RADIUS
RADIUS (Remote Authentication Dial-In User Service) is a networking protocol that provides centralized authentication, authorization, and accounting (AAA) management for users who connect and use a network service. It is commonly used by Internet Service Providers (ISPs), enterprises, and educational institutions to control access to networks or network resources. The protocol operates in a client-server model where network access servers (clients) communicate with a central RADIUS server to authenticate users and authorize their access.
Developers should learn RADIUS when working on network security, VPNs, Wi-Fi authentication, or any system requiring centralized user access control, as it is a standard for AAA in many environments. It is particularly useful in scenarios like enterprise Wi-Fi networks, dial-up or broadband internet access, and network device administration, where secure and scalable user authentication is critical. Understanding RADIUS helps in integrating authentication systems with directory services like LDAP or Active Directory.