1 .\" $KAME: rtadvd.conf.5,v 1.50 2005/01/14 05:30:59 jinmei Exp $
3 .\" Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
4 .\" All rights reserved.
6 .\" Redistribution and use in source and binary forms, with or without
7 .\" modification, are permitted provided that the following conditions
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.
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
30 .\" $FreeBSD: stable/10/usr.sbin/rtadvd/rtadvd.conf.5 233522 2012-03-26 21:22:53Z joel $
37 .Nd config file for router advertisement daemon
39 This file describes how the router advertisement packets must be constructed
40 for each of the interfaces.
44 you do not have to set this configuration file up at all,
45 unless you need some special configurations.
46 You may even omit the file as a whole.
49 daemon will automatically configure itself using default values
50 specified in the specification.
55 Each line in the file describes a network interface.
56 Fields are separated by a colon
58 and each field contains one capability description.
59 Lines may be concatenated by the
62 The comment marker is the
66 Capabilities describe the value to be filled into ICMPv6 router
67 advertisement messages and to control
70 Therefore, you are encouraged to read IETF neighbor discovery documents
71 if you would like to modify the sample configuration file.
73 Note that almost all items have default values.
74 If you omit an item, the default value of the item will be used.
76 There are two items which control the interval of sending router advertisements.
77 These items can be omitted, then
79 will use the default values.
80 .Bl -tag -width indent
82 (num) The maximum time allowed between sending unsolicited
83 multicast router advertisements
85 The default value is 600.
86 Its value must be no less than 4 seconds
87 and no greater than 1800 seconds.
89 (num) The minimum time allowed between sending unsolicited multicast
92 The default value is the one third of value of
94 Its value must be no less than 3 seconds and no greater than .75 *
99 The following items are for ICMPv6 router advertisement message
101 These items can be omitted, then
103 will use the default values.
104 .Bl -tag -width indent
106 (num) The value for Cur Hop Limit field.
107 The default value is 64.
109 (str or num) A 8-bit flags field in router advertisement message header.
110 This field can be specified either as a case-sensitive string or as an
112 A string consists of characters each of which corresponds to a
113 particular flag bit(s).
114 An integer should be the logical OR of all enabled bits.
119 means Managed address configuration flag bit,
124 means Other stateful configuration flag bit.
133 are used to encode router preference.
138 means high, 00 means medium, and 11
143 Bits 10 is reserved, and must not be specified.
144 There is no character to specify the medium preference explicitly.
145 The default value of the entire flag is 0
149 which means no additional
150 configuration methods, and the medium router preference.
152 (num) Router lifetime field
154 The value must be either zero or between
160 runs on a host, this value must explicitly set 0 on all the
161 advertising interfaces as described in
163 The default value is 1800.
165 (num) Reachable time field
166 .Pq unit: milliseconds .
167 The default value is 0, which means unspecified by this router.
169 (num) Retrans Timer field
170 .Pq unit: milliseconds .
171 The default value is 0, which means unspecified by this router.
174 The following items are for ICMPv6 prefix information option,
175 which will be attached to router advertisement header.
176 These items can be omitted, then
178 will automatically get appropriate prefixes from the kernel's routing table,
179 and advertise the prefixes with the default parameters.
184 can be augmented with a number, like
186 to specify multiple prefixes.
187 .Bl -tag -width indent
189 (bool) Specifies no prefix on the network interfaces will be advertised.
192 automatically gathers on-link prefixes from all of the network interfaces
196 disables that behavior.
197 If this is specified and no
199 keyword is specified, no prefix information option will be included in the
202 (num) Time skew to adjust link propagation delays and clock skews
203 between routers on the link
205 This value is used in consistency check for locally-configured and
206 advertised prefix lifetimes, and has its meaning when the local router
207 configures a prefix on the link with a lifetime that decrements in
209 If the value is 0, it means the consistency check will be skipped
211 The default value is 0.
213 (num) Prefix length field.
214 The default value is 64.
216 (str or num) A 8-bit flags field in prefix information option.
217 This field can be specified either as a case-sensitive string or as an
219 A string consists of characters each of which corresponds to a
220 particular flag bit(s).
221 An integer should be the logical OR of all enabled bits.
226 means On-link flag bit,
231 means Autonomous address-configuration flag bit.
232 The default value is "la" or 0xc0, i.e., both bits are set.
234 (str) The address filled into Prefix field.
239 file format as well as IPv6 numeric address, the field MUST be quoted by
240 doublequote character.
242 (num) Valid lifetime field
244 The default value is 2592000 (30 days).
246 (bool) This item means the advertised valid lifetime will decrement
247 in real time, which is disabled by default.
249 (num) Preferred lifetime field
251 The default value is 604800 (7 days).
253 (bool) This item means the advertised preferred lifetime will decrement
254 in real time, which is disabled by default.
257 The following item is for ICMPv6 MTU option,
258 which will be attached to router advertisement header.
259 This item can be omitted, then
261 will use the default value.
262 .Bl -tag -width indent
264 (num or str) MTU (maximum transmission unit) field.
265 If 0 is specified, it means that the option will not be included.
266 The default value is 0.
267 If the special string
269 is specified for this item, MTU option will be included and its value
270 will be set to the interface MTU automatically.
273 The following item controls ICMPv6 source link-layer address option,
274 which will be attached to router advertisement header.
275 As noted above, you can just omit the item, then
277 will use the default value.
278 .Bl -tag -width indent
287 will try to get link-layer address for the interface from the kernel,
288 and attach that in source link-layer address option.
289 If this capability exists,
291 will not attach source link-layer address option to
292 router advertisement packets.
295 The following item controls ICMPv6 home agent information option,
296 which was defined with mobile IPv6 support.
297 It will be attached to router advertisement header just like other options do.
298 .Bl -tag -width indent
300 (num) Specifies home agent preference.
303 must be present as well.
305 (num) Specifies home agent lifetime.
308 When mobile IPv6 support is turned on for
310 advertisement interval option will be attached to router advertisement
311 packet, by configuring
315 The following items are for ICMPv6 route information option,
316 which will be attached to router advertisement header.
317 These items are optional.
318 Each items can be augmented with number, like
320 to specify multiple routes.
321 .Bl -tag -width indent
323 (str) The prefix filled into the Prefix field of route information option.
328 file format as well as IPv6 numeric address, the field MUST be quoted by
329 doublequote character.
331 (num) Prefix length field in route information option.
332 The default value is 64.
334 (str or num) A 8-bit flags field in route information option.
335 Currently only the preference values are defined.
336 The notation is same as that of the raflags field.
346 are used to encode the route preference for the route.
347 The default value is 0x00, i.e., medium preference.
349 (num) route lifetime field in route information option.
351 Since the specification does not define the default value of this
352 item, the value for this item should be specified by hand.
355 allows this item to be unspecified, and uses the router lifetime
356 as the default value in such a case, just for compatibility with an
357 old version of the program.
360 In the above list, each keyword beginning with
362 could be replaced with the one beginning with
364 for backward compatibility reason.
367 is accepted instead of
369 However, keywords that start with
371 have basically been obsoleted, and should not be used any more.
373 The following items are for ICMPv6 Recursive DNS Server Option and
374 DNS Search List Option
376 which will be attached to router advertisement header.
377 These items are optional.
378 .Bl -tag -width indent
380 (str) The IPv6 address of one or more recursive DNS servers.
381 The argument must be inside double quotes.
382 Multiple DNS servers can be specified in a comma-separated string.
383 If different lifetimes are needed for different servers,
384 separate entries can be given by using
389 options with corresponding
395 Note that the maximum number of servers depends on the receiver side.
398 manual page for resolver implementation in
404 The default value is 3/2 of the interval time.
406 (str) One or more domain names in a comma-separated string.
407 These domain names will be used when making DNS queries on a
408 non-fully-qualified domain name.
409 If different lifetimes are needed for different domains, separate entries
410 can be given by using
415 options with corresponding
421 Note that the maximum number of names depends on the receiver side.
424 manual page for resolver implementation in
429 DNS search list entries.
430 The default value is 3/2 of the interval time.
433 You can also refer one line from another by using
438 for details on the capability.
440 As presented above, all of the advertised parameters have default values
441 defined in specifications, and hence you usually do not have to set them
442 by hand, unless you need special non-default values.
443 It can cause interoperability problem if you use an ill-configured
446 To override a configuration parameter, you can specify the parameter alone.
447 With the following configuration,
449 overrides the router lifetime parameter for the
452 .Bd -literal -offset indent
457 The following example manually configures prefixes advertised from the
460 The configuration must be used with the
464 .Bd -literal -offset indent
466 :addr="2001:db8:ffff:1000::":prefixlen#64:
469 The following example configures the
471 interface and adds two DNS servers and a DNS domain search options
472 using the default option lifetime values.
473 .Bd -literal -offset indent
475 :addr="2001:db8:ffff:1000::":prefixlen#64:\\
476 :rdnss="2001:db8:ffff::10,2001:db8:ffff::2:43":\\
477 :dnssl="example.com":
480 The following example presents the default values in an explicit manner.
481 The configuration is provided just for reference purposes;
482 YOU DO NOT NEED TO HAVE IT AT ALL.
483 .Bd -literal -offset indent
485 :chlim#64:raflags#0:rltime#1800:rtime#0:retrans#0:\\
486 :pinfoflags="la":vltime#2592000:pltime#604800:mtu#0:
488 :addr="2001:db8:ffff:1000::":prefixlen#64:tc=default:
500 .%T Neighbor Discovery for IP version 6 (IPv6)
507 .%T Neighbor Discovery for IP version 6 (IPv6)
508 .%R RFC 2461 (obsoleted by RFC 4861)
512 .%T Default Router Preferences and More-Specific Routes
513 .%R draft-ietf-ipngwg-router-selection-xx.txt
520 .%T IPv6 Router Advertisement Options for DNS Configuration
526 and the configuration file
528 first appeared in WIDE Hydrangea IPv6 protocol stack kit.