1.\" $NetBSD: rtadvd.8,v 1.17 2002/05/29 14:48:49 wiz Exp $ 2.\" $KAME: rtadvd.8,v 1.18 2002/04/28 10:43:02 jinmei Exp $ 3.\" 4.\" Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5.\" All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the project nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.Dd May 17, 1998 32.Dt RTADVD 8 33.Os 34.Sh NAME 35.Nm rtadvd 36.Nd router advertisement daemon 37.Sh SYNOPSIS 38.Nm 39.Op Fl c Ar configfile 40.Op Fl dDfMRs 41.Ar interface ... 42.Sh DESCRIPTION 43.Nm 44sends router advertisement packets to the specified 45.Ar interfaces . 46.Pp 47The program will daemonize itself on invocation. 48It will then send router advertisement packets periodically, as well 49as in response to router solicitation messages sent by end hosts. 50.Pp 51Router advertisements can be configured on a per-interface basis, as 52described in 53.Xr rtadvd.conf 5 . 54.Pp 55If there is no configuration file entry for an interface, 56or if the configuration file does not exist altogether, 57.Nm 58sets all the parameters to their default values. 59In particular, 60.Nm 61reads all the interface routes from the routing table and advertises 62them as on-link prefixes. 63.Pp 64.Nm 65also watches the routing table. 66By default, if an interface direct route is 67added/deleted on an advertising interface and no static prefixes are 68specified by the configuration file, 69.Nm 70adds/deletes the corresponding prefix to/from its advertising list, 71respectively. 72The 73.Fl s 74option may be used to disable this behavior. 75Moreover, if the status of an advertising interface changes, 76.Nm 77will start or stop sending router advertisements according 78to the latest status. 79.Pp 80Basically, hosts MUST NOT send Router Advertisement messages at any 81time (RFC 2461, Section 6.2.3). 82However, it would sometimes be useful to allow hosts to advertise some 83parameters such as prefix information and link MTU. 84Thus, 85.Nm 86can be invoked if router lifetime is explicitly set zero on every 87advertising interface. 88.Pp 89The command line options are: 90.Bl -tag -width indent 91.\" 92.It Fl c 93Specify an alternate location, 94.Ar configfile , 95for the configuration file. 96By default, 97.Pa /etc/rtadvd.conf 98is used. 99.It Fl d 100Print debugging information. 101.It Fl D 102Even more debugging information is printed. 103.It Fl f 104Foreground mode (useful when debugging). 105Log messages will be dumped to stderr when this option is specified. 106.It Fl M 107Specify an interface to join the all-routers site-local multicast group. 108By default, 109.Nm 110tries to join the first advertising interface appearing on the command 111line. 112This option has meaning only with the 113.Fl R 114option, which enables routing renumbering protocol support. 115.\".It Fl m 116.\"Enables mobile IPv6 support. 117.\"This changes the content of router advertisement option, as well as 118.\"permitted configuration directives. 119.It Fl R 120Accept router renumbering requests. 121If you enable it, certain IPsec setup is suggested for security reasons. 122.\"On KAME-based systems, 123.\".Xr rrenumd 8 124.\"generates router renumbering request packets. 125This option is currently disabled, and is ignored by 126.Nm 127with a warning message. 128.It Fl s 129Do not add or delete prefixes dynamically. 130Only statically configured prefixes, if any, will be advertised. 131.El 132.Pp 133Upon receipt of signal 134.Dv SIGUSR1 , 135.Nm 136will dump the current internal state into 137.Pa /var/run/rtadvd.dump . 138.Pp 139Use 140.Dv SIGTERM 141to kill 142.Nm 143gracefully. 144In this case, 145.Nm 146will transmit router advertisement with router lifetime 0 147to all the interfaces 148.Pq in accordance with RFC2461 6.2.5 . 149.Sh EXIT STATUS 150The 151.Nm 152program exits 0 on success, and \*[Gt]0 on failures. 153.Sh FILES 154.Bl -tag -width Pa -compact 155.It Pa /etc/rtadvd.conf 156The default configuration file. 157.It Pa /var/run/rtadvd.pid 158contains the pid of the currently running 159.Nm rtadvd . 160.It Pa /var/run/rtadvd.dump 161The file in which 162.Nm 163dumps its internal state. 164.El 165.Sh SEE ALSO 166.Xr rtadvd.conf 5 , 167.Xr rtsol 8 168.Sh HISTORY 169The 170.Nm 171command first appeared in the WIDE Hydrangea IPv6 protocol stack kit. 172.Sh BUGS 173There used to be some text that recommended users not to let 174.Nm 175advertise Router Advertisement messages on an upstream link to avoid 176undesirable 177.Xr icmp6 4 178redirect messages. 179However, based on the later discussion in the IETF ipng working group, 180all routers should rather advertise the messages regardless of 181the network topology, in order to ensure reachability. 182