Windows Server® 2008 Bible

Chapter 20. Active Directory Physical Architecture

IN THIS CHAPTER

• Past, present, and future

• Forests and trusts

• Domain controllers and global catalogs

• Sites

• Active Directory replication

• Directory synchronization

• Active Directory site design and configuration

This chapter reviews the physical structures of Active Directory. It also introduces you to the relationships between domain controllers (DCs) and the various roles of domain controllers, global catalogs (GCs), and sites.

Past, Present, and Future

Past operating systems had no awareness of the underlying physical network structure on which they were deployed. For small companies, or even reasonably large ones, the network layout, interconnection points and subnets, remote offices, and so on were either laid out long before Windows NT became pervasive or were installed independently of the network operating systems that depended on them.

We typically build networks for which the servers reside on 1000-Mbps media, the backbone. There are 1000-Mbps media between floors, and then this network is extended into a 20–100Mbps network down to the users. Windows NT did not care if the networks were 10 Mbps or 10,000 Mbps... it had no built-in means of catering to the available resources.

This is no longer sufficient because Windows Server 2008's physical structure and its multimaster replication technology, GC services, public key infrastructure, directory synchronization, Kerberos authentication, and more do need to be sensibly and carefully built ...