RADIUS - remote authentication protocol explained

Remote Authentication Dial-In User Service

Unlocking the Power of RADIUS Servers

In the realm of network authentication, RADIUS (Remote Authentication Dial-In User Service) servers stand as the cornerstone, providing robust authentication, authorization, and accounting for network access. But what exactly is a RADIUS server, and how does it revolutionize network security in the IoT era?

Understanding the Essence of RADIUS Servers

A RADIUS server is a critical component of network infrastructure, operating on port 1812 to facilitate secure authentication and authorization for network access. Developed by Livingston Enterprises, Inc. in 1991, RADIUS was initially designed for dial-up remote access but has evolved to become a staple in wired and wireless Internet service providers' and organizations' arsenal for ensuring secure Internet access.

Deciphering RADIUS Server Authentication

At its core, a RADIUS server acts as the gatekeeper to network resources, verifying user credentials provided by the RADIUS client to authorize access. Utilizing a shared secret, which is never transmitted over the network, RADIUS ensures secure authentication and data transmission between the client and the server.

Configuring RADIUS Servers for Enhanced Security

Configuring a RADIUS server involves setting up the shared secret, typically configured as a text string on both the RADIUS client and the server, to authenticate transactions securely. This shared secret plays a pivotal role in securing the information transmitted between the client and the server, safeguarding against unauthorized access and data breaches.

Exploring RADIUS Server Protocols and Transport

Operating at the application layer (layer 7), RADIUS is a client/server protocol that can utilize either TCP or UDP as its transport protocol. This flexibility in transport protocols ensures seamless communication between the RADIUS client and server, facilitating efficient authentication and authorization processes.

Summary

Remote Authentication Dial-In User Service (RADIUS) is a widely deployed system operating on port 1812, to provide authentication, authorization and accounting for network access. RADIUS was developed by Livingston Enterprises, Inc. in 1991 and was initially used for dial-up remote access, but nowadays, RADIUS is used by many (wired and wireless) Internet service providers and end user organizations to provide secure Internet access. When a user wants to get access to the network, the user first provides user credentials (in most cases username and password) to a local RADIUS client. The RADIUS client passes this information to a RADIUS server. This server verifies that the information is correct and then authorizes access.

Transactions between the client and RADIUS server are authenticated through the use of a shared secret, which is never sent over the network. The shared secret is used to secure the information that is transmitted between the client and the server. The shared secret is commonly configured as a text string on both the RADIUS client (user) and the RADIUS server. RADIUS is a client/server protocol that runs on the application layer (layer 7), and can use either TCP or UDP as its transport protocol. RADIUS is often the back-end choice for 802.1X authentication.