|Lesson 2||Prerequisites |
|Objective|| Verify that you have the right background for this course.|
Active Directory Course Prerequisites
- Windows 2008 or 2012 knowledge and experience
- A thorough understanding of DHCP, WINS, and Internet Protocol (IP) subnetting and routing
- Experience supporting networks and end users
Most of the terms found on this website can be found on the web.
This course is intended for Active Directory Technology Specialists, Server and Enterprise Administrators who want to learn how to implement Active Directory Domain Services in Windows Server environments.
Those participating in this course would be interested in learning how to secure domains by using Group Policies, restore, monitor, and troubleshoot configuration to ensure trouble-free operation of Active Directory Domain Services.
In the next lesson, you will learn what you need to take this course.
History of Relays and Networks
Some would argue that the X.25 networks, the first cloud services in widespread use, were popular in the 1970s and 1980s for remote mainframe terminal access are the beginnings of the Enterprise WAN.
Previsouly, if you wanted to connect LANs that were not in the same location, you used point-to-point leased lines.
These were typically DS0 (56 Kilo bits per second) connections, and then the more expensive T1/E1 connections, and because they were expensive, fractional T1 or T3 become available.
The connections were first done using remote bridges at each end, and later with devices called routers, popularized by Cisco.
At the beginning of the 1990s, Frame Relay service was introduced. While using the same DS0 and fractional or full T1/E1 and T3/E3 connections, by connecting to a cloud from a service provider,
you no longer needed to purchase and manage individual links between each of the locations that you wanted to connect.
Frame Relay service offered much lower monthly WAN costs, far fewer physical connections to manage, allowed the expensive last-mile link bandwidth to be shared (and thus used more efficiently) across multiple remote connections, and required less expensive router hardware than the point-to-point alternative.
This story of OpEx and CapEx caused a revolution in the corporate WAN and contributed to its rapid growth. Within 5 years of its introduction, even the most conservative enterprises such as banks
had migrated to Frame Relay. It was the fastest uptake of any WAN service in history including the Internet.
Elements of Point-to-Point Leased Lines
A point-to-point leased line is the most reliable solution for the communication and connectivity that modern businesses require.
Leased, since the service is paid for with a fixed fee for an agreed upon duration and service capacity. The fixed points in a private network are connected through dedicated digital circuits that vary in capacity and speeds.
This allows businesses to extend the coverage of the business wide area network using secured, highly-reliable and high-speed network connections.
Evolution of the Microsoft NOS
Network operating system is the term used to describe a networked environment in which various types of resources, such as user, group, and computer accounts, are stored in a central repository that is controlled by administrators and accessible to end users. Typically, a NOS environment is comprised of one or more servers that provide NOS services, such as authentication, authorization, and account manipulation, and multiple end users that access those services.
Microsoft's first integrated NOS environment became available in 1990 with the release of Windows NT 3.0, which combined many features of the LAN Manager protocols and of the OS/2 operating system. The NT NOS slowly evolved over the next eight years until Active Directory was first released in beta form in 1997.
Under Windows NT, the domain concept was introduced, providing a way to group resources based on administrative and security boundaries. NT domains were flat structures limited to about 40,000 objects (users, groups, and computers). For large
organizations, this limitation imposed superficial boundaries on the design of the domain
structure. Often, domains were geographically limited as well because the replication of data between domain controllers
(for example, servers providing the NOS services to end users) performed poorly over high-latency or low-bandwidth links.
Another significant problem with the NT NOS was delegation of administration, which typically
tended to be an all-or-nothing matter at the domain level. Microsoft was well aware of these limitations and the need to rearchitect its NOS model into something that would be much more scalable and flexible. It looked to LDAP-based
directory services as a possible solution.