The most important task that we need to focus on before any other task, when planning for Active Directory Domain Controller, is to our network services' topology. For our Active Directory services to provide a resilient service, we need to be effective in creating a simple (yet descriptive) and scalable architecture that will fit our environment's needs and requirements.

Active Directory Domain Controller can provide us with a centralized management point for our network devices and thus gives us full control over a large number of objects (for example, users and machines). This is the key to achieving a lower cost in administrative tasks, resource control, and security (authentication and authorization) management in a specific network. To organize users and resources in a way that is simple to manage and is scalable (for example, facilitates delegation) is the key. On top of that, there is no reason to have a Domain Controller in our network...