1.\" $NetBSD: rtadvd.conf.5,v 1.20 2018/04/21 09:31:08 wiz Exp $ 2.\" $KAME: rtadvd.conf.5,v 1.50 2005/01/14 05:30:59 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 April 20, 2018 32.Dt RTADVD.CONF 5 33.Os 34.Sh NAME 35.Nm rtadvd.conf 36.Nd config file for router advertisement daemon 37.Sh DESCRIPTION 38This file describes how the router advertisement packets must be constructed 39for each of the interfaces. 40.Pp 41As described in 42.Xr rtadvd 8 , 43you do not have to set this configuration file up at all, 44unless you need some special configurations. 45You may even omit the file as a whole. 46In such cases, the 47.Nm rtadvd 48daemon will automatically configure itself using default values 49specified in the specification. 50.Pp 51It obeys the famous 52.Xr capfile 5 53file format. 54Each line in the file describes a network interface. 55Fields are separated by a colon 56.Pq Sq \&: , 57and each field contains one capability description. 58Lines may be concatenated by the 59.Sq \e 60character. 61The comment marker is the 62.Sq \&# 63character. 64.Sh CAPABILITIES 65Capabilities describe the value to be filled into ICMPv6 router 66advertisement messages and to control 67.Xr rtadvd 8 68behavior. 69Therefore, you are encouraged to read IETF neighbor discovery documents 70if you would like to modify the sample configuration file. 71.Pp 72Note that almost all items have default values. 73If you omit an item, the default value of the item will be used. 74.Pp 75There are two items which control the interval of sending router advertisements. 76These items can be omitted, then 77.Nm rtadvd 78will use the default values. 79.Bl -tag -width indent 80.It Cm \&maxinterval 81(num) The maximum time allowed between sending unsolicited 82multicast router advertisements 83.Pq unit: seconds . 84The default value is 600. 85Its value must be no less than 4 seconds 86and no greater than 65535 seconds. 87.It Cm \&mininterval 88(num) The minimum time allowed between sending unsolicited multicast 89router advertisements 90.Pq unit: seconds . 91The default value is the one third of value of 92.Cm maxinterval . 93Its value must be no less than 3 seconds and no greater than .75 * 94the value of 95.Cm maxinterval . 96.El 97.Pp 98The following items are for ICMPv6 router advertisement message 99header. 100These items can be omitted, then 101.Nm rtadvd 102will use the default values. 103.Bl -tag -width indent 104.It Cm \&chlim 105(num) The value for Cur Hop Limit field. 106The default value is 64. 107.It Cm \&raflags 108(str or num) A 8-bit flags field in router advertisement message header. 109This field can be specified either as a case-sensitive string or as an 110integer. 111A sting consists of characters each of which corresponds to a 112particular flag bit(s). 113An integer should be the logical OR of all enabled bits. 114Bit 7 115.Po 116.Li 'm' or 0x80 117.Pc 118means Managed address configuration flag bit, 119and Bit 6 120.Po 121.Li 'o' or 0x40 122.Pc 123means Other stateful configuration flag bit. 124Bit 4 125.Po 126.Li 0x10 127.Pc 128and Bit 3 129.Po 130.Li 0x08 131.Pc 132are used to encode router preference. 133Bits 01 134.Po 135or 'h' 136.Pc 137means high, 00 means medium, and 11 138.Po 139or 'l' 140.Pc 141means low. 142Bits 10 is reserved, and must not be specified. 143There is no character to specify the medium preference explicitly. 144The default value of the entire flag is 0 145(or a null string), 146which means no additional 147configuration methods, and the medium router preference. 148.It Cm \&rltime 149(num) Router lifetime field 150.Pq unit: seconds . 151The value must be either zero or between 152the value of 153.Cm maxinterval 154and 65535. 155When 156.Nm rtadvd 157runs on a host, this value must explicitly set 0 on all the 158advertising interfaces as described in 159.Xr rtadvd 8 . 160The default value is 1800. 161.It Cm \&rtime 162(num) Reachable time field 163.Pq unit: milliseconds . 164The default value is 0, which means unspecified by this router. 165.It Cm \&retrans 166(num) Retrans Timer field 167.Pq unit: milliseconds . 168The default value is 0, which means unspecified by this router. 169.El 170.Pp 171The following items are for ICMPv6 prefix information option, 172which will be attached to router advertisement header. 173These items can be omitted, then 174.Nm rtadvd 175will automatically get appropriate prefixes from the kernel's routing table, 176and advertise the prefixes with the default parameters, unless the 177.Cm noifprefix 178flag is specified. 179Keywords other than 180.Cm clockskew 181and 182.Cm noifprefix 183can be augmented with a number, like 184.Dq Li prefix2 , 185to specify multiple prefixes. 186.Bl -tag -width indent 187.It Cm \&noifprefix 188(bool) Specified whether 189.Nm rtadvd 190should gather prefix information from the interface if no 191.Cm addr 192is specified. 193If no 194.Cm addr 195is given, and 196.Cm noifprefix 197is set, 198.Nm rtadvd 199will send RA packets with no prefix information. 200.It Cm \&clockskew 201(num) Time skew to adjust link propagation delays and clock skews 202between routers on the link 203.Pq unit: seconds . 204This value is used in consistency check for locally-configured and 205advertised prefix lifetimes, and has its meaning when the local router 206configures a prefix on the link with a lifetime that decrements in 207real time. 208If the value is 0, it means the consistency check will be skipped 209for such prefixes. 210The default value is 0. 211.It Cm \&prefixlen 212(num) Prefix length field. 213The default value is 64. 214.It Cm \&pinfoflags 215(str or num) A 8-bit flags field in prefix information option. 216This field can be specified either as a case-sensitive string or as an 217integer. 218A sting consists of characters each of which corresponds to a 219particular flag bit(s). 220An integer should be the logical OR of all enabled bits. 221Bit 7 222.Po 223.Li 'l' or 0x80 224.Pc 225means On-link flag bit, 226and Bit 6 227.Po 228.Li 'a' or 0x40 229.Pc 230means Autonomous address-configuration flag bit. 231The default value is "la" or 0xc0, i.e., both bits are set. 232.It Cm \&addr 233(str) The address filled into Prefix field. 234Since 235.Dq \&: 236is used for 237.Xr capfile 5 238file format as well as IPv6 numeric address, the field MUST be quoted by 239doublequote character. 240.It Cm \&vltime 241(num) Valid lifetime field 242.Pq unit: seconds . 243The default value is 2592000 (30 days). 244.It Cm \&vltimedecr 245(bool) This item means the advertised valid lifetime will decrement 246in real time, which is disabled by default. 247.It Cm \&pltime 248(num) Preferred lifetime field 249.Pq unit: seconds . 250The default value is 604800 (7 days). 251.It Cm \&pltimedecr 252(bool) This item means the advertised preferred lifetime will decrement 253in real time, which is disabled by default. 254.El 255.Pp 256The following item is for ICMPv6 MTU option, 257which will be attached to router advertisement header. 258This item can be omitted, then 259.Nm rtadvd 260will use the default value. 261.Bl -tag -width indent 262.It Cm \&mtu 263(num or str) MTU (maximum transmission unit) field. 264If 0 is specified, it means that the option will not be included. 265The default value is 0. 266If the special string 267.Dq auto 268is specified for this item, MTU option will be included and its value 269will be set to the interface MTU automatically. 270.El 271.Pp 272The following item controls ICMPv6 source link-layer address option, 273which will be attached to router advertisement header. 274As noted above, you can just omit the item, then 275.Nm rtadvd 276will use the default value. 277.Bl -tag -width indent 278.It Cm \&nolladdr 279(bool) By default 280.Po 281if 282.Cm \&nolladdr 283is not specified 284.Pc , 285.Xr rtadvd 8 286will try to get link-layer address for the interface from the kernel, 287and attach that in source link-layer address option. 288If this capability exists, 289.Xr rtadvd 8 290will not attach source link-layer address option to 291router advertisement packets. 292.El 293.Pp 294The following items are for ICMPv6 route information option, 295which will be attached to router advertisement header. 296These items are optional. 297Each items can be augmented with number, like 298.Dq Li rtplen2 , 299to specify multiple routes. 300.Bl -tag -width indent 301.It Cm \&rtprefix 302(str) The prefix filled into the Prefix field of route information option. 303Since 304.Dq \&: 305is used for 306.Xr capfile 5 307file format as well as IPv6 numeric address, the field MUST be quoted by 308doublequote character. 309.It Cm \&rtplen 310(num) Prefix length field in route information option. 311The default value is 64. 312.It Cm \&rtflags 313(str or num) A 8-bit flags field in route information option. 314Currently only the preference values are defined. 315The notation is same as that of the raflags field. 316Bit 4 317.Po 318.Li 0x10 319.Pc 320and Bit 3 321.Po 322.Li 0x08 323.Pc 324are used to encode the route preference for the route. 325The default value is 0x00, i.e. medium preference. 326.It Cm \&rtltime 327(num) route lifetime field in route information option. 328.Pq unit: seconds . 329Since the specification does not define the default value of this 330item, the value for this item should be specified by hand. 331However, 332.Nm rtadvd 333allows this item to be unspecified, and uses the router lifetime 334as the default value in such a case, just for compatibility with an 335old version of the program. 336.El 337.Pp 338In the above list, each keyword beginning with 339.Dq Li rt 340could be replaced with the one beginning with 341.Dq Li rtr 342for backward compatibility reason. 343For example, 344.Cm rtrplen 345is accepted instead of 346.Cm rtplen . 347However, keywords that start with 348.Dq Li rtr 349have basically been obsoleted, and should not be used any more. 350.Pp 351The following items are for ICMPv6 Recursive DNS Server Option and 352DNS Search List Option 353.Pq RFC 6106 , 354which will be attached to router advertisement header. 355These items are optional. 356.Bl -tag -width indent 357.It Cm \&rdnss 358(str) The IPv6 address of one or more recursive DNS servers. 359The argument must be inside double quotes. 360Multiple DNS servers can be specified in a comma-separated string. 361If different lifetimes are needed for different servers, 362separate entries can be given by using 363.Cm rdnss , 364.Cm rdnss0 , 365.Cm rdnss1 , 366.Cm rdnss2 ... 367options with corresponding 368.Cm rdnssltime , 369.Cm rdnssltime0 , 370.Cm rdnssltime1 , 371.Cm rdnssltime2 ... 372entries. 373Note that the maximum number of servers depends on the receiver side. 374See also the 375.Xr resolv.conf 5 376manual page for the resolver implementation. 377.It Cm \&rdnssltime 378The lifetime of the 379.Cm rdnss 380DNS server entries. 381The default value is 3/2 of the interval time. 382.It Cm \&dnssl 383(str) One or more domain names in a comma-separated string. 384These domain names will be used when making DNS queries on a 385non-fully-qualified domain name. 386If different lifetimes are needed for different domains, separate entries 387can be given by using 388.Cm dnssl , 389.Cm dnssl0 , 390.Cm dnssl1 , 391.Cm dnssl2 ... 392options with corresponding 393.Cm dnsslltime , 394.Cm dnsslltime0 , 395.Cm dnsslltime1 , 396.Cm dnsslltime2 ... 397entries. 398Note that the maximum number of names depends on the receiver side. 399See also the 400.Xr resolv.conf 5 401manual page for the resolver implementation. 402.It Cm \&dnsslltime 403The lifetime of the 404.Cm dnssl 405DNS search list entries. 406The default value is 3/2 of the interval time. 407.El 408.Pp 409You can also refer one line from another by using 410.Cm tc 411capability. 412See 413.Xr capfile 5 414for details on the capability. 415.Sh EXAMPLES 416As presented above, all of the advertised parameters have default values 417defined in specifications, and hence you usually do not have to set them 418by hand, unless you need special non-default values. 419It can cause interoperability problem if you use an ill-configured 420parameter. 421.Pp 422To override a configuration parameter, you can specify the parameter alone. 423With the following configuration, 424.Xr rtadvd 8 425overrides the router lifetime parameter for the 426.Li ne0 427interface. 428.Bd -literal 429ne0:\\ 430 :rltime#0: 431.Ed 432.Pp 433The following example manually configures prefixes advertised from the 434.Li ef0 435interface. 436The configuration must be used with the 437.Fl s 438option to 439.Xr rtadvd 8 . 440.Bd -literal 441ef0:\\ 442 :addr="2001:db8:ffff:1000::":prefixlen#64: 443.Ed 444.Pp 445The following example configures the 446.Li wlan0 447interface and adds two DNS servers and a DNS domain search options 448using the default option lifetime values. 449.Bd -literal -offset 8n 450wlan0:\\ 451 :addr="2001:db8:ffff:1000::":prefixlen#64:\\ 452 :rdnss="2001:db8:ffff::10,2001:db8:ffff::2:43":\\ 453 :dnssl="example.com": 454.Ed 455.Pp 456The following example presents the default values in an explicit manner. 457The configuration is provided just for reference purposes; 458YOU DO NOT NEED TO HAVE IT AT ALL. 459.Bd -literal 460default:\\ 461 :chlim#64:raflags#0:rltime#1800:rtime#0:retrans#0:\\ 462 :pinfoflags="la":vltime#2592000:pltime#604800:mtu#0: 463ef0:\\ 464 :addr="2001:db8:ffff:1000::":prefixlen#64:tc=default: 465.Ed 466.Sh SEE ALSO 467.Xr capfile 5 , 468.Xr rtadvd 8 , 469.Xr rtsol 8 470.Pp 471Thomas Narten, Erik Nordmark and W. A. Simpson, 472.Do 473Neighbor Discovery for IP version 6 (IPv6) 474.Dc , 475RFC 2461 476.Pp 477Richard Draves, 478.Do 479Default Router Preferences and More-Specific Routes 480.Dc , 481RFC 4191 482.Pp 483J. Jeong, S. Park, L. Beloeil, S. Madanapalli 484.Do 485IPv6 Router Advertisement Options for DNS Configuration 486.Dc , 487RFC 6106 488.Sh HISTORY 489The 490.Xr rtadvd 8 491and the configuration file 492.Nm 493first appeared in WIDE Hydrangea IPv6 protocol stack kit. 494.\" .Sh BUGS 495.\" (to be written) 496