->Zone Types

There are a number of zones used in Windows Server 2003 DNS:
1. Primary zone: This is only zone type that can be directly updated or edited because the data in the zone is the original source of the data for all domains in the zone. Updates made to the primary zone are made by the DNS server that is authoritative for the specific primary zone. You can also back up data from a primary zone to a secondary zone.

2. Secondary zone: This is a read-only copy of the zone that was copied from the master server during zone transfer. In fact, a secondary zone can only be updated through zone transfer.

3. Active Directory-integrated zone: This is an authoritative primary zone that stores its data in Active Directory. Active Directory-integrated zones can be regarded as enhanced standard primary zones. Zone data of an Active Directory-integrated zone is replicated during the Active Directory replication process. Active Directory-integrated zones also enjoy the security features of Active Directory.

4. Stub zone: Stub zones only contain those resource records necessary to identify the authoritative DNS servers for the master zone. Stub zones therefore contain only a copy of a zone, and are used to resolve recursive queries and iterative queries:
· Iterative queries: The DNS server provides the best answer it can. This can be:
oThe resolved name
o A referral to a different DNS server
· Recursive queries: The DNS server has to reply with the requested information, or with an error. The DNS server cannot provide a referral to a different DNS server.

Stub zones contain the following information:
*Start of Authority (SOA) resource records of the zone.
*Resource records that list the authoritative DNS servers of the zone
*Glue address (A) resource records that are necessary for contacting the authoritative servers of the zone.