A forest is a single domain, but can contain multiple domains depending on the requirements of the business. The first domain installed becomes the forest root domain.
A domain added to the forest may inherit a portion of its namespace from its parent domain. A new domain tree will start its own namespace inside the forest.
Two-way transitive trust relationships are automatically established between all parent and child domains within the same forest.
An explicit trust must be defined between two forests.
Domains within the same tree share a contiguous namespace (that is, a child domain inherits a portion of its namespace from its parent domain).
Domains requiring a unique namespace can be established as a new tree within a forest.
Two-way transitive trusts are automatically established between any new trees established within the forest and the forest root domain; this creates a trust path throughout the forest, making resources available forest-wide.
Windows Server 2003 can interoperate with vendors' versions of DNS. DNS versions BIND 4.9.7 and later support SRV records. BIND 8.2.2 and later support dynamic update.
Windows Server 2003 supports a forest trust. This allows two separate forests to be linked together with a one-way or two-way transitive trust. Doing so can form a transitive trust between every domain in each forest.
