230 lines
7.1 KiB
Groff
230 lines
7.1 KiB
Groff
.\" $NetBSD: rtadvd.8,v 1.26 2017/11/06 15:15:04 christos Exp $
|
|
.\" $KAME: rtadvd.8,v 1.24 2002/05/31 16:16:08 jinmei Exp $
|
|
.\"
|
|
.\" Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. Neither the name of the project nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.Dd November 6, 2017
|
|
.Dt RTADVD 8
|
|
.Os
|
|
.Sh NAME
|
|
.Nm rtadvd
|
|
.Nd router advertisement daemon
|
|
.Sh SYNOPSIS
|
|
.Nm
|
|
.Op Fl DdfRs
|
|
.Op Fl c Ar configfile
|
|
.Op Fl M Ar ifname
|
|
.Op Fl p Ar pidfile
|
|
.Ar interface ...
|
|
.Sh DESCRIPTION
|
|
.Nm
|
|
sends router advertisement packets to the specified interfaces.
|
|
.Pp
|
|
The program will daemonize itself on invocation.
|
|
It will then send router advertisement packets periodically, as well
|
|
as in response to router solicitation messages sent by end hosts.
|
|
.Pp
|
|
Router advertisements can be configured on a per-interface basis, as
|
|
described in
|
|
.Xr rtadvd.conf 5 .
|
|
.Pp
|
|
If there is no configuration file entry for an interface,
|
|
or if the configuration file does not exist at all,
|
|
.Nm
|
|
sets all the parameters to their default values.
|
|
In particular,
|
|
.Nm
|
|
reads all the interface routes from the routing table and advertises
|
|
them as on-link prefixes.
|
|
.Pp
|
|
.Nm
|
|
also watches the routing table.
|
|
If an interface direct route is
|
|
added on an advertising interface and no static prefixes are
|
|
specified by the configuration file,
|
|
.Nm
|
|
adds the corresponding prefix to its advertising list.
|
|
.Pp
|
|
Similarly, when an interface direct route is deleted,
|
|
.Nm
|
|
will start advertising the prefixes with zero valid and preferred
|
|
lifetimes to help the receiving hosts switch to a new prefix when
|
|
renumbering.
|
|
Note, however, that the zero valid lifetime cannot invalidate the
|
|
autoconfigured addresses at a receiving host immediately.
|
|
According to the specification, the host will retain the address
|
|
for a certain period, which will typically be two hours.
|
|
The zero lifetimes rather intend to make the address deprecated,
|
|
indicating that a new non-deprecated address should be used as the
|
|
source address of a new connection.
|
|
This behavior will last for two hours.
|
|
Then
|
|
.Nm
|
|
will completely remove the prefix from the advertising list,
|
|
and succeeding advertisements will not contain the prefix information.
|
|
.Pp
|
|
Moreover, if the status of an advertising interface changes,
|
|
.Nm
|
|
will start or stop sending router advertisements according
|
|
to the latest status.
|
|
.Pp
|
|
The
|
|
.Fl s
|
|
option may be used to disable this behavior;
|
|
.Nm
|
|
will not watch the routing table and the whole functionality described
|
|
above will be suppressed.
|
|
.Pp
|
|
Basically, hosts MUST NOT send Router Advertisement messages at any
|
|
time (RFC 2461, Section 6.2.3).
|
|
However, it would sometimes be useful to allow hosts to advertise some
|
|
parameters such as prefix information and link MTU.
|
|
Thus,
|
|
.Nm
|
|
can be invoked if router lifetime is explicitly set to zero on every
|
|
advertising interface.
|
|
.Pp
|
|
The command line options are:
|
|
.Bl -tag -width indent
|
|
.\"
|
|
.It Fl c Ar configfile
|
|
Specify an alternate location,
|
|
.Ar configfile ,
|
|
for the configuration file.
|
|
By default,
|
|
.Pa /etc/rtadvd.conf
|
|
is used.
|
|
.It Fl D
|
|
Instead of printing errors using
|
|
.Xr syslog 3
|
|
send them to
|
|
.Dv stderr .
|
|
Also when
|
|
.Xr poll 2
|
|
fails, exit instead of retrying.
|
|
.It Fl d
|
|
Print debugging information.
|
|
Repeating this option, adds more verbose debugging.
|
|
.It Fl f
|
|
Foreground mode (useful when debugging).
|
|
Log messages will be dumped to stderr when this option is specified.
|
|
.It Fl M Ar ifname
|
|
Specify an interface to join the all-routers site-local multicast group.
|
|
By default,
|
|
.Nm
|
|
tries to join the first advertising interface appearing on the command
|
|
line.
|
|
This option has meaning only with the
|
|
.Fl R
|
|
option, which enables routing renumbering protocol support.
|
|
.\".It Fl m
|
|
.\"Enables mobile IPv6 support.
|
|
.\"This changes the content of router advertisement option, as well as
|
|
.\"permitted configuration directives.
|
|
.It Fl p Ar pidfile
|
|
Specify an alternate location,
|
|
.Ar pidfile ,
|
|
for the PID file.
|
|
By default,
|
|
.Pa /var/run/rtadvd.pid
|
|
is used.
|
|
.It Fl R
|
|
Accept router renumbering requests.
|
|
If you enable it, an
|
|
.Xr ipsec 4
|
|
setup is suggested for security reasons.
|
|
.\"On KAME-based systems,
|
|
.\".Xr rrenumd 8
|
|
.\"generates router renumbering request packets.
|
|
This option is currently disabled, and is ignored by
|
|
.Nm
|
|
with a warning message.
|
|
.It Fl s
|
|
Do not add or delete prefixes dynamically.
|
|
Only statically configured prefixes, if any, will be advertised.
|
|
.El
|
|
.Pp
|
|
Use
|
|
.Dv SIGHUP
|
|
to reload the configuration file
|
|
.Pa /etc/rtadvd.conf .
|
|
If an invalid parameter is found in the configuration file upon the reload, the
|
|
entry will be ignored and the old configuration will be used.
|
|
When parameters in an existing entry are updated,
|
|
.Nm
|
|
will send Router Advertisement messages with the old configuration but zero
|
|
router lifetime to the interface first, and then start to send a new message.
|
|
.Pp
|
|
Upon receipt of signal
|
|
.Dv SIGUSR1 ,
|
|
.Nm
|
|
will dump the current internal state into
|
|
.Pa /var/run/rtadvd.dump .
|
|
.Pp
|
|
Use
|
|
.Dv SIGTERM
|
|
to kill
|
|
.Nm
|
|
gracefully.
|
|
In this case,
|
|
.Nm
|
|
will transmit router advertisement with router lifetime 0
|
|
to all the interfaces
|
|
.Pq in accordance with RFC 2461 6.2.5 .
|
|
.Sh FILES
|
|
.Bl -tag -width /var/run/rtadvd.dumpXX -compact
|
|
.It Pa /etc/rtadvd.conf
|
|
The default configuration file.
|
|
.It Pa /var/run/rtadvd.pid
|
|
Contains the PID of the currently running
|
|
.Nm .
|
|
.It Pa /var/run/rtadvd.dump
|
|
The file in which
|
|
.Nm
|
|
dumps its internal state.
|
|
.El
|
|
.Sh EXIT STATUS
|
|
.Ex -std rtadvd
|
|
.Sh SEE ALSO
|
|
.Xr rtadvd.conf 5 ,
|
|
.Xr rtsol 8
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
command first appeared in the WIDE Hydrangea IPv6 protocol stack kit.
|
|
.Sh BUGS
|
|
There used to be some text that recommended users not to let
|
|
.Nm
|
|
advertise Router Advertisement messages on an upstream link to avoid
|
|
undesirable
|
|
.Xr icmp6 4
|
|
redirect messages.
|
|
However, based on later discussion in the IETF IPng working group,
|
|
all routers should rather advertise the messages regardless of
|
|
the network topology, in order to ensure reachability.
|