Most organizations have a Microsoft Active Directory in place. The Active Directory (or, in short, AD) builds the foundation of their on-premises infrastructure for managing users, performing their primary network authentication and authentication to AD-integrated applications such as Microsoft Exchange Server, and some network infrastructure services including client configuration management based on Group Policies. AD is a purpose-built directory service that is optimized for supporting these requirements. One of the specific capabilities are Group Policies – client management commonly is out-of-scope of directory services. Another example are the sophisticated replication features of AD. These are required to provide (amongst others) seamless authentication and load-balancing of authentication requests and user management.
This works well for the employees and the on-premise IT infrastructure. However, when it comes to external users, things becoming more challenging. While most organizations manage the “long term” externals – the ones who spend a lot of time on-premises, need access to internal IT systems and frequently even have a company e-mail address – in the Active Directory, organizations struggle with managing all the other externals such as employees of business partners with occasional access only to a selected application or customers.
The purpose-built AD is not targeted towards these use cases. On-boarding and off-boarding thousands of employees of an insurance broker or managing the local operators of an airline across the world are not the standard use cases for AD. And what about managing millions of customers that need access to some applications?
There are workarounds, but none of these workarounds is really convincing. These external users might be managed in a separate forest or in a separate domain within an existing forest. They might even be managed within an existing domain (particularly in ADs that follow a single-domain approach), but that makes security management pretty cumbersome. And we do not yet speak about some challenges such as schema changes for specific requirements or the replication issues caused by managing a multitude of users than just the employees in the Active Directory.
The common answer on these challenges is to set up another, separate directory service for external users or customers. Microsoft’s lightweight answer is AD LDS (Active Directory Lightweight Directory Services). Other vendors provide their LDAP (Lightweight Directory Access Protocol) directory servers to manage these users and authenticate them.
But there is another answer now: cloud-based User and Access Management as part of the emerging cloud IAM offerings. Several vendors deliver solutions that allow managing customers and external users in integration with the existing on-premise infrastructure. Microsoft’s own answer in that field is the Azure Active Directory, a cloud-based directory service that it is quite different from the traditional Active Directory. It supports flexible schemas, scales virtually unlimited (Microsoft Office 365 is based on it), and provides functionality that helps managing external users far better than the on-premise Active Directory can do – and potentially better than other on-premise directory services can do. With upcoming extensions, Microsoft will further add capabilities for managing external users.
There are challenges such as synchronizing and/or federating the existing users of AD and other directory services to Azure Active Directory (or other services in that field).
Nevertheless, there are new options now to extend the existing AD to the cloud and to serve new business demand of on-boarding, off-boarding, and managing business partners and customers – delivered by Microsoft and other players in the market. This creates a situation for organizations using AD in which they should start reviewing and rethinking their Active Directory strategy. There are various options for extending the on-premise AD to the cloud, and it is time for defining the future strategy around AD. That future, for most organizations, will be hybrid.
This article was originally published in the KuppingerCole Analysts' View Newsletter.