1.\" $NetBSD: dhcpcd.conf.5.in,v 1.23 2015/08/21 10:39:00 roy Exp $ 2.\" Copyright (c) 2006-2015 Roy Marples 3.\" All rights reserved 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.Dd August 1, 2015 27.Dt DHCPCD.CONF 5 28.Os 29.Sh NAME 30.Nm dhcpcd.conf 31.Nd dhcpcd configuration file 32.Sh DESCRIPTION 33Although 34.Nm dhcpcd 35can do everything from the command line, there are cases where it's just easier 36to do it once in a configuration file. 37Most of the options found in 38.Xr dhcpcd 8 39can be used here. 40The first word on the line is the option and the rest of the line is the value. 41Leading and trailing whitespace for the option and value are trimmed. 42You can escape characters in the value using the \\ character. 43.Pp 44Blank lines and lines starting with # are ignored. 45.Pp 46Here's a list of available options: 47.Bl -tag -width indent 48.It Ic allowinterfaces Ar pattern 49When discovering interfaces, the interface name must match 50.Ar pattern 51which is a space or comma separated list of patterns passed to 52.Xr fnmatch 3 . 53If the same interface is matched in 54.Ic denyinterfaces 55then it is still denied. 56.It Ic denyinterfaces Ar pattern 57When discovering interfaces, the interface name must not match 58.Ar pattern 59which is a space or comma separated list of patterns passed to 60.Xr fnmatch 3 . 61.It Ic arping Ar address Op address 62.Nm dhcpcd 63will arping each address in order before attempting DHCP. 64If an address is found, we will select the replying hardware address as the 65profile, otherwise the ip address. 66Example: 67.Pp 68.D1 interface bge0 69.D1 arping 192.168.0.1 70.Pp 71.D1 profile 192.168.0.1 72.D1 static ip_address=192.168.0.10/24 73.It Ic authprotocol Ar protocol Ar algorithm Ar rdm 74Authenticate DHCP messages. 75See the Supported Authentication Protocols section. 76.It Ic authtoken Ar secretid Ar realm Ar expire Ar key 77Define a shared key for use in authentication. 78.Ar realm can be "" to for use with the 79.Ar delayed 80prptocol. 81.Ar expire 82is the date the token expires and should be formatted "yyy-mm-dd HH:MM". 83You can use the keyword 84.Ar forever 85or 86.Ar 0 87which means the token never expires. 88For the token protocol, 89.Ar secretid 90needs to be 0 and 91.Ar realm 92needs to be "". 93If 94.Nm dhcpcd 95has the error 96.D1 dhcp_auth_encode: Invalid argument 97then it means that 98.Nm dhcpcd 99could not find the correct authentication token in your configuration. 100.It Ic background 101Background immediately. 102This is useful for startup scripts which don't disable link messages for 103carrier status. 104.It Ic blacklist Ar address Ns Op /cidr 105Ignores all packets from 106.Ar address Ns Op /cidr . 107.It Ic whitelist Ar address Ns Op /cidr 108Only accept packets from 109.Ar address Ns Op /cidr . 110.Ic blacklist 111is ignored if 112.Ic whitelist 113is set. 114.It Ic bootp 115Be a BOOTP client. 116Basically, this just doesn't send a DHCP Message Type option and will only 117interact with a BOOTP server. 118All other DHCP options still work. 119.It Ic broadcast 120Instructs the DHCP server to broadcast replies back to the client. 121Normally this is only set for non Ethernet interfaces, 122such as FireWire and InfiniBand. 123In most cases, 124.Nm dhcpcd 125will set this automatically. 126.It Ic controlgroup Ar group 127Sets the group ownership of 128.Pa @RUNDIR@/dhcpcd.sock 129so that users other than root can connect to 130.Nm dhcpcd . 131.It Ic debug 132Echo debug messages to the stderr and syslog. 133.It Ic dev Ar value 134Load the 135.Ar value 136.Pa /dev 137management module. 138.Nm dhcpcd 139will load the first one found to work, if any. 140.It Ic env Ar value 141Push 142.Ar value 143to the environment for use in 144.Xr dhcpcd-run-hooks 8 . 145For example, you can force the hostname hook to always set the hostname with 146.Ic env 147.Va force_hostname=YES . 148Or set which driver 149.Xr wpa_supplicant 8 150should use with 151.Ic env 152.Va wpa_supplicant_driver=nl80211 153.Pp 154If the hostname is set, will be will set to the FQDN if possible as per 155RFC 4702 section 3.1. 156If the FQDN option is missing, 157.Nm dhcpcd 158will still try and set a FQDN from the hostname and domain options for 159consistency. 160To override this, set 161.Ic env 162.Va hostname_fqdn=[YES|NO|SERVER] . 163A value of server means just what the server says, don't manipulate it. 164This could lead to an inconsistent hostname on a DHCPv4 and DHCPv6 network 165where the DHCPv4 hostname is short and the DHCPv6 has an FQDN. 166DHCPv6 has no hostname option. 167.It Ic clientid Ar string 168Send the 169.Ar clientid . 170If the string is of the format 01:02:03 then it is encoded as hex. 171For interfaces whose hardware address is longer than 8 bytes, or if the 172.Ar clientid 173is an empty string then 174.Nm dhcpcd 175sends a default 176.Ar clientid 177of the hardware family and the hardware address. 178.It Ic duid 179Generate an 180.Rs 181.%T "RFC 4361" 182.Re 183compliant DHCP Unique Identifier. 184If persistent storage is available then a DUID-LLT (link local address + time) 185is generated, otherwise DUID-LL is generated (link local address). 186This, plus the IAID will be used as the 187.Ic clientid . 188The DUID-LLT generated will be held in 189.Pa @SYSCONFDIR@/dhcpcd.duid 190and should not be copied to other hosts. 191.It Ic iaid Ar iaid 192Set the Interface Association Identifier to 193.Ar iaid . 194This option must be used in an 195.Ic interface 196block. 197This defaults to the last 4 bytes of the hardware address assigned to the 198interface. 199Each instance of this should be unique within the scope of the client and 200.Nm dhcpcd 201warns if a conflict is detected. 202If there is a conflict, it is only a problem if the conflicted IAIDs are 203used on the same network. 204.It Ic dhcp 205Enable DHCP on the interface, on by default. 206.It Ic dhcp6 207Enable DHCPv6 on the interface, on by default. 208.It Ic ipv4 209Enable IPv4 on the interface, on by default. 210.It Ic ipv6 211Enable IPv6 on the interface, on by default. 212.It Ic persistent 213.Nm dhcpcd 214normally de-configures the interface and configuration when it exits. 215Sometimes, this isn't desirable if, for example, you have root mounted over 216NFS or SSH clients connect to this host and they need to be notified of 217the host shutting down. 218You can use this option to stop this from happening. 219.It Ic fallback Ar profile 220Fallback to using this profile if DHCP fails. 221This allows you to configure a static profile instead of using ZeroConf. 222.It Ic hostname Ar name 223Sends 224.Ar hostname 225to the DHCP server so it can be registered in DNS. 226If 227.Ar hostname 228is an empty string then the current system hostname is sent. 229If 230.Ar hostname 231is a FQDN (ie, contains a .) then it will be encoded as such. 232.It Ic hostname_short 233Sends the short hostname to the DHCP server instead of the FQDN. 234This is useful because DHCP servers will not register the FQDN in their 235DNS if the domain part does not match theirs. 236.Pp 237Also, see the 238.Ic env 239option above to control how the hostname is set on the host. 240.It Ic ia_na Op Ar iaid Op / address 241Request a DHCPv6 Normal Address for 242.Ar iaid . 243.Ar iaid 244defaults to the 245.Ic iaid 246option as described above. 247You can request more than one ia_na by specifying a unique 248.Ar iaid 249for each one. 250.It Ic ia_ta Op Ar iaid 251Request a DHCPv6 Temporary Address for 252.Ar iaid . 253You can request more than one ia_ta by specifying a unique 254.Ar iaid 255for each one. 256.It Ic ia_pd Op Ar iaid Oo / Ar prefix / Ar prefix_len Oc Op Ar interface Op / Ar sla_id Op / Ar prefix_len 257Request a DHCPv6 Delegated Prefix for 258.Ar iaid . 259This option must be used in an 260.Ic interface 261block. 262Unless a 263.Ar sla_id 264of 0 is assigned, a reject route is installed for the Delegated Prefix to 265stop unallocated addresses being resolved upstream. 266This reject route is in essence SLA 0, thus you need space within the prefix 267to assign a SLA per interface. 268If no 269.Ar interface 270is given then we will assign a prefix to every other interface with a 271.Ar sla_id 272equivalent to the interface index assigned by the OS. 273Otherwise addresses are only assigned for each 274.Ar interface 275and 276.Ar sla_id . 277Each assigned address will have a suffix of 1. 278You cannot assign a prefix to the requesting interface unless the 279DHCPv6 server supports 280.Li RFC6603 281Prefix Exclude Option. 282.Nm dhcpcd 283has to be running for all the interfaces it is delegating to. 284A default 285.Ar prefix_len 286of 64 is assumed, unless the maximum 287.Ar sla_id 288does not fit. 289In this case 290.Ar prefix_len 291is increased to the highest multiple of 8 that can accommodate the 292.Ar sla_id . 293.Ar sla_id 294is an integer and is added to the prefix which must fit inside 295.Ar prefix_len 296less the length of the delegated prefix. 297.Ar sla_id can be 0 only if the Delegated Prefix is assigned to one interface. 298You can specify multiple 299.Ar interface / 300.Ar sla_id / 301.Ar prefix_len 302per 303.Ic ia_pd , 304space separated. 305IPv6RS should be disabled globally when requesting a Prefix Delegation. 306.Pp 307In the following example eth0 is the externally facing interface to be 308configured for both IPv4 and IPv6. 309The DHCPv4 server will provide us with an IPv4 address and a default route. 310The DHCPv6 server is going to provide us with an IPv6 address, a default 311route and a /64 subnet to be delegated to the internal interface. 312The eth1 interface will be automatically configured 313for IPv6 using the first address (::1) from the delegated prefix. 314A second prefix is requested and assigned to two other interfaces. 315.Xr rtadvd 8 316can be used with an empty configuration file on eth1, eth2 and eth3, 317to provide automatic 318IPv6 address configuration for the internal network. 319.Bd -literal -indent 320noipv6rs # disable routing solicitation 321denyinterfaces eth2 # Don't touch eth2 at all 322interface eth0 323 ipv6rs # enable routing solicitation get the 324 # default IPv6 route 325 ia_na 1 # request an IPv6 address 326 ia_pd 2 eth1/0 # request a PD and assign it to eth1 327 ia_pd 3 eth2/1 eth3/2 # req a PD and assign it to eth2 and eth3 328 # we cannot use SLA 0 above because we are 329 # assinging the PD to more than one interface 330.Ed 331.It Ic ipv4only 332Only configure IPv4. 333.It Ic ipv6only 334Only confgiure IPv6. 335.It Ic fqdn Op disable | ptr | both 336ptr just asks the DHCP server to update the PTR 337record of the host in DNS whereas both also updates the A record. 338disable will disable the FQDN option. 339The default is both. 340.Nm dhcpcd 341itself never does any DNS updates. 342.Nm dhcpcd 343encodes the FQDN hostname as specified in 344.Li RFC1035 . 345.It Ic interface Ar interface 346Subsequent options are only parsed for this 347.Ar interface . 348.It Ic ipv6ra_autoconf 349Generate SLAAC addresses for each Prefix advertised by a 350Router Advertisement message with the Auto flag set. 351On by default. 352.It Ic ipv6ra_noautoconf 353Disables the above option. 354.It Ic ipv6ra_fork 355By default, when 356.Nm dhcpcd 357receives an IPv6 RA, 358.Nm dhcpcd 359will only fork to the background if the RA contains at least one unexpired 360RDNSS option and a valid prefix or no DHCPv6 instruction. 361Set this option so to make 362.Nm dhcpcd 363always fork on an RA. 364.It Ic ipv6ra_own 365Disables kernel IPv6 Router Advertisment processing so dhcpcd can manage 366addresses and routes. 367.It Ic ipv6ra_own_default 368Each time dhcpcd receives an IPv6 Router Adveristment, dhcpcd will manage 369the default route only. 370This allows dhcpcd to prefer an interface for outbound traffic based on metric 371and/or user selection rather than the kernel. 372.It Ic ipv6ra_accept_nopublic 373Some IPv6 routers advertise themselves as a default router without any 374public prefixes or managed addresses. 375Generally, this is incorrect behaviour and 376.Nm dhcpcd 377will ignore the advertisement unless this option is turned on. 378.It Ic ipv6rs 379Enables IPv6 Router Advertisment solicitation. 380This is on by default, but is documented here in the case where it is disabled 381globally but needs to be enabled for one interface. 382.It Ic leasetime Ar seconds 383Request a leasetime of 384.Ar seconds . 385.It Ic logfile Ar logfile 386Writes to the specified 387.Ar logfile 388rather than 389.Xr syslog 3 . 390The 391.Ar logfile 392is truncated when opened and is reopened when 393.Nm dhcpcd 394receives the 395.Dv SIGUSR2 396signal. 397.It Ic metric Ar metric 398Metrics are used to prefer an interface over another one, lowest wins. 399.Nm dhcpcd 400will supply a default metric of 200 + 401.Xr if_nametoindex 3 . 402An extra 100 will be added for wireless interfaces. 403.It Ic noalias 404Any pre-existing IPv4 addresses existing address will be removed from the 405interface when adding a new IPv4 address. 406.It Ic noarp 407Don't send any ARP requests. 408This also disables IPv4LL. 409.It Ic noauthrequired 410Don't require authentication even though we requested it. 411Also allows FORCERENEW and RECONFIGURE messages without authentication. 412.It Ic nodelay 413Don't delay for an initial randomised time when starting protocols. 414.It Ic nodev 415Don't load 416.Pa /dev 417management modules. 418.It Ic nodhcp 419Don't start DHCP or listen to DHCP messages. 420This is only useful when allowing IPv4LL. 421.It Ic nodhcp6 422Don't start DHCPv6 or listen to DHCPv6 messages. 423Normally DHCPv6 is started by a RA instruction or configuration. 424.It Ic nogateway 425Don't install any default routes. 426.It Ic gateway 427Install a default route if available (default). 428.It Ic nohook Ar script 429Don't run this hook script. 430Matches full name, or prefixed with 2 numbers optionally ending with 431.Pa .sh . 432.Pp 433So to stop 434.Nm dhcpcd 435from touching your DNS settings or starting wpa_supplicant you would do:- 436.D1 nohook resolv.conf, wpa_supplicant 437.It Ic noipv4 438Don't attempt to configure an IPv4 address. 439.It Ic noipv4ll 440Don't attempt to obtain an IPv4LL address if we failed to get one via DHCP. 441See 442.Rs 443.%T "RFC 3927" 444.Re 445.It Ic noipv6 446Don't attmept to configure an IPv6 address. 447.It Ic noipv6rs 448Disable solicitation and receipt of IPv6 Router Advertisements. 449.It Ic nolink 450Don't receive link messages about carrier status. 451You should only set this for buggy interface drivers. 452.It Ic noup 453Don't bring the interface up when in master mode. 454If 455.Nm 456cannot determine the carrier state, 457.Nm 458will enter a tight polling loop until the interface is marked up and running 459or a valid carrier state is reported. 460.It Ic option Ar option 461Requests the 462.Ar option 463from the server. 464It can be a variable to be used in 465.Xr dhcpcd-run-hooks 8 466or the numerical value. 467You can specify more 468.Ar option Ns s 469separated by commas, spaces or more 470.Ic option 471lines. 472.Ar option 473Prepend dhcp6_ to 474.Ar option 475to request a DHCPv6 option. 476If no DHCPv6 options are configured, 477then DHCPv4 options are mapped to equivalent DHCPv6 options. 478.Pp 479Prepend nd_ to 480.Ar option 481to handle ND options, but this only works for the 482.Ic nooption , 483.Ic reject 484and 485.Ic require 486options. 487.It Ic nooption Ar option 488Remove the option from the message before it's processed. 489.It Ic require Ar option 490Requires the 491.Ar option 492to be present in all messages, otherwise the message is ignored. 493To enforce that 494.Nm dhcpcd 495only responds to DHCP servers and not BOOTP servers, you can 496.Ic require 497.Ar dhcp_message_type . 498This isn't an exact science though because a BOOTP server can send DHCP like 499options. 500.It Ic reject Ar option 501Reject a message that contains the 502.Ar option . 503This is useful when you cannot use 504.Ic require 505to select / de-select BOOTP messages. 506.It Ic destination Ar option 507If 508.Nm 509detects an address added to a point to point interface (PPP, TUN, etc) then 510it will set the listed DHCP options to the destination address of the 511interface. 512.It Ic profile Ar name 513Subsequent options are only parsed for this profile 514.Ar name . 515.It Ic quiet 516Suppress any dhcpcd output to the console, except for errors. 517.It Ic reboot Ar seconds 518Allow 519.Ar reboot 520seconds before moving to the DISCOVER phase if we have an old lease to use 521and moving from DISCOVER to IPv4LL if no reply. 522The default is 5 seconds. 523A setting of 0 seconds causes 524.Nm dhcpcd 525to skip the REBOOT phase and go straight into DISCOVER. 526This is desirable for mobile users because if you change from network A to 527network B and they use the same subnet and the address from network A isn't 528in use on network B, then the DHCP server will remain silent even if authorative 529which means 530.Nm dhcpcd 531will timeout before moving back to the DISCOVER phase. 532.It Ic release 533.Nm dhcpcd 534will release the lease prior to stopping the interface. 535.It Ic script Ar script 536Use 537.Ar script 538instead of the default 539.Pa @SCRIPT@ . 540.It Ic ssid Ar ssid 541Subsequent options are only parsed for this wireless 542.Ar ssid . 543.It Ic slaac Op Ar hwaddr | Ar private 544Selects the interface identifier used for SLAAC generated IPv6 addresses. 545If 546.Ar private 547is used, a RFC7217 address is generated. 548.It Ic static Ar value 549Configures a static 550.Ar value . 551If you set 552.Ic ip_address 553then 554.Nm dhcpcd 555will not attempt to obtain a lease and just use the value for the address with 556an infinite lease time. 557.Pp 558Here is an example which configures a static address, routes and dns. 559.D1 interface eth0 560.D1 static ip_address=192.168.0.10/24 561.D1 static routers=192.168.0.1 562.D1 static domain_name_servers=192.168.0.1 563.Pp 564Here is an example for PPP which gives the destination a default route. 565It uses the special destination keyword to insert the destination address 566into the value. 567.D1 interface ppp0 568.D1 static ip_address= 569.D1 destination routers 570.It Ic timeout Ar seconds 571Timeout after 572.Ar seconds , 573instead of the default 30. 574A setting of 0 575.Ar seconds 576causes 577.Nm dhcpcd 578to wait forever to get a lease. 579If 580.Nm dhcpcd 581is working on a single interface then 582.Nm dhcpcd 583will exit when a timeout occurs, otherwise 584.Nm dhcpcd 585will fork into the background. 586If using IPv4LL then 587.Nm dhcpcd 588start the IPv4LL process after the timeout and then wait a little longer 589before really timing out. 590.It Ic userclass Ar string 591Tag the DHCPv4 messages with the userclass. 592You can specify more than one. 593.It Ic vendor Ar code , Ns Ar value 594Add an encapsulated vendor option. 595.Ar code 596should be between 1 and 254 inclusive. 597To add a raw vendor string, omit 598.Ar code 599but keep the comma. 600Examples. 601.Pp 602Set the vendor option 01 with an IP address. 603.D1 vendor 01,192.168.0.2 604Set the vendor option 02 with a hex code. 605.D1 vendor 02,01:02:03:04:05 606Set the vendor option 03 with an IP address as a string. 607.D1 vendor 03,\e"192.168.0.2\e" 608Set un-encapsulated vendor option to hello world. 609.D1 vendor ,"hello world" 610.It Ic vendorclassid Ar string 611Set the DHCP Vendor Class. 612DHCPv6 has it's own option as shown below. 613The default is 614dhcpcd-<version>:<os>:<machine>:<platform>. 615For example 616.D1 dhcpcd-5.5.6:NetBSD-6.99.5:i386:i386 617If not set then none is sent. 618Some badly configured DHCP servers reject unknown vendorclassids. 619To work around it, try and impersonate Windows by using the MSFT vendorclassid. 620.It Ic vendclass Ar en Ar data 621Add the DHCPv6 Vendor Indetifying Vendor Class with the IANA assigned Enterprise 622Number 623.Ar en 624with the 625.Ar data . 626This option can be set more than once to add more data, but the behaviour, 627as per 628.Xr RFC 3925 629is undefined if the Enterprise Number differs. 630.It Ic waitip Op 4 | 6 631Wait for an address to be assigned before forking to the background. 6324 means wait for an IPv4 address to be assigned. 6336 means wait for an IPv6 address to be assigned. 634If no argument is given, 635.Nm 636will wait for any address protocol to be assigned. 637It is possible to wait for more than one address protocol and 638.Nm 639will only fork to the background when all waiting conditions are satisfied. 640.It Ic xidhwaddr 641Use the last four bytes of the hardware address as the DHCP xid instead 642of a randomly generated number. 643.El 644.Ss Defining new options 645DHCP, ND and DHCPv6 allow for the use of custom options. 646Each option needs to be started with the 647.Ic define , 648.If definend 649or 650.Ic define6 651directive. 652This can optionally be followed by both 653.Ic embed 654or 655.Ic encap 656options. 657Both can be specified more than once and 658.Ic embed 659must come before 660.Ic encap . 661.Bl -tag -width indent 662.It Ic define Ar code Ar type Ar variable 663Defines the DHCP option 664.Ar code 665of 666.Ar type 667with a name of 668.Ar variable 669exported to 670.Xr dhcpcd-run-hooks 8 . 671.It Ic definend Ar code Ar type Ar variable 672Defines the ND option 673.Ar code 674of 675.Ar type 676with a name of 677.Ar variable 678exported to 679.Xr dhcpcd-run-hooks 8 , 680with a prefix of 681.Va _nd . 682.It Ic define6 Ar code Ar type Ar variable 683Defines the DHCPv6 option 684.Ar code 685of 686.Ar type 687with a name of 688.Ar variable 689exported to 690.Xr dhcpcd-run-hooks 8 , 691with a prefix of 692.Va _dhcp6 . 693.It Ic vendopt Ar code Ar type Ar variable 694Defines the Vendor-Identifying Vendor Options. 695The 696.Ar code 697is the IANA Enterprise Number which will unqiuely describe the encapsulated 698options. 699.Ar type 700is normally 701.Ar encap . 702.Ar variable 703names the Vendor option to be exported. 704.It Ic embed Ar type Ar variable 705Defines an embedded variable within the defined option. 706The length is determined by the 707.Ar type . 708If the 709.Ar variable 710is not the same as defined in the parent option, 711it is prefixed with the parent 712.Ar variable 713first with an underscore. 714If the 715.Ar variable 716has the name of 717.Ar reserved 718then it is not processed. 719.It Ic encap Ar code Ar type Ar variable 720Defines an encapsulated variable within the defined option. 721The length is determined by the 722.Ar type . 723If the 724.Ar variable 725is not the same as defined in the parent option, 726it is prefixed with the parent 727.Ar variable 728first with an underscore. 729.El 730.Ss Type prefix 731These keywords come before the type itself, to describe it more fully. 732You can use more than one, but they must appear in the order listed below. 733.Bl -tag -width -indent 734.It Ic request 735Requests the option by default without having to be specified in user 736configuration 737.It Ic norequest 738This option cannot be requested, regardless of user configuration 739.It Ic index 740The option can appear more than once and will be indexed. 741.It Ic array 742The option data is split into a space separated array, each element being 743the same type. 744.El 745.Ss Types to define 746The type directly affects the length of data consumed inside the option. 747Any remaining data is normally discarded. 748Lengths can be specified for string and binhex types, but this is generally 749with other data embedded afterwards in the same option. 750.Bl -tag -width indent 751.It Ic ipaddress 752An IPv4 address, 4 bytes. 753.It Ic ip6address 754An IPv6 address, 16 bytes. 755.It Ic string Op : Ic length 756A NVT ASCII string of printable characters. 757.It Ic byte 758A byte. 759.It Ic bitflags : Ic flags 760A byte represented as a string of flags, most significant bit first. 761For example, using ABCDEFGH then A would equal 10000000, B 01000000, 762C 00100000, etc. 763If the bit is not set, the flag is not printed. 764A flag of 0 is not printed even if the bit postition is set. 765This is to allow reservation of the first bits while assinging the last bits. 766.It Ic int16 767A signed 16bit integer, 2 bytes. 768.It Ic uint16 769An unsigned 16bit integer, 2 bytes. 770.It Ic int32 771A signed 32bit integer, 4 bytes. 772.It Ic uint32 773An unsigned 32bit integer, 4 bytes. 774.It Ic flag 775A fixed value (1) to indicate that the option is present, 0 bytes. 776.It Ic domain 777A RFC 3397 encoded string. 778.It Ic dname 779A RFC 1035 validated string. 780.It Ic binhex Op : Ic length 781Binary data expressed as hexadecimal. 782.It Ic embed 783Contains embedded options (implies encap as well). 784.It Ic encap 785Contains encapsulated options (implies embed as well). 786.It Ic option 787References an option from the global definition. 788.El 789.Ss Example definition 790.D1 # DHCP option 81, Fully Qualified Domain Name, RFC4702 791.D1 define 81 embed fqdn 792.D1 embed byte flags 793.D1 embed byte rcode1 794.D1 embed byte rcode2 795.D1 embed domain fqdn 796.Pp 797.D1 # DHCP option 125, Vendor Specific Information Option, RFC3925 798.D1 define 125 encap vsio 799.D1 embed uint32 enterprise_number 800.D1 # Options defined for the enterprise number 801.D1 encap 1 ipaddress ipaddress 802.Ss Supported Authentication Protocols 803.Bl -tag -width -indent 804.It Ic token 805Sends and expects the token with the secretid 0 and realm of "" in each message. 806.It Ic delayedrealm 807Delayed Authentication. 808.Nm dhcpcd 809will send an authentication option with no key or MAC. 810The server will see this option, and select a key for 811.Nm , writing the 812.Ar realm 813and 814.Ar secretid 815in it. 816.Nm dhcpcd 817will then look for a non-expired token with a matching realm and secretid. 818This token is used to authenicate all other messages. 819.It Ic delayed 820Same as above, but without a realm. 821.El 822.Ss Supported Authentication Algorithms 823If none specified, 824.Ic hmac-md5 825is the default. 826.Bl -tag -width -indent 827.It Ic hmac-md5 828.El 829.Ss Supported Replay Detection Mechanisms 830If none specified, 831.Ic monotonic 832is the default. 833If this is changed from what was previously used, 834or the means of calculating or storing it is broken then the DHCP server 835will probably have to have its notion of the clients Replay Detection Value 836reset. 837.Bl -tag -width -indent 838.It Ic monocounter 839Read the number in the file 840.Pa @DBDIR@/dhcpcd-rdm.monotonic 841and add one to it. 842.It Ic monotime 843Create a NTP timestamp from the system time. 844.It Ic monotonic 845Same as 846.Ic monotime . 847.El 848.Sh SEE ALSO 849.Xr fnmatch 3 , 850.Xr if_nametoindex 3 , 851.Xr dhcpcd 8 , 852.Xr dhcpcd-run-hooks 8 853.Sh AUTHORS 854.An Roy Marples Aq Mt roy@marples.name 855.Sh BUGS 856Please report them to 857.Lk http://roy.marples.name/projects/dhcpcd 858