Internet Authentication Service

Internet Authentication Service (IAS) provides centralized user authentication and authorization, centralized auditing and accounting. While RRAS security is sufficient for small networks, a largest enterprise often needs a dedicated infrasrtracture for authentication. RADIUS is a standard for dedicated authentication servers. Windows Server 2003 includes Microsoft Internet Authentication Service (IAS), an implementation of RADIUS server. IAS supports authentication for Windows-based clients, as well as for third-party clients that adhere to the RADIUS standard. IAS stores its authentication information in Active Directory (AD), and you can manage it with Remote Access Policies.

While IAS requires the use of an additional server component, it provides a number of advantages over the standard methods of RRAS authentication. These advantages include centralized authentication for users, auditing and accounting features, scalability, and seamless integration with the existing features of RRAS.