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.TH radrelay.conf 5 "27 May 2005" "" "FreeRADIUS configuration file"
.SH NAME
radrelay.conf - configuration file for the FreeRADIUS server "radrelay" personality
.SH DESCRIPTION
The \fBradrelay.conf\fP file resides in the radius database directory,
by default \fB/etc/freeradius/3.0\fP.  It defines the global configuration for
the FreeRADIUS server, when the server is operating as "radrelay".
.SH "FILE FORMAT"
For a detailed description of the file format, see "man radiusd.conf".
The configuration entries are much the same for radrelay.conf, with a
few differences as noted here.
.SH "REPLICATION FOR BACKUPS"
Many sites run multiple radius servers; at least one primary and one
backup server. When the primary goes down, most NASes detect that and
switch to the backup server.

That will cause your accounting packets to go to the backup server -
and some NASes don't even switch back to the primary server when it
comes back up.

The result is that accounting records are missed, and/or the
administrator must jump through hoops in order to combine the
different detail files from multiple servers. It also means that the
session database ("radutmp", used for radwho and simultaneous use
detection) gets out of sync.

radrelay solves this issue by "relaying" packets from one server to
another, so they both have the same set of accounting data.
.SH "BUFFERING FOR HIGH-LOAD SERVERS"
If the RADIUS server suddenly receives a many accounting packets,
there may be insufficient CPU power to process them all in a timely
manner.  This problem is especially noticeable when the accounting
packets are going to a back-end database.

Similarly, you may have one database that tracks "live" sessions, and
another that tracks historical accounting data.  In that case,
accessing the first database is fast, as it is small.  Accessing the
second database many be slower, as it may contain multiple gigabytes
of data.  In addition, writing to the first database in a timely
manner is important, while data may be written to the second database
with a few minutes delay, without any harm being done.
.SH "RELAYING OF ACCOUNTING PACKETS"
The \fBradrelay.conf\fP file controls the "radrelay" personality of
the server, which can perform both of the functions above at the same
time.
.SH USAGE
First, you should configure the main radius server to log to an extra,
single detail file.  This may be done by adding an extra instance of
the detail module to \fBradiusd.conf\fP:

For example:

.DS
	detail radrelay-detail {
.br
		filename = ${radacctdir}/radrelay/detail
.br
		permissions = 0600
.br
		dir_permissions = 0755
.br
		locking = yes
.br
	}
.br
	...
.br
	accounting {
.br
		...
.br
		radrelay-detail
.br
		...
.br
	}
.br
.DE
This configuration will cause accounting packets to be logged to the
\fI${radacctdir}/radrelay/detail\fP file.  This file should not be
rotated by standard log rotation scripts, as the \fBradrelay\fP
program will read and rotate it.
.SH RADRELAY.CONF EXAMPLE
See the \fBradrelay.conf\fP file for detailed instructions on
configuration entries, what they mean, and how to use them.

To have the "radrelay" portion of the server read the above detail
file, configure \fBradrelay.conf\fP with the following section:

.DS
.br
	listen {
.br
		type = detail
.br
		filename = ${radacctdir}/radrelay/detail
.br
		max_outstanding = 100
.br
		identity = radrelay
.br
	}
.br
.DE

The server will read the accounting packets from the detail file, and
process them just as if it had received them from the NAS.  Therefore,
you should configure the "accounting" section of \fBradrelay.conf\fP
to write the accounting records to an "sql" module, or to proxy them
to another RADIUS server.

Then, start the server via the following command:

$ radiusd \-n radrelay

The server should start up, read the detail file, and process
accounting packets from it.
.SH NOTES
The \fBradiusd.conf\fP file is not read at all when the server is
running as radrelay.  Please edit \fBradrelay.conf\fP.
.SH CREDITS
The original "radrelay" program was written by Miquel van Smoorenburg
for the Cistron radius project, and ported to FreeRADIUS by Simon
Ekstrand.  The "radsqlrelay" was written by Kostas Kalavras.  It was
never released as part of an official FreeRADIUS release, but served as
a basis for the design of this implementation.
.PP
.SH FILES
/etc/freeradius/3.0/radrelay.conf
.SH "SEE ALSO"
.BR radiusd (8),
.BR radiusd.conf (5)
.SH AUTHOR
Alan DeKok <aland@ox.org>