1.\" $KAME: rtadvd.8,v 1.24 2002/05/31 16:16:08 jinmei Exp $ 2.\" 3.\" Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the project nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.Dd February 25, 2013 31.Dt RTADVD 8 32.Os 33.Sh NAME 34.Nm rtadvd 35.Nd router advertisement daemon 36.Sh SYNOPSIS 37.Nm 38.Op Fl dDfRs 39.Op Fl c Ar configfile 40.Op Fl C Ar ctlsock 41.Op Fl M Ar ifname 42.Op Fl p Ar pidfile 43.Op Ar interface ... 44.Sh DESCRIPTION 45.Nm 46sends router advertisement packets to the specified 47.Ar interfaces . 48If no interfaces are specified, 49.Nm 50will still run, but will not advertise any routes until interfaces are 51added using 52.Xr rtadvctl 8 . 53.Pp 54The program will daemonize itself on invocation. 55It will then send router advertisement packets periodically, as well 56as in response to router solicitation messages sent by end hosts. 57.Pp 58Router advertisements can be configured on a per-interface basis, as 59described in 60.Xr rtadvd.conf 5 . 61.Pp 62If there is no configuration file entry for an interface, 63or if the configuration file does not exist altogether, 64.Nm 65sets all the parameters to their default values. 66In particular, 67.Nm 68reads all the interface routes from the routing table and advertises 69them as on-link prefixes. 70.Pp 71.Nm 72also watches the routing table. 73If an interface direct route is 74added on an advertising interface and no static prefixes are 75specified by the configuration file, 76.Nm 77adds the corresponding prefix to its advertising list. 78.Pp 79Similarly, when an interface direct route is deleted, 80.Nm 81will start advertising the prefixes with zero valid and preferred 82lifetimes to help the receiving hosts switch to a new prefix when 83renumbering. 84Note, however, that the zero valid lifetime cannot invalidate the 85autoconfigured addresses at a receiving host immediately. 86According to the specification, the host will retain the address 87for a certain period, which will typically be two hours. 88The zero lifetimes rather intend to make the address deprecated, 89indicating that a new non-deprecated address should be used as the 90source address of a new connection. 91This behavior will last for two hours. 92Then 93.Nm 94will completely remove the prefix from the advertising list, 95and succeeding advertisements will not contain the prefix information. 96.Pp 97Moreover, if the status of an advertising interface changes, 98.Nm 99will start or stop sending router advertisements according 100to the latest status. 101.Pp 102The 103.Fl s 104option may be used to disable this behavior; 105.Nm 106will not watch the routing table and the whole functionality described 107above will be suppressed. 108.Pp 109Basically, hosts MUST NOT send Router Advertisement messages at any 110time (RFC 4861, Section 6.2.3). 111However, it would sometimes be useful to allow hosts to advertise some 112parameters such as prefix information and link MTU. 113Thus, 114.Nm 115can be invoked if router lifetime is explicitly set zero on every 116advertising interface. 117.Pp 118The command line options are: 119.Bl -tag -width indent 120.\" 121.It Fl c 122Specify an alternate location, 123.Ar configfile , 124for the configuration file. 125By default, 126.Pa /etc/rtadvd.conf 127is used. 128.It Fl C 129Specify an alternate location for the control socket used by 130.Xr rtadvctl 8 . 131The default is 132.Pa /var/run/rtadvd.sock . 133.It Fl d 134Print debugging information. 135.It Fl D 136Even more debugging information is printed. 137.It Fl f 138Foreground mode (useful when debugging). 139Log messages will be dumped to stderr when this option is specified. 140.It Fl M 141Specify an interface to join the all-routers site-local multicast group. 142By default, 143.Nm 144tries to join the first advertising interface appearing on the command 145line. 146This option has meaning only with the 147.Fl R 148option, which enables routing renumbering protocol support. 149.It Fl p 150Specify an alternative file in which to store the process ID. 151The default is 152.Pa /var/run/rtadvd.pid . 153.It Fl R 154Accept router renumbering requests. 155If you enable it, certain IPsec setup is suggested for security reasons. 156This option is currently disabled, and is ignored by 157.Nm 158with a warning message. 159.It Fl s 160Do not add or delete prefixes dynamically. 161Only statically configured prefixes, if any, will be advertised. 162.El 163.Pp 164Use 165.Dv SIGHUP 166to reload the configuration file 167.Pa /etc/rtadvd.conf . 168If an invalid parameter is found in the configuration file upon the reload, 169the entry will be ignored and the old configuration will be used. 170When parameters in an existing entry are updated, 171.Nm 172will send Router Advertisement messages with the old configuration but 173zero router lifetime to the interface first, and then start to send a new 174message. 175.Pp 176Use 177.Dv SIGTERM 178to kill 179.Nm 180gracefully. 181In this case, 182.Nm 183will transmit router advertisement with router lifetime 0 184to all the interfaces 185.Pq in accordance with RFC 4861 6.2.5 . 186.Sh FILES 187.Bl -tag -width Pa -compact 188.It Pa /etc/rtadvd.conf 189The default configuration file. 190.It Pa /var/run/rtadvd.pid 191The default process ID file. 192.El 193.Sh EXIT STATUS 194.Ex -std 195.Sh SEE ALSO 196.Xr rtadvd.conf 5 , 197.Xr rtadvctl 8 , 198.Xr rtsol 8 199.Rs 200.%A Thomas Narten 201.%A Erik Nordmark 202.%A W. A. Simpson 203.%A Hesham Soliman 204.%T Neighbor Discovery for IP version 6 (IPv6) 205.%R RFC 4861 206.Re 207.Rs 208.%A Thomas Narten 209.%A Erik Nordmark 210.%A W. A. Simpson 211.%T Neighbor Discovery for IP version 6 (IPv6) 212.%R RFC 2461 (obsoleted by RFC 4861) 213.Re 214.Rs 215.%A Richard Draves 216.%T Default Router Preferences and More-Specific Routes 217.%R draft-ietf-ipngwg-router-selection-xx.txt 218.Re 219.Rs 220.%A J. Jeong 221.%A S. Park 222.%A L. Beloeil 223.%A S. Madanapalli 224.%T IPv6 Router Advertisement Options for DNS Configuration 225.%R RFC 6106 226.Re 227.Sh HISTORY 228The 229.Nm 230command first appeared in the WIDE Hydrangea IPv6 protocol stack kit. 231.Sh BUGS 232There used to be some text that recommended users not to let 233.Nm 234advertise Router Advertisement messages on an upstream link to avoid 235undesirable 236.Xr icmp6 4 237redirect messages. 238However, based on the later discussion in the IETF ipng working group, 239all routers should rather advertise the messages regardless of 240the network topology, in order to ensure reachability. 241