6.6 Using Application Partitions for DNS

Application partitions, as described in Chapter 3, are user-defined partitions that have customized replication scope. Domain controllers that are configured to contain replicas of an application partition will be the only servers that replicate the data contained within the partition. One of the benefits of application partitions is that they are not limited by domain boundaries. You can configure domain controllers in completely different domains to replicate an application partition. It is for these reasons that application partitions make a lot of sense for storing AD Integrated DNS zones. No longer do you have to store DNS data within the domain context and replicate to every domain controller in the domain, even if only a handful are DNS servers. With application partitions you can configure Active Directory to replicate only the DNS data between the domain controllers running the DNS service within a domain or forest.

When installing a new Windows Server 2003 Active Directory forest, the default DNS application partitions are created automatically. If you are upgrading from Windows 2000, you can manually create them by using the DNS MMC snap-in or the dnscmd.exe utility. There is one default application partition for each domain and forest. When configuring an AD Integrated zone in a Windows Server 2003 forest, you have several options for storing the DNS data. These options are listed in Table 6-2.

Table 6-2. Active Directory Integrated DNS zone storage options

Distinguished name	Replication scope
cn=System,DomainDN Example: cn=System,dc=amer,dc=mycorp,dc=com	To all domain controllers in the domain. This is the only storage method available under Windows 2000.
dc=domaindnszones,DomainDN Example: dc=domaindnszones,dc=amer, dc=mycorp,dc=com	To domain controllers in the domain that are also DNS servers.
dc=forestdnszones,ForestDN Example: dc=forestdnszones,dc=mycorp,dc=com	To domain controllers in the forest that are also DNS servers.
AppPartitionDN Example: dc=dnsdata,dc=mycorp,dc=com	To domain controllers that have been configured to replicate the application partition.