What is the role of an RADIUS server?

The role of an RADIUS server is primarily to provide centralized authentication for users accessing a network. RADIUS, which stands for Remote Authentication Dial-In User Service, is a networking protocol that enables the management of user access to network resources through a centralized server.

When a user attempts to access a network, their credentials (such as username and password) are sent to the RADIUS server for validation. The server checks these credentials against a database and responds with either access approval or denial. This centralized approach simplifies user management and policy enforcement across multiple network devices, ensuring a consistent authentication process and improving security.

By contrast, connecting network devices is not the primary function of a RADIUS server. While it may interact with devices like access points or switches during the authentication process, its core role is fundamentally about user authentication rather than device connectivity. Additionally, acting as a firewall involves different functions focused on filtering traffic based on security rules, which is not within the purview of RADIUS. Likewise, serving as a DHCP server entails assigning IP addresses to devices on the network, a task separate from user authentication.