Vocab List - Module 1 Flashcards
Module 1
A predefined keyword that is prefixed with a #. it is an LMHOSTS keyword and facilitates domain activity such as logon validation over a router or account sychronization and browsing.
DOM
An LMHOSTS file keyword that defines which entries should be initially preloaded as permanent entries in the name cache. The preloaded entries can reduce network broadcasts, because the names will be resolved from cache rather than making a broadcast.
PRE
An application that has been written using the 16 bit length for communicating data.
16-bit Application
An application that has been written using the 32 bit length for communicating data.
32-bit Application
An application that has been written using the 64 bit length for communicating data.
64-bit Application
A mechanism to lock out accounts after multiple failed logon attempts. This reduces the chance of an unauthorized person gaining access to the network.
Account lockout
A specific user who has been designated an Account Operator can create, delete, and modify user accounts, global and local groups, and set account policies.
Account Operator
Determines the characteristics of passwords for user accounts. The policy sets requirements for password age, length, and uniqueness.
Account policy
A list that contains information on allowed and denied access to folders and files.
ACL (Access Control List)
A feature of Microsoft Internet Explorer that lets you display content from Web pages on the computer desktop, using Dynamic HTML, Webcasting, and active channels.
Active Desktop
The new Windows 2000 directory service. It stores information about all the network resources such as user accounts, computers, printers, servers, and so on. Active Directory makes it easy for administrators to manage the network resources, and makes it easy for users to locate and use the resources.
Active Directory
A Microsoft Management Console (MMC) snap-in that lets you create and work with the configuration partition of an Active Directory database.
Active Directory Sites and Services Snap-In
Microsoft’s answer to the slower and more limited performance of CGI scripts written in Perl. They combine HTML pages, scripts, programming objects, and ActiveX components to create dynamic Web pages.
Active Server Pages (ASP)
A set of programming tools based on the Component Object Model (COM), which provides the low-level services that allow programming objects to communicate with each other. ActiveX is used for Internet applications that need to be optimized for speed and size.
ActiveX
The Advertised Distance (AD) is the cost to the destination network as reported by the neighbor router. The AD is also called the reported distance (RD).
AD (Advertised Distance)
A wireless networking architecture topology that does the following:
Works in peer-to-peer mode without a WAP (the wireless NICs in each host communicate directly with one another)
Uses a physical mesh topology
Cheap and easy to set up but cannot handle more than four hosts Requires special modifications to reach wired networks
Ad hoc
The physical interface between the computer and the network cable. An adapter card communicates with the computer’s hardware, firmware, and software to allow the computer to communicate with the local area network. Also called a network adapter card, network card, or NIC.
Adapter card
Adapter teaming is the use of two or more adapter cards in a system to eliminate a network adapter as a single point of failure. In adapter teaming:
Up to four adapter teams can be supported with two to four adapters in each team.
Each adapter is connected to the same network segment via a network switch or hub.
Adapter teaming
A protocol that maps an IP address to the Media Access Control (MAC) address of a computer on a network.
Address Resolution Protocol (ARP)
An adjacency is the connection that is established when neighboring routers transfer packets.
Adjacency
An ADMD is a public operating agency that controls an X.400 management domain. These domains are the backbone for transferring electronic messages. ADMDs handle messages sent between PRMDs.
ADMD (Administration Management Domain)
An ADMD is a public operating agency that controls an X.400 management domain. These domains are the backbone for transferring electronic messages. ADMDs handle messages sent between PRMDs.
Administration Management Domain (ADMD)
The administrative distance is a metric used to show how trustworthy a router deems information from a specific protocol.
Protocols with lower administrative distances are considered more trustworthy.
Administrative distance
Windows 2000 provides share names that are used for administration. These names are C$, D$, E$, etc. and Admin$.The $ hides the shared folder from a user who browses the computer.
Administrative share
A group of registry settings stored in a file (Registry.pol). can be distributed using Active Directory-based Group Policy Objects (GPOs).
Administrative template
A user who is granted rights to create, delete, or modify user accounts. They also have rights to create user policies, move folders, add and remove hardware from the computer, and access the file system.
Administrator
A built-in group in Windows 2000. Members of the Administrators group have full administrative capabilities (see Administrator).
Administrators
A graphical Windows 2000 support tool that lets you view, edit, and create objects and attributes in the Active Directory database.
ADSI Edit
The first group to conduct packet-switching network experiments.
Advanced Research Projects Agency (ARPA)
The project became the foundation for what is now known as the Internet.
The syntax used for recovering data in a secondary partition. ARC paths specify the hardware adapter and disk controller, the numbers of the hardware adapter, the SCSI bus, the disk, and the partition.
Advanced RISC Computing (ARC) naming convention
it is the cost to the destination network as reported by the neighbor router.
Advertised Distance (AD)
it is one of two services comprising IPSec, Encapsulating Security Payload (ESP) being the other. it is used primarily for authenticating the two communication partners of an IPSec link. The ___ provides message integrity through authentication, verifying that data are received unaltered from the trusted destination. ___ provides no privacy however, and is often combined with ESP to achieve integrity and confidentiality.
AH (Authentication Header)
An action, defined by an administrator, that takes place in response to an administrator-specified event. The action can be the execution of a job, or e- mailing/paging a particular operator.
Alert
A standards body that provides computing standards. It is a voluntary organization comprised of corporate, government, and other members that coordinates standards-related activities, approves U.S. national standards, and develops positions for the United States in international standards organizations
American National Standards Institute (ANSI)
A U.S. standard set of wire sizes that apply to copper wires, including household electrical wiring and telephone lines. The higher the number, the thinner the wire.
American Wire Gauge (AWG)
The internal process used by TCP/IP to determine whether a packet is destined for a host on a local or remote network. TCP/IP performs the function of ANDing the host’s IP address with its subnet mask. When a packet is sent on the network, the destination IP address is ANDed with the same subnet mask.
ANDing process
An authentication method that does not require the user to enter a username and password to gain access to resources such as Web sites. Some anonymous access methods (like FTP) require an e-mail address as a username, but this is not a secure solution because a fake e-mail address can be used.
Anonymous authentication
A standards body that provides computing standards. It is a voluntary organization comprised of corporate, government, and other members that coordinates standards-related activities, approves U.S. national standards, and develops positions for the United States in international standards organizations. ANSI helps develop international and U.S. standards relating to, among other things, communications and networking. ANSI is a member of the IEC and the ISO.
ANSI (American National Standards Institute)
The API can be provided by any vendor to provide functionality to an application or operating system. Each vendor publishes its API’s so that developers can code to that application’s APIs.
API (Application Programming Interface)
APIPA is a Microsoft implementation of automatic IP address assignment without a DHCP server. Using APIPA, hosts assign themselves an IP address on the 169.254.0.0 network (mask of 255.255.0.0). With APIPA:
The host is configured to obtain IP information from a DHCP server (this is the default configuration).
If a DHCP server can’t be contacted, the host uses APIPA to assign itself an IP address.
The host only configures the IP address and mask. It does not assign itself the default gateway and DNS server addresses. For this reason, APIPA can only be used on a single subnet.
APIPA (Automatic Private IP Addressing)
The proprietary Macintosh operating system used by Apple computers.
Apple MacOS
A small application built into another application or an operating system. The programs in the Windows Control Panel are applets. Also called programs in Microsoft documentation.
Applet
The set of network protocols native to Apple computers.
AppleTalk
A software program that performs a specific function for the user or another program. For example, word processors, database programs, spreadsheets, and graphics packages are applications.
Application
Files necessary for an application to run, such as .EXE, .DLL, and other files.
Application files
Layer 7 of the OSI reference model. This layer provides services to application processes (such as electronic mail, file transfer, and terminal emulation) that are outside of the OSI model. The application layer identifies and establishes the availability of intended communication partners (and the resources required to connect with them), synchronizes cooperating applications, and establishes agreement on procedures for error recovery and control of data integrity.
Corresponds roughly with the transaction services layer in the SNA model. See also data link layer, network layer, physical layer, presentation layer, session layer, and transport layer.
Application Layer (OSI model)
An Event Viewer file containing application events such as file errors. Application developers determine the events that their applications write to the application log.
Application log
The API can be provided by any vendor to provide functionality to an application or operating system. Each vendor publishes its API’s so that developers can code to that application’s APIs.
Application Programming Interface (API)
Application servers run certain software applications that can be accessed by users.
Application Server
The syntax used for recovering data in a secondary partition. ARC paths specify the hardware adapter and disk controller, the numbers of the hardware adapter, the SCSI bus, the disk, and the partition.
ARC (Advanced RISC Computing) naming convention
An archive bit is a file attribute that indicates whether a file was backed up since it was modified.
Archive Bit
A protocol that maps an IP address to the Media Access Control (MAC) address of a computer on a network.
ARP (Address Resolution Protocol)
A portion of memory that is used to store a hardware address and IP address. The ARP cache is always checked for an IP address/hardware address mapping before an ARP request broadcast is initiated.
ARP cache
The first group to conduct packet-switching network experiments.
ARPA (Advanced Research Projects Agency)
In the late 1960s and early 1970s, the United States Department of Defense sponsored this project to create a network between government and research institutions. The project became the foundation for what is now known as the Internet.
ARPANET (Advanced Research Projects Agency Network)
An Autonomous System (AS) is a set of routers under a common administration and with common routing policies. Each Autonomous System (AS) in BGP appears to other autonomous systems to have a single coherent interior routing plan.
AS (Autonomous System)
The AS path (type code 2) is a well-known mandatory BGP attribute that lists the different autonomous systems to reach a network.
AS path
An Autonomous System Boundary Router (ASBR) is a router that has an interface to an external autonomous system (e.g. RIP or EIGRP). ASBRs can import and export non-OSPF network information to and from the OSPF network.
ASBR (Autonomous System Boundary Router)
Microsoft’s answer to the slower and more limited performance of CGI scripts written in Perl. They combine HTML pages, scripts, programming objects, and ActiveX components to create dynamic Web pages.
ASP (Active Server Pages)
The loss of signal strength over distance.
Attenuation
A counter that identifies how many times the value for an Active Directory attribute has changed. During replication, attribute values with higher version numbers override values of the same attribute with lower version numbers.
Attribute version number
A file containing information about events you have chosen to monitor, such as logging on and logging off, accessing files and objects, and system shutdowns. You may want to save auditing logs to help you track trends. Tracking trends helps you plan for growth and detect unauthorized use of resources. For more accurate trend information, it is better to view logs that are kept over a few months.
Audit log
The process of supplying a valid user name and password in order to access resources on a network or computer.
Authentication
Authentication Header (AH) is one of two services comprising IPSec, Encapsulating Security Payload (ESP) being the other. AH is used primarily for authenticating the two communication partners of an IPSec link. The AH provides message integrity through authentication, verifying that data are received unaltered from the trusted destination. AH provides no privacy however, and is often combined with ESP to achieve integrity and confidentiality.
Authentication Header (AH)
A domain is considered authoritative if your organization hosts mailboxes for recipients within the domain.
A restoration method which uses the Backup utility to return Active Directory database to the state it was in before the backup, then uses NTDSUTIL to mark an object as the most current. Most current objects will not be overwritten with the data from the server’s replication partners during Windows 2000 replication. Use the authoritative restore when an object is deleted after the last backup.
Restore the database with the last backup file, then update all the data modified after the last backup, except the one you marked with NTDSUTIL.
Authoritative domain Authoritative restore
An authoritative server is a DNS server that has a full, complete copy of all the records for a particular domain.
Authoritative Server
The Autodiscover service in Exchange 2007 is designed to make it easier for users to set up their profiles in Outlook or for their Exchange Active Sync devices. The Autodiscover service automatically adds the following information to a user’s profile:
The server on which the user’s mailbox resides The user’s display name
Separate connection settings for internal and external connectivity The URLs for Exchange features associated with the user Outlook Anywhere server settings
Autodiscover service
APIPA is a Microsoft implementation of automatic IP address assignment without a DHCP server. Using APIPA, hosts assign themselves an IP address on the 169.254.0.0 network (mask of 255.255.0.0). With APIPA:
The host is configured to obtain IP information from a DHCP server (this is the default configuration).
If a DHCP server can’t be contacted, the host uses APIPA to assign itself an IP address.
The host only configures the IP address and mask. It does not assign itself the default gateway and DNS server addresses. For this reason, APIPA can only be used on a single subnet.
Automatic Private IP Addressing (APIPA)
An Autonomous System (AS) is a set of routers under a common administration and with common routing policies. Each Autonomous System (AS) in BGP appears to other autonomous systems to have a single coherent interior routing plan.
Autonomous System (AS)
An Autonomous System Boundary Router (ASBR) is a router that has an interface to an external autonomous system (e.g. RIP or EIGRP). ASBRs can import and export non-OSPF network information to and from the OSPF network.
Autonomous System Boundary Router (ASBR)
Autosummarization transpires when a router that uses a classful routing protocol sends and update about a subnet of a classful network across an interface belonging to a different classful network and assumes that the remote router will use the default subnet mask for that class of IP address.
The following protocols use autosummarization:
RIP EIGRP BGP
Autosummarization
The server where database operations occur. The back end fulfills client requests by receiving structured requests from the client, processing the requests, and returning the results. It is usually more powerful than the client.
Back end
A backbone area acts as a hub for inter-area transit traffic and the distribution of routing information between areas. All OSPF networks have at least one backbone area, also known as an area 0.
Backbone area
A backbone router is located in the perimeter of the backbone area. Backbone routers:
Maintain OSPF routing information using the same procedures and algorithms as internal routers.
Have at least one interface that is connected to area 0.
Backbone router
On each subnet, a single OSPF router is identified as the Backup Designated Router (BDR). The BDR becomes the Designated Router (DR) if the DR becomes unavailable.
Backup Designated Router (BDR)
A server containing a replicated copy of the domain database. Each Windows NT domain will have one PDC (Primary Domain Controller) with zero or more BDCs (backup domain controllers).
Backup Domain Controller (BDC)
A text file that records backup operations. The log is helpful when restoring data. You can print it or read it in a text editor.
Backup log
Windows Backup can set a backup marker, also known as the archive attribute, indicating that the file has been backed up.
Backup marker
A group that has permission to perform backups on a system. This group should have only sufficient rights to perform a backup. They typically use the Windows backup software.
Backup Operators
A term used to describe a group of files or folders on a single volume from a single backup operation. A group of tapes is called a family set.
Backup set
Baseband signalling allows one signal at a time on the network medium (cabling).
Baseband
A server baseline is a snapshot of the performance statistics of your server that is used as a logical basis for future comparison. Server baselines enable you to effectively monitor the performance of your system to determine when changes negatively impact performance or when systems need upgrading or replacing.
Baseline
Documenting a network’s average performance statistics over time.
Baselining
An authentication method that requires the user to enter a valid username and password for a Windows user account. This information passes between the server and client in clear text.
Basic authentication
Basic multicast supports multicast applications within an enterprise campus. It is an interactive, intra-domain form of multicast that provides integrity within a network when combined with a reliable multicast transport such as PGM.
Basic multicast
A set of commands used to perform a specific operation on a computer.
Batch file
The number of bits per second that are physically signaled over a communication medium. The term “baud” originally referred to the number of dots per second that could be signaled using Morse code over particular telegraph systems. The unit of measure was named after J.M.E. Baudot, the developer of the first printer for telegraph systems.
Baud rate
A server containing a replicated copy of the domain database. Each Windows NT domain will have one PDC (Primary Domain Controller) with zero or more BDCs (backup domain controllers).
BDC (Backup Domain Controller)
On each subnet, a single OSPF router is identified as the Backup Designated Router (BDR). The BDR becomes the Designated Router (DR) if the DR becomes unavailable.
BDR (Backup Designated Router)
Using the split horizon method (also called best information), routers keep track of where the information about a route came from. Routers do not report route information to the routers on that path. In other words, routers do not report information back to the router from which their information originated.
Best information
Border Gateway Protocol (BGP) is a policy-based, interautonomous system routing protocol that exchanges reachability information with other BGP systems.
BGP (Border Gateway Protocol)
r The Cisco BGP Address Family Identifier (AFI) model was introduced with multiprotocol BGP. It is designed to be scalable and modular, and to support multiple AFI and Subsequent Address Family Identifier (SAFI) configurations.
BGP Address Family Identifie (AFI)
BGP attributes are used to select the best path to be entered into the routing table and propagated to the BGP neighbors. BGP attributes can be well-known mandatory, well-known discretionary, optional transitive, or optional nontransitive. The following definitions are used to define BGP attributes:
Well-known attributes are standard. All implementations of BGP support standard attributes.
Well-known mandatory attributes have to be present in all implementations of BGP.
Well-known discretionary attributes are implemented according to the needs of individual implementations of BGP.
Optional attributes are non-standard, meaning they are specific to particular implementations of BGP.
Optional transitive attributes are transmitted between two or more autonomous systems.
Optional nontransitive attributes remain in a single autonomous system.
BGP attributes
A BGP peer (also called a neighbor) is a BGP speaker that is configured to form a neighbor relationship with another BGP speaker. Neighbor relationships allow BGP speakers to directly exchange BGP routing information with one another.
BGP peer
A BGP peer group consists of the neighbors of a router that is being configured. All routers in a BGP peer group have the same update policies; thus allowing updates to be generated only once for the entire peer group.
BGP peer group
A BGP speaker is any router that runs BGP.
The BGP synchronization rule states that a BGP router cannot use or advertise a route that it has learned from internal BGP (iBGP) to an external neighbor unless it has also been established through an internal gateway protocol, such as RIP or OSPF.
BGP speaker
BGP synchronization rule
Bidirectional PIM explicitly builds shared bi-directional trees. Bidirectional PDM:
Never builds a shortest path tree.
May have longer end-to-end delays than PIM-SM. Is scalable because it needs no source-specific state.
Bidirectional PIM
An application that runs on any Windows-supported platform, not only on the hardware for which it was originally compiled.
Binary compatible
A Data Link layer protocol for synchronous communication devices.
Binary Synchronous Communications Protocol (BISYNC)
The system that networks running Novell NetWare use to validate user accounts and passwords. It is the equivalent of the directory database in Windows NT.
Bindery
The process of assigning services to network components.
Binding
A Data Link layer protocol for synchronous communication devices.
BISYNC (Binary Synchronous Communications Protocol)
The smallest unit of data a computer uses. A bit is a binary value, either a 0 or a 1.
Bit
A proposed standard of the IEEE 802.15 committee, designed to allow people to connect in PAN (personal area network) configurations using cell phones, PDAs (personal digital assistants), printers, mice, keyboards and other Bluetooth equipped devices.
Bluetooth
A type of broadcast used by NetBIOS over TCP/IP. The B-node uses UDP datagrams to broadcast for name registration and resolution. B-node broadcasts are usually not forwarded by routers, and only computers on the local network can respond.
B-node
Body parts are the codes for the text, data, and other information included in an e-mail message.
Body parts
A floppy disk containing an operating system that is used to boot up a PC in the absence of the PC’s operating system.
Boot disk
The partition on a hard drive where the Windows operating system files reside.
Boot partition
A file that builds the Boot Loader Operating System Selection menu. The screen that is displayed is known as the boot loader screen and allows a user to select an operating system from the screen. If no selection is made, NTLDR loads the operating system specified by the default parameter in the Boot.ini file. To change the default entry, you must edit the Boot.ini file.
Boot.ini
BootP is used to discover the IP address of a device with a known MAC address. BootP is an enhancement to RARP, and is more commonly implemented than RARP. As its name implies, BootP is used by computers as they boot to receive an IP address from a BootP server. The BootP address request packet sent by the host is answered by the server.
BootP (Bootstrap Protocol)
BootP is used to discover the IP address of a device with a known MAC address. BootP is an enhancement to RARP, and is more commonly implemented than RARP. As its name implies, BootP is used by computers as they boot to receive an IP address from a BootP server. The BootP address request packet sent by the host is answered by the server.
A Bootstrap Router (BSR) is a capability that was added in PIM version 2 to automate and simplify the Auto-RP process. It is enabled by default in Cisco IOS releases supporting PIMv2.
Bootstrap Protocol (BootP)
Bootstrap Router (BSR)
Border Gateway Protocol (BGP) is a policy-based, interautonomous system routing protocol that exchanges reachability information with other BGP systems.
Border Gateway Protocol (BGP)
A bottleneck is a point in a system of processes that does not have the capacity to perform the functions required of it. This lack of processing capacity impedes overall information flow and negatively impacts the performance of the whole system. Changes in the system, including increased volume, can cause bottlenecks.
Bottleneck
The longest acceptable round-trip time for a test message to travel between the monitor’s home server and the target server.
Bounce
Parts of the network architecture that provide a common programming interface. Programmers can use these components to create independently- coded drivers and other programs which extend the operating system’s abilities. Boundary layers in Windows include the Transport Driver Interface (TDI) and the Network Device Interface Specification (NDIS) 4.0.
Boundary layer
A data forwarding device that provides data transfer at the data link layer in the OSI model. A bridge is not used as much in networks because routers have assumed the responsibility for routing data at the network layer of the OSI model.
Bridge
A domain controller that participates in intersite replication.
Bridgehead server
Broadband signalling divides the network medium (cabling) into multiple channels, allowing several signals to traverse the medium at the same time.
Broadband
In broadcast transmission, a single device transits a message to all of the other devices in a given address range. Broadcast messages can be received by all hosts on the subnet, all subnets, or all hosts on all subnets.
Broadcast
The portion of the network that can receive a broadcast. Not all routers have the capability to forward broadcasts. Those that do usually disable this feature and keep the broadcast on the local network.
Broadcast domain
A broadcast storm occurs when so many messages are broadcast across the network at the same time that they exceed the network’s bandwidth.
Broadcast storm
A request from the source host for a name query request on the local network. Each computer on the local network receives the broadcast and checks its local NetBIOS table to see if it owns the requested name.
Broadcasts
A device that combines the features of a bridge and a router. For data packets that use a non-routable network/transport protocol, a brouter acts like a bridge. For data packets that use a routable network/transport protocol, a brouter acts like a router.
Brouter
A Bootstrap Router (BSR) is a capability that was added in PIM version 2 to automate and simplify the Auto-RP process. It is enabled by default in Cisco IOS releases supporting PIMv2.
BSR (Bootstrap Router)
A built-in account is an account already created by Windows. The Guest account and the Administrator account are built-in accounts.
Built-in account
Built-in groups are predefined groups that have predetermined set of user rights.
Built-in capabilities
Bus is a network topology that consists of a trunk cable with nodes either inserted directly into the trunk, or nodes tapping into the trunk using offshoot cables called drop cables.
Bus
A unit of information made up of eight bits. Usually, a byte represents a character.
Byte
Channel Definition Format files. Text files that contain a personalized index for a Web site, so you can download only the content that interests you. Using a
.CDF converts a Web site into a channel.
Exchange 2007’s database engine is referred to as the Extensible Storage Engine (ESE). ESE is a transactional database that writes information into RAM memory and into a log file. Once it is in the log file, it will be written to disk.
There are a number of files used to store information:
An .edb file is located in the actual database itself. All of a user’s messages, folders, public folders, contacts, appointment information, etc. is all stored on the .edb file. An .edb file size can exceed multiple GB.
A .log file is an ESE transaction log file. All .log files are 1 MB.
A .jrs file is a reserve log file which is used to commit any transactions that are still in memory in the event of the server running out of disk space. All .jrs files are 1 MB.
A .chk file is used to identify which log files have been committed to the database. The size of .chk file varies from 2-3 KB.
The ESE takes the following steps to write information into database files:
1. The ESE writes a message into memory RAM when it arrives at the server.
2. At the same time that information is written to RAM, it’s written into the current .log file. All current log files are named E00.log. The information is written in a sequential format until the log file is full. When the log file is full, it will be renamed.
3. Once it has been committed to the log file, the information is written to the .edb file.
4. The checkpoint file is updated to indicate that the transaction log that has been committed to the database.
.CDF file
.CHK file
A comma-delimited text file.
Cache
A file that contains host information needed to resolve names outside of authoritative domains. It also contains names and addresses of root name servers.
Cache Manager
CAL (Client Access License)
A part of the I/O Manager that improves a computer’s performance by temporarily storing files in memory instead of reading and writing them to the hard disk. The Cache Manager uses virtual address space to cache data.
A client access license permits a client to connect to a Windows 2000 server.
Callback
A remote access server configuration that provides network security by restricting network access to a specified list of phone numbers. When a client calls the server, the server hangs up, then calls the client back at the appropriate phone number.
Canonical Name (CNAME) record
Enables you to associate more than one host name with an IP address. This concept is also referred to as aliasing.
Carrier Sense Media Access/Collision Avoidance (CSMA/CA)
CSMA/CA is the technology used by Ethernet and wireless networks to control media access and avoid (rather than detect) collisions. CSMA/CD works as follows:
If a host detects traffic on the network, it experiences a longer back-off time than hosts on a wired network before attempting to transmit again. Every transmission must be acknowledged. As every frame is acknowledged by the receiving host, other hosts receive a message indicating that they must wait to transmit.
Carrier Sense Multiple Access with Collision Detection (CSMA/CD)
CSMA/CD is the technology used by Ethernet. CSMA/CD works as follows:
1. The system listens for traffic, if the line is clear it begins transmitting.
2. During the transmission, the system listens for collisions.
3. If no collisions are detected, the communication succeeds. If collisions are detected, an interrupt jam signal is broadcast to stop all transmissions. Each system waits a random amount of time before starting over at step 1.
CAS (Client Access server)
Client Access server role is required in every Exchange 2007 organization because it supports the client applications Outlook Web Access and Exchange ActiveSync and also the Post Office Protocol version 3 (POP3), and Internet Message Access Protocol version 4rev1 (IMAP4) protocols.
Cascading physical star
A logical ring topology created with the FDDI standard. In this topology, single- attachment hubs connect single-attachment stations to a network.
Case sensitive
All capital and lower-case characters must be typed exactly as they appear. For example, if the password was “Himalayas” and you typed “himalayas,” you would not be allowed to log on.
CCR (Local Continuous Replication)
Cluster Continuous Replication (CCR) combines the asynchronous log shipping and replay technology of Exchange 2007 with the failover and management features provided by the Microsoft Windows Cluster service. CCR does not have a single point of failure and provides high availability by replicating data on a passive node, so the clustered Mailbox server can operate on either node at any time.
CD File System (CDFS)
A read-only file system for CD-ROMs, supported by Windows 2000.
CDFS (CD File System)
A read-only file system for CD-ROMs, supported by Windows 2000.
Central Processing Unit (CPU) The logic circuitry that responds to instructions and runs the computer. Also
called a processor.
A configuration in which all the data and applications are stored and executed on a mainframe computer. The terminals act only to accept keystrokes on the keyboard and display data from the mainframe computer.
Centralized computing
The ability to manage network resources from a centralized database location. The Windows 2000 directory service provides the capability to manage resources centrally.
Centralized network administration
A digitally signed statement issued by a Certification Authority (CA). It contains a public key and certifies that a specific person, organization, device, or service is the only holder of the corresponding private key. Certificates commonly use the ITU-T X.509 international standard.
Certificate
A certificate authority (CA) is the component of the public key infrastructure entrusted to issue, store, and revoke certificates. A certificate authority accepts certificate requests, verifies the information provided by the requester, creates and digitally signs the certificate, and issues the certificate to the requester. It also revokes certificates and publishes a certificate revocation list (CRL).
Certificate authority
Digital certificates usually expire after one year, but CAs can revoke certificates earlier for various reasons. All revoked certificates are stored in the certification revocation list, which is open to all users. This allows users to check the list to verify whether a given certificate is valid.
Certificate Revocation List (CRL)
The Microsoft Windows 2000 component that lets a system administrator create a certificate authority to issue, revoke, and manage digital certificates as part of a public key infrastructure.
Certificate Services
A Certification Authority server creates new encryption keys for clients and publishes public keys for users. The Exchange KM Server is a Certification Authority server.
Certification Authority server
A software program that allows Web servers to send data to an application and receive information back from the application, regardless of the operating system the application is running under.
CGI (Common Gateway Interface)
Cisco Group Management Protocol (CGMP) is a Cisco proprietary protocol that works between the router and the switch. In CGMP, the switch only allows multicast traffic to flow through specific ports according to client data from the router instead of flooding data across all ports. CGMP:
Enables routers to inform each of their directly-connected switches of IGMP registrations from hosts accessible through the switch.
Forwards multicast traffic only to ports on which the requesting routers are located.
Is the most common multicast switching solution.
Is based on a client/server model in which the router acts as a server and the switch acts as a client.
CGMP(Cisco Group Management Protocol)
function on the challenge and compares its result with that received from the client. If they don’t match the session is terminated.
A hardware device that converts a digital data frame from a LAN format into a WAN format and vice versa.
Channel Service Unit/Data Service Unit (CSU/DSU)
Web sites that you can customize with a .CDF file to give you only the information that you want to see. When you subscribe to a channel, Internet Explorer monitors the Web sites included in the channel and downloads only the information that fits the channel’s parameters.
Channels
CHAP is an authentication encryption protocol designed to protect passwords while in transit from a client to the logon server.
CHAP periodically verifies the identity of a peer using a three-way handshake. CHAP ensures that the same client or system exists throughout a communication session by repeatedly and randomly re-testing the validated system. This test involves the security server sending a challenge message to the client. The client then performs a one-way hash function on the challenge and returns the result to the security server. The security server performs its own function on the challenge and compares its result with that received from the client. If they don’t match the session is terminated.
CHAP (Challenge Handshake Authentication Protocol)
A set of 256 letters, digits, and symbols specific to a country or language. The character set selected during SQL installation specifies the characters SQL Server will recognize in the various data types. The first 128 values are called printable characters, and the last 128 values are called extended characters.
Printable characters are the same for each set; extended characters vary from set to set. See also Unicode characters.
Character set
A marked point in a SQL transaction log. It represents a point at which completed transactions and modified database pages were written to disk.
Checkpoint
An MS-DOS utility you can use to scan and repair both FAT and Windows NT NTFS volumes.
Chkdsk
A technique used to collapse Class C entries into a single entry corresponding to all the Class IDs that are being used by that organization. This allows companies to use many Class C addresses rather than requesting a Class B address, since the availability of IP addresses is scarce.
CIDR (Classless Inter-Domain Routing)
A circuit switched network uses a dedicated connection between sites. Circuit switching is ideal for transmitting data that must arrive quickly in the order it is sent, as is the case with real-time audio and video.
Circuit Switching
A circuit-level gateway monitors traffic between trusted hosts and un-trusted hosts via virtual circuits or sessions. A circuit-level gateway:
Verifies sequencing of session packets.
Hides the private network from the public network.
Does not filter packets. Rather it allows or denies sessions.
Circuit-level Gateway
Circular logging is a logging method in which older logs are overwritten with new logging information. This method saves disk space but does not provide as much fault tolerance.
Circular logging
Cisco Group Management Protocol (CGMP) is a Cisco proprietary protocol that works between the router and the switch. In CGMP, the switch only allows
Cisco Group Management Protocol (CGMP)
An IP address range that is assigned to networks with very large numbers of hosts. The Class A address assigns the high order bit to zero. The next seven bits complete the network ID portion of the address. The remaining 24 bits make up the host ID. The address range for the first octet (8 bits) is 1-126.
Class A address
An IP address range that is assigned to networks with medium to large networks. The Class B address assigns the two high order bits to binary 1 0 . The next 14 bits complete the network ID. The last 16 bits are used for the host ID. The address range for the first octet (8 bits) is 128 B 191.
Class B address
An IP address range that is used for small local area networks. The Class C address assigns the three high order bits to binary 1 1 0. The next 21 bits are used to complete the network ID. The last 8 bits are used to represent the network ID. The address range for the first octet (8 bits) is 192 B223.
Class C address
Classful addresses are IP addresses that use the default subnet mask.
Classful IP addresses
Classful routing protocols do not include default subnet mask information in routing updates. The default subnet mask is used to identify the network and host portions of the address. Classful routing protocols are:
Interior Gateway Routing Protocol (IGRP) Routing Information Protocol version 1(RIPv1)
Classful routing protocols
A technique used to collapse Class C entries into a single entry corresponding to all the Class IDs that are being used by that organization. This allows companies to use many Class C addresses rather than requesting a Class B address, since the availability of IP addresses is scarce.
Classless Inter-Domain Routing (CIDR)
Classless addresses are IP addresses that use a custom mask value to separate network and host portions of the IP address.
Classless IP addresses
Classless routing protocols use a custom mask value to separate network and host portions of the IP address. They are considered to be second-generation protocols because they improve on the limitations of classful protocols. The most common routing protocols are:
Enhanced Interior gateway Routing Protocol (EIGRP) Intermediate System-to-Intermediate System (IS-IS) Open Shortest Path First (OSPF)
Routing Information Protocol version 2 (RIPv2)
Classless routing protocols
A computer that uses files and resources from another computer on a network. Also called a workstation.
Client
A client access license permits a client to connect to a Windows 2000 server.
Client Access License (CAL)
Client Access server role is required in every Exchange 2007 organization because it supports the client applications Outlook Web Access and Exchange ActiveSync and also the Post Office Protocol version 3 (POP3), and Internet Message Access Protocol version 4rev1 (IMAP4) protocols.
A service included with Windows 2000 that allows a Windows workstation to use file and print resources residing on NetWare servers.
Client Access server (CAS)
Client Service for NetWare (CSNW)
Tools that allow you to perform several network administration tasks from a Windows 95/98 or Windows 2000 Professional workstation, such as creating users and groups, sharing folders, and assigning permissions to access resources.
Client-based administration tools
A Windows shared resource that uses OLE to store up to 127 pieces of information, each called a ClipBook Viewer Page. Users can create and share these pages for use in OLE applications.
ClipBook Viewer
Connectionless Network Service (CLNS) is an address family that is used to identify routing sessions for protocols that use standard network service access point (NSAP) address prefixes, such as BGP.
CLNS (Connectionless Network Service)
Cluster Continuous Replication (CCR) combines the asynchronous log shipping and replay technology of Exchange 2007 with the failover and management features provided by the Microsoft Windows Cluster service. CCR does not have a single point of failure and provides high availability by replicating data on a passive node, so the clustered Mailbox server can operate on either node at any time.
Cluster Continuous Replication (CCR)
A situation in which groups of independent computers work together as a single system.
Clustering
Enables you to associate more than one host name with an IP address. This concept is also referred to as aliasing.
CNAME (Canonical Name) record)
Coaxial cable is a type of network transmission media. It is an older technology that is usually implemented with a bus topology. It is not suitable for ring or star topologies because the ends of the cable must be terminated. It is composed of two conductors, which share a common axis, within a single cable.
Coaxial Cable
A cold site is a fault tolerant strategy which provides a redundant work location. If a disaster renders a work site unusable, the effected organization may have a cold site in which to relocate. Cold sites have the following characteristics:
This is the least ready of alternative site types, but it is probably the most common.
The site is ready for equipment to be brought in during an emergency because there is no hardware on site.
The site might have electrical power and HVAC, but it may or may not have communication links.
A cold site is low cost, and may be better than nothing.
A cold site often offers a false sense of security. The actual amount of work involved in getting a cold site up and running might be more than expected and might take too long to adequately keep the business running.
Cold Site
A method that allows objects to communicate with each other. It is the basis for both OLE and ActiveX.
COM (Component Object Model)
Codes you can use at the command prompt when starting an application or installation program to customize the way the program runs.
Command line switches
The 32-bit Windows command-line interface similar to the MS-DOS prompt. You can use it to start programs and type Windows commands.
Command prompt
A software program that allows Web servers to send data to an application and receive information back from the application, regardless of the operating system the application is running under.
Common Gateway Interface (CGI)
A community is a group that contains hosts that are running the SNMP service. These communities are identified by a community name and provide the first level of security and context checking for agents.
Community
The community (type code 8) is an optional BGP transitive attribute that filters incoming or outgoing routes. BGP communities are routes that share some common properties and policies, which allows routers to act on the community as a whole rather than on individual routes.
Community attribute
In this Windows NT network model, every domain on the network trusts every other domain. No single domain has control over the other domains. The complete trust model distributes administration of users, groups, domains, and resources among different departments rather than using a centralized approach.
Complete trust domain model
A method that allows objects to communicate with each other. It is the basis for both OLE and ActiveX.
Component Object Model (COM)
An account entry in the local SAM database or the Active Directory domain database that identifies a computer (workstation) as part of a domain.
Computer account
The configuration container is used to store information about the configuration of the Active Directory environment in Exchange 2007, such as site configuration and areas of optimal connectivity. When AD is employed over a WAN, a site for each end of the WAN link is defined along with the site link that represents the WAN connection. Exchange 2007 uses this site information to route messages within the environment. The configuration container also contains additional Exchange configuration such as the definition of the connectors within the environment, the accepted domains, and which servers hold which roles.
Configuration container
An Active Directory partition that stores the domain, site, and replication structure of a Windows 2000 network.
Configuration partition
An Active Directory object that represents a uni-directional connection between a source and target replication partner over which Active Directory data is replicated.
Connection object
Connectionless communications assume an existing link between devices and allow transmission without extensive session establishment. Connectionless communications use no error checking, session establishment, or acknowledgements. Connectionless protocols allow quick, efficient communication at the risk of data errors and packet loss. Connectionless protocols are a good choice where speed is important and smaller chunks of data are being sent.
Connectionless communication
Connection-oriented communication does not assume that there is an existing link between devices. Connection-oriented communications use error detection/correction, session establishment, or acknowledgements, and, if necessary, retransmission. Connection-oriented communication provides a more reliable communication when are delivery is more important than speed and is a good method to use when larger chunks of data are being sent.
Connection-oriented communication
The Microsoft Management Console (MMC) is a graphical interface for the administration of Windows 2000 and some earlier Microsoft operating systems. It accommodates various “snap-in” tools.
Console
The left pane of the Microsoft Management Console (MMC). It shows a hierarchical structure of functions and/or objects.
Console tree
A Windows utility that displays other utilities that are used to manage the local computer.
Control Panel
A routing metric is a value used by routing protocols to determine the length of paths within a network. Different routing protocols use various measurements to calculate metrics, such as:
Bandwidth Network delay Hop count Interface speed Path cost
Load MTU
Reliability Communication cost
Convergence
Marker downloaded from Internet servers and stored on the hard drives of client computers. Cookies store information about your preferences, browser settings, location, and so on. They identify you (or your browser) to Web sites.
Cookie
A system in which each application currently running a process voluntarily passes control of the CPU to another application between processes. It is also called non-preemptive multitasking.
Cooperative multitasking
A specific type of backup that backs up selected files and folders but does not mark their archive attributes.
Copy backup
The logic circuitry that responds to instructions and runs the computer. Also called a processor.
CPU (Central Processing Unit)
Cyclic redundancy checking is a method used to verify correct transmission and reception of data that has been sent across a network.
CRC (Cyclic Redundancy Checking)
A built-in group that is used for network administration. It includes the user that created or took ownership of a resource.
Creator Owner
Digital certificates usually expire after one year, but CAs can revoke certificates earlier for various reasons. All revoked certificates are stored in the certification revocation list, which is open to all users. This allows users to check the list to verify whether a given certificate is valid.
CRL (Certificate Revocation List)
A cable connecting one hub with another hub or with a repeater in a network.
Crossover cable
CSMA/CD is the technology used by Ethernet. CSMA/CD works as follows:
1. The system listens for traffic, if the line is clear it begins transmitting.
2. During the transmission, the system listens for collisions.
3. If no collisions are detected, the communication succeeds. If collisions are detected, an interrupt jam signal is broadcast to stop all transmissions. Each system waits a random amount of time before starting over at step 1.
CSMA/CD (Carrier Sense Multiple Access with Collision Detection)
A service included with Windows 2000 that allows a Windows workstation to use file and print resources residing on NetWare servers.
CSNW (Client Service for NetWare)
The Windows subsystem that supports 32- and 16-bit Windows and MS-DOS applications within Windows 2000. Also called the Win32 subsystem, client/server subsystem, or CSRSS.
CSR subsystem
A hardware device that converts a digital data frame from a LAN format into a WAN format and vice versa.
CSU/DSU (Channel Service Unit/Data Service Unit)
A subnet mask that is defined by a network administrator. Each host on a TCP/IP network requires a subnet mask. If a custom subnet mask is not used, then a default subnet mask is automatically used.
Custom subnet mask
A specific backup type that copies only files and folders that have changed during that day. It does not mark their archive attributes.
Daily copy backup
The agency of the U.S. Department of Defense which created the industry- standard TCP/IP suite of protocols based on packet-switching network experiments conducted in the late 1960’s and 1970’s.
DARPA (Department of Defense Advanced Research Projects Agency)
The process of creating a database and associated objects, such as tables, indexes, constraints, defaults, rules, procedures, triggers, and views.
Data definition
Data Encryption Standard is a common symmetric cryptography method. It was created in 1972 and re-certified in 1993. DES has a limitation of 56-bit keys and offers little encryption security since it can be easily broken.
Data Encryption Standard (DES)
A non-routable protocol. Windows NT computers use DLC to connect to IBM mainframes via 3270 terminal emulators and to connect to IBM AS/400 computers via 5250 emulators. Microsoft SNA Server for Windows NT uses DLC to communicate with mainframes on a token ring network. DLC is also used with some HP print devices that are attached to the network through a built-in adapter card.
Data Link Control (DLC)
A collection of information, tables, and other objects organized and presented to serve a specific purpose, such as facilitating searching, sorting, and recombining data. Databases are stored in files.
Database
The process by which a WINS server can resolve NetBIOS names of hosts registered with another WINS server. For example, if a host on subnet A is registered with a local WINS server, but wants to communicate with a host on subnet B where the host is registered with a different WINS server, the NetBIOS name cannot be resolved unless the two WINS servers have replicated their databases with each other.
Database replication
Another term used to describe a packet. The term is also used to describe the Internet protocol known as the User Datagram Protocol, a connectionless protocol that does not guarantee delivery of datagrams.
Datagram
A method of configuring a client/server application so that several computers can use it at the same time. DCOM uses remote procedure calls (RPCs) to allow applications to interoperate and communicate with each other.
DCOM (Distributed Component Object Model)
A system by which applications can share data and commands. Both applications must support DDE.
DDE (Dynamic Data Exchange)
Digital lines to which a computer can connect using a channel service unit/digital service unit (CSU/DSU). These kinds of lines carry 99 percent error- free digital signals at speeds ranging from 2.4 to 56 kilobits per second. DDS lines are normally leased lines rather than on-demand. An exception is Switched 56, which is a system of on-demand (dial-up) 56 Kbps DDS lines.
DDS (Digital Data Service)
A computer manufacturing company that makes RISC-based processors such as Alpha.
DEC (Digital Equipment Corporation)
An action that a system performs, or a characteristic that it displays unless explicitly instructed otherwise.
Default
The gateway you always want to use to communicate with a host on a different network. It receives packets from the local network and transfers them to another gateway on the other network. You specify a default gateway when you configure TCP/IP.
Default gateway
If a default route is configured, the router will send packets via that route in cases where a dynamic route is not provided. This can be used to create sufficient reachability, especially for route between an edge and the core.
Default routes also reduce the burden on network resources caused by dynamic routing.
Default route
A subnet mask that is used on TCP/IP networks that are not divided into subnets. All TCP/IP hosts require a subnet mask even if the network is a single segment.
Default subnet mask
A Windows process that moves data between the computer’s RAM and a paging file on the hard drive.
Demand paging
The agency of the U.S. Department of Defense which created the industry- standard TCP/IP suite of protocols based on packet-switching network experiments conducted in the late 1960’s and 1970’s.
Department of Defense Advanced Research Projects Agency (DARPA)
Data Encryption Standard is a common symmetric cryptography method. It was created in 1972 and re-certified in 1993. DES has a limitation of 56-bit keys and offers little encryption security since it can be easily broken.
DES (Data Encryption Standard)
A Designated Router (DR) is a router in a PIM-Sparse Mode tree that initiates the Join/Prune message cascade upstream in response to the IGMP membership information that is received from IGMP hosts.
Designated Router (DR)
A replication partner that receives updates from a source replication partner. Also called a target replication partner.
Destination replication partner
A software component that allows a hardware device to communicate with the operating system of a computer.
Device driver
A file management system that lets users and administrators create a virtual file structure such that a folder or hierarchy of folders appear to contain a collection of files that are, if fact, located on multiple computers or drives connected at various physical locations on the network. A Dfs directory tree helps users to browse through, search for, and access data on the network.
DFS (Distributed File System)
A protocol that dynamically assigns IP addresses to each computer on a network.
DHCP (Dynamic Host Configuration Protocol)
A message that makes a request for an IP lease. The message contains the client’s hardware address and computer name, so that DHCP servers know which client sent the request.
DHCP discover
A Microsoft utility used to manage DHCP servers.
DHCP Manager
All DHCP servers that have valid IP addressing information available send a DHCP offer to the client when the client makes a request.
DHCP offer
The client will initialize TCP/IP and broadcasts a request for the location of a DHCP server and IP addressing information.
DHCP request
The ability to set a start and end range for the assignment of IP addresses using DHCP. Addresses can also be excluded from the available addresses as well.
The scope is set using the DHCP Console.
DHCP scope
A software program that allows a client computer to connect to an external or remote network via modem. It is the client version of RAS. Examples of dial-up networking include connecting from home to a computer at work over the phone lines or connecting with an internet service provider by modem.
Dial-up Networking
A backup process that copies to tape only those files that have not been marked by previous backups. A differential backup does not mark the files after backing them up.
Differential backup
One mode that an infrared device operates in is diffuse mode (also called scatter mode), which operates by broadcasting a large beam of light rather than a
Diffuse Mode (Scatter Mode)
Encoded computer information that provides verification of the identity of a client or server. These certificates include encoded information that identifies a particular person, company, or computer, and are often used to distribute public encryption keys to recipients.
Digital certificates
Digital lines to which a computer can connect using a channel service unit/digital service unit (CSU/DSU). These kinds of lines carry 99 percent error- free digital signals at speeds ranging from 2.4 to 56 kilobits per second. DDS lines are normally leased lines rather than on-demand. An exception is Switched 56, which is a system of on-demand (dial-up) 56 Kbps DDS lines.
Digital Data Service (DDS)
A method of hiding the content of a message from anyone but the recipient. The sender uses the recipient’s public key to encrypt the contents of the message.
The recipient uses her own private key to decrypt and read the message.
Digital envelope
A computer manufacturing company that makes RISC-based processors such as Alpha.
Digital Equipment Corporation (DEC)
In the mid-1970s, Digital Equipment Corporation developed a protocol suite known as Digital Network Architecture (DNA). It is also known as DECnet. The Physical and Data Link layers of DNA were the predecessors of the Ethernet IEEE 802.3 standard.
Digital Network Architecture (DNA)
A method of verifying the sender of a message, but does not encrypt the message itself. The sender uses his own private key to encrypt a digital signature attached to a message. The recipient uses the sender’s public key to decrypt the signature and verify the sender’s identity.
Digital signature
DSL or Digital Subscriber Line is a form of high-speed dial-up connection used to connect remote systems to the Internet. DSL operates over existing copper phone lines and is an economical choice for homes and small businesses.
Digital Subscriber Line (DSL)
An electrical device that you can use to diagnose cable problems. A DVM can determine if there is a break or short in the cable by testing the resistance (measured in ohms) of the network cable.
Digital Volt Meter (DVM)
Direct Memory Access (DMA) channels are conduits used by high-speed devices to communicate directly with RAM, bypassing the CPU.
Direct Memory Access (DMA)
Directory replication is the process of sharing directory information between servers inside and between sites.
Directory replication
A process that runs on a domain controller and provides access to the Active Directory database.
Directory Service Agent (DSA)
A special safe mode you use to restore the system state data on a domain controller.
Directory Services Restore Mode
less secure then other forms of signalling, such as Frequency Hopping Spread Spectrum (FHSS).
A low-level API that provides fast response to user input. Microsoft designed DirectX specifically to run graphically-intensive computer games. DirectX components are Microsoft DirectDraw, Microsoft DirectPlay, and Microsoft DirectSound.
DirectX APIs
Also called a partition. A portion of the free space on a hard disk that you format with a file system. Partitions can be either primary or extended.
Disk partition
Distance Vector Multicast Routing Protocol (DVMRP) is a protocol that shares information between routers to transport IP Multicast packets among networks.
Distance Vector Multicast Routing Protocol (DVMRP)
Class of routing algorithms that iterate on the number of hops in a route to find a shortest-path spanning tree. Distance vector routing algorithms call for each router to send its entire routing table in each update, but only to its neighbors. Distance vector routing algorithms can be prone to routing loops, but are computationally simpler than link state routing algorithms. Also called Bellman-Ford routing algorithm. See also link state routing algorithm.
Distance vector routing protocol
A distribute list is a type of access list that is applied to routing updates. Unlike normal access lists, distribute lists can control routing updates no matter their origin.
Distribute list
Applications that split processing tasks between a client (front-end) and a server (back-end).
Distributed applications
A method of configuring a client/server application so that several computers can use it at the same time. DCOM uses remote procedure calls (RPCs) to allow applications to interoperate and communicate with each other.
Distributed Component Object Model (DCOM)
A file management system that lets users and administrators create a virtual file structure such that a folder or hierarchy of folders appear to contain a collection of files that are, if fact, located on multiple computers or drives connected at various physical locations on the network. A Dfs directory tree helps users to browse through, search for, and access data on the network.
Distributed File System (DFS)
The Distributed Management Interface (DMI) is a standard for organizing information about desktop, notebook, and server computers. DMI is part of the System Management BIOS (SMBIOS) specification which allows data about a system to be stored in the individual system’s BIOS. Management software interfaces with the BIOS on a monitored system to gather this information and assemble it into an administrator-specified format such as a report or a database.
Distributed Management Interface (DMI)
Distributed parity is a method of data protection used in a RAID 5 configuration. Duplicate data (parity) is placed on multiple disks (distributed) to protect against data loss in the event of a storage disk failure.
Distributed Parity
A technique of using both the client and server’s processors to complete a task. The client or “front end” accepts input and runs simple calculations, while the server or “back end” handles processes that require more processing power.
Distributed processing
A distribution group is a universal group that has been mail-enabled, such as a security group. A distribution group can be used to send an e-mail to a large number of people in an Exchange organization, such as entire departments or groups.
Distribution group
A distribution list contains addresses for individual users, public folders, and other distribution lists. They allow each member to receive a copy of a message sent to the entire list. Applications use distribution lists.
Distribution list
A distribution tree shows the source of multicast information and the path that multicast traffic use across the network infrastructure.
A non-routable protocol. Windows NT computers use DLC to connect to IBM mainframes via 3270 terminal emulators and to connect to IBM AS/400 computers via 5250 emulators. Microsoft SNA Server for Windows NT uses DLC to communicate with mainframes on a token ring network. DLC is also used with some HP print devices that are attached to the network through a built-in adapter card.
Distribution tree
DLC (Data Link Control)
Direct Memory Access (DMA) channels are conduits used by high-speed devices to communicate directly with RAM, bypassing the CPU.
DMA (Direct Memory Access)
The Distributed Management Interface (DMI) is a standard for organizing information about desktop, notebook, and server computers. DMI is part of the System Management BIOS (SMBIOS) specification which allows data about a system to be stored in the individual system’s BIOS. Management software interfaces with the BIOS on a monitored system to gather this information and assemble it into an administrator-specified format such as a report or a database.
DMI (Distributed Management Interface)
DMZ (Demilitarized Zone) is a buffer subnet. A DMZ should only contain servers that are to be accessed by external visitors. Often it is assumed that any server placed in the DMZ will be compromised. Thus, no mission critical or sensitive systems are located in a DMZ.
A domain controller may appear in a DMZ when the DMZ is an entire isolated domain, however this is not common. User workstations are never located in a DMZ. Backup servers, unless specifically deployed for just the DMZ, are never located in a DMZ.
DMZ (Demilitarized Zone)
In the mid-1970s, Digital Equipment Corporation developed a protocol suite known as Digital Network Architecture (DNA). It is also known as DECnet. The Physical and Data Link layers of DNA were the predecessors of the Ethernet IEEE 802.3 standard.
DNA (Digital Network Architecture)
A server that maintains a database of IP address/computer name mappings. A DNS server can run on Windows NT, Unix, or NetWare (5). The DNS has the responsibility to resolve fully qualified domain names and other host names to IP addresses. In DNS, the clients are called resolvers and the servers are called name servers.
DNS (Domain Name Server)
A hierarchical client/server-based database management system that translates computer names into IP addresses. DNS maps to the application layer and uses UDP and TCP as the underlying protocols. Clients, known as resolvers, contact name servers for the IP address they are seeking.
DNS (Domain Name System)
A domain that defines different levels of authority in a hierarchical structure. The highest level is called the root domain. The other levels of domains are currently defined as com, edu, org, net, gov, mil, num, and arpa. Second level domains are any domains defined by companies such as Microsoft.com or Novell.com.
DNS Domain
A service location feature used in Zeroconf networking implementation. DNS- SD allows IP hosts to automatically find available services, such as file servers, printers, and routers. DNS-SD is a Mac OS related feature.
DNS Service Discovery (DNS-SD)
A logical grouping of computers and users. In a domain, all users have access to a central directory database that stores security and user account information for the domain.
Domain
A built-in global group that is added automatically to the Administrators local group, making all members of Domain Admins group domain administrators.
Domain Admins
Windows 2000 domain controllers contain copies of the Active Directory database. They provide a centralized approach to administration and account maintenance.
Domain controller
A configuration of Dfs in which Active Directory stores the information about the virtual file structure. Advantages include fault-tolerance.
Domain Dfs
A built-in global group in which the Guest user account is a member.
Domain Guests
A domain name locates entities (for example, websites) on the Internet. Domain names are managed within a domain name system (DNS), which is a hierarchy that is made up of the following components:
. (dot) domain (also called the root domain)
Top Level Domains (TLDs) such as .com, .edu, .gov Additional domains such as yahoo.com, microsoft.com, etc.
Domain Name
A server that maintains a database of IP address/computer name mappings. A DNS server can run on Windows NT, Unix, or NetWare (5). The DNS has the responsibility to resolve fully qualified domain names and other host names to IP addresses. In DNS, the clients are called resolvers and the servers are called name servers.
Domain Name Server (DNS)
A hierarchical client/server-based database management system that translates computer names into IP addresses. DNS maps to the application layer and uses UDP and TCP as the underlying protocols. Clients, known as resolvers, contact name servers for the IP address they are seeking.
Domain Name System (DNS)
An Active Directory partition that stores objects, attribute, and attribute values for a particular domain. Each domain in Active Directory has its own domain partition.
Domain partition
User name and password information stored in the Active Directory database on the domain controllers.
Domain user accounts
Any user account created in a Windows domain is a domain user. Domain Users is a global group.
Domain Users
See MS-DOS.
DOS
A Designated Router (DR) is a router in a PIM-Sparse Mode tree that initiates the Join/Prune message cascade upstream in response to the IGMP membership information that is received from IGMP hosts.
DR (Designated Router)
A specific letter used to map a drive or volume on a workstation or server.
Drive mapping
Any other router that is not a DR or a BDR is called a DROTHER. This is simply a term used to describe a non-DR or non-BDR router. It is not technically an OSPF router role.
DROTHER
A process that runs on a domain controller and provides access to the Active Directory database.
DSA (Directory Service Agent)
DSL or Digital Subscriber Line is a form of high-speed dial-up connection used to connect remote systems to the Internet. DSL operates over existing copper
DSL (Digital Subscriber Line)
A dual ring is an enhanced version of the ring networking topology. A dual ring network includes two rings; the primary and secondary rings, which increase performance and fault tolerance. A break in one ring in a dual ring configuration has no effect on communications. A decrease in bandwidth might result, but data can be sent on the other ring.
Dual Ring
A method used to allow concurrent support for both IPv4 and IPv6 within the same network.
Dual Stack
The ability to boot a computer with either one of two operating systems. Both operating systems must be loaded on the computer. At bootup a menu prompts the user to load the operating system the computer should use.
Dual-boot
Simplex and duplex are methods of communication transmission. Simplex is the one-way transmission of a signal across a medium. Duplex is the two-way transmission of a signals across a medium. There are two types of duplex transmission; half-duplex and full-duplex. Half-duplex allows transmission of signals, one party at a time. Full-duplex allows transmission and reception of signals to occur concurrently.
Duplex (Simplex)
An electrical device that you can use to diagnose cable problems. A DVM can determine if there is a break or short in the cable by testing the resistance (measured in ohms) of the network cable.
DVM (Digital Volt Meter)
Distance Vector Multicast Routing Protocol (DVMRP) is a protocol that shares information between routers to transport IP Multicast packets among networks.
DVMRP (Distance Vector Multicast Routing Protocol)
A system by which applications can share data and commands. Both applications must support DDE.
Dynamic Data Exchange (DDE)
A disk device managed by Windows 2000 Disk Management. Dynamic disks do not contain partitions or logical drives. They can contain only dynamic volumes created with Disk Management. They cannot be accessed by earlier version of Windows or by MS-DOS.
Dynamic disk
A dynamic distribution group is an Exchange distribution group whose membership is defined by the results of a query which is executed every time a message is sent to the group. This is optimal for environments in which people move groups or buildings often and e-mail groups need to be able to accommodate changes as they occur.
Dynamic distribution group
A protocol that dynamically assigns IP addresses to each computer on a network.
Dynamic Host Configuration Protocol (DHCP)
Dynamic routing is an addressing method that senses changes in the network topology and responds accordingly without administrator involvement.
Dynamic routing
Propagate changes and shifts in the network topology to each router in the network, causing the routing tables on each router to always be up to date. Are responsible for all networks to which they are connected.
Dynamic routers
Exchange 2007’s database engine is referred to as the Extensible Storage Engine (ESE). ESE is a transactional database that writes information into RAM memory and into a log file. Once it is in the log file, it will be written to disk.
There are a number of files used to store information:
An .edb file is located in the actual database itself. All of a user’s messages, folders, public folders, contacts, appointment information, etc. is all stored on the .edb file. An .edb file size can exceed multiple GB.
A .log file is an ESE transaction log file. All .log files are 1 MB.
A .jrs file is a reserve log file which is used to commit any transactions that are still in memory in the event of the server running out of disk space. All .jrs files are 1 MB.
A .chk file is used to identify which log files have been committed to the database. The size of .chk file varies from 2-3 KB.
The ESE takes the following steps to write information into database files:
1. The ESE writes a message into memory RAM when it arrives at the server.
2. At the same time that information is written to RAM, it’s written into the current .log file. All current log files are named E00.log. The information is written in a sequential format until the log file is full. When the log file is full, it will be renamed.
3. Once it has been committed to the log file, the information is written to the .edb file.
4. The checkpoint file is updated to indicate that the transaction log that has been committed to the database.
.EDB file
EAP is an authentication protocol (an extension of PPP). It is a set of interface standards that provide various authentication methods (smartcards, biometrics, and digital certificates), define access definitions, providing protection mechanisms and custom solutions, and does not maintain a database of user accounts and passwords.
EAP (Extensible Authentication Protocol)
The Extensible Authentication Protocol over LAN is used for authentication of 802.1X port access control over either wired or wireless LANs.
EAPoL (Extensible Authentication Protocol over LAN)
ThickNet (10Base5 coax), 10Base2 (ThinNet coax), and 10BaseT (STP and UTP) are very susceptible to tapping and eavesdropping.
External BGP (EBGP) is used by BGP to route information between autonomous systems.
EBGP (External BGP)
Transport policy agents apply transport policies to e-mails within an Exchange organization. There are two types of transport policy agents in Exchange 2007:
A Transport Rules agent runs on a Hub Transport server and implements policies set by administrators to all e-mail that travels in and out of an Exchange organization.
An Edge Rules agent runs on an Edge Transport server and helps control spam and unwanted mail flow within an organization.
Edge Rules agent
The Edge Transport server handles all Internet-facing mail flow and provides Simple Mail Transfer Protocol (SMTP) relay and smart host services for the Exchange 2007 organization.
Edge Transport server
NetWare 4.x and higher uses a directory service called eDirectory (formerly called Novell Directory Services (NDS)). User accounts are configured in the directory. eDirectory can also run on other servers such as Windows and Linux.
EDirectory
The combined rights a user has to perform specific network functions and access network resources.
Effective permission
Exterior Gateway Protocol (EGP) is a routing protocol that exchanges routing information between autonomous systems. BGP is the most common EGP protocol.
EGP (Exterior Gateway Protocol)
A standard electronic interface that allows a computer to communicate with a storage device such as the hard drive or a CD-ROM drive.
EIDE (Enhanced Integrated Drive Electronics)
A 32-bit I/O bus slot providing compatibility with 386 through Pentium machines. EISA buses:
Have a maximum throughput rate of 33 MB/s.
Offer bus mastering which is a mini-processor on the expansion card. The mini-processor assumes the task from the CPU of transferring data to and from memory.
Offer a second row of pins to a standard ISA bus. Provide backward compatibility with ISA cards.
Allow EISA cards to take advantage of both rows of pins (the 32-bit data path) to improve transfer rates and increase addressable memory.
Allow for automatic configuration of system resources (addresses, DMA channels and IRQs).
Support sharing of system resources.
Allow multiple EISA cards to share the same interrupt.
EISA supports multiprocessing by allowing more than one CPU to share the bus.
Are usually black, though they are sometimes white.
EISA (Extended Industry Standard Architecture)
The disruption of one electronic device, caused by an electromagnetic field (in the radio frequency spectrum) generated by another electronic device.
Electromagnetic Interference (EMI)
generate e-mail addresses for a number of environments, such as SMTP, X400, Lotus Notes, or Novell GroupWise.
An e-mail client is a software application that supports specific protocols and provides the user with an interface to a server.
E-mail client
A backup disk that can provide the necessary files to bring back the Windows operating system in the case of a disk disaster running the Windows operating system. You create an ERD using Windows 2000.
Emergency Repair Disk (ERD)
The disruption of one electronic device, caused by an electromagnetic field (in the radio frequency spectrum) generated by another electronic device.
EMI (Electromagnetic Interference)
Encapsulating Security Payload (ESP) is one of two services comprising IPSec. ESP supports both authentication of the sender and is used primarily to encrypt and secure the data transferred between IPSec partners.
Encapsulating Security Payload (ESP)
The process of adding an additional header to a packet before transporting the packet onto the network. For example, NetBIOS can be encapsulated with an IP header.
Encapsulation
A security technique that uses a cryptographic algorithm to encode information so that only someone with the proper key can unencode it.
Encryption
A standard electronic interface that allows a computer to communicate with a storage device such as the hard drive or a CD-ROM drive.
Enhanced Integrated Drive Electronics (EIDE)
A type of hard disk that uses CHS addressing and has a 1024 cylinder limitation. ESDI hard disks are predecessors of the newer IDE disks.
Enhanced Small Device Interface (ESDI)
A backup disk that can provide the necessary files to bring back the Windows operating system in the case of a disk disaster running the Windows operating system. You create an ERD using Windows 2000.
ERD (Emergency Repair Disk)
The values Windows uses to determine what to do in case of an error in loading or initializing drivers. The levels are 0x0 (ignore the error), 0x1 (display an error message then ignore the error), 0x2 (use the LastKnownGood control set and restart), 0x3 (stop the boot sequence and display an error message).
ErrorControl levels
A type of hard disk that uses CHS addressing and has a 1024 cylinder limitation. ESDI hard disks are predecessors of the newer IDE disks.
ESDI (Enhanced Small Device Interface)
Encapsulating Security Payload (ESP) is one of two services comprising IPSec. ESP supports both authentication of the sender and is used primarily to encrypt and secure the data transferred between IPSec partners.
ESP (Encapsulating Security Payload)
One of the major families of network architectures. The structure of all Ethernet networks is based on the bus topology. Most Ethernet networks use baseband signaling and CSMA/CD as a media access method.
Ethernet
The identification for the event that displays in the Event Detail window in the Event Viewer.
Event ID
Any of three log files in which Windows records monitored events such as errors, warnings, and the success or failure of tasks. Event logs include the system, security, and application logs. You can view these logs in the Event Viewer.
Event log
An administration tool that provides information about such events as errors, warnings, and the success or failure of tasks.
Event Viewer
A special group or identity that includes all users and can be used to assign permissions that all users in a domain hold in common, including guests and users from other domains.
Everyone
The Exchange 2007 Management Console is a graphic interface used to manage an Exchange environment. It has been simplified from previous versions of Exchange so it now focuses only on the most commonly executed tasks.
Additional tasks that could traditionally only be performed in REGEDIT or ADSIEDIT were also added to the Exchange Management Console to improve ease of use.
In Exchange 2003, the information shown in the tree-pane was dependent on the configuration of your Exchange Server. This pane is now static in Exchange 2007 Management Console so no matter how many servers you have, what options have been chosen, or what has been installed, the tree-pane will always be the same.
Exchange 2007 Management Console
Exchange ActiveSync is a protocol used by Internet-enabled mobile devices to send and retrieve Exchange data.
Exchange ActiveSync
The Exchange Management Console is the graphical administration tool. It is comprised of a three-paned view that includes a tree view, results, and an actions pane. It cannot perform many of the administrative tasks that can be performed in the Exchange Management Shell.
Exchange Management Console
primary platform for all administration; the graphical interface is simply running atop of the command shell.
The Exchange 2007 Management Shell environment allows administrators to perform all of their tasks from a command line environment, thus making it easier to automate tasks. The PowerShell must be installed before Exchange 2007 is fully installed, then extensions are installed to the PowerShell during Exchange 2007 installation to create the Exchange 2007 PowerShell environment. The PowerShell uses with verb/noun-based syntax and is the primary platform for all administration; the graphical interface is simply running atop of the command shell.
Exchange Management Shell
Microsoft Exchange Management Shell (Windows PowerShell) is a command line environment designed for automating administration and maintenance. The Exchange Management Shell is the primary management interface of 2007.
Exchange PowerShell
A Microsoft Exchange storage group is a collection of Exchange stores (databases). A Recovery Storage Group (RSG) is a special storage group used for recovering Mailbox stores.
Exchange storage group
The central component of Windows network architecture. It includes the managers and device drivers that run in kernel mode.
Executive Services
A 32-bit I/O bus slot providing compatibility with 386 through Pentium machines. EISA buses:
Have a maximum throughput rate of 33 MB/s.
Offer bus mastering which is a mini-processor on the expansion card. The mini-processor assumes the task from the CPU of transferring data to and from memory.
Offer a second row of pins to a standard ISA bus. Provide backward compatibility with ISA cards.
Allow EISA cards to take advantage of both rows of pins (the 32-bit data path) to improve transfer rates and increase addressable memory.
Allow for automatic configuration of system resources (addresses, DMA channels and IRQs).
Support sharing of system resources.
Allow multiple EISA cards to share the same interrupt.
EISA supports multiprocessing by allowing more than one CPU to share the bus.
Are usually black, though they are sometimes white.
Extended Industry Standard Architecture (EISA)
A partition you create from free space on a hard disk and can be subdivided into logical drives. You can have only one extended partition on a single hard disk.
Extended partition
EAP is an authentication protocol (an extension of PPP). It is a set of interface standards that provide various authentication methods (smartcards, biometrics, and digital certificates), define access definitions, providing protection mechanisms and custom solutions, and does not maintain a database of user accounts and passwords.
Extensible Authentication Protocol (EAP)
The Extensible Authentication Protocol over LAN is used for authentication of 802.1X port access control over either wired or wireless LANs.
Extensible Authentication Protocol over LAN (EAPoL)
Exchange 2007’s database engine is referred to as the Extensible Storage Engine (ESE). ESE is a transactional database that writes information into RAM memory and into a log file. Once it is in the log file, it will be written to disk.
There are a number of files used to store information:
Extensible Storage Engine (ESE)
Exterior Gateway Protocol (EGP) is a routing protocol that exchanges routing information between autonomous systems. BGP is the most common EGP protocol.
Exterior Gateway Protocol (EGP)
External BGP (EBGP) is used by BGP to route information between autonomous systems.
External BGP (EBGP)
Accepted domains identify the domains for which the organization is solely responsible and the SMTP domains from which the server will accept messages. There are three types of accepted domains in Exchange 2007:
Authoritative is the domain over which the Exchange server has sole responsibility. In a typical environment, the organization will have an e- mail domain of “company.com” which is hosted by the company’s e-mail server. If another e-mail system or domain exists in the environment, internal and external relays are employed.
An internal relay is an e-mail domain that is hosted by another Active Directory Forest within the Exchange organization. This system uses different e-mail addresses, but all incoming mail goes through the Exchange organization.
An external relay accepts e-mail for an external organization and then delivers it to an external entity such as the Internet via the Edge Transport server.
External relay
An extranet is a division of a private network that is accessible to a limited number of external users, such as business partners, suppliers, and certain customers.
Extranet
Failover is the process of moving services from a failed server to another available server.
Failover
A file system that is required for Windows 95 and MS-DOS based computers.
FAT (File Allocation Table)
A 32-bit file allocation table which was first shipped with Windows 95. FAT32 supports large volumes and is more efficient than the 16-bit FAT system.
FAT32
Fibre Channel (FC) is an integrated set of standards developed to provide a reliable method for quickly transferring large amounts of data. FC is the recommended method of implementing a shared disk array because of its high bandwidth and high capacity. FC communication can also be used to link workstations, mainframes, and other peripherals.
FC (Fibre Channel)
Fibre Channel over IP (FCIP) is an IP-based storage networking technology developed by the Internet Engineering Task Force (IETF). FCIP enables the transmission of data to and from FC storage devices over standard Ethernet copper cabling and switches.
FCIP
The Feasible Distance (FD) is the lowest total cost to a destination network.
FD (Feasible Distance)
A standard produced by the American National Standards Committee for transmitting data on fiber optic lines. FDDI is based on token ring topology and can support a large network over large geographic areas.
FDDI (Fiber Distributed Data Interface)
An MS-DOS utility you can use to create a primary partition or logical drive on a hard disk.
FDISK
The Feasible Distance (FD) is the lowest total cost to a destination network.
Feasible Distance (FD)
A type of signalling method, used by a wireless networking architecture, where a narrow frequency band ‘hops’ data signals in a predictable sequence from frequency to frequency over a wide band of frequencies. Because FHSS hops between frequencies, it can avoid interference on one cable as it shifts to another. Hopping between frequencies increases transmission security by making eavesdropping and data capture more difficult. Because FHSS shifts automatically between frequencies, it can avoid interference that may be on a single frequency.
FHSS (Frequency Hopping Spread Spectrum)
A standard produced by the American National Standards Committee for transmitting data on fiber optic lines. FDDI is based on token ring topology and can support a large network over large geographic areas.
Fiber Distributed Data Interface (FDDI)
Fiber optic cable uses glass strands to transmit light pulses rather than electricity to communicate. Thus, it is not susceptible to most forms of interference or wire taping technologies. The biggest disadvantage to fiber optic cable is the high cost of the cable, its components and installation.
Fiber optic cable
Fibre Channel (FC) is an integrated set of standards developed to provide a reliable method for quickly transferring large amounts of data. FC is the recommended method of implementing a shared disk array because of its high bandwidth and high capacity. FC communication can also be used to link workstations, mainframes, and other peripherals.
Fibre Channel (FC)
Fibre Channel over IP (FCIP) is an IP-based storage networking technology developed by the Internet Engineering Task Force (IETF). FCIP enables the transmission of data to and from FC storage devices over standard Ethernet copper cabling and switches.
Fibre Channel over IP (FCIP)
A file system that is required for Windows 95 and MS-DOS based computers.
File Allocation Table (FAT)
A software component that allows NetWare clients to access file and print services on a Windows 2000 server.
This protocol provides bi-directional file transfers between two TCP/IP hosts. These hosts must be running FTP software.
File and Print Services for NetWare (FPNW)
File transfer protocol (FTP)
Security that is applied to individual files and folders on a local computer.
File-level security
The final partition is the domain naming context partition in Exchange 2007. This is used to hold all of the user accounts, groups, and computer accounts. If mail-enabled context is used, then it is stored in the final partition. The domain naming context stores the largest amount of information in a typical employment.
Final partition
A TCP/IP service that allows you to gather system information from a remote computer.
Finger service
A firewall is the best device to deploy to protect your private network from a public untrusted network. Firewalls are used to control traffic entering and leaving your trusted network environment. Firewalls can manage traffic based on source or destination IP address, port number, service protocol, application or service type, user account, and even traffic content.
Firewall
Firewire is a type of media (cable and connectors) that interface between computers to create a network.
Firewire
Computer instructions contained in programmable read-only memory (PROM). Firmware comes as part of a hardware device such as a printer or modem.
Firmware
With the triggered update method (also known as a flash updates), routers that receive updated (changed) information broadcast those changes immediately rather than waiting for the next reporting interval. With this method, routers broadcast their routing tables periodically, punctuated by special broadcasts if conditions have changed. This method reduces the convergence time.
Flash updates
A floating static route is a static route whose administrative distance has been manually configured to be greater than the administrative distance of dynamic routes; thus making it less desirable than the dynamic route it supports.
Floating static route
A Foreign connector is a logical object that controls the sending of messages to non-SMTP mail systems or to fax systems.
Foreign connector
In Windows 2000, a forest is collection of one or more domains linked with two-way transitive trusts and sharing a common schema, configuration, and global catalog.
Forest
To set up partitions and volumes on a hard disk that will use file system such as FAT or NTFS.
Format
The query process in which DNS domain names are resolved to IP addresses. In contrast, reverse lookup is the query process in which IP addresses are resolved to domain names.
Forward lookup
Forwarders are designated DNS servers that accept and resolve recursively all queries regarding external or off-site addresses. Other servers are configured to send all such queries to the forwarder.
Forwarder
A software component that allows NetWare clients to access file and print services on a Windows 2000 server.
FPNW (File and Print Services for NetWare)
Host names inside domains that are added to the beginning of the domain name. For example, any name given that is placed in front of Microsoft.com, such as support.Microsoft.com, is a fully qualified domain name.
A setting that controls how a network adapter card formats the data you want to send over the network. Ethernet network can operate using various frame types. Ethernet frames are between 64 and 1518 bytes in length. For two computers to communicate, they must use the same frame type. These are the four Ethernet frame types: Ethernet 802.3, Ethernet 802.2, Ethernet II, and Ethernet SNAP.
FQDN (Fully Qualified Domain Names)
Frame type
A type of signalling method, used by a wireless networking architecture, where a narrow frequency band ‘hops’ data signals in a predictable sequence from frequency to frequency over a wide band of frequencies. Because FHSS hops between frequencies, it can avoid interference on one cable as it shifts to another. Hopping between frequencies increases transmission security by making eavesdropping and data capture more difficult. Because FHSS shifts automatically between frequencies, it can avoid interference that may be on a single frequency.
Frequency Hopping Spread Spectrum (FHSS)
The client in the client/server computing model. It provides an interface for the user to enter requests, formats user requests so that the server understands them, and displays data from the server.
Front end
This protocol provides bi-directional file transfers between two TCP/IP hosts. These hosts must be running FTP software.
FTP (File transfer protocol)
A mesh topology exists when there are multiple paths between any two nodes on a network. Mesh topologies are created using point-to-point connections. A full Mesh topology connects every node in a point-to-point connection with every other node. Full mesh topologies are usually impractical because the number of connections increases dramatically with every new node added to the network. However, a full mesh topology becomes more practical through the implementation of an ad-hoc wireless network.
Full Mesh
Full-mesh iBGP is an iBGP network in which each BGP speaker has a neighbor statement containing updated information for all other iBGP speakers in the AS.
Full-mesh iBGP
Host names inside domains that are added to the beginning of the domain name. For example, any name given that is placed in front of Microsoft.com, such as support.Microsoft.com, is a fully qualified domain name.
Fully Qualified Domain Names (FQDN)
A Windows 2000 domain controller that stores at least partial replicas of each partition in the forest. The partial replicas are read-only and make it possible to search the Active Directory database on a forest-wide basis.
Global catalog server
A protocol that makes it easier to browse resources on the Internet by displaying Internet resources in a menu structure.
Gopher
An Active Directory object that contains user-specific and/or computer-specific settings that Windows 2000 must enforce.
GPO (Group Policy Object)
A command-line Windows 2000 Server Resource Kit tool that lets you check replication status of Group Policy Objects (GPOs) on a computer.
Gpotool.exe
A command-line Windows 2000 Server Resource Kit tool that lists the group policy settings applied to a particular user or computer.
Gpresult.exe
The portion of a Group Policy Object (GPO) that is stored on the domain controller’s file system.
GPT (Group Policy Template)
A group of users that have common privileges only in the domain which they were created. Local groups can contain both users and global groups. Global groups are lists of user accounts from within a single domain. A global group can include user accounts from only the domain in which the global group was created.
Group account
The primary Windows 2000 desktop administration feature. Use Group Policy to create Group Policy objects to control and manage users’ computing environments. This includes desktop features such as Start menu options, shortcuts, and available applications, as well as security settings, home folder assignments, auditing, and more.
Group Policy
The portion of a Group Policy Object (GPO) that is stored in Active Directory.
Group Policy Container (GPC)
A domain global group that lets members create Group Policy Objects (GPOs) within the domain.
Group Policy Creator Owners Group
An Active Directory object that contains user-specific and/or computer-specific settings that Windows 2000 must enforce.
Group Policy Object (GPO)
A Microsoft Management Console (MMC) snap-in that lets you view and edit settings for a Group Policy Object (GPO). Also called the Group Policy Editor.
Group Policy Snap-In
The portion of a Group Policy Object (GPO) that is stored on the domain controller’s file system.
Group Policy Template (GPT)
A Windows 2000 service that allows a Windows 2000 server to use file and print resources on a NetWare server.
GSNW (Gateway Services for NetWare)
A built-in account that is used to give occasional users the ability to log on and access limited resources.
Guest
Software that makes it easy for operating systems to interact with different types of hardware.
HAL (Hardware Abstraction Layer)
A magnetic storage device used to store computer data. Workstation computers and servers both have hard disks.
Hard disk
Software that makes it easy for operating systems to interact with different types of hardware.
Hardware Abstraction Layer (HAL)
A list of hardware devices that have been tested by Microsoft and are known to be compatible with Windows 2000.
Hardware Compatibility List (HCL)
A registry entry that lists the physical devices and services on your computer that Windows 2000 should enable on startup. Profiles can be created for
Hardware profile
The header is the initial section of an IPM which contains addressing and routing information for the e-mail message.
Header
A Hello PDU; such as End System Hello (ESH), Intermediate System Hello (ISH), or IS to IS Hello (IIH); establishes and maintain adjacencies.
Hello PDU
A network that consists of many foreign TCP/IP-based hosts is known as a heterogeneous environment. TCP/IP provides the protocol to connect many foreign computer systems, because each system uses the same protocol.
Heterogenous
Hierarchical Storage Management (HSM) monitors the way data is used, then automatically moves data between high- and low-cost storage media in a way that will maximize storage utilization. The bulk of an organization’s data is kept on slower devices, then a copy of that data is transferred to faster disk drives when needed. This process optimizes utilization by allowing the high-speed disk drives to act as caches for the slower mass storage devices.
Hierarchical Storage Management (HSM)
A logical formatting process that prepares the disk to be used by a specific file system. It scans the disk and marks bad sectors, creates the partition boot sector, modifies the partition table on the hard disk, creates the File Allocation Table for FAT volumes, and creates the Master File Table for NTFS volumes.
High-level formatting
A server’s highest local USN value for which another server has received updates. For example, if Server2 has received updates from Server1 up to Server1’s local USN value 4653, then 4653 is Server2’s high-water mark for Server1.
High-water mark
Sections of the Registry made up of keys, subkeys, and values, which are saved as files on your hard disk.
Hives
A protocol used to support NetBIOS over TCP/IP. It is a combination of the p- node and b-node. The default function of an h-node is a P-node. If it cannot resolve a name through the NetBIOS name server, it uses a broadcast to resolve the name.
H-node
The hold time is the amount of time that a neighbor is considered to be functioning properly without a router receiving a packet from the neighbor.
Hold time
With the hold-down method, routers will, for a period of time, “hold” an update that reinstates an expired link. The time period typically reflects the time required to attain convergence on the network. The hold-down timer is reset when the timer runs out or when a network change occurs.
Hold-down method
A designated folder that is accessible to the user and can contain his or her files and programs. The home directory is assigned in Active Directory Users and Computers or Local Users and Groups and can be assigned to one user or shared by many.
Home directory
A hop is a stage on an electronic message’s journey from sender to receiver.
Hop
Alternative names that differentiate multiple Web sites hosted on the same Microsoft Internet Information Server computer. You can allow Web sites to use the same IP address and port number by configuring a unique host header for each site.
An identifier of a workstation, server, router, or other TCP/IP host within a segment. The network ID must be unique to the network ID.
Host headers
Host IDs
An alias assigned to a computer by an administrator to identify a TCP/IP host. The host name can be any 256-character string. Multiple host names can be assigned to the same host. Many utilities can use host names rather than the TCP/IP address. A host name always corresponds to an IP address that is stored in a HOSTS file or in a database on a DNS or NetBIOS name server.
Host name
The process of mapping TCP/IP host names to IP addresses.
Host name resolution
A local text file in the same format as the 4.3 Berkeley Software Distribution (BSD) UNIX\etc\host file that maps host names to IP addresses. This file is used to resolve host names for TCP/IP utilities.
HOSTS file
A hot site is a fault tolerant strategy which provides a redundant work location. If a disaster renders a work site unusable, the effected organization may have a hot site in which to relocate. Hot sites have the following characteristics:
This is a fully configured facility with power, A/C, etc., fully functional servers and clients that are up-to-date mirroring the production system. A hot site is immediately available in the event of a disaster.
The site is expensive to maintain; requires constant maintenance of the hardware, software, data, and applications; and presents a security risk. This facility is necessary when an organization cannot tolerate any downtime.
Hot Site
A hot spare is a component that is connected to a system. A hot spare can take over automatically when another component fails.
Hot Spare
A component that is hot-swappable can be removed and replaced while the system is still running.
Hot Swap
Hierarchical Storage Management (HSM) monitors the way data is used, then automatically moves data between high- and low-cost storage media in a way that will maximize storage utilization. The bulk of an organization’s data is kept on slower devices, then a copy of that data is transferred to faster disk drives when needed. This process optimizes utilization by allowing the high-speed disk drives to act as caches for the slower mass storage devices.
HSM (Hierarchical Storage Management)
A series of rules for formatting documents that you can transfer between platforms. It is the language used to format ASCII text files as pages for the World Wide Web.
HTML (Hypertext Markup Language)
The standard protocol for Internet browsing. Using the Hypertext Transfer Protocol (HTTP) with Exchange lets both users and anonymous users access mailboxes, public folders, and address lists by typing the Exchange server’s URL into an Internet browser.
HTTP (Hypertext Transfer Protocol)
HTTPS is a secure form of HTTP that uses SSL as a sublayer for security.
HTTPS (Hypertext Transfer Protocol over Secure Socket Layer)
A network device that ties multiple workstations (or other devices) together for communication on a network. A hub can come with 5 ports or more and is basically a repeater of data. Also called a multi-port repeater.
The Hub Transport server is responsible for handling all message delivery in Exchange 2007.
Hub
Hub Transport server
A word, phrase, or graphic formatted so that clicking it allows you to display data from another file on your computer, the network, or the Internet.
Hyperlink
A series of rules for formatting documents that you can transfer between platforms. It is the language used to format ASCII text files as pages for the World Wide Web.
Hypertext Markup Language (HTML)
The standard protocol for Internet browsing. Using the Hypertext Transfer Protocol (HTTP) with Exchange lets both users and anonymous users access mailboxes, public folders, and address lists by typing the Exchange server’s URL into an Internet browser.
Hypertext Transfer Protocol (HTTP)
HTTPS is a secure form of HTTP that uses SSL as a sublayer for security.
Hypertext Transfer Protocol over Secure Socket Layer (HTTPS)
Files that contain the necessary Registry keys for specific policy settings. You use the System Preparation Tool and the Setup Manager Wizard to create .INF files for Windows 2000.
A technical advisory group of the Internet Society responsible for setting Internet standards including publishing RFC’s and overseeing the standards process. This organization governs the Internet Engineering Task Force (IETF), Internet Assigned Number Authority (IANA), and the Internet Research Task Force (IRTF).
.INF file
IAB (Internet Architecture Board)
Software services that furnish authentication and security for dial-in users.
IAS (Internet Authentication Service)
Internal BGP (IBGP) is used by BGP to exchange information within the autonomous system.
IBGP (Internal BGP)
ICANN, or the Internet Corporation for Assigned Names and Numbers, is a private non-profit corporation tasked with IP address space allocation, protocol assignment, and domain name system management.
ICANN (Internet Corporation for Assigned Names and Numbers)
An Internet protocol used to report errors and control messages on behalf of IP. ICMP reports errors and provides feedback on specific conditions. ICMP messages are carried as IP datagrams and therefore are not reliable.
ICMP (Internet Control Message Protocol)
A standard electronic interface that allows a computer to communicate with a storage device such as the hard drive or a CD-ROM drive.
IDE (Integrated Device Electronics)
A technical professional group that, among other contributions, develops standards (such as the 802.x series of standards) that often become national and international standards.
IEEE (Institute of Electrical and Electronics Engineers)
This organization works to develop solutions to technical problems as they occur on the Internet. They also work to develop Internet standards and protocols.
IETF (Internet Engineering Task Force)
Informs routers that hosts of a certain multicast group are available on a given network. This information is then passed to other routers so that each router that supports multicasting is aware of which host groups are on a particular network.
IGMP (Internet Group Management Protocol)
IGMP messages to exchange information, such as routing diagrams, with other routers.
IGMP snooping enables a switch to detect multicast patterns and multicast traffic in the overall traffic flow on a network; thus making a switch aware of Layer 3. IGMP Snooping listens to multicast join and remove messages to:
Restrict unwanted traffic flow.
Allow traffic to flow to the optimal ports.
IGMP packets are transported using IP datagrams, and are considered
unreliable.
Interior Gateway Protocol (IGP) is a routing protocol that exchanges information within an autonomous system and can be controlled by the system in which they operate. The most common examples of IGPs are Routing Information Protocol (RIP), Open Shortest Path First (OSPF), Intermediate System-Intermediate System (IS-IS), and Enhanced Interior Gateway Routing Protocol (EIGRP).
IGMP message IGMP snooping
A network server that allows you to send HTML documents using HTTP. IIS installs with Windows 2000 Server. Peer Web Services (PWS) installs with Windows 2000 Professional.
IGP (Interior Gateway Protocol)
Like POP3, IMAP4 is a protocol that allows a client to download messages from a server. (It does not allow you to send messages.) IMAP4 is much more powerful than POP3. For example, with IMAP4, you can open all folders in your mailbox, not just the Inbox, as well as public folders on the server.
IIS (Internet Information Server)
A type of name service record that can be defined by using the DNS Console utility.
IMAP4 (Internet Message Access Protocol Version 4)
In-band management uses a normal network connection with the server for performing management tasks. Tools such as Telnet, Remote Desktop, or SNMP provide in-band server management.
IN record
A backup method that copies to tape only those files that have not been marked by the previous normal or incremental backups. After backing the files to tape, an incremental backup marks each file as having been backed up.
In-band management
The NTFS file system provides the ability to assign individual users access rights to files and folders.
Incremental backup
A 16-bit I/O bus slot found on 286 through Pentium machines. ISA buses:
Have DIP switches and jumpers. Have 98 pins.
Are backwards compatible with earlier 8-bit designs.
Are more likely to be paired with PCI buses rather than being replaced by EISA.
Are normally black plastic.
Individual NTFS permissions (special access permissions)
Infrared (IR) wireless networking employs light waves that are outside of the visible light spectrum. IR networks are very insecure because the signals are not encrypted, and they can be easily intercepted.
Industry Standard Architecture (ISA)
A hardware device that lets you reset the relays on a multi-station access unit.
Infrared (IR)
A technical professional group that, among other contributions, develops standards (such as the 802.x series of standards) that often become national and international standards.
A standard electronic interface that allows a computer to communicate with a storage device such as the hard drive or a CD-ROM drive.
Initialization aid
ISDN is another alternative to traditional dial-up that can be used to connect to the Internet or to directly communicate with another computer connected to the ISDN network. ISDN is more common in Europe than in the U.S. ISDN can use regular telephone wiring, but must be connected to a special ISDN network.
Levels of ISDN service include:
BRI (Basic Rate Interface):
2 64-Kbps bearer (B) channels can transfer data up to 128 Kbps. Only one B channel is used during phone use.
1 16-Kbps delta (D) channel for connection control.
PRI (Primary Rate Interface):
23 B channels (each at 64 Kbps) for data transmission. 1 D channel (at 64 Kbps) for connection control.
Institute of Electrical and Electronics Engineers (IEEE)
Integrated Device Electronics (IDE)
A computer containing an IBM-compatible processor built by Intel, Cyrix, or AMD.
Integrated Services Digital Network (ISDN)
The Intelligent Platform Management Interface (IPMI) is a specification for monitoring physical information about a computer. IPMI is an embedded chip on the motherboard, referred to as the baseboard management controller, which provides system information that allows the network administrator to monitor and manage a remote system, even if the remote system is not powered on.
Intel x86 machines
A system group that is not used for network administration but automatically includes a user who logs on to the computer locally. Interactive members access resources on the computer at which they are physically sitting by logging on and interacting with that computer.
Intelligent Platform Management Interface (IPMI)
Interior Gateway Protocol (IGP) is a routing protocol that exchanges information within an autonomous system and can be controlled by the system in which they operate. The most common examples of IGPs are Routing Information Protocol (RIP), Open Shortest Path First (OSPF), Intermediate System-Intermediate System (IS-IS), and Enhanced Interior Gateway Routing Protocol (EIGRP).
Interactive
Sectors on a hard disk are not consecutively numbered. Instead, they are interleaved. this gives the hard disk drive interface time to process the data before the subsequently-numbered sector passes beneath the read/write head. An interleave ratio of 1:1 has no interleave at all, a 1:2 ratio means the subsequently-numbered sector is the second sector from the current one, a 1:3 ratio means the next sector is three sectors from the current one, and so on.
Interior Gateway Protocol (IGP)
Interleaving increases the rate at which data can be written to or read from a memory module by grouping data into contiguous blocks instead of dispersing data intermittently. The following components must be interleaving-enabled in order for interleaving to work:
Motherboard BIOS
Memory Module
Intermediate System to Intermediate System (IS-IS) is an OSI-based link-state routing protocol.
Interleave ratio
Internal BGP (IBGP) is used by BGP to exchange information within the autonomous system.
Interleaving
Intermediate System to Intermediate System (IS-IS)
Accepted domains identify the domains for which the organization is solely responsible and the SMTP domains from which the server will accept messages. There are three types of accepted domains in Exchange 2007:
Authoritative is the domain over which the Exchange server has sole responsibility. In a typical environment, the organization will have an e- mail domain of “company.com” which is hosted by the company’s e-mail server. If another e-mail system or domain exists in the environment, internal and external relays are employed.
An internal relay is an e-mail domain that is hosted by another Active Directory Forest within the Exchange organization. This system uses different e-mail addresses, but all incoming mail goes through the Exchange organization.
An external relay accepts e-mail for an external organization and then delivers it to an external entity such as the Internet via the Edge Transport server.
Internal BGP (IBGP)
An internal router is located in the same area as all other interfaces. All internal routers with an area have the same are have identical LSDBs.
Internal relay
A committee that has set most standards related to modems since the late 1980s.
Internal router
A general name for the informal system of connected computers all around the world. These computers (and therefore their users) use telephone lines to send and receive data from other computers. In order to send and receive data accurately, the networking software inside the computers uses a set of commonly agreed upon protocols and computer languages.
International Telecommunications Union (ITU)
A technical advisory group of the Internet Society responsible for setting Internet standards including publishing RFC’s and overseeing the standards process. This organization governs the Internet Engineering Task Force (IETF), Internet Assigned Number Authority (IANA), and the Internet Research Task Force (IRTF).
Internet
Software services that furnish authentication and security for dial-in users.
Internet Architecture Board (IAB)
A client computer using SMTP, POP3, IMAP4, HTTP, LDAP, MIME, and/or NNTP protocols to connect to Web sites and receive and send Internet mail.
Internet Authentication Service (IAS)
An Internet protocol used to report errors and control messages on behalf of IP. ICMP reports errors and provides feedback on specific conditions. ICMP messages are carried as IP datagrams and therefore are not reliable.
ICANN, or the Internet Corporation for Assigned Names and Numbers, is a private non-profit corporation tasked with IP address space allocation, protocol assignment, and domain name system management.
Internet clients
This organization works to develop solutions to technical problems as they occur on the Internet. They also work to develop Internet standards and protocols.
Internet Control Message Protocol (ICMP)
Internet Corporation for Assigned Names and Numbers (ICANN)
Informs routers that hosts of a certain multicast group are available on a given network. This information is then passed to other routers so that each router that supports multicasting is aware of which host groups are on a particular network. IGMP packets are transported using IP datagrams, and are considered unreliable.
Internet Engineering Task Force (IETF)
A network server that allows you to send HTML documents using HTTP. IIS installs with Windows 2000 Server. Peer Web Services (PWS) installs with Windows 2000 Professional.
Internet Group Management Protocol (IGMP)
The layer in the TCP/IP protocol suite that includes four Internet protocols. They are Internet Protocol, Address Resolution Protocol, Internet Control Message Protocol, and Internet Group Management Protocol.
Internet Information Server (IIS)
Like POP3, IMAP4 is a protocol that allows a client to download messages from a server. (It does not allow you to send messages.) IMAP4 is much more powerful than POP3. For example, with IMAP4, you can open all folders in your mailbox, not just the Inbox, as well as public folders on the server.
Internet Layer
The protocol in TCP/IP that addresses and sends TCP packets on a network.
Internet Message Access Protocol Version 4 (IMAP4)
IPSec is a security mechanism that can be used as its own VPN protocol for network to network links or it can serve as the data encryption mechanism for other VPN protocols, such as L2TP.
IPSec (Internet Protocol Security) can be used to encrypt any traffic supported by the IP protocol. This includes Web, e-mail, telnet, file transfer, and SNMP traffic as well as countless others. IPSec is fully capable of providing a secure means to communicate for any LAN or Internet based system using TCP/IP.
IPSec is the most widely deployed VPN technology used for network to network VPN links. IPSec can be used to connect two individual systems, a system to a network, or two networks together. VPNs are used to connect trusted systems together over an untrusted network. The Internet is a common untrusted network used to connect distant networks together.
Use IPSec to encrypt data in a VPN tunnel as it passes between two communication partners. Even if someone intercepts the traffic, they will be unable to extract the contents of the messages because they are encrypted.
Internet Protocol (IP)
Internet Protocol version 4 (IPv4) is an address family that is used to identify routing sessions for protocols that use standard IP version 4 address prefixes, such as BGP. In the IPv4 address family:
Unicast or multicast address prefixes can be specified.
Unicast routing information is advertised by default when a BGP peer is configured unless the advertisement of unicast IPv4 information is
Internet Protocol Security (IPSec)
A global organization created in 1992. Responsible for the internetworking technologies and applications of the Internet. It is also responsible for the further development of the standards and protocols that allow the Internet to function.
Internet Society (ISOC)
A network that consists of multiple network segments. Each segment is defined by a separate network address. Internetworks are connected by routers that maintain tables with the addresses of each segment on the network.
Internetwork
IPX/SPX (Internetwork Packet Exchange/Sequenced Packet Exchange) is an older communication protocol used to interconnect clients and servers on a Novell NetWare operating system environment. IPX is a connectionless packet protocol that operates at the Network layer of communication. SPX is a transport layer protocol that sits on top of the IPX layer providing connection- oriented services between network nodes.
Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX)
The Internet organization that has the responsibility to allocate all IP addresses.
InterNIC
The methods by which tasks and processes to exchange data under a multitasking operating system. Mailboxes, queues, semaphores, shared memory, and signals are all IPC mechanisms.
Interprocess communications mechanisms
A physical line that devices use to send signals to the processor when they want to send or receive information.
Interrupt Request Line (IRQ)
A connection object whose source and target replication partners exist in different sites.
Intersite connection object
Replication between sites.
Intersite replication
A domain controller whose Knowledge Consistency Checker (KCC) establishes inbound intersite Connection objects for all bridgehead servers in a site.
Intersite Topology Generator (ISTG)
An intranet is a private network that happens to employ Internet information services.
Intranet
A connection object whose source and target replication partners exist in the same site.
Intrasite connection object
Replication within a site.
Intrasite replication
The process used to resolve the host name associated with a known IP address when a host resolver sends a request to a name server.
Inverse lookup
The protocol in TCP/IP that addresses and sends TCP packets on a network.
IP (Internet Protocol)
A unique address assigned to each computer (workstation or server) on an IP network so they can communicate with each other. IP addresses are usually written in dotted-decimal notation. Each address is made up of four ‘octets’ separated by periods. A typical IP address is written in decimal format. An IP address can be assigned permanently to a single computer (static) or assigned on a session basis by a service such as DHCP (dynamic).
IP Address
IP multicasting is a very efficient and effective tool for transmitting large amounts of data to multiple destinations.
IP multicasting
A TCP/IP utility. Type “ipconfig” at the command prompt to display the TCP/IP information for the computer.
The Intelligent Platform Management Interface (IPMI) is a specification for monitoring physical information about a computer. IPMI is an embedded chip on the motherboard, referred to as the baseboard management controller, which provides system information that allows the network administrator to monitor and manage a remote system, even if the remote system is not powered on.
Ipconfig
IPMI (Intelligent Platform Management Interface)
IPSec is a security mechanism that can be used as its own VPN protocol for network to network links or it can serve as the data encryption mechanism for other VPN protocols, such as L2TP.
IPSec (Internet Protocol Security) can be used to encrypt any traffic supported by the IP protocol. This includes Web, e-mail, telnet, file transfer, and SNMP traffic as well as countless others. IPSec is fully capable of providing a secure means to communicate for any LAN or Internet based system using TCP/IP.
IPSec is the most widely deployed VPN technology used for network to network VPN links. IPSec can be used to connect two individual systems, a system to a network, or two networks together. VPNs are used to connect trusted systems together over an untrusted network. The Internet is a common untrusted network used to connect distant networks together.
Use IPSec to encrypt data in a VPN tunnel as it passes between two communication partners. Even if someone intercepts the traffic, they will be unable to extract the contents of the messages because they are encrypted.
IPSec (Internet Protocol Security)
