---
name: "radius"
section: "8"
platform: "linux"
package: "inn"
version: "2.7.4-4"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/radius"
---

# radius(8)

nnrpd RADIUS password authenticator

## NAME

radius - nnrpd RADIUS password authenticator

## SYNOPSIS

**radius** \[**-h**\] \[**-f** *config*\]

## DESCRIPTION

**radius** is an **nnrpd** authenticator, accepting a username and password from **nnrpd** (given to **nnrpd** by a reader connection) and attempting to authenticate that username and password against a RADIUS server.  See [readers.conf(5)](/readers.conf/5.md) for more information on how to configure an **nnrpd** authenticator.  It is useful for a site that already does user authentication via RADIUS and wants to authenticate news reading connections as well.

By default, **radius** reads *pathetc*/inn-radius.conf for configuration information, but a different configuration file can be specified with **-f**.  See [inn-radius.conf(5)](/inn-radius.conf/5.md) for a description of the configuration file.

## OPTIONS

- **-f** *config*

  Read *config* instead of *pathetc*/inn-radius.conf for configuration information.

- **-h**

  Print out a usage message and exit.

## EXAMPLE

The following [readers.conf(5)](/readers.conf/5.md) fragment tells **nnrpd** to authenticate all connections using this authenticator:

```
    auth radius {
        auth: radius
        default: <FAIL>
        default-domain: example.com
    }
```

`"@example.com"` will be appended to the user-supplied identity, and if RADIUS authentication fails, the user will be assigned an identity of `"<FAIL>@example.com"`.

## BUGS

It has been reported that this authenticator doesn't work with Ascend RADIUS servers, but does work with Cistron RADIUS servers.  It's also believed to work with Livingston's RADIUS server.  Contributions to make it work better with different types of RADIUS servers would be gratefully accepted.

This code has not been audited against the RADIUS protocol and may not implement it correctly.

## HISTORY

The RADIUS authenticator was originally written by Aidan Cully.  This documentation was written by Russ Allbery \<eagle@eyrie.org\>.

## SEE ALSO

[inn-radius.conf(5)](/inn-radius.conf/5.md), [nnrpd(8)](/nnrpd/8.md), [readers.conf(5)](/readers.conf/5.md).