What is Freeradius?

Freeradius is a server that provides AAA, ie it gives the ability to do Authentication, Authorization and Accounting, along with the Radius protocol. It can perform authentications via PAP, CHAP, MS-CHAP, EAP-MD5, EAP-GTC, EAP-TLS, EAP-TTLS, PEAPv0, LEAP, EAP-SIM according to their creators. It is very modular and flexible, but like most open-source products, it needs to be tuned to achieve better performance and also provide easyness of use and scalability, to be able to manage thousands of users, and why not millions.

Sections

These articles give some directions to understand why and how to do it (in some ways). We focused on installations based on Linux Redhat and a Mysql backend. These remain valid for other systems of course. Check this out:

• Daily Accounting Or how to generate accounting daily in a Mysql database, as oppose to only when the session terminates
  
  

• Large Values of Traffic Or how to handle values larger than 64GB
  
  

• Reset a Session Or how to reset a session with the 'Packet of Disconnect'
  
  

• Archive Old Data Or how to archive old accounting in a Mysql database
  
  

• Usage Graphs ... or how to generate daily usage graphs from the accounting records
  
  

• Which database for Freeradius ... Mysql or Postgresql?
  
  

• Traffic encryption ... Or how to encrypt traffic going from Freeradius to Mysql
  
  

Alternatives

Due or thanks to Freeradius flexibility and the infinite number of configurations, many more articles could be done.
If you want a quicker solution or additional features pre-installed such as replication or redundancy , or a license including full support , you may have a look at a commercial Radius server. Here are a few on the section beside. The list isn't exhaustive but gives a good idea of what's on the market.

Other Radius Servers