RADIUSD(8)

✨ RADIUSD(8) ✨

okay so bestie, welcome to the FreeRADIUS Daemon page πŸ’– this is radiusd(8), the main character of the whole FreeRADIUS situation. buckle up, she's iconic πŸ‘‘


🌸 NAME 🌸

radiusd β€” the Authentication, Authorization and Accounting server, aka the bouncer, the clipboard girlie, and the accountant all in one 🫢


πŸ¦‹ SYNOPSIS πŸ¦‹

radiusd [-C] [-d config_directory] [-D dictionary_directory] [-f] [-h]
[-i ip-address] [-l log_file] [-m] [-n name] [-p port] [-P] [-s] [-t]
[-v] [-x] [-X]

πŸ’œ DESCRIPTION πŸ’œ

FreeRADIUS is a high-performance and highly configurable RADIUS server, no cap. she supports so many database back-ends it's honestly giving overachiever: flat-text files, SQL, LDAP, Perl, Python, etc. 😭✨

and the authentication protocols?? literally a whole roster: PAP, CHAP, MS-CHAP(v2), HTTP Digest, and EAP (that's EAP-MD5, EAP-TLS, PEAP, EAP-TTLS, EAP-SIM, etc. β€” she does the whole alphabet fr fr πŸ’…).

she also has full support for Cisco's VLAN Query Protocol (VMPS) and DHCP. versatile queen 🌈

bestie pls actually read the DEBUGGING section below. it has the instructions for quickly configuring the server for your local system and it will save your whole life πŸ™ˆ

πŸŽ€ OPTIONS πŸŽ€

the following command-line options are accepted by the server:

  • -C β€” check the configuration and exit immediately πŸ’… if there's a problem reading the configuration, the server exits with a non-zero status code. if the configuration appears acceptable, she exits with a zero status code. and yes, there are limitations to this check β€” because almost-starting a RADIUS server is so complicated, these checks are necessarily incomplete 😭 the server can return a zero status code when run with -C, but may still exit with an error when run normally. check the output of radiusd -XC for the informative list of which modules get checked for correct configuration, and which get skipped (and therefore not checked) πŸ‘€
  • -d config directory β€” defaults to /etc/freeradius. Radiusd looks here for its configuration files such as the dictionary and the users files πŸ—‚οΈ
  • -D dictionary directory β€” set main dictionary directory. defaults to /usr/share/freeradius πŸ“š
  • -f β€” do not fork, stay running as a foreground process πŸ§β™€οΈ
  • -h β€” print usage help information πŸ™‹β™€οΈ
  • -i ip-address β€” defines which IP address the server uses for sending and receiving packets. if this command-line option is given, then the "bind_address" and all "listen{}" entries in radiusd.conf are ignored 🚫 this option MUST be used in conjunction with -p. periodt.
  • -l log_file β€” defaults to ${logdir}/radius.log. Radiusd writes its logging information to this file πŸ“ if log_file is the string "stdout" then logging gets written to stdout instead, cute πŸ’–
  • -m β€” on SIGINT or SIGQUIT, exit cleanly instead of immediately. most useful when you're running the server with "valgrind" 🧚
  • -n name β€” read freeradius/name.conf instead of freeradius/radiusd.conf πŸ“›
  • -p port β€” defines which port is used for receiving authentication packets. accounting packets are received on "port + 1" πŸ”’ when this command-line option is given, all "listen" sections in radiusd.conf are ignored 🚫 this option MUST be used in conjunction with -i. again. periodt.
  • -P β€” always write out PID, even with -f πŸ†”
  • -s β€” run in "single server" mode. normally the server runs with multiple threads and/or processes, which can lower its response time to requests. some systems have issues with threading though, so "single server" mode may help address those issues πŸ› οΈ in single server mode, the server will also not "daemonize" (auto-background) itself πŸšΆβ™€οΈ
  • -t β€” do not spawn threads 🧡🚫
  • -v β€” print server version information and exit πŸ‘‹
  • -X β€” debugging mode. equivalent to "-sfxx -l stdout" πŸ” when you're trying to understand how the server works, ALWAYS run it with "radiusd -X". for production servers, use "raddebug" instead ⚠️
  • -x β€” finer-grained debug mode. in this mode the server prints details of every request on its stdout output πŸ‘€ you can specify this option multiple times (-x -x or -xx) to get more detailed output. stack 'em bestie πŸ“šβœ¨

πŸ”₯ DEBUGGING πŸ”₯

the default configuration is set to work in the widest possible circumstances 🌍 it requires minimal changes for your system. lowkey a gift.

but your needs may be complex, and may require significant changes to the server configuration. and making random changes is a guaranteed method of failure πŸ’€ instead, we STRONGLY RECOMMEND proceeding via the following steps:

  1. always run the server in debugging mode ( radiusd -X ) after making a configuration change. we cannot emphasize this enough 😀 if you are not running the server in debugging mode, you will not be able to see what it is doing, and you will not be able to correct any problems. if you ask questions on the mailing list, the first response will be to tell you "run the server in debugging mode". please, follow these instructions 🫢
  2. change as little as possible in the default configuration files. the server contains a decade of experience with protocols, databases, and different systems 🧠 its default configuration is designed to work almost everywhere, and to do almost everything you need ✨
  3. when you make a small change, test it before changing anything else. if the change works, save a copy of the configuration, and make another change πŸ’Ύ if the change doesn't work, debug it, and try to understand why it doesn't work πŸ” if you begin by making large changes to the server configuration, it will never work, and you will never be able to debug the problem 😭
  4. if you need to add a connection to a database FOO (e.g. LDAP or SQL), then:
    1. edit freeradius/modules/foo β€” this file contains the default configuration for the module. it contains comments describing what can be configured, and what those configuration entries mean πŸ“–
    2. edit freeradius/sites-available/default β€” this file contains the default policy for the server. e.g. "enable CHAP, MS-CHAP, and EAP authentication". look in this file for all references to your module "foo". read the comments, and remove the leading hash '#' from the lines referencing the module. this enables the module βœ…
    3. edit freeradius/sites-available/inner-tunnel β€” this file contains the default policy for the "tunneled" portion of certain EAP methods. perform the same kind of edits as above, for the "default" file. if you are not using EAP (802.1X), then this step can be skipped πŸ™ˆ
    4. start the server in debugging mode ( radiusd -X ), and start testing πŸ§ͺ
  5. ask questions on the mailing list (freeradius-users@lists.freeradius.org) πŸ’Œ when asking questions, include the output from debugging mode ( radiusd -X ). this information will allow people to help you. if you do not include it, the first response to your message will be "post the output of debug mode" 😭 ask questions earlier, rather than later. if you cannot solve a problem in a day, ask a question on the mailing list. most questions have been seen before, and can be answered quickly ⚑

🌈 BACKGROUND 🌈

RADIUS is a protocol spoken between an access server β€” typically a device connected to several modems or ISDN lines β€” and a radius server πŸ“‘ when a user connects to the access server, (s)he is asked for a loginname and a password. this information is then sent to the radius server. the server replies with "access denied", or "access OK" 🚦 in the latter case login information is sent along, such as the IP address in the case of a PPP connection 🌐

the access server also sends login and logout records to the radius server so accounting can be done 🧾 these records are kept for each terminal server separately in a file called detail, and in the wtmp compatible logfile /var/log/radwtmp πŸ“‚


🧚 CONFIGURATION 🧚

Radiusd uses a number of configuration files. each file has its own manpage describing the format of the file πŸ“„ these files are:

  • radiusd.conf β€” the main configuration file, which sets the administrator-controlled items πŸ‘‘
  • dictionary β€” this file is usually static. it defines all the possible RADIUS attributes used in the other configuration files πŸ“š you don't have to modify it. it includes other dictionary files in the same directory πŸ—‚οΈ
  • hints β€” defines certain hints to the radius server based on the user's loginname or other attributes sent by the access server πŸ’‘ it also provides for mapping user names (such as Pusername -> username). this provides the functionality that the Livingston 2.0 server has as "Prefix" and "Suffix" support in the users file, but is more general ✨ of course the Livingston way of doing things is also supported, and you can even use both at the same time (within certain limits) 🀝
  • huntgroups β€” defines the huntgroups that you have, and makes it possible to restrict access to certain huntgroups to certain (groups of) users 🎯
  • users β€” here the users are defined πŸ‘₯ on a typical setup, this file mainly contains DEFAULT entries to process the different types of logins, based on hints from the hints file. authentication is then based on the contents of the UNIX /etc/passwd file πŸ” however it is also possible to define all users, and their passwords, in this file πŸ“

πŸ’– SEE ALSO πŸ’–

radiusd.conf(5), users(5), huntgroups(5), hints(5), dictionary(5), raddebug(8) β€” go read them bestie, iykyk 🫢


πŸ‘‘ AUTHOR πŸ‘‘

The FreeRADIUS Server Project (http://www.freeradius.org) β€” literal icons, we stan 🌟


and that's the whole page babes πŸ’… this was the RADIUSD(8) manual from the FreeRADIUS Daemon, dated 26 Apr 2012 ✨ slay, go run radiusd -X and hydrate πŸ’§πŸŽ€