The FreeRADIUS Project
FreeRADIUS is the most widely deployed RADIUS server in the world. It is the basis for multiple commercial offerings. It supplies the AAA needs of many Fortune-500 companies and Tier 1 ISPs.
Beginners to RADIUS should read
Technical Guide. Chapter 2 describes RADIUS concepts, such as
"authorization", "accounting", and how the NAS and server communicate.
i.e. how RADIUS works. Chapter 3 describes how to install FreeRADIUS.
Chapter 4 describes what configuration files are distributed with the
server, and what they are used for. This includes describing the
packet processing lists (
etc.), and the various configuration sections
We recommend reading Chapter 4 to anyone who wants to understand how the server works.
There is extensive documentation for the server available via the Network RADIUS Documentation page. The "introduction" and "concepts" chapters are not available there yet, as those subjects are covered in the Technical guide.
We recommend in particular the modules page, which contains documentation for nearly every module distributed with the server. We also recommend the Unlang keywords page, which describes what each keyword does, and how it is used.
The "stable release" of FreeRADIUS is version 3. The goal of this version is stability. Version 3 introduces a number of major changes over Version 2. The debugging output is clearer (and colourised!), more errors are found while the configuration files are parsed instead of at run-time, RADIUS over TLS (i.e. RadSec) and RADIUS over TCP are supported. The raddb/ directory has been re-arranged so that files are easier to find.
Upgrading to v3 from v2? Please read the upgrade guide.
The "previous stable" release of FreeRADIUS was version 2.
The v2.2.x series is now End Of Life. Only security fixes will be applied to v2.2.x. Users of 2.2.x are encouraged to migrate to the latest version 3 release