routers where to send each packet of data. On an AppleTalk network, a seed router initially defines the network numbers and zones for a network. Services for Macintosh servers, and third-party hardware routers can function as seed routers.
- seek time
- The amount of time required for a disk head to position itself at the right disk cylinder to access requested data.
- selective acknowledgement (SACK)
- A Transmission Control Protocol (TCP) option that allows the receiver to re-request only the missing data from the sender.
- sender
- A Systems Management Server thread component that uses an existing connectivity system to communicate among sites. A sender manages the connection, ensures the integrity of transferred data, recovers from errors, and closes connections when they are no longer needed.
- Sequenced Packet Exchange (SPX)
- A transport layer protocol built on top of IPX.
- SerialKeys
- A Windows feature that uses a communications aid interface device to allow keystrokes and mouse controls to be accepted through a computer's serial port.
- server
- A computer that provides shared resources to network users.
- Server Announcement
- A specific datagram generated by computers on Microsoft networks to announce their presence on the network to master browsers.
- server cluster
- A cluster created and administered by the Cluster service and associated software (.exe and .dll files), between whose nodes the Cluster service provides failover support for applications running on the servers. The server cluster includes the hardware and the cluster configuration as well as the Cluster service. See also cluster; node.
- Server Cluster API
- The collection of functions that are implemented by the Cluster service and used by cluster-aware applications, cluster management applications, and resource DLLs. The Server Cluster API includes functions for managing server cluster objects and the cluster database.
- Server Message Block (SMB)
- A file-sharing protocol designed to allow networked computers to transparently access files that reside on remote systems over a variety of networks. The SMB protocol defines a series of commands that pass information between computers. SMB uses four message types: session control, file, printer, and message.
- Server service
- A software component that provides RPC (remote procedure call) support and file, print, and Named Pipe sharing. See also Named Pipe; remote procedure call (RPC).
- service
- A program, routine, or process that performs a specific system function to support other programs, particularly at a low (close to the hardware) level. When services are provided over a network, they can be published in Active Directory, facilitating service-centric administration and usage.
- service (SRV) resource record
- A resource record used in a zone to register and locate well-known TCP/IP services. The SRV resource record is specified in RFC 2052 and is used in Windows 2000 to locate domain controllers for Active Directory service. See also resource record.
- service access point
- A logical address that allows a system to route data between a remote device and the appropriate communications support.
- service level agreement (SLA)
- A contract between your IT group and users that specifies what performance levels are acceptable for services, such as equipment replacement and network downtime.
- service name
- The name by which a port is known.
- service ticket
- See session ticket.
- session
- In the context of load balancing TCP/IP traffic, a set of client requests directed to a server. These requests can be invoked with multiple, possibly concurrent, TCP connections. The server program sometimes maintains state information between requests. To preserve access to the server state, Network Load Balancing needs to direct all requests within a session to the same cluster host when load balancing. See also client request; server; TCP/IP.
- session key
- A key used primarily for encryption and decryption. Session keys are typically used with symmetric encryption algorithms where the same key is used for both encryption and decryption. For this reason, session and symmetric keys usually refer to the same type of key. See also symmetric key encryption.
- session layer
- A network layer that allows two applications on different computers to establish, use, and end a session. This layer establishes dialog control between the two computers in a session, regulating which side transmits, as well as when and how long it transmits.
- session ticket
- A credential presented by a client to a service in the Kerberos authentication protocol. Because session tickets are used to obtain authenticated connections to services, they are sometimes called service tickets. See also Kerberos authentication protocol; Key Distribution Center (KDC).
- sessions
- A logical connection created between two hosts to exchange data. Typically, sessions use sequencing and acknowledgments to send data reliably.
- share name
- A name that refers to a shared resource on a server. Each shared folder on a server has a share name used by personal computer users to refer to the folder. Users of Macintosh computers use the name of the Macintosh-accessible volume that corresponds to a folder, which may be the same as the share name. See also Macintosh-accessible volume.
- shared nothing
- A scalability concept in clusters and SMP systems whereby a workload is partitioned among available hardware resources. These resources are used on the workload independently, without sharing of processors, disks, or other hardware resources.
- shared printer
- A printer that receives input from more than one computer. For example, a printer attached to another computer on the network can be shared so that it is available for many users. Also called a network printer.
- shell
- The command interpreter that is used to pass commands to the operating system.
- Shiva Password Authentication Protocol (SPAP)
- A two-way, reversible encryption mechanism for authenticating PPP connections employed by Shiva remote access servers.
- short name
- A valid MS-DOS or OS/2 8.3 file name (with up to 8 characters followed by a period and an extension of up to 3 characters) that a computer running Windows 2000 Server creates for every Macintosh folder name or file name on the server. Personal computer users refer to files on the server by their short names; Macintosh users refer to them by their long names. See also name mapping.
- shortcut trust
- A two-way trust relationship that is explicitly created between two Windows 2000 domains in the same forest. The purpose of a shortcut trust is to optimize the inter-domain authentication process by shortening the trust path. All shortcut trusts are transitive and must be created manually in each direction. See also domain tree; forest; transitive trust relationship.
- ShowSounds
- A global flag that instructs programs to display captions for speech and system sounds to alert users with hearing impairments or people who work in a noisy location such as a factory floor.
- silent discard
- When a packet is discarded and the sending host is not informed as to why the packet was discarded.
- silent RIP
- The capability of a computer to listen for and process Routing Information Protocol (RIP) announcements but without announcing its own routes.
- Simple Mail Transfer Protocol (SMTP)
- A protocol used on the Internet to transfer mail. SMTP is independent of the particular transmission subsystem and requires only a reliable, ordered, data stream channel.
- Simple Network Management Protocol (SNMP)
- A network management protocol installed with TCP/IP and widely used on TCP/IP and Internet Package Exchange (IPX) networks. SNMP transports management information and commands between a management program run by an administrator and the network management agent running on a host. The SNMP agent sends status information to one or more hosts when the host requests it or when a significant event occurs.
- single point of failure
- Any component in your environment that would block data or applications if it failed.
- single-path routing infrastructure
- A routing infrastructure where only a single path exists between any two network segments in the internetwork.
- sip-and-puff device
- An alternative input device that allows a user to operate a computer by breath control. For users who are unable to use standard input devices, such as a mouse or keyboard.
- site
- A location in a network that holds Active Directory servers. A site is defined as one or more well-connected TCP/IP subnets. ("Well-connected" means that network connectivity is highly reliable and fast-for example, LAN speeds of 10 MM bits-per-second or greater) Because computers in the same site are close to each other in network terms, communication among them is reliable, fast, and efficient. Defining a site as a set of subnets allows administrators to configure Active Directory access and replication topology to take advantage of the physical network. When users log on to the network, Active Directory clients find Active Directory servers in the same site as the client. In Systems Management Server, site servers and client computers bounded by a group of subnets, such as an IP subnet or an IPX network number. See also domain controller locator; subnet; replication topology.
- site link
- An Active Directory object that represents a set of sites that can communicate at uniform cost through some intersite transport. For IP transport, a typical site link connects just two sites and corresponds to an actual WAN link. An IP site link connecting more than two sites might correspond to an ATM backbone connecting more than two clusters of buildings on a large campus, or several offices in a large metropolitan area connected via leased lines and IP routers. See also connection object; site link bridge.
- site link bridge
- An Active Directory object that represents a set of site links, all of whose sites can communicate via some transport. Typically a site link bridge corresponds to a router (or a set of routers) in an IP network. By default, the Knowledge Consistency Checker may form a route through any and all site links in a transitive manner. If this behavior is turned off, each site link represents its own distinct and isolated network. Sets of site links that can be treated as a single route are expressed through a site link bridge. Each bridge represents an isolated communication environment for network traffic.
- site server
- A computer running Windows NT Server on which Systems Management Server (SMS) site setup has been run. When SMS is installed on a computer, that computer is assigned the site server role. The site server, which hosts SMS components needed to monitor and manage an SMS site, typically performs several additional SMS roles, including component server, client access point, and distribution point.
- slave
- A server that does not attempt to resolve queries on its own. Instead, it sends all queries to forwarders. See also forwarder.
- slow link processing
- A configurable Group Policy processing mode that allows administrators to define which Group Policy settings will not be processed over slow network links.
- SlowKeys
- A Windows feature that instructs the computer to disregard keystrokes that are not held down for a minimum period of time, which allows the user to brush against keys without any effect. See also FilterKeys.
- Small Computer System Interface (SCSI)
- A standard high-speed parallel interface defined by the X3T9.2 committee of the American National Standards Institute (ANSI). A SCSI interface is used for connecting microcomputers to peripheral devices, such as hard disks and printers, and to other computers and local area networks.
- Small Office/Home Office (SOHO)
- An office with a few computers that can be considered a small business or part of a larger network.
- smart card
- A credit card-sized device that is used with a PIN number to enable certificate-based authentication and single sign-on to the enterprise. Smart cards securely store certificates, public and private keys, passwords, and other types of personal information. A smart card reader attached to the computer reads the smart card. See also authentication; certificate; nonrepudiation.
- smart-card reader
- A device that is installed in computers to enable the use of smart cards for enhanced security features. See also smart card.
- SMTP
- See Simple Mail Transfer Protocol.
- sniffer
- An application or device that can read, monitor, and capture network data exchanges and read network packets. If the packets are not encrypted, a sniffer provides a full view of the data inside the packet.
- SNMP
- See Simple Network Management Protocol.
- SNMP Management Console
- The interface through which a manager, either a user or a program, performs management activities.
- SOA (start of authority) resource record
- See start of authority (SOA) resource record.
- socket
- A bidirectional pipe for incoming and outgoing data between networked computers. The Windows Sockets API is a networking API used by programmers to create TCP/IP-based sockets programs.
- soft affinity
- A mechanism designed to optimize performance in a multiprocessor environment. Soft affinity favors scheduling threads on the processor in which they recently ran or the ideal processor for the thread. With soft affinity, the efficiency of the processor cache is higher because threads often run on the processor on which they previously ran. Soft affinity does not restrict a thread to run on a given processor.
- software inventory
- In Systems Management Server, the automated process that SMS uses to gather information about software on client computers.
- software metering
- In Systems Management Server, the process by which SMS monitors and manages the use of software applications to ensure compliance with software licensing agreements or to understand software usage.
- software router
- A router that is not dedicated to performing routing but performs routing as one of multiple processes running on the router computer.
- software trap
- In programming, an event that occurs when a microprocessor detects a problem with executing an instruction, which causes it to stop.
- SoundSentry
- A Windows feature that produces a visual cue, such as a screen flash or a blinking title bar instead of system sounds.
- source routing
- The practice of specifying the list of networks or routers in the network layer header to forward a packet along a specific path in an internetwork.
- sparse file
- A file that is handled in a way that requires less disk space than would otherwise be needed by allocating only meaningful non-zero data. Sparse support allows an application to create very large files without committing disk space for every byte.
- speech synthesizer
- An assistive device that produces spoken words, either by splicing together prerecorded words or by programming the computer to produce the sounds that make up spoken words.
- split horizon
- A route-advertising algorithm that prevents the advertising of routes in the same direction in which they were learned. Split horizon helps prevent routing loops. See also poison reverse.
- spooling
- A process on a server in which print documents are stored on a disk until a printer is ready to process them. A spooler accepts each document from each client, stores it, and sends it to a printer when the printer is ready.
- SRV (service) resource record
- See service (SRV) resource record.
- stand-alone certification authority
- A Windows 2000 certification authority that is not integrated with Active Directory. See also certification authority; enterprise certification authority.
- stand-alone Dfs
- Implementation of Dfs that stores its configuration in the local registry. It is intended for backward compatibility with previous versions of Dfs. A stand-alone Dfs root has the following characteristics: it does not use Active Directory (or FRS file replication) and it cannot have replicas at the root level.
- stand-alone server
- A computer that runs Windows 2000 Server but does not participate in a domain. A stand-alone server has only its own database of users, and it processes logon requests by itself. It does not share account information with any other computer and cannot provide access to domain accounts. See also member server; domain controller; global group; local group.
- standard error (STDERR)
- In UNIX, the defined receiver of error messages about a process. By default, the standard error goes to the terminal.
- standard input (STDIN)
- In UNIX, the defined source of input for a process. By default, standard input comes from the terminal.
- standard output (STDOUT)
- In UNIX, the defined receiver for output from a process. By default, the standard output goes to the terminal.
- Standard TCP/IP Port Monitor
- A port monitor that connects a Windows 2000 print server to network-interface printers that use the TCP/IP protocol. It replaces LPRMON for TCP/IP printers connected directly to the network through a network adapter. Printers connected to a UNIX or VAX host that requires RFC 1179 compliance may still require LPRMON on the print server.
- start of authority (SOA) resource record
- A record that indicates the starting point or original point of authority for information stored in a zone. The SOA resource record (RR) is the first RR created when adding a new zone. It also contains several parameters used by others to determine how long other DNS servers will use information for the zone and how often updates are required. See also authoritative; zone.
- stateless
- As related to servers, not involving the update of a server-side database based on a client request. As related to the handling of files, the content of the file is not modified or noticed. For Web servers, a stateless client request, which members of a Network Load Balancing cluster can process, is one that returns a static Web page to the client.
- static router
- A router with manually configured routing tables. A network administrator, with knowledge of the internetwork topology, manually builds and updates the routing table, programming all routes in the routing table. Static routers can work well for small internetworks but do not scale well to large or dynamically changing internetworks due to their manual administration.
- static routing
- Routing limited to fixed routing tables, as opposed to dynamically updated routing tables. See also dynamic routing; routing; routing table.
- static services
- An IPX service that is permanently stored in a SAP table. Static services are advertised using normal SAP processes. Static SAP services are typically used to define the services that are available across a demand-dial connection.
- status area
- The area on the taskbar to the right of the taskbar buttons. The status area displays the time and can also contain icons that provide quick access to programs, such as Volume Control and Power Options. Other icons can appear temporarily, providing information about the status of activities. For example, the printer icon appears after a document has been sent to the printer and disappears when printing is complete.
- StickyKeys
- An accessibility feature built into Windows that causes modifier keys such as SHIFT, CTRL, WINDOWS LOGO, or ALT to stay on after they are pressed, eliminating the need to press multiple keys simultaneously. This feature facilitates the use of modifier keys for users who are unable to hold down one key while pressing another.
- Stop error
- A serious error that affects the operating system and that could place data at risk. The operating system generates an obvious message, a screen with the Stop message, rather than continuing on and possibly corrupting data. Also known as a fatal system error. See also Stop message.
- Stop message
- A character-based, full-screen error message displayed on a blue background. A Stop message indicates that the Windows 2000 kernel detected a condition from which it cannot recover. Each message is uniquely identified by a Stop error code (a hexadecimal number) and a string indicating the error's symbolic name. Stop messages are usually followed by up to four additional hexadecimal numbers, enclosed in parentheses, which identify developer-defined error parameters. A driver or device may be identified as the cause of the error. A series of troubleshooting tips are also displayed, along with an indication that, if the system was configured to do so, a memory dump file was saved for later use by a kernel debugger. See also Stop error.
- storage hierarchy
- A directed cyclic graph of linked storage pools.
- storage pool
- A unit of storage administered by Removable Storage and composed of homogenous storage media. A storage pool is a self-contained storage area with homogenous characteristics (for example, random access, sequential access, read/write, and write-once).
- storage-class resource
- A required dependency for many resource types: a resource that manages a disk in the cluster that can be accessed using a drive letter. Windows 2000 Advanced Server provides one storage-class resource: Physical Disk. However, vendors or resellers may supply other storage-class resource types. See also resource type.
- store-and-forward replication
- A replication model, used by Active Directory, in which changes are not sent directly from one domain controller to all other domain controllers. Instead, a system of replication partners is created automatically by the system, taking advantage of the existing connections. Replication through neighboring systems is also called transitive replication. See also Active Directory replication; multimaster replication.
- stream
- A sequence of bits, bytes, or other small structurally uniform units.
- Stream Input/Output (Stream I/O)
- A protocol that provides access to IBM host data one file at a time, as opposed to one record at a time, such as with Structured Query Language (SQL).
- stream socket
- A socket using the Windows Sockets API that provides a two-way, reliable, sequenced, and unduplicated flow of data.
- streaming media servers
- Software (such as Microsoft Media Technologies) that provides multimedia support, allowing you to deliver content by using Advanced Streaming Format over an intranet or the Internet.
- stripe set
- The saving of data across identical partitions on different drives. A stripe set does not provide fault tolerance; however, stripe sets with parity do provide fault tolerance. See also fault tolerance; partition; stripe set with parity; volume set.
- stripe set with parity
- A method of data protection in which data is striped in large blocks across all the disks in an array. Data redundancy is provided by the parity information. This method provides fault tolerance. See also stripe set, fault tolerance.
- striped volume
- A volume that stores data in stripes on two or more physical disks. Data in a striped volume is allocated alternately and evenly (in stripes) to these disks. Striped volumes offer the best performance of all volumes available in Windows 2000, but they do not provide fault tolerance. If a disk in a striped volume fails, the data in the entire volume is lost. You can create striped volumes only on dynamic disks. Striped volumes cannot be mirrored or extended. In Windows NT 4.0, a striped volume was known as a stripe set. See also dynamic disk, dynamic volume, fault tolerance, volume.
- structural classes
- The only classes that can have instances in the directory. That is, you can create directory objects whose class is one of the structural classes.
- structured query language (SQL)
- A widely accepted standard database sublanguage used in querying, updating, and managing relational databases.
- stub area
- An OSPF area that does not advertise individual external networks. Routing to all external networks in a stub area is done through a default route (destination 0.0.0.0 with the network mask of 0.0.0.0).
- subarea
- An area composed of one subarea node (a type 5 host node or a type 4 node [a Front End Processor]) and the resources it controls, including type 2 nodes.
- subclass
- A classSchema object that inherits from some other classSchema object. For example, a subclass inherits structure and content rules from the parent object.
- subClassOf
- The class from which this object inherits attributes. For structural classes, the subClassOf can be a structural or abstract class. For abstract classes, the subClassOf can only be an abstract class. For auxiliary classes, the subClassOf can be an abstract or auxiliary class.
The value is the lDAPDisplayName of a class. You must ensure that the class exists or will exist when the new class is written to the directory. If class does not exist, the classSchema object will fail to be added to the directory.
- subdomain
- A DNS domain located directly beneath another domain name (the parent domain) in the namespace tree. For example, "eu.reskit.com" is a subdomain of the domain "reskit.com."
- subject
- An entity acting on an object. For example, when a thread of execution opens a file, the thread is a subject and the file is the object of its action. See also object; thread.
- subkey
- In the registry, a key within a key. Subkeys are analogous to subdirectories in the registry hierarchy. Keys and subkeys are similar to the section header in .ini files; however, subkeys can carry out functions. See also key.
- subnet
- A subdivision of an IP network. Each subnet has its own unique subnetted network ID.
- subnet mask
- A 32-bit value expressed as four decimal numbers from 0 to 255, separated by periods (for example, 255.255.0.0). This number allows TCP/IP to determine the network ID portion of an IP address.
- subnetted network ID
- A network ID for a subnetted network segment that is the result of a subdivision of a TCP/IP network ID.
- subnetted reverse lookup zone
- A reverse lookup zone authoritative for only a portion of a Class C network address. Subnetted reverse lookup zones are not required even if a network is subnetted; they are merely an administrative choice. See also reverse lookup zone.
- subnetting
- The act of subdividing the address space of a TCP/IP network ID into smaller network segments, each with its own subnetted network ID.
- subordinate reference
- In Active Directory, knowledge of a partition or partitions directly below a partition held by a domain controller.
- subordinate referral
- In an LDAP search, information about a directory location that is returned by a subtree search. If a subtree search has a search base that includes child directory partitions, the domain controller uses subordinate references to return a subordinate referral to a domain controller that stores the requested partition.
- subtree search
- See search scope.
- superclass
- The class from which a subclass derives all mandatory and optional attributes in addition to those specific to the class itself.
- superior reference
- In Active Directory, knowledge about a referral location that is used when the domain controller has no knowledge of the search base.
- supernetting
- The practice of expressing a range of IP network IDs using a single IP network ID and subnet mask. Supernettting is a route aggregation and summarization technique.
- superscope
- An administrative grouping of scopes that can be used to support multiple, logical IP subnets on the same physical subnet. Superscopes contain a list of member scopes, or child scopes, that can be activated as a collection.
- switch
- A computer or other network-enabled device that controls routing and operation of a signal path. In clustering, a switch is used to connect the cluster hosts to a router or other source of incoming network connections. See also routing.
- switched virtual circuit (SVC)
- A connection established dynamically between devices on an ATM network through the use of signaling.
- symmetric interrupt distribution
- A mechanism for distributing interrupts across available processors.
- symmetric key
- A single key that is used with symmetric encryption algorithms for both encryption and decryption. See also bulk encryption; encryption; decryption; session key.
- symmetric key encryption
- An encryption algorithm that requires the same secret key to be used for both encryption and decryption. This is often called secret key encryption. Because of its speed, symmetric encryption is typically used rather than public key encryption when a message sender needs to encrypt large amounts of data.
- symmetric multiprocessing (SMP)
- A computer architecture in which multiple processors share the same memory, which contains one copy of the operating system, one copy of any applications that are in use, and one copy of the data. Because the operating system divides the workload into tasks and assigns those tasks to whatever processors are available, SMP reduces transaction time.
- symmetric-key algorithm
- A symmetric cipher that uses the same key for encryption and decryption. See also symmetric key encryption; symmetric key; public key algorithm.
- symmetric-key cryptography
- A type of cryptography that uses symmetric keys to provide confidentiality. See also cryptography; symmetric-key encryption; symmetric-key algorithm.
- Synchronization Manager
- In Windows 2000, the tool used to ensure that a file or directory on a client computer contains the same data as a matching file or directory on a server.
- Synchronized Accessible Media Interchange (SAMI)
- A format optimized for creating captions and audio descriptions in a single document.
- synchronous processing
- The default Group Policy processing mode in Windows 2000. In this default mode users cannot log on until all computer Group Policy objects have been processed and cannot begin working on their computers until all user Group Policy objects have been processed.
- Syspart
- A process that executes through an optional parameter of Winnt32.exe. Used for clean installations to computers that have dissimilar hardware. This automated installation method reduces deployment time by eliminating the file-copy phase of Setup. See automated installation.
- Sysprep
- A tool that prepares the hard disk on a source computer for duplication to target computers and then runs a third-party disk-imaging process. This automated installation method is used when the hard disk on the master computer is identical to those of the target computers. See automated installation.
- system access control list (SACL)
- The part of an object's security descriptor that specifies which events are to be audited per user or group. Examples of auditing events are file access, logon attempts, and system shutdowns. See also access control entry (ACE); discretionary access control list (DACL); object; security descriptor.
- system call
- A routine that makes the operating system available to a program or that requests services from the operating system.
- system files
- Files that are used by Windows to load, configure, and run the operating system. Generally, system files must never be deleted or moved.
- System Key (SysKey)
- A tool provided with Windows 2000 to protect all symmetric cryptographic keys in a domain or organizational unit by encrypting them with a 128-bit random key.
- System Monitor
- A tool that supports detailed monitoring of the use of operating system resources. System Monitor is hosted, along with Performance Logs and Alerts, in the Performance console. The functionality of System Monitor is based on Windows NT Performance Monitor, not Windows 98 System Monitor.
- system policy
- In network administration, the part of Group Policy that is concerned with the current user and local computer settings in the registry. In Windows 2000, system policy is sometimes called software policy and is one of several services provided by Group Policy, a Microsoft Management Console (MMC) snap-in. The Windows NT 4.0 System Policy Editor, Poledit.exe, is included with Windows 2000 for backward compatibility. That is, administrators need it to set system policy on Windows NT 4.0 and Windows 95 computers. See also Microsoft Management Console (MMC); registry.
- System State
- A collection of system-specific data that can be backed up and restored. For all Windows 2000 operating systems, the System State data includes the registry, the class registration database, and the system boot files. For Windows 2000 Server, the system state data also includes the Certificate Services database (if the server is operating as a certificate server). If the server is a domain controller, the system state data also includes Active Directory and the Sysvol directory. See also Active Directory; domain controller; Sysvol.
- system-Only attributes
- Attributes on which Windows 2000 and Active Directory depend for normal operations.
- systemAuxiliaryClass
- A multivalued property that specifies the auxiliary classes from which a class inherits. After creation of the class, this property cannot be changed.
Each value is the lDAPDisplayName of a class. You must ensure that the classes exist, or will exist, when the new class is written to the directory. If one of the classes does not exist, the classSchema object will fail to be added to the directory.
The full set of auxiliary classes that this class inherits from is the union of the systemAuxiliaryClass and auxiliaryClass on this class as well as the systemAuxiliaryClass and auxiliaryClass properties of all inherited classes.
- systemMayContain
- A multi-valued property that specifies the attributes that may 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 class. After creation of the class, this property 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 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.
- systemMustContain
- A multivalued 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 property 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.
- systemPossSuperiors
- A multivalued property that specifies the structural classes that can be legal parents of instances of this class. After creation of the class, this property cannot be changed.
Each value is the lDAPDisplayName of a class. You must ensure that the classes exist or will exist when the new class is written to the directory. If one of the classes does not exist, the classSchema object will fail to be added to the directory.
The full set of possible superiors is the union of the systemPossSuperiors and possSuperiors on this class as well as the systemPossSuperiors and possSuperiors properties of all inherited superclasses (structural or abstract classes). Note that possSuperiors are not inherited from auxiliary classes.
- systemroot
- The path and folder name where the Windows 2000 system files are located. Typically, this is C:\Winnt, although a different drive or folder can be designated when Windows 2000 is installed. The value %systemroot% can be used to replace the actual location of the folder that contains the Windows 2000 system files. To identify your systemroot folder, click Start, click Run, and then type %systemroot%.
- Systems Management Server
- A part of the Windows BackOffice suite of products. Systems Management Server (SMS) includes inventory collection, deployment, and diagnostic tools. SMS can significantly automate the task of upgrading software, allow remote problem solving, provide asset management information, manage software licenses, and monitor computers and networks.
- Systems Network Architecture (SNA)
- A communications framework developed by IBM to define network functions and establish standards for enabling computers to share and process data.
- Sysvol
- A shared directory that stores the server's copy of the domain's public files, which are replicated among all domain controllers in the domain. See also domain controller.