Even with the features and complexity of the server. it is designed to be simple to install and configure. When installing from source, just follow the 4-line instructions on the download page. Or, install a package for your operating system.

Once the server has been installed, edit the raddb/users file, and add the following line of text at the top:

bob   Cleartext-Password := "hello"

Then in a terminal window, start the server in debugging mode:

$ radiusd -X

When the debug messages finish scrolling, go to another terminal window on the same machine, and type:

$ radtest bob hello localhost 0 testing123

The radtest program will send a test packet to the server, and the server will respond. The server should respond with an Access-Accept message. If it doesn't, something has gone wrong, and the debugging output of the server will explain any problems.

If it does work (and it should), then almost all of the available authentication types will now work. In Version 2.0 with the test certificates, most EAP authentication types will also work, including PEAP and EAP-TTLS.

The default configuration has been designed to work in the widest possible set of circumstances. Only minor edits to the configuration files are required to enable most features. Those edits are usually limited to un-commenting a feature everywhere it is mentioned in the configuration files (e.g. use of LDAP). Then, adding a small amount of per-site configuration (e.g. point to a local LDAP server).

In general, making large changes to the default configuration files will break common use-cases. We strongly recommend using a careful process for editing the configuration files, such as the following:

  1. Save a backup of the current configuration.
  2. Make a minor edit.
  3. Test it.
  4. If it works, repeat from the top.

Of course, not all changes may work. If the changes do not behave as expected, then the configuration can be reverted to the known-working backup. The server will then continue to run with the last configuration, giving you time to understand more about how it should be configured to meet your needs.