A Guide to Active Directory Replication
Prior to the introduction of Windows 2000 Server and Active Directory, many corporate environments relied on Windows NT for their server infrastructure and identity and access management. By the time Windows NT 4.0 rolled out, it was a solid offering in the network operating system (NOS) space, but it had a number of drawbacks that made it difficult to deploy across a large enterprise. For starters, Windows NT utilized a flat namespace to store network resources, which meant that there wasn't a good way to separate resources into smaller subsets or to configure any sort of granular administration. You could not, for example, configure a departmental container for the resources in your marketing department or configure a local administrator who had rights to reset passwords for the users within that department only. In this manner, Windows NT security was largely all-or-nothing; if you wanted to delegate administrative tasks to a desktop support engineer, you often were forced to grant far more permissions than you would have otherwise.
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