The Active Directory architecture
allows the Reporter data collection to focus on a particular
DC. By focusing on a particular DC for collection, the speed of the
data collection can increase.
For example, your organization
might have offices in New York, Seattle, and Boston, with
computers from all sites located in the same domain and connected
across a WAN. If a DC is not preset, Active Directory returns the
first available DC in your network, regardless of its distance
across the WAN or its speed. This can cause delays and reduce the
speed of the data collection.