Network Terms "V"

Values

In the Registry, values contain the value name, the type of data the value uses, and the value. Both keys and subkeys can contain values.

In Active Directory, properties common to all objects contain values that correspond to a single user, computer, and so on.

VDD (Virtual Device Driver)

Component that an NTVDM uses to intercept the calls an MS-DOS application makes to the computer's hardware and send them to the Win32 system instead. The application behaves as if it interacts directly with the hardware device.

Vector-based routing protocol

A routing protocol that uses a vector of nearest routers to create a routing table.

VGA (Video Graphics Array)

A display system that is the standard for PC computers.

Video Graphics Array (VGA)

A display system that is the standard for PC computers.

Virtual Device Driver (VDD)

Component that an NTVDM uses to intercept the calls an MS-DOS application makes to the computer's hardware and send them to the Win32 system instead. The application behaves as if it interacts directly with the hardware device.

Virtual directory

A feature of Microsoft Internet Information Server that lets you include information from other folders (besides the designated home directory) in your Web, FTP, and other sites without physically copying the material.

Virtual LAN (VLAN)

Use a switch to create virtual LANs (VLANs). The various ports on a switch can be assigned to a specific VLAN to create logically distinct networks on the same physical network topology.

VLANs reduce the likelihood of traffic interception because the switch creating the VLANs transmits traffic only over the specific port hosting the intended recipient of a message. Thus, eavesdropping on any given segment will reveal only the traffic occurring on that specific segment rather than from the entire network. VLANs decrease broadcast traffic and allow the connection of geographically separate systems into the same network. VLANs usually reduce collisions.

Routers, gateways, and hubs do not support the creation of VLANs.

Virtual link

A virtual link is a link that allows for discontinuous area 0s to be connected. Virtual links also all disconnected areas to be connected to area 0.

Virtual memory

A Windows technique of using hard disk space like RAM. Windows uses a paging file to store information that would otherwise be stored in RAM. Virtual memory allows you to run more applications simultaneously than your system's RAM would normally allow.

Virtual Memory Manager (VMM)

A component of the virtual memory architecture in Windows NT. It intercepts data storage requests from an application, figures out how much space is needed for the data, then gives the data an unused memory address in either virtual or physical memory. With the VMM, an application does not have to keep track of how the physical memory is organized.

Virtual memory page file

Pagefile.sys. A file on a hard disk that Windows uses to transfer information in and out of RAM and virtual memory. Also called a swap file or a paging file.

Virtual private network

Sometimes called a VPN. A VPN is the extension of a private network over a shared or public network such as the Internet. It makes use of encrypted and authenticated links that provide remote access and routed connections between private networks or computers.

Virtual Private Network (VPN)

Sometimes called a VPN. A VPN is the extension of a private network over a shared or public network such as the Internet. It makes use of encrypted and authenticated links that provide remote access and routed connections between private networks or computers.

Virtual server

An independent Web, FTP, or other site hosted on a Microsoft Internet Information Server. You can configure each virtual server independently, as if it were a physically separate server.

Virus

A virus is the common name for a program that has no useful purpose, but attempts to spread itself to other systems and often damages resources on the systems where it is found. Viruses are a serious threat to computer systems, especially if they are connected to the Internet. It is often a minimal requirement to have an anti-virus scanner installed on every machine of a secured network to protect against viruses.

E-mail is the most common means of virus distribution. Often viruses will employ self-contained SMTP servers to facilitate self-replication and distribution over the Internet. Viruses are able to spread quickly and broadly by exploiting the communication infrastructure of Internet e-mail. For this reason, it is important to keep your anti-virus software updated so as to block any possible attempt of viruses to infect your systems or to spread to other systems from your system.

Floppy disks, downloaded music files, and commercial software CDs all have the potential to spread viruses, but they are not as common as e-mail.

VLAN (Virtual LAN)

Use a switch to create virtual LANs (VLANs). The various ports on a switch can be assigned to a specific VLAN to create logically distinct networks on the same physical network topology.

VLANs reduce the likelihood of traffic interception because the switch creating the VLANs transmits traffic only over the specific port hosting the intended recipient of a message. Thus, eavesdropping on any given segment will reveal only the traffic occurring on that specific segment rather than from the entire network. VLANs decrease broadcast traffic and allow the connection of geographically separate systems into the same network. VLANs usually reduce collisions.

Routers, gateways, and hubs do not support the creation of VLANs.

VMM (Virtual Memory Manager)

A component of the virtual memory architecture in Windows NT. It intercepts data storage requests from an application, figures out how much space is needed for the data, then gives the data an unused memory address in either virtual or physical memory. With the VMM, an application does not have to keep track of how the physical memory is organized.

Volume

A partition or several partitions you have formatted to use a file system such as FAT or NTFS.

Volume set

A method of combining areas on different hard drives into a single volume. Data fills each part of the volume before filling the next.

Volume Shadow Copy Service (VSS)

Volume Shadow Copy Service (VSS) is a component of Windows Server 2003 that takes a point-in-time snapshot of files on the disk. By enabling VSS, you can quickly back up and restore files.

VPN (Virtual Private Network)

Sometimes called a VPN. A VPN is the extension of a private network over a shared or public network such as the Internet. It makes use of encrypted and authenticated links that provide remote access and routed connections between private networks or computers.

VSS (Volume Shadow Copy Service)

Volume Shadow Copy Service (VSS) is a component of Windows Server 2003 that takes a point-in-time snapshot of files on the disk. By enabling VSS, you can quickly back up and restore files.