What is the purpose of the command "radius-server host"?

The command "radius-server host" is specifically used to configure a RADIUS (Remote Authentication Dial-In User Service) server within a network device, typically a router or switch. This command allows the device to communicate with a designated RADIUS server for authentication, authorization, and accounting (AAA) purposes. When implementing network security, it's essential to ensure that devices can verify the identity of users attempting to gain access, and the "radius-server host" command plays a critical role in establishing that connection with the RADIUS server.

Using this command, network administrators can specify the IP address of the RADIUS server and configure additional parameters, such as the shared secret used for secure communications. This setup is vital for centralized user management and can help streamline administration across multiple devices, improve security protocols, and simplify the authentication process for users.

In contrast, the other options do not pertain directly to the RADIUS server configuration: configuring a local user pertains to user management on the device itself; clearing RADIUS sessions deals with managing current authentication sessions rather than establishing them; and viewing RADIUS statistics relates to monitoring session data and performance metrics, which are secondary functions of network management.