F

failback

A term that defines how failed over application services are moved back to the original server node once the node is back online. See also failover.

failover

A term associated with cluster servers, this refers to the ability of a backup server to immediate begin servicing requests if a primary server fails, without an interruption in servicing user requests. See also failback.

filter rules

Rules created using recipient policies. Filter rules are generated using Lightweight Directory Access Protocol (LDAP) syntax and allow you to specify what kind of e-mail address is generated for each recipient object.

firewall

A hardware and software security system that functions to limit access to network resources across subnets. Typically, a firewall is used between a private network and the Internet to prevent outsiders from accessing the private network and limiting what Internet services users of the private network can access.

forest

A grouping of Active Directory trees that have a trust relationship between them. Forests can consist of noncontiguous namespace and, unlike domains and trees, do not have to be given a specific name. An Active Directory forest can only support a single Microsoft Exchange Server 2003 organization.

ForestPrep

A Microsoft Exchange Server 2003 Setup switch that prepares Active Directory for the Exchange Server 2003 installation by extending the schema to support the Exchange Server 2003–specific attributes and classes.

forest root domain

The first domain created in an Active Directory forest.

FQDN

See fully qualified domain name (FQDN).

front-end/back-end

A Microsoft Exchange Server 2003 configuration where servers are used either strictly for authentication and fault tolerance (front-end) or to physically store data (back-end).

fully qualified domain name (FQDN)

A Domain Name System (DNS) domain name that unambiguously describes the location of the host within a domain tree. An example of an FQDN is www.contoso.com.