A component of an application
filter that monitors content, as in a check for viruses,
and that can also modify content.
data filter
object
In application filters, a COM object that implements the
IFWXDataFilter
interface.
data packet
A sequence of binary digits, including data and control
signals, that is transmitted and switched as a composite whole. The
data, control signals, and, possibly, error control information are
arranged in a specific format.
data source
name (DSN)
The logical name that allows a connection to an Open Database
Connectivity (ODBC) data source, such as a SQL Server
database.
demand-dial
connections
A process used by autodial to perform on-demand outgoing
connections either to an Internet service provider or to a
corporate office from a branch office.
DHCP
See Dynamic Host Configuration Protocol (DHCP).
Digest
authentication
An authentication method for HTTP clients, in which an
encrypted digest or hash of the user’s credentials and additional
data is created in a process known as hashing. This way, no other
user can impersonate the original sender of the request. A hash
cannot feasibly be decrypted to recover the original user name and
password. Digest authentication can be used only in Windows
Server 2003 and Windows 2000 domains for users who have
an account stored in Active Directory. See also Basic
authentication, Integrated
authentication, and Advanced
Digest authentication.
digital
certificate
A digital document that is commonly used for authentication and
secure exchange of information on open networks, such as the
Internet, extranets, and intranets. A certificate securely binds a
public key to the entity that holds the corresponding private key.
Certificates are digitally signed by the issuing certification
authority and can be issued for a user, a computer, or a service.
The most widely accepted format for certificates is defined by the
ITU-T X.509 version 3 international standard.
discretionary
access control list (DACL)
A list that is controlled by the owner of an object and that
specifies the access that particular users or groups can have to
the object.
distributed
caching
The caching of Internet objects in an array or chain of ISA
Server computers, providing load balancing and fault tolerance.
Client requests are sent through the array, to upstream ISA Server
computers, or any combination thereof.
The computer name that substitutes for a network IP address.
For example, www.microsoft.com is a computer name that represents
the IP address 157.45.60.81. A computer name is also called a
friendly name. See also Domain Name System (DNS).
Domain Name
System (DNS)
A protocol and computer-naming hierarchy used throughout the
Internet to map computer IP addresses to their domain names. DNS is
sometimes referred to as the BIND service.
driver
A software component that allows a computer to send and receive
information to and from a hardware device.
DSN
See data source name (DSN).
dynamic filters
Filters that are automatically started by the Microsoft
Firewall service, Web proxy, or SOCKS proxy service. This feature
allows the ISA Server services to automatically open and close
communication ports on the external interface when transmission of
packets is needed.
Dynamic
Host Configuration Protocol (DHCP)
A protocol that offers dynamic assignment of IP addresses and
related information for temporarily connected network users. DHCP
provides safe, reliable, and simple TCP/IP network configuration,
prevents address conflicts, and helps conserve the use of IP
addresses through centralized management of address
allocation.