This course will teach you FreeRADIUS, an open-source carrier grade RADIUS server.
FreeRADIUS is the most known, open-source implementation of RADIUS service, an IETF protocol for AAA (Authorization, Authentication, and Accounting). In this course, Configuring and Troubleshooting FreeRADIUS, you'll learn to manage FreeRADIUS. First, you'll explore the pivotal role that AAA plays in ISP infrastructure. Next, you'll discover how to install and configure FreeRADIUS. Finally, you'll learn how to tailor your FreeRADIUS solution to cover the requirements of an ISP. When you're finished with this course, you'll have the skills and knowledge needed to configure, troubleshoot, and manage FreeRADIUS.
https://www.pluralsight.com/courses/freeradius-configuring-troubleshooting-cert