This chapter described many of the critical objects found in Active Directory and its structure. Active Directories are created using forests (to define a common schema), trees (to define the domain namespace), and finally domains (to define security and replication boundaries).
This chapter also provided descriptions of Active Directory replication and the components that are involved. Sites are used to define areas of high bandwidth, where intrasite replication can take place between domain controllers. Site links are used to link sites together to perform intersite replication.
Case Study - Learning by Example: the "Molly Pitcher Pharmaceuticals, Inc." Company
After reviewing the case study for Molly Pitcher Pharmaceuticals, Inc., there are some issues that need to be analyzed.
Domain namespace: Currently, Molly Pitcher Pharmaceuticals has an Internet presence at mollypitcher.com. As a result, they already have an external namespace. You have two choices to consider here: to keep the existing external namespace (mollypitcher.com) and use it for Active Directory, or create a subdomain off of mollypitcher.com, such as ad.mollypitcher.com. This domain would become the forest root for Active Directory. I would recommend using ad.mollypitcher.com, because the company is already utilizing mollypitcher.com for its Web infrastructure. Using a subdomain gives you more flexibility.
Forest/tree structure: From the case study, there are no obvious reasons to utilize multiple forests (that is, differing schema) or multiple trees (this is, discontiguous namespaces). Because of this, Molly Pitcher's Active Directory infrastructure will be implemented in a single forest/tree structure, where ad.mollypitcher.com is the forest root domain.
Using existing Windows NT domain structure: You could retain the existing Windows NT domain structure, which in this case is a single master domain model. However, the company has stated that the reason they are implementing Active Directory is to avoid the complexity that is inherent in their existing domain structure.
Site structure and replication: Molly Pitcher is a geographically dispersed company, with 13 locations throughout the United States. There are 12 remote offices and headquarters located in Valley Forge, PA. These remote offices are connected to headquarters via T1 lines. Because of this WAN topology, you need to implement Active Directory sites to route replication traffic efficiently. It will also help make directory queries and authentication requests more efficient for users in the remote offices. In this design, you need to create 13 sites and their associated site links. In this case, a single site link is created between the headquarters and each remote office. There are no site links between remote offices. The transport for the site links should be RPC over IP, because the network infrastructure is considered stable.