Plan the Hub Site Deployment
Applies To: Windows Server 2008
Plan to deploy Windows Server 2008 writeable domain controllers in your hub sites before you begin to deploy read-only domain controllers (RODCs) in branch offices.
As a best practice, make all your bridgehead servers run Windows Server 2008 before you install any RODCs. This helps ensure that RODC replication connections are evenly load-balanced across all the bridgehead servers and that failover for RODCs works automatically. You should also make sure that hub site bridgehead servers host all the partitions that RODCs must replicate, including global catalog partitions and DNS application directory partitions.
If you are using preferred bridgehead server lists, make sure that they include at least one writeable Windows Server 2008 domain controller in the same domain as the RODCs. RODC replication will fail if the servers in the list do not host all the partitions that the RODCs must replicate. We recommend that all the bridgehead servers run Windows Server 2008 to make troubleshooting replication errors easier and to ensure that branch RODCs can fail over if a hub site domain controller fails. In addition, ensure that the bridgehead servers host all the directory partitions that the branch office domain controllers need to replicate, including Domain Name System (DNS) partitions and other application directory partitions and the global catalog.
We also recommend that you deploy a hotfix that prevents Windows Server 2003 domain controllers from performing automatic site coverage for a site that includes an RODC. You must apply this hotfix to any Windows Server 2003 domain controllers that you plan to continue to use and that are configured to perform automatic site coverage. For more information about how Windows Server 2003 domain controllers perform automatic site coverage for a site that has an RODC, see article 944043 in the Microsoft Knowledge Base (http://go.microsoft.com/fwlink/?LinkId=122974). For more information about other known issues related to RODCs, see Known Issues for Deploying RODCs (http://go.microsoft.com/fwlink/?LinkId=152838).
The following topics describe hub site deployment issues in more detail: