DNS on Windows Server 2003, 3rd Edition

Storing Zones in Active Directory

One of Microsoft’s innovative uses of Active Directory is for storing (and replicating) DNS zone data. A traditional name server stores copies of the zones it supports in files on a local disk. In this model, you have a primary master name server that replicates the zone data to secondary name servers. A secondary can process updates to a zone from its master name server in two different ways. The original method supported by DNS is zone transfer, which allows secondary name servers to request a full copy of a zone. A newer method, which is an improvement on the zone transfer process, is incremental zone transfer. With incremental zone transfer, a secondary name server can request just the updates to the zone that occurred since its last transfer.

Active Directory provides another method for replicating zone content, albeit only for name servers running on domain controllers. You can make a zone AD-integrated, which means that instead of storing zone content in text files, it is stored in the Active Directory database. This makes a lot of sense because you take advantage of Active Directory’s multimaster replication scheme, which means that any domain controller that is also a primary name server for the AD-integrated zone can update it directly, like a primary name server. With AD-integrated zones, replication is handled automatically, so you don’t need to develop your own zone transfer replication topology.

One other note about Active Directory-integrated ...