DNS on Windows Server 2003, 3rd Edition

The Impact on Replication

While AD-integrated zones have many advantages, the one potential drawback is how zone data gets replicated in Active Directory. Under Windows 2000, AD-integrated zones are stored in the System container in a domain. That means that every domain controller in that domain replicates that zone data regardless of whether the domain controller is a name server or not. For domain controllers that are not name servers, there is no benefit to replicating the data, which results in needless replication traffic. This can be a serious issue for those that have large zones with many domain controllers that are not name servers. Fortunately, a new feature in Windows Server 2003 called application partitions provides a better alternative.

Another issue with Windows 2000 AD-integrated zones is that domain controllers in subdomains could not replicate the forest root zone resource records through AD replication. You would have to configure the subdomain domain controller as a secondary and enable zone transfer. The requirement to replicate forest root records is common in branch office deployments where a certain amount of autonomy is needed due to potential network outages. Application partitions also help with this requirement.