radvd.8.man

.\"
.\"
.\"   Authors:
.\"    Lars Fenneberg		<lf@elemental.net>
.\"    Robin H. Johnson		<robbat2@gentoo.org>
.\"
.\"   This software is Copyright 1996-2026 by the above mentioned author(s),
.\"   All Rights Reserved.
.\"
.\"   The license which is distributed with this software in the file COPYRIGHT
.\"   applies to this software. If your distribution is missing this file, you
.\"   may request it from https://github.com/radvd-project/radvd/issues
.\"
.\"
.\"
.TH RADVD 8 "30 Dec 2024" "radvd @VERSION@" ""
.SH NAME
radvd \- router advertisement daemon for IPv6
.SH SYNOPSIS
.B radvd
.B "[ \-hsvc ]"
.BI "[ \-d " debuglevel " ]"
.BI "[ \-C " configfile " ]"
.BI "[ \-p " pidfile " ]"
.BI "[ \-m " logmethod " ]"
.BI "[ \-l " logfile " ]"
.BI "[ \-n " nodaemon " ]"
.BI "[ \-f " facility " ]"
.BI "[ \-t " chrootdir " ]"
.BI "[ \-u " username " ]"

.SH DESCRIPTION
.B radvd
is the router advertisement daemon for IPv6. It listens to router
solicitations and sends router advertisements as described in
"Neighbor Discovery for IP Version 6 (IPv6)" (RFC 4861).
With these advertisements hosts can automatically configure their
addresses and some other parameters. It also defines "Neighbor Discovery
Optimization for IPv6 over Low-Power Wireless Personal Area Networks (6LoWPANs)" (RFC6775).
They also can choose a default router based on these advertisements.

The configuration file must not be writable by others, and if
non-root operation is requested, not even by self/own group.

.SH OPTIONS

For every one character option there is also a long option, which
is listed right next to the "short" option name:

.TP
.BR "\-v" , " \-\-version"
Displays the version of
.I radvd
and then aborts.
.TP
.BR "\-h" , " \-\-help"
Displays a short usage description and then aborts.
.TP
.BR "\-c" , " \-\-configtest"
Test configuration and do startup tests and then exit.
.TP
.BR "\-n" , " \-\-nodaemon"
Prevent the daemonizing.
.TP
.BR "\-d " debuglevel, " \-\-debug " debuglevel
With this option you turn on debugging information. The debugging level is
an integer in the range from 1 to 5, from  quiet to very verbose. A
debugging level of 0 completely turns off debugging. If a debugging level
greater than 0 is used,
.I radvd
doesn't background itself on start. The default debugging level is 0.
.TP
.BR "\-C " configfile, " \-\-config " configfile
Specifies an alternate config file. Normally the compiled in default
.I @PATH_RADVD_CONF@
is used.
.TP
.BR "\-p " pidfile, " \-\-pidfile " pidfile
Specifies an alternate pidfile. Normally the compiled in default
.I @PATH_RADVD_PID@
is used.
.TP
.BR "\-m " method, " \-\-logmethod " method
Specifies the logging method to use. Possibly values are:
.RS
.TP
.B none
Completely disables any logging.
.TP
.B logfile
Logs to the logfile which is specified by the
.I \-l
option. If no logfile is specified on the command line, then
a compiled in default is used (see next option).
.TP
.B stderr
Logs to standard error.
.TP
.B stderr_syslog
Logs only the high messages (of at least LOG_ERR priority) to standard
error, and everything to syslog (default method).
.TP
.B syslog
Logs to syslog.
.RE
.PP
.TP
.BR "\-l " logfile, " \-\-logfile " logfile
Specifies the logfile to use when using the logging method
.IR logfile .
The default logfile is
.IR @PATH_RADVD_LOG@ .
.TP
.BR "\-f " facility, " \-\-facility " facility
Specifies the facility (as an integer) when using syslog logging. Default
is @LOG_FACILITY@.
.TP
.BR "\-t " chrootdir, " \-\-chrootdir " chrootdir
If specified, switches to
.I chrootdir
before doing anything else.  This directory and its
subdirectories must have been populated first.
For security reasons,
.I \-u
must always be used when using
.IR chrootdir .

Note that on Linux
.I radvd
requires access to the
.I /proc
filesystem,
so it is more challenging to set up the chroot environment.
.TP
.BR "\-u " username, " \-\-username " username
If specified, drops root privileges and changes user ID to
.I username
and group ID to the primary group of
.IR username .
This is recommended for security reasons.
You might also need to use
.I \-p
to point to a file in a
.I username
-writable directory (e.g. /var/run/radvd/radvd.pid).
.SH FILES

.nf
@sbindir@/radvd
@PATH_RADVD_CONF@
@PATH_RADVD_PID@
@PATH_RADVD_LOG@
.fi
.SH BUGS

There certainly are some bugs. If you find them or have other
suggestions please send to https://github.com/radvd-project/radvd/issues

.SH "SEE ALSO"

.BR radvd.conf (5),
.BR radvdump (8)
.SH AUTHORS

.nf
@AUTHORS@

.fi