2 .\" $KAME: rtadvd.8,v 1.24 2002/05/31 16:16:08 jinmei Exp $
4 .\" Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 .\" All rights reserved.
7 .\" Redistribution and use in source and binary forms, with or without
8 .\" modification, are permitted provided that the following conditions
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.
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
36 .Nd router advertisement daemon
40 .Op Fl c Ar configfile
44 sends router advertisement packets to the specified
47 The program will daemonize itself on invocation.
48 It will then send router advertisement packets periodically, as well
49 as in response to router solicitation messages sent by end hosts.
51 Router advertisements can be configured on a per-interface basis, as
55 If there is no configuration file entry for an interface,
56 or if the configuration file does not exist altogether,
58 sets all the parameters to their default values.
61 reads all the interface routes from the routing table and advertises
62 them as on-link prefixes.
65 also watches the routing table.
66 If an interface direct route is
67 added on an advertising interface and no static prefixes are
68 specified by the configuration file,
70 adds the corresponding prefix to its advertising list.
72 Similarly, when an interface direct route is deleted,
74 will start advertising the prefixes with zero valid and preferred
75 lifetimes to help the receiving hosts switch to a new prefix when
77 Note, however, that the zero valid lifetime cannot invalidate the
78 autoconfigured addresses at a receiving host immediately.
79 According to the specification, the host will retain the address
80 for a certain period, which will typically be two hours.
81 The zero lifetimes rather intend to make the address deprecated,
82 indicating that a new non-deprecated address should be used as the
83 source address of a new connection.
84 This behavior will last for two hours.
87 will completely remove the prefix from the advertising list,
88 and succeeding advertisements will not contain the prefix information.
90 Moreover, if the status of an advertising interface changes,
92 will start or stop sending router advertisements according
97 option may be used to disable this behavior;
99 will not watch the routing table and the whole functionality described
100 above will be suppressed.
102 Basically, hosts MUST NOT send Router Advertisement messages at any
103 time (RFC 2461, Section 6.2.3).
104 However, it would sometimes be useful to allow hosts to advertise some
105 parameters such as prefix information and link MTU.
108 can be invoked if router lifetime is explicitly set zero on every
109 advertising interface.
111 The command line options are:
112 .Bl -tag -width indent
115 Specify an alternate location,
117 for the configuration file.
122 Print debugging information.
124 Even more debugging information is printed.
126 Foreground mode (useful when debugging).
127 Log messages will be dumped to stderr when this option is specified.
129 Specify an interface to join the all-routers site-local multicast group.
132 tries to join the first advertising interface appearing on the command
134 This option has meaning only with the
136 option, which enables routing renumbering protocol support.
138 Accept router renumbering requests.
139 If you enable it, certain IPsec setup is suggested for security reasons.
140 This option is currently disabled, and is ignored by
142 with a warning message.
144 Do not add or delete prefixes dynamically.
145 Only statically configured prefixes, if any, will be advertised.
148 Upon receipt of signal
151 will dump the current internal state into
152 .Pa /var/run/rtadvd.dump .
161 will transmit router advertisement with router lifetime 0
162 to all the interfaces
163 .Pq in accordance with RFC2461 6.2.5 .
167 program exits 0 on success, and >0 on failures.
169 .Bl -tag -width Pa -compact
170 .It Pa /etc/rtadvd.conf
171 The default configuration file.
172 .It Pa /var/run/rtadvd.pid
173 contains the pid of the currently running
175 .It Pa /var/run/rtadvd.dump
178 dumps its internal state.
186 command first appeared in the WIDE Hydrangea IPv6 protocol stack kit.
188 There used to be some text that recommended users not to let
190 advertise Router Advertisement messages on an upstream link to avoid
194 However, based on the later discussion in the IETF ipng working group,
195 all routers should rather advertise the messages regardless of
196 the network topology, in order to ensure reachability.