Active Directory relies heavily on DNS. In fact, Microsoft has shifted completely away from WINS for name resolution within the NOS in favor of standards-based DNS. The DC locator process is a core DNS-based function used within Active Directory to help domain controllers and clients locate domain controllers that have certain properties, such as residing in a particular site or being a Global Catalog server or PDC emulator. Deciding how to manage the AD DNS zones can be a difficult decision, with each option having its own advantages and disadvantages. If you delegate the zones to domain controllers, AD Integrated zones can save a lot of time in maintenance and upkeep. In Windows Server 2003, you can use application partitions to replicate AD Integrated zones to only the domain controllers that are acting as DNS servers. This can greatly reduce replication traffic in some situations compared to Windows 2000 Active Directory, which replicated DNS data to every domain controller in a domain regardless of whether it was a DNS server.