1RADVD.CONF(5) RADVD.CONF(5)
2
6 radvd.conf - configuration file of the router advertisement daemon
7 radvd
8
10 This file describes the information which is included in the router
11 advertisement (RA) of a specific interface.
12 The file contains one or more interface definitions of the form:
14 interface name {
16 list of interface specific options
17 list of prefix definitions
18 list of route definitions
19 list of RDNSS definitions
20 };
21 All the possible interface specific options are detailed below. Each
23 option has to be terminated by a semicolon.
24 Prefix definitions are of the form:
26 prefix prefix/length {
28 list of prefix specific options
29 };
30 Prefix can be network prefix or the address of the inferface. The
32 address of interface should be used when using Mobile IPv6 extensions.
33 All the possible prefix specific options are described below. Each
35 option has to be terminated by a semicolon.
36 Decimal values are allowed only for MinDelayBetweenRAs, MaxRtrAdvInter‐
38 val and MinRtrAdvInterval. Decimal values should be used only when
39 using Mobile IPv6 extensions.
40 Route definitions are of the form:
42 route prefix/length {
44 list of route specific options
45 };
46 The prefix of a route definition should be network prefix; it can be
48 used to advertise more specific routes to the hosts.
49 RDNSS (Recursive DNS server) definitions are of the form:
51 RDNSS ip [ip] [ip] {
53 list of rdnss specific options
54 };
55
58 IgnoreIfMissing on|off
59 A flag indicating whether or not the interface is ignored if it
61 does not exist at start-up. By default, radvd exits.
62 This is useful for dynamic interfaces which are not active when
64 radvd starts or which are dynamically disabled and re-enabled
65 during the time radvd runs.
66 Current versions of radvd automatically try to re-enable inter‐
68 faces.
69 Enabling IgnoreIfMissing also quenches certain warnings in log
71 messages relating to missing interfaces.
72 Default: off
74 AdvSendAdvert on|off
77 A flag indicating whether or not the router sends periodic
79 router advertisements and responds to router solicitations.
80 This option no longer has to be specified first, but it needs to
82 be on to enable advertisement on this interface.
83 Default: off
85 UnicastOnly on|off
88 Indicates that the interface link type only supports unicast.
90 This will prevent unsolicited advertisements from being sent,
91 and will cause solicited advertisements to be unicast to the
92 soliciting node. This option is necessary for non-broadcast,
93 multiple-access links, such as ISATAP.
94 Default: off
96 MaxRtrAdvInterval seconds
99 The maximum time allowed between sending unsolicited multicast
101 router advertisements from the interface, in seconds.
102 Must be no less than 4 seconds and no greater than 1800 seconds.
104 Minimum when using Mobile IPv6 extensions: 0.07.
106 For values less than 0.2 seconds, 0.02 seconds is added to
108 account for scheduling granularities as specified in RFC3775.
109 Default: 600 seconds
111 MinRtrAdvInterval seconds
114 The minimum time allowed between sending unsolicited multicast
116 router advertisements from the interface, in seconds.
117 Must be no less than 3 seconds and no greater than 0.75 * MaxR‐
119 trAdvInterval.
120 Minimum when using Mobile IPv6 extensions: 0.03.
122 Default: 0.33 * MaxRtrAdvInterval
124 MinDelayBetweenRAs seconds
127 The minimum time allowed between sending multicast router adver‐
129 tisements from the interface, in seconds.
130 This applies to solicited multicast RAs. This is defined as the
132 protocol constant MIN_DELAY_BETWEEN_RAS in RFC2461. MIPv6 rede‐
133 fines this parameter to have a minimum of 0.03 seconds.
134 Minimum when using Mobile IPv6 extensions: 0.03.
136 Default: 3
138 AdvManagedFlag on|off
141 When set, hosts use the administered (stateful) protocol for
143 address autoconfiguration in addition to any addresses autocon‐
144 figured using stateless address autoconfiguration. The use of
145 this flag is described in RFC 2462.
146 Default: off
148 AdvOtherConfigFlag on|off
151 When set, hosts use the administered (stateful) protocol for
153 autoconfiguration of other (non-address) information. The use
154 of this flag is described in RFC 2462.
155 Default: off
157 AdvLinkMTU integer
160 The MTU option is used in router advertisement messages to
162 insure that all nodes on a link use the same MTU value in those
163 cases where the link MTU is not well known.
164 If specified, i.e. not 0, must not be smaller than 1280 and not
166 greater than the maximum MTU allowed for this link (e.g. ether‐
167 net has a maximum MTU of 1500. See RFC 2464).
168 Default: 0
170 AdvReachableTime milliseconds
173 The time, in milliseconds, that a node assumes a neighbor is
175 reachable after having received a reachability confirmation.
176 Used by the Neighbor Unreachability Detection algorithm (see
177 Section 7.3 of RFC 2461). A value of zero means unspecified (by
178 this router).
179 Must be no greater than 3,600,000 milliseconds (1 hour).
181 Default: 0
183 AdvRetransTimer milliseconds
186 The time, in milliseconds, between retransmitted Neighbor Solic‐
188 itation messages. Used by address resolution and the Neighbor
189 Unreachability Detection algorithm (see Sections 7.2 and 7.3 of
190 RFC 2461). A value of zero means unspecified (by this router).
191 Default: 0
193 AdvCurHopLimit integer
196 The default value that should be placed in the Hop Count field
198 of the IP header for outgoing (unicast) IP packets. The value
199 should be set to the current diameter of the Internet. The
200 value zero means unspecified (by this router).
201 Default: 64
203 AdvDefaultLifetime seconds
206 The lifetime associated with the default router in units of sec‐
208 onds. The maximum value corresponds to 18.2 hours. A lifetime
209 of 0 indicates that the router is not a default router and
210 should not appear on the default router list. The router life‐
211 time applies only to the router's usefulness as a default
212 router; it does not apply to information contained in other mes‐
213 sage fields or options. Options that need time limits for their
214 information include their own lifetime fields.
215 Must be either zero or between MaxRtrAdvInterval and 9000 sec‐
217 onds.
218 Default: 3 * MaxRtrAdvInterval (Minimum 1 second).
220 AdvDefaultPreference low|medium|high
223 The preference associated with the default router, as either
225 "low", "medium", or "high".
226 Default: medium
228 AdvSourceLLAddress on|off
231 When set, the link-layer address of the outgoing interface is
233 included in the RA.
234 Default: on
236 AdvHomeAgentFlag on|off
239 When set, indicates that sending router is able to serve as
241 Mobile IPv6 Home Agent. When set, minimum limits specified by
242 Mobile IPv6 are used for MinRtrAdvInterval and MaxRtrAdvInter‐
243 val.
244 Default: off
246 AdvHomeAgentInfo on|off
249 When set, Home Agent Information Option (specified by Mobile
251 IPv6) is included in Router Advertisements. AdvHomeAgentFlag
252 must also be set when using this option.
253 Default: off
255 HomeAgentLifetime seconds
258 The length of time in seconds (relative to the time the packet
260 is sent) that the router is offering Mobile IPv6 Home Agent ser‐
261 vices. A value 0 must not be used. The maximum lifetime is
262 65520 seconds (18.2 hours). This option is ignored, if AdvHome‐
263 AgentInfo is not set.
264 If both HomeAgentLifetime and HomeAgentPreference are set to
266 their default values, Home Agent Information Option will not be
267 sent.
268 Default: AdvDefaultLifetime
270 HomeAgentPreference integer
273 The preference for the Home Agent sending this Router Advertise‐
275 ment. Values greater than 0 indicate more preferable Home
276 Agent, values less than 0 indicate less preferable Home Agent.
277 This option is ignored, if AdvHomeAgentInfo is not set.
278 If both HomeAgentLifetime and HomeAgentPreference are set to
280 their default values, Home Agent Information Option will not be
281 sent.
282 Default: 0
284 AdvMobRtrSupportFlag on|off
287 When set, the Home Agent signals it supports Mobile Router reg‐
289 istrations (specified by NEMO Basic). AdvHomeAgentInfo must
290 also be set when using this option.
291 Default: off
293 AdvIntervalOpt on|off
296 When set, Advertisement Interval Option (specified by Mobile
298 IPv6) is included in Router Advertisements. When set, minimum
299 limits specified by Mobile IPv6 are used for MinRtrAdvInterval
300 and MaxRtrAdvInterval.
301 The advertisement interval is based on the configured MaxRtrAdv‐
303 Interval parameter except where this is less than 200ms. In
304 this case, the advertised interval is ( MaxRtrAdvInterval + 20ms
305 ).
306 Default: off
308
311 AdvOnLink on|off
312 When set, indicates that this prefix can be used for on-link
314 determination. When not set the advertisement makes no state‐
315 ment about on-link or off-link properties of the prefix. For
316 instance, the prefix might be used for address configuration
317 with some of the addresses belonging to the prefix being on-link
318 and others being off-link.
319 Default: on
321 AdvAutonomous on|off
324 When set, indicates that this prefix can be used for autonomous
326 address configuration as specified in RFC 2462.
327 Default: on
329 AdvRouterAddr on|off
332 When set, indicates that the address of interface is sent
334 instead of network prefix, as is required by Mobile IPv6. When
335 set, minimum limits specified by Mobile IPv6 are used for MinR‐
336 trAdvInterval and MaxRtrAdvInterval.
337 Default: off
339 AdvValidLifetime seconds|infinity
342 The length of time in seconds (relative to the time the packet
344 is sent) that the prefix is valid for the purpose of on-link
345 determination. The symbolic value infinity represents infinity
346 (i.e. a value of all one bits (0xffffffff)). The valid lifetime
347 is also used by RFC 2462.
348 Default: 2592000 seconds (30 days)
350 AdvPreferredLifetime seconds|infinity
353 The length of time in seconds (relative to the time the packet
355 is sent) that addresses generated from the prefix via stateless
356 address autoconfiguration remain preferred. The symbolic value
357 infinity represents infinity (i.e. a value of all one bits
358 (0xffffffff)). See RFC 2462.
359 Default: 604800 seconds (7 days)
361 Base6to4Interface name
364 If this option is specified, this prefix will be combined with
366 the IPv4 address of interface name to produce a valid 6to4 pre‐
367 fix. The first 16 bits of this prefix will be replaced by 2002
368 and the next 32 bits of this prefix will be replaced by the IPv4
369 address assigned to interface name at configuration time. The
370 remaining 80 bits of the prefix (including the SLA ID) will be
371 advertised as specified in the configuration file. See the next
372 section for an example.
373 If interface name is not available at configuration time, a
375 warning will be written to the log and this prefix will be dis‐
376 abled until radvd is reconfigured.
377 This option enables systems with dynamic IPv4 addresses to
379 update their advertised 6to4 prefixes simply by restarting radvd
380 or sending a SIGHUP signal to cause radvd to reconfigure itself.
381 Note that 6to4 prefixes derived from dynamically-assigned IPv4
383 addresses should be advertised with a significantly shorter
384 lifetime (see the AdvValidLifetime and AdvPreferredLifetime
385 options).
386 For more information on 6to4, see RFC 3056.
388 Default: 6to4 is not used
390
393 AdvRouteLifetime seconds|infinity
394 The lifetime associated with the route in units of seconds. The
396 symbolic value infinity represents infinity (i.e. a value of all
397 one bits (0xffffffff)).
398 Default: 3 * MaxRtrAdvInterval
400 AdvRoutePreference low|medium|high
403 The preference associated with the default router, as either
405 "low", "medium", or "high".
406 Default: medium
408
411 AdvRDNSSPreference integer;
412 The preference of the DNS server, compared to other DNS servers
414 advertised and used. 0 to 7 means less important than manually
415 configured nameservers in resolv.conf, while 12 to 15 means more
416 important.
417 Default: 8
419 AdvRDNSSOpen on|off;
422 "Service Open" flag. When set, indicates that RDNSS continues to
424 be available to hosts even if they moved to a different subnet.
425 Default: off
427 AdvRDNSSLifetime seconds|infinity;
430 The maximum duration how long the RDNSS entries are used for
431 name resolution. A value of 0 means the nameserver should no
432 longer be used. The maximum duration how long the RDNSS entries
433 are used for name resolution. A value of 0 means the nameserver
434 should no longer be used. The value, if not 0, must be at least
435 MaxRtrAdvInterval. To ensure stale RDNSS info gets removed in a
436 timely fashion, this should not be greater than 2*MaxRtrAdvIn‐
437 terval.
438 Default: 2*MaxRtrAdvInterval
440
443 interface eth0
444 {
445 AdvSendAdvert on;
446 prefix 2001:db8:0:1::/64
447 {
448 AdvOnLink on;
449 AdvAutonomous on;
450 };
451 };
452 It says that router advertisement daemon should advertise (AdvSendAd‐
454 vert on;) the prefix 2001:db8:0:1:: which has a lenght of 64 on the
455 interface eth0. Also the prefix should be marked as autonomous (AdvAu‐
456 tonomous on;) and as on-link (AdvOnLink on;). All the other options
457 are left on their default values.
458 To support movement detection of Mobile IPv6 Mobile Nodes, the address
460 of interface should be used instead of network prefix:
461 interface eth0
463 {
464 AdvSendAdvert on;
465 prefix 2001:db8:0:1::4/64
466 {
467 AdvOnLink on;
468 AdvAutonomous on;
469 AdvRouterAddr on;
470 };
471 };
472 For 6to4 support, include the Base6to4Interface option in each prefix
474 section. When using a dynamic IPv4 address, set small prefix lifetimes
475 to prevent hosts from retaining unreachable prefixes after a new IPv4
476 address has been assigned. When advertising to on a dynamic interface
477 (e.g., Bluetooth), skip the interface if it is not active yet.
478 interface bnep0
480 {
481 IgnoreIfMissing on;
482 AdvSendAdvert on;
483 # Advertise at least every 30 seconds
485 MaxRtrAdvInterval 30;
486 prefix 0:0:0:5678::/64
488 {
489 AdvOnLink on;
490 AdvAutonomous on;
491 Base6to4Interface ppp0;
492 # Very short lifetimes for dynamic addresses
494 AdvValidLifetime 300;
495 AdvPreferredLifetime 120;
496 };
497 };
498 Since 6to4 is enabled, the prefix will be advertised as
500 2002:WWXX:YYZZ:5678::/64, where WW.XX.YY.ZZ is the IPv4 address of ppp0
501 at configuration time. (IPv6 addresses are written in hexadecimal
502 whereas IPv4 addresses are written in decimal, so the IPv4 address
503 WW.XX.YY.ZZ in the 6to4 prefix will be represented in hex.)
504 In this specific case, the configuration scripts may send HUP signal to
506 radvd when taking bnep0 up or down to notify about the status; in the
507 current radvd releases, sending HUP is no longer mandatory when the
508 link comes back up.
509
512 /usr/sbin/radvd
513 /etc/radvd.conf
514 /var/run/radvd/radvd.pid
515 /var/log/radvd.log
516
519 The description of the different flags and variables is in large parts
520 taken from RFC 2461.
521
524 Narten, T., E. Nordmark, W. Simpson, "Neighbor Discovery for IP Version
525 6 (IPv6)", RFC 2461, December 1998
526 Thomson, S., and T. Narten, "IPv6 Stateless Address Autoconfiguration",
528 RFC 2462, December 1998.
529 Deering, S., and R. Hinden, "IP Version 6 Addressing Architecture", RFC
531 3513, April 2003.
532 Conta, A., and S. Deering, "Internet Control Message Protocol (ICMPv6)
534 for the Internet Protocol Version 6 (IPv6)", RFC 2463, December 1998.
535 Crawford, M., "Transmission of IPv6 Packets over Ethernet Networks",
537 RFC 2464, December 1998.
538 Carpenter B., K. Moore, "Connection of IPv6 Domains via IPv4 Clouds",
540 RFC 3056, February 2001. (6to4 specification)
541 Draves, R., D. Thaler, "Default Router Preferences and More-Specific
543 Routes", RFC 4191, November 2005.
544 Johnson, D., Perkins, C., and J. Arkko, "Mobility Support in IPv6", RFC
546 3775, June 2004.
547 Devarapalli, V., Wakikawa, R., Petrescu, A., and P. Thubert "Network
549 Mobility (NEMO) Basic Support Protocol", RFC 3963, January 2005.
550 J. Jeong, L. Beloeil, and S. Madanapalli, "IPv6 Router Advertisement
552 Option for DNS Configuration", IETF Draft v08 (January 18, 2006).
553
556 radvd(8), radvdump(8)
557radvd 1.0 20 Aug 2004 RADVD.CONF(5)