Episode 144: Centralized Authentication — TACACS+, RADIUS, SSO, and Directory Services

Centralized authentication simplifies user management while enhancing security. In this episode, we compare two core protocols—TACACS+ and RADIUS—and explain their roles in authenticating access to network infrastructure devices. You’ll learn how TACACS+ provides command-level control and full separation of authentication, authorization, and accounting, while RADIUS is more common in end-user access scenarios like VPNs and wireless login.

We also explore Single Sign-On (SSO) systems and directory services like Active Directory and LDAP. These systems allow users to log in once and gain access to multiple services, reducing password fatigue and enabling centralized enforcement of security policies. Centralized authentication is critical for scalable IT environments, and understanding it prepares you for everything from infrastructure hardening to enterprise onboarding.