Where can I find documentation for FreeRadius?

Question

linux

In the process of integrating the OpenConnect server, I realized that for advanced user access control, Radius is needed.
Installed, configured authentication for VPN, WiFi and DaloRadius interface.
In essence, Radius - gives a set of attributes that can be attached to the user. Where is the CLEAR documentation on all this?
In particular, I'm interested in the IP ranges received by connected clients / groups of clients, the login time limit, by IP from which you can connect.
On the FreeRadius website, there are only vague references to this. Further search did not lead me to any intelligible articles.
If you met with a subject - share please.

Answer 1

The set of available attributes is determined by dictionaries, usually
/etc/raddb/dictionary, /usr/share/freeradius/dictionary.*, see man dictionary
while attributes are standard and vendor-specific.
A table of possible values ​​for standard attributes is maintained by the IANA
www.iana.org/assignments/radius-types/radius-types...
Documentation on Vendor-specific attributes is often not available at all. Do not proceed from the FreeRADIUS capabilities, tk. it doesn't care what attributes to work with, if some attributes are missing, then you can add them to the dictionaries manually, but from which RADIUS attributes are supported by the OpenConnect server.

Answer 2

RADIUS is a protocol - https://en.wikipedia.org/wiki/RADIUS , basic knowledge in it.
The FreeRadius server provides it - freeradius.org/doc
To understand "from and to" - you need to understand the protocol. It has RFCs and stuff. The FreeRaduis server itself is as simple as a plug.
In fact - using the Radius protocol, you connect your OpenConnect with an information base about accesses.