Annotation of embedaddon/dhcp/common/dhcp-options.5, revision 1.1
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! 30: .TH dhcp-options 5
! 31: .SH NAME
! 32: dhcp-options - Dynamic Host Configuration Protocol options
! 33: .SH DESCRIPTION
! 34: The Dynamic Host Configuration protocol allows the client to receive
! 35: .B options
! 36: from the DHCP server describing the network configuration and various
! 37: services that are available on the network. When configuring
! 38: .B dhcpd(8)
! 39: or
! 40: .B dhclient(8) ,
! 41: options must often be declared. The syntax for declaring options,
! 42: and the names and formats of the options that can be declared, are
! 43: documented here.
! 44: .SH REFERENCE: OPTION STATEMENTS
! 45: .PP
! 46: DHCP \fIoption\fR statements always start with the \fIoption\fR
! 47: keyword, followed by an option name, followed by option data. The
! 48: option names and data formats are described below. It is not
! 49: necessary to exhaustively specify all DHCP options - only those
! 50: options which are needed by clients must be specified.
! 51: .PP
! 52: Option data comes in a variety of formats, as defined below:
! 53: .PP
! 54: The
! 55: .B ip-address
! 56: data type can be entered either as an explicit IP
! 57: address (e.g., 239.254.197.10) or as a domain name (e.g.,
! 58: haagen.isc.org). When entering a domain name, be sure that that
! 59: domain name resolves to a single IP address.
! 60: .PP
! 61: The
! 62: .B ip6-address
! 63: data specifies an IPv6 address, like ::1 or 3ffe:bbbb:aaaa:aaaa::1.
! 64: .PP
! 65: The
! 66: .B int32
! 67: data type specifies a signed 32-bit integer. The
! 68: .B uint32
! 69: data type specifies an unsigned 32-bit integer. The
! 70: .B int16
! 71: and
! 72: .B uint16
! 73: data types specify signed and unsigned 16-bit integers. The
! 74: .B int8
! 75: and
! 76: .B uint8
! 77: data types specify signed and unsigned 8-bit integers.
! 78: Unsigned 8-bit integers are also sometimes referred to as octets.
! 79: .PP
! 80: The
! 81: .B text
! 82: data type specifies an NVT ASCII string, which must be
! 83: enclosed in double quotes - for example, to specify a root-path
! 84: option, the syntax would be
! 85: .nf
! 86: .sp 1
! 87: option root-path "10.0.1.4:/var/tmp/rootfs";
! 88: .fi
! 89: .PP
! 90: The
! 91: .B domain-name
! 92: data type specifies a domain name, which must not be
! 93: enclosed in double quotes. This data type is not used for any
! 94: existing DHCP options. The domain name is stored just as if it were
! 95: a text option.
! 96: .PP
! 97: The
! 98: .B domain-list
! 99: data type specifies a list of domain names, enclosed in double quotes and
! 100: separated by commas ("example.com", "foo.example.com").
! 101: .PP
! 102: The
! 103: .B flag
! 104: data type specifies a boolean value. Booleans can be either true or
! 105: false (or on or off, if that makes more sense to you).
! 106: .PP
! 107: The
! 108: .B string
! 109: data type specifies either an NVT ASCII string
! 110: enclosed in double quotes, or a series of octets specified in
! 111: hexadecimal, separated by colons. For example:
! 112: .nf
! 113: .sp 1
! 114: option dhcp-client-identifier "CLIENT-FOO";
! 115: or
! 116: option dhcp-client-identifier 43:4c:49:45:54:2d:46:4f:4f;
! 117: .fi
! 118: .SH SETTING OPTION VALUES USING EXPRESSIONS
! 119: Sometimes it's helpful to be able to set the value of a DHCP option
! 120: based on some value that the client has sent. To do this, you can
! 121: use expression evaluation. The
! 122: .B dhcp-eval(5)
! 123: manual page describes how to write expressions. To assign the result
! 124: of an evaluation to an option, define the option as follows:
! 125: .nf
! 126: .sp 1
! 127: \fBoption \fImy-option \fB= \fIexpression \fB;\fR
! 128: .fi
! 129: .PP
! 130: For example:
! 131: .nf
! 132: .sp 1
! 133: option hostname = binary-to-ascii (16, 8, "-",
! 134: substring (hardware, 1, 6));
! 135: .fi
! 136: .SH STANDARD DHCPV4 OPTIONS
! 137: The documentation for the various options mentioned below is taken
! 138: from the latest IETF draft document on DHCP options. Options not
! 139: listed below may not yet be implemented, but it is possible to use
! 140: such options by defining them in the configuration file. Please see
! 141: the DEFINING NEW OPTIONS heading later in this document for more
! 142: information.
! 143: .PP
! 144: Some of the options documented here are automatically generated by
! 145: the DHCP server or by clients, and cannot be configured by the user.
! 146: The value of such an option can be used in the configuration file of
! 147: the receiving DHCP protocol agent (server or client), for example in
! 148: conditional expressions. However, the value of the option cannot be
! 149: used in the configuration file of the sending agent, because the value
! 150: is determined only \fIafter\fR the configuration file has been
! 151: processed. In the following documentation, such options will be shown
! 152: as "not user configurable"
! 153: .PP
! 154: The standard options are:
! 155: .PP
! 156: .B option \fBall-subnets-local\fR \fIflag\fR\fB;\fR
! 157: .RS 0.25i
! 158: .PP
! 159: This option specifies whether or not the client may assume that all
! 160: subnets of the IP network to which the client is connected use the
! 161: same MTU as the subnet of that network to which the client is
! 162: directly connected. A value of true indicates that all subnets share
! 163: the same MTU. A value of false means that the client should assume that
! 164: some subnets of the directly connected network may have smaller MTUs.
! 165: .RE
! 166: .PP
! 167: .B option \fBarp-cache-timeout\fR \fIuint32\fR\fB;\fR
! 168: .RS 0.25i
! 169: .PP
! 170: This option specifies the timeout in seconds for ARP cache entries.
! 171: .RE
! 172: .PP
! 173: .B option \fBbcms-controller-address\fR \fIip-address\fR [\fB,\fR
! 174: \fIip-address\fR... ]\fB;\fR
! 175: .RS 0.25i
! 176: .PP
! 177: This option configures a list of IPv4 addresses for use as Broadcast and
! 178: Multicast Controller Servers ("BCMS").
! 179: .RE
! 180: .PP
! 181: .B option \fBbcms-controller-names\fR \fIdomain-list\fR\fB;\fR
! 182: .RS 0.25i
! 183: .PP
! 184: This option contains the domain names of local Broadcast and
! 185: Multicast Controller Servers ("BCMS") controllers which the client
! 186: may use.
! 187: .RE
! 188: .PP
! 189: .B option \fBbootfile-name\fR \fItext\fR\fB;\fR
! 190: .RS 0.25i
! 191: .PP
! 192: This option is used to identify a bootstrap file. If supported by the
! 193: client, it should have the same effect as the \fBfilename\fR
! 194: declaration. BOOTP clients are unlikely to support this option. Some
! 195: DHCP clients will support it, and others actually require it.
! 196: .RE
! 197: .PP
! 198: .B option \fBboot-size\fR \fIuint16\fR\fB;\fR
! 199: .RS 0.25i
! 200: .PP
! 201: This option specifies the length in 512-octet blocks of the default
! 202: boot image for the client.
! 203: .RE
! 204: .PP
! 205: .B option \fBbroadcast-address\fR \fIip-address\fR\fB;\fR
! 206: .RS 0.25i
! 207: .PP
! 208: This option specifies the broadcast address in use on the client's
! 209: subnet. Legal values for broadcast addresses are specified in
! 210: section 3.2.1.3 of STD 3 (RFC1122).
! 211: .RE
! 212: .PP
! 213: .B option \fBcookie-servers\fR \fIip-address\fR [\fB,\fR \fIip-address\fR...
! 214: ]\fB;\fR
! 215: .RS 0.25i
! 216: .PP
! 217: The cookie server option specifies a list of RFC 865 cookie
! 218: servers available to the client. Servers should be listed in order
! 219: of preference.
! 220: .RE
! 221: .PP
! 222: .B option \fBdefault-ip-ttl\fR \fIuint8;\fR
! 223: .RS 0.25i
! 224: .PP
! 225: This option specifies the default time-to-live that the client should
! 226: use on outgoing datagrams.
! 227: .RE
! 228: .PP
! 229: .B option \fBdefault-tcp-ttl\fR \fIuint8\fR\fB;\fR
! 230: .RS 0.25i
! 231: .PP
! 232: This option specifies the default TTL that the client should use when
! 233: sending TCP segments. The minimum value is 1.
! 234: .RE
! 235: .PP
! 236: .B option \fBdefault-url\fR \fIstring\fR\fB;\fR
! 237: .RS 0.25i
! 238: .PP
! 239: The format and meaning of this option is not described in any standards
! 240: document, but is claimed to be in use by Apple Computer. It is not known
! 241: what clients may reasonably do if supplied with this option. Use at your
! 242: own risk.
! 243: .RE
! 244: .PP
! 245: .B option \fBdhcp-client-identifier\fR \fIstring\fR\fB;\fR
! 246: .RS 0.25i
! 247: .PP
! 248: This option can be used to specify a DHCP client identifier in a
! 249: host declaration, so that dhcpd can find the host record by matching
! 250: against the client identifier.
! 251: .PP
! 252: Please be aware that some DHCP clients, when configured with client
! 253: identifiers that are ASCII text, will prepend a zero to the ASCII
! 254: text. So you may need to write:
! 255: .nf
! 256:
! 257: option dhcp-client-identifier "\\0foo";
! 258:
! 259: rather than:
! 260:
! 261: option dhcp-client-identifier "foo";
! 262: .fi
! 263: .RE
! 264: .PP
! 265: .B option \fBdhcp-lease-time\fR \fIuint32\fR\fB;\fR
! 266: .RS 0.25i
! 267: .PP
! 268: This option is used in a client request (DHCPDISCOVER or DHCPREQUEST)
! 269: to allow the client to request a lease time for the IP address. In a
! 270: server reply (DHCPOFFER), a DHCP server uses this option to specify
! 271: the lease time it is willing to offer.
! 272: .PP
! 273: This option is not directly user configurable in the server; refer to the
! 274: \fImax-lease-time\fR and \fIdefault-lease-time\fR server options in
! 275: .B dhcpd.conf(5).
! 276: .RE
! 277: .PP
! 278: .B option \fBdhcp-max-message-size\fR \fIuint16\fR\fB;\fR
! 279: .RS 0.25i
! 280: .PP
! 281: This option, when sent by the client, specifies the maximum size of
! 282: any response that the server sends to the client. When specified on
! 283: the server, if the client did not send a dhcp-max-message-size option,
! 284: the size specified on the server is used. This works for BOOTP as
! 285: well as DHCP responses.
! 286: .RE
! 287: .PP
! 288: .B option \fBdhcp-message\fR \fItext\fR\fB;\fR
! 289: .RS 0.25i
! 290: .PP
! 291: This option is used by a DHCP server to provide an error message to a
! 292: DHCP client in a DHCPNAK message in the event of a failure. A client
! 293: may use this option in a DHCPDECLINE message to indicate why the
! 294: client declined the offered parameters.
! 295: .PP
! 296: This option is not user configurable.
! 297: .RE
! 298: .PP
! 299: .B option \fBdhcp-message-type\fR \fIuint8\fR\fB;\fR
! 300: .RS 0.25i
! 301: .PP
! 302: This option, sent by both client and server, specifies the type of DHCP
! 303: message contained in the DHCP packet. Possible values (taken directly from
! 304: RFC2132) are:
! 305: .PP
! 306: .nf
! 307: 1 DHCPDISCOVER
! 308: 2 DHCPOFFER
! 309: 3 DHCPREQUEST
! 310: 4 DHCPDECLINE
! 311: 5 DHCPACK
! 312: 6 DHCPNAK
! 313: 7 DHCPRELEASE
! 314: 8 DHCPINFORM
! 315: .fi
! 316: .PP
! 317: This option is not user configurable.
! 318: .PP
! 319: .RE
! 320: .B option \fBdhcp-option-overload\fR \fIuint8\fR\fB;\fR
! 321: .RS 0.25i
! 322: .PP
! 323: This option is used to indicate that the DHCP \'sname\' or \'file\'
! 324: fields are being overloaded by using them to carry DHCP options. A
! 325: DHCP server inserts this option if the returned parameters will
! 326: exceed the usual space allotted for options.
! 327: .PP
! 328: If this option is present, the client interprets the specified
! 329: additional fields after it concludes interpretation of the standard
! 330: option fields.
! 331: .PP
! 332: Legal values for this option are:
! 333: .PP
! 334: .nf
! 335: 1 the \'file\' field is used to hold options
! 336: 2 the \'sname\' field is used to hold options
! 337: 3 both fields are used to hold options
! 338: .fi
! 339: .PP
! 340: This option is not user configurable.
! 341: .PP
! 342: .RE
! 343: .PP
! 344: .B option \fBdhcp-parameter-request-list\fR \fIuint16\fR [\fB,\fR
! 345: \fIuint16\fR... ]\fB;\fR
! 346: .RS 0.25i
! 347: .PP
! 348: This option, when sent by the client, specifies which options the
! 349: client wishes the server to return. Normally, in the ISC DHCP
! 350: client, this is done using the \fIrequest\fR statement. If this
! 351: option is not specified by the client, the DHCP server will normally
! 352: return every option that is valid in scope and that fits into the
! 353: reply. When this option is specified on the server, the server
! 354: returns the specified options. This can be used to force a client to
! 355: take options that it hasn't requested, and it can also be used to
! 356: tailor the response of the DHCP server for clients that may need a
! 357: more limited set of options than those the server would normally
! 358: return.
! 359: .RE
! 360: .PP
! 361: .B option \fBdhcp-rebinding-time\fR \fIuint32\fR\fB;\fR
! 362: .RS 0.25i
! 363: .PP
! 364: This option specifies the number of seconds from the time a client gets
! 365: an address until the client transitions to the REBINDING state.
! 366: .PP
! 367: This option is not user configurable.
! 368: .PP
! 369: .RE
! 370: .PP
! 371: .B option \fBdhcp-renewal-time\fR \fIuint32\fR\fB;\fR
! 372: .RS 0.25i
! 373: .PP
! 374: This option specifies the number of seconds from the time a client gets
! 375: an address until the client transitions to the RENEWING state.
! 376: .PP
! 377: This option is not user configurable.
! 378: .PP
! 379: .RE
! 380: .PP
! 381: .B option \fBdhcp-requested-address\fR \fIip-address\fR\fB;\fR
! 382: .RS 0.25i
! 383: .PP
! 384: This option is used by the client in a DHCPDISCOVER to
! 385: request that a particular IP address be assigned.
! 386: .PP
! 387: This option is not user configurable.
! 388: .PP
! 389: .RE
! 390: .PP
! 391: .B option \fBdhcp-server-identifier\fR \fIip-address\fR\fB;\fR
! 392: .RS 0.25i
! 393: .PP
! 394: This option is used in DHCPOFFER and DHCPREQUEST messages, and may
! 395: optionally be included in the DHCPACK and DHCPNAK messages. DHCP
! 396: servers include this option in the DHCPOFFER in order to allow the
! 397: client to distinguish between lease offers. DHCP clients use the
! 398: contents of the \'server identifier\' field as the destination address
! 399: for any DHCP messages unicast to the DHCP server. DHCP clients also
! 400: indicate which of several lease offers is being accepted by including
! 401: this option in a DHCPREQUEST message.
! 402: .PP
! 403: The value of this option is the IP address of the server.
! 404: .PP
! 405: This option is not directly user configurable. See the
! 406: \fIserver-identifier\fR server option in
! 407: .B \fIdhcpd.conf(5).
! 408: .PP
! 409: .RE
! 410: .PP
! 411: .B option \fBdomain-name\fR \fItext\fR\fB;\fR
! 412: .RS 0.25i
! 413: .PP
! 414: This option specifies the domain name that client should use when
! 415: resolving hostnames via the Domain Name System.
! 416: .RE
! 417: .PP
! 418: .B option \fBdomain-name-servers\fR \fIip-address\fR [\fB,\fR \fIip-address\fR...
! 419: ]\fB;\fR
! 420: .RS 0.25i
! 421: .PP
! 422: The domain-name-servers option specifies a list of Domain Name System
! 423: (STD 13, RFC 1035) name servers available to the client. Servers
! 424: should be listed in order of preference.
! 425: .RE
! 426: .PP
! 427: .B option \fBdomain-search\fR \fIdomain-list\fR\fB;\fR
! 428: .RS 0.25i
! 429: .PP
! 430: The domain-search option specifies a \'search list\' of Domain Names to be
! 431: used by the client to locate not-fully-qualified domain names. The difference
! 432: between this option and historic use of the domain-name option for the same
! 433: ends is that this option is encoded in RFC1035 compressed labels on the wire.
! 434: For example:
! 435: .nf
! 436: .sp 1
! 437: option domain-search "example.com", "sales.example.com",
! 438: "eng.example.com";
! 439: .fi
! 440: .RE
! 441: .PP
! 442: .B option \fBextensions-path\fR \fItext\fR\fB;\fR
! 443: .RS 0.25i
! 444: .PP
! 445: This option specifies the name of a file containing additional options
! 446: to be interpreted according to the DHCP option format as specified in
! 447: RFC2132.
! 448: .RE
! 449: .PP
! 450: .B option \fBfinger-server\fR \fIip-address\fR [\fB,\fR
! 451: \fIip-address\fR... ]\fB;\fR
! 452: .RS 0.25i
! 453: .PP
! 454: The Finger server option specifies a list of Finger servers available
! 455: to the client. Servers should be listed in order of preference.
! 456: .RE
! 457: .PP
! 458: .B option \fBfont-servers\fR \fIip-address\fR [\fB,\fR \fIip-address\fR...
! 459: ]\fB;\fR
! 460: .RS 0.25i
! 461: .PP
! 462: This option specifies a list of X Window System Font servers available
! 463: to the client. Servers should be listed in order of preference.
! 464: .RE
! 465: .PP
! 466: .B option \fBhost-name\fR \fIstring\fR\fB;\fR
! 467: .RS 0.25i
! 468: .PP
! 469: This option specifies the name of the client. The name may or may
! 470: not be qualified with the local domain name (it is preferable to use
! 471: the domain-name option to specify the domain name). See RFC 1035 for
! 472: character set restrictions. This option is only honored by
! 473: .B dhclient-script(8)
! 474: if the hostname for the client machine is not set.
! 475: .RE
! 476: .PP
! 477: .B option \fBieee802-3-encapsulation\fR \fIflag\fR\fB;\fR
! 478: .RS 0.25i
! 479: .PP
! 480: This option specifies whether or not the client should use Ethernet
! 481: Version 2 (RFC 894) or IEEE 802.3 (RFC 1042) encapsulation if the
! 482: interface is an Ethernet. A value of false indicates that the client
! 483: should use RFC 894 encapsulation. A value of true means that the client
! 484: should use RFC 1042 encapsulation.
! 485: .RE
! 486: .PP
! 487: .B option \fBien116-name-servers\fR \fIip-address\fR [\fB,\fR \fIip-address\fR...
! 488: ];
! 489: .RS 0.25i
! 490: .PP
! 491: The ien116-name-servers option specifies a list of IEN 116 name servers
! 492: available to the client. Servers should be listed in order of
! 493: preference.
! 494: .RE
! 495: .PP
! 496: .B option \fBimpress-servers\fR \fIip-address\fR [\fB,\fR \fIip-address\fR...
! 497: ]\fB;\fR
! 498: .RS 0.25i
! 499: .PP
! 500: The impress-server option specifies a list of Imagen Impress servers
! 501: available to the client. Servers should be listed in order of
! 502: preference.
! 503: .RE
! 504: .PP
! 505: .B option \fBinterface-mtu\fR \fIuint16\fR\fB;\fR
! 506: .RS 0.25i
! 507: .PP
! 508: This option specifies the MTU to use on this interface. The minimum
! 509: legal value for the MTU is 68.
! 510: .RE
! 511: .PP
! 512: .B option \fBip-forwarding\fR \fIflag\fR\fB;\fR
! 513: .RS 0.25i
! 514: .PP
! 515: This option specifies whether the client should configure its IP
! 516: layer for packet forwarding. A value of false means disable IP
! 517: forwarding, and a value of true means enable IP forwarding.
! 518: .RE
! 519: .PP
! 520: .B option \fBirc-server\fR \fIip-address\fR [\fB,\fR
! 521: \fIip-address\fR... ]\fB;\fR
! 522: .RS 0.25i
! 523: .PP
! 524: The IRC server option specifies a list of IRC servers available
! 525: to the client. Servers should be listed in order of preference.
! 526: .RE
! 527: .PP
! 528: .B option \fBlog-servers\fR \fIip-address\fR [\fB,\fR \fIip-address\fR...
! 529: ]\fB;\fR
! 530: .RS 0.25i
! 531: .PP
! 532: The log-server option specifies a list of MIT-LCS UDP log servers
! 533: available to the client. Servers should be listed in order of
! 534: preference.
! 535: .RE
! 536: .PP
! 537: .B option \fBlpr-servers\fR \fIip-address \fR [\fB,\fR \fIip-address\fR...
! 538: ]\fB;\fR
! 539: .RS 0.25i
! 540: .PP
! 541: The LPR server option specifies a list of RFC 1179 line printer
! 542: servers available to the client. Servers should be listed in order
! 543: of preference.
! 544: .RE
! 545: .PP
! 546: .B option \fBmask-supplier\fR \fIflag\fR\fB;\fR
! 547: .RS 0.25i
! 548: .PP
! 549: This option specifies whether or not the client should respond to
! 550: subnet mask requests using ICMP. A value of false indicates that the
! 551: client should not respond. A value of true means that the client should
! 552: respond.
! 553: .RE
! 554: .PP
! 555: .B option \fBmax-dgram-reassembly\fR \fIuint16\fR\fB;\fR
! 556: .RS 0.25i
! 557: .PP
! 558: This option specifies the maximum size datagram that the client
! 559: should be prepared to reassemble. The minimum legal value is
! 560: 576.
! 561: .RE
! 562: .PP
! 563: .B option \fBmerit-dump\fR \fItext\fR\fB;\fR
! 564: .RS 0.25i
! 565: .PP
! 566: This option specifies the path-name of a file to which the client's
! 567: core image should be dumped in the event the client crashes. The
! 568: path is formatted as a character string consisting of characters from
! 569: the NVT ASCII character set.
! 570: .RE
! 571: .PP
! 572: .B option \fBmobile-ip-home-agent\fR \fIip-address\fR [\fB,\fR \fIip-address\fR... ]\fB;\fR
! 573: .RS 0.25i
! 574: .PP
! 575: This option specifies a list of IP addresses indicating mobile IP
! 576: home agents available to the client. Agents should be listed in
! 577: order of preference, although normally there will be only one such
! 578: agent.
! 579: .RE
! 580: .PP
! 581: .B option \fBnds-context\fR \fIstring\fR\fB;\fR
! 582: .RS 0.25i
! 583: .PP
! 584: The nds-context option specifies the name of the initial Netware
! 585: Directory Service for an NDS client.
! 586: .RE
! 587: .PP
! 588: .B option \fBnds-servers\fR \fIip-address\fR [\fB,\fR \fIip-address\fR... ]\fB;\fR
! 589: .RS 0.25i
! 590: .PP
! 591: The nds-servers option specifies a list of IP addresses of NDS servers.
! 592: .RE
! 593: .PP
! 594: .B option \fBnds-tree-name\fR \fIstring\fR\fB;\fR
! 595: .RS 0.25i
! 596: .PP
! 597: The nds-tree-name option specifies NDS tree name that the NDS client
! 598: should use.
! 599: .RE
! 600: .PP
! 601: .B option \fBnetbios-dd-server\fR \fIip-address\fR [\fB,\fR \fIip-address\fR...
! 602: ]\fB;\fR
! 603: .RS 0.25i
! 604: .PP
! 605: The NetBIOS datagram distribution server (NBDD) option specifies a
! 606: list of RFC 1001/1002 NBDD servers listed in order of preference.
! 607: .RE
! 608: .PP
! 609: .B option \fBnetbios-name-servers\fR \fIip-address\fR [\fB,\fR \fIip-address\fR...]\fB;\fR
! 610: .RS 0.25i
! 611: .PP
! 612: The NetBIOS name server (NBNS) option specifies a list of RFC
! 613: 1001/1002 NBNS name servers listed in order of preference. NetBIOS
! 614: Name Service is currently more commonly referred to as WINS. WINS
! 615: servers can be specified using the netbios-name-servers option.
! 616: .RE
! 617: .PP
! 618: .B option \fBnetbios-node-type\fR \fIuint8\fR\fB;\fR
! 619: .RS 0.25i
! 620: .PP
! 621: The NetBIOS node type option allows NetBIOS over TCP/IP clients which
! 622: are configurable to be configured as described in RFC 1001/1002. The
! 623: value is specified as a single octet which identifies the client type.
! 624: .PP
! 625: Possible node types are:
! 626: .PP
! 627: .TP 5
! 628: .I 1
! 629: B-node: Broadcast - no WINS
! 630: .TP
! 631: .I 2
! 632: P-node: Peer - WINS only
! 633: .TP
! 634: .I 4
! 635: M-node: Mixed - broadcast, then WINS
! 636: .TP
! 637: .I 8
! 638: H-node: Hybrid - WINS, then broadcast
! 639: .RE
! 640: .PP
! 641: .B option \fBnetbios-scope\fR \fIstring\fR\fB;\fR
! 642: .RS 0.25i
! 643: .PP
! 644: The NetBIOS scope option specifies the NetBIOS over TCP/IP scope
! 645: parameter for the client as specified in RFC 1001/1002. See RFC1001,
! 646: RFC1002, and RFC1035 for character-set restrictions.
! 647: .RE
! 648: .PP
! 649: .B option \fBnetinfo-server-address\fR \fIip-address\fR [\fB,\fR
! 650: \fIip-address\fR... ]\fB;\fR
! 651: .RS 0.25i
! 652: .PP
! 653: The \fBnetinfo-server-address\fR option has not been described in any
! 654: RFC, but has been allocated (and is claimed to be in use) by Apple
! 655: Computers. It's hard to say if the above is the correct format, or
! 656: what clients might be expected to do if values were configured. Use
! 657: at your own risk.
! 658: .RE
! 659: .PP
! 660: .B option \fBnetinfo-server-tag\fR \fItext\fR\fB;\fR
! 661: .RS 0.25i
! 662: .PP
! 663: The \fBnetinfo-server-tag\fR option has not been described in any
! 664: RFC, but has been allocated (and is claimed to be in use) by Apple
! 665: Computers. It's hard to say if the above is the correct format,
! 666: or what clients might be expected to do if values were configured. Use
! 667: at your own risk.
! 668: .RE
! 669: .PP
! 670: .B option \fBnis-domain\fR \fItext\fR\fB;\fR
! 671: .RS 0.25i
! 672: .PP
! 673: This option specifies the name of the client's NIS (Sun Network
! 674: Information Services) domain. The domain is formatted as a character
! 675: string consisting of characters from the NVT ASCII character set.
! 676: .RE
! 677: .PP
! 678: .B option \fBnis-servers\fR \fIip-address\fR [\fB,\fR \fIip-address\fR...
! 679: ]\fB;\fR
! 680: .RS 0.25i
! 681: .PP
! 682: This option specifies a list of IP addresses indicating NIS servers
! 683: available to the client. Servers should be listed in order of
! 684: preference.
! 685: .RE
! 686: .PP
! 687: .B option \fBnisplus-domain\fR \fItext\fR\fB;\fR
! 688: .RS 0.25i
! 689: .PP
! 690: This option specifies the name of the client's NIS+ domain. The
! 691: domain is formatted as a character string consisting of characters
! 692: from the NVT ASCII character set.
! 693: .RE
! 694: .PP
! 695: .B option \fBnisplus-servers\fR \fIip-address\fR [\fB,\fR \fIip-address\fR...
! 696: ]\fB;\fR
! 697: .RS 0.25i
! 698: .PP
! 699: This option specifies a list of IP addresses indicating NIS+ servers
! 700: available to the client. Servers should be listed in order of
! 701: preference.
! 702: .RE
! 703: .PP
! 704: .B option \fBnntp-server\fR \fIip-address\fR [\fB,\fR
! 705: \fIip-address\fR... ]\fB;\fR
! 706: .RS 0.25i
! 707: .PP
! 708: The NNTP server option specifies a list of NNTP servesr available
! 709: to the client. Servers should be listed in order of preference.
! 710: .RE
! 711: .PP
! 712: .B option \fBnon-local-source-routing\fR \fIflag\fR\fB;\fR
! 713: .RS 0.25i
! 714: .PP
! 715: This option specifies whether the client should configure its IP
! 716: layer to allow forwarding of datagrams with non-local source routes
! 717: (see Section 3.3.5 of [4] for a discussion of this topic). A value
! 718: of false means disallow forwarding of such datagrams, and a value of true
! 719: means allow forwarding.
! 720: .RE
! 721: .PP
! 722: .B option \fBntp-servers\fR \fIip-address\fR [\fB,\fR \fIip-address\fR...
! 723: ]\fB;\fR
! 724: .RS 0.25i
! 725: .PP
! 726: This option specifies a list of IP addresses indicating NTP (RFC 1035)
! 727: servers available to the client. Servers should be listed in order
! 728: of preference.
! 729: .RE
! 730: .PP
! 731: .B option \fBnwip-domain\fR \fIstring\fR\fB;\fR
! 732: .RS 0.25i
! 733: .PP
! 734: The name of the NetWare/IP domain that a NetWare/IP client should
! 735: use.
! 736: .RE
! 737: .PP
! 738: .B option \fBnwip-suboptions\fR \fIstring\fR\fB;\fR
! 739: .RS 0.25i
! 740: .PP
! 741: A sequence of suboptions for NetWare/IP clients - see RFC2242 for
! 742: details. Normally this option is set by specifying specific
! 743: NetWare/IP suboptions - see the NETWARE/IP SUBOPTIONS section for more
! 744: information.
! 745: .RE
! 746: .PP
! 747: .B option \fBpath-mtu-aging-timeout\fR \fIuint32\fR\fB;\fR
! 748: .RS 0.25i
! 749: .PP
! 750: This option specifies the timeout (in seconds) to use when aging Path
! 751: MTU values discovered by the mechanism defined in RFC 1191.
! 752: .RE
! 753: .PP
! 754: .B option \fBpath-mtu-plateau-table\fR \fIuint16\fR [\fB,\fR \fIuint16\fR...
! 755: ]\fB;\fR
! 756: .RS 0.25i
! 757: .PP
! 758: This option specifies a table of MTU sizes to use when performing
! 759: Path MTU Discovery as defined in RFC 1191. The table is formatted as
! 760: a list of 16-bit unsigned integers, ordered from smallest to largest.
! 761: The minimum MTU value cannot be smaller than 68.
! 762: .RE
! 763: .PP
! 764: .B option \fBperform-mask-discovery\fR \fIflag\fR\fB;\fR
! 765: .RS 0.25i
! 766: .PP
! 767: This option specifies whether or not the client should perform subnet
! 768: mask discovery using ICMP. A value of false indicates that the client
! 769: should not perform mask discovery. A value of true means that the
! 770: client should perform mask discovery.
! 771: .RE
! 772: .PP
! 773: .nf
! 774: .B option \fBpolicy-filter\fR \fIip-address ip-address\fR
! 775: [\fB,\fR \fIip-address ip-address\fR...]\fB;\fR
! 776: .RE
! 777: .fi
! 778: .RS 0.25i
! 779: .PP
! 780: This option specifies policy filters for non-local source routing.
! 781: The filters consist of a list of IP addresses and masks which specify
! 782: destination/mask pairs with which to filter incoming source routes.
! 783: .PP
! 784: Any source routed datagram whose next-hop address does not match one
! 785: of the filters should be discarded by the client.
! 786: .PP
! 787: See STD 3 (RFC1122) for further information.
! 788: .RE
! 789: .PP
! 790: .B option \fBpop-server\fR \fIip-address\fR [\fB,\fR \fIip-address\fR... ]\fB;\fR
! 791: .RS 0.25i
! 792: .PP
! 793: The POP3 server option specifies a list of POP3 servers available
! 794: to the client. Servers should be listed in order of preference.
! 795: .RE
! 796: .PP
! 797: .B option \fBresource-location-servers\fR \fIip-address\fR
! 798: [\fB, \fR\fIip-address\fR...]\fB;\fR
! 799: .fi
! 800: .RS 0.25i
! 801: .PP
! 802: This option specifies a list of RFC 887 Resource Location
! 803: servers available to the client. Servers should be listed in order
! 804: of preference.
! 805: .RE
! 806: .PP
! 807: .B option \fBroot-path\fR \fItext\fB;\fR\fR
! 808: .RS 0.25i
! 809: .PP
! 810: This option specifies the path-name that contains the client's root
! 811: disk. The path is formatted as a character string consisting of
! 812: characters from the NVT ASCII character set.
! 813: .RE
! 814: .PP
! 815: .B option \fBrouter-discovery\fR \fIflag\fR\fB;\fR
! 816: .RS 0.25i
! 817: .PP
! 818: This option specifies whether or not the client should solicit
! 819: routers using the Router Discovery mechanism defined in RFC 1256.
! 820: A value of false indicates that the client should not perform
! 821: router discovery. A value of true means that the client should perform
! 822: router discovery.
! 823: .RE
! 824: .PP
! 825: .B option \fBrouter-solicitation-address\fR \fIip-address\fR\fB;\fR
! 826: .RS 0.25i
! 827: .PP
! 828: This option specifies the address to which the client should transmit
! 829: router solicitation requests.
! 830: .RE
! 831: .PP
! 832: .B option routers \fIip-address\fR [\fB,\fR \fIip-address\fR...
! 833: ]\fB;\fR
! 834: .RS 0.25i
! 835: .PP
! 836: The routers option specifies a list of IP addresses for routers on the
! 837: client's subnet. Routers should be listed in order of preference.
! 838: .RE
! 839: .PP
! 840: .B option slp-directory-agent \fIboolean ip-address
! 841: [\fB,\fR \fIip-address\fR... ]\fB;\fR
! 842: .RS 0.25i
! 843: .PP
! 844: This option specifies two things: the IP addresses of one or more
! 845: Service Location Protocol Directory Agents, and whether the use of
! 846: these addresses is mandatory. If the initial boolean value is true,
! 847: the SLP agent should just use the IP addresses given. If the value
! 848: is false, the SLP agent may additionally do active or passive
! 849: multicast discovery of SLP agents (see RFC2165 for details).
! 850: .PP
! 851: Please note that in this option and the slp-service-scope option, the
! 852: term "SLP Agent" is being used to refer to a Service Location Protocol
! 853: agent running on a machine that is being configured using the DHCP
! 854: protocol.
! 855: .PP
! 856: Also, please be aware that some companies may refer to SLP as NDS.
! 857: If you have an NDS directory agent whose address you need to
! 858: configure, the slp-directory-agent option should work.
! 859: .RE
! 860: .PP
! 861: .B option slp-service-scope \fIboolean text\fR\fB;\fR
! 862: .RS 0.25i
! 863: .PP
! 864: The Service Location Protocol Service Scope Option specifies two
! 865: things: a list of service scopes for SLP, and whether the use of this
! 866: list is mandatory. If the initial boolean value is true, the SLP
! 867: agent should only use the list of scopes provided in this option;
! 868: otherwise, it may use its own static configuration in preference to
! 869: the list provided in this option.
! 870: .PP
! 871: The text string should be a comma-separated list of scopes that the
! 872: SLP agent should use. It may be omitted, in which case the SLP Agent
! 873: will use the aggregated list of scopes of all directory agents known
! 874: to the SLP agent.
! 875: .RE
! 876: .PP
! 877: .B option \fBsmtp-server\fR \fIip-address\fR [\fB,\fR
! 878: \fIip-address\fR... ]\fB;\fR
! 879: .RS 0.25i
! 880: .PP
! 881: The SMTP server option specifies a list of SMTP servers available to
! 882: the client. Servers should be listed in order of preference.
! 883: .RE
! 884: .PP
! 885: .nf
! 886: .B option \fBstatic-routes\fR \fIip-address ip-address\fR
! 887: [\fB,\fR \fIip-address ip-address\fR...]\fB;\fR
! 888: .fi
! 889: .RS 0.25i
! 890: .PP
! 891: This option specifies a list of static routes that the client should
! 892: install in its routing cache. If multiple routes to the same
! 893: destination are specified, they are listed in descending order of
! 894: priority.
! 895: .PP
! 896: The routes consist of a list of IP address pairs. The first address
! 897: is the destination address, and the second address is the router for
! 898: the destination.
! 899: .PP
! 900: The default route (0.0.0.0) is an illegal destination for a static
! 901: route. To specify the default route, use the
! 902: .B routers
! 903: option. Also, please note that this option is not intended for
! 904: classless IP routing - it does not include a subnet mask. Since
! 905: classless IP routing is now the most widely deployed routing standard,
! 906: this option is virtually useless, and is not implemented by any of the
! 907: popular DHCP clients, for example the Microsoft DHCP client.
! 908: .RE
! 909: .PP
! 910: .nf
! 911: .B option \fBstreettalk-directory-assistance-server\fR \fIip-address\fR
! 912: [\fB,\fR \fIip-address\fR...]\fB;\fR
! 913: .fi
! 914: .RS 0.25i
! 915: .PP
! 916: The StreetTalk Directory Assistance (STDA) server option specifies a
! 917: list of STDA servers available to the client. Servers should be
! 918: listed in order of preference.
! 919: .RE
! 920: .PP
! 921: .B option \fBstreettalk-server\fR \fIip-address\fR [\fB,\fR \fIip-address\fR... ]\fB;\fR
! 922: .RS 0.25i
! 923: .PP
! 924: The StreetTalk server option specifies a list of StreetTalk servers
! 925: available to the client. Servers should be listed in order of
! 926: preference.
! 927: .RE
! 928: .PP
! 929: .B option subnet-mask \fIip-address\fR\fB;\fR
! 930: .RS 0.25i
! 931: .PP
! 932: The subnet mask option specifies the client's subnet mask as per RFC
! 933: 950. If no subnet mask option is provided anywhere in scope, as a
! 934: last resort dhcpd will use the subnet mask from the subnet declaration
! 935: for the network on which an address is being assigned. However,
! 936: .I any
! 937: subnet-mask option declaration that is in scope for the address being
! 938: assigned will override the subnet mask specified in the subnet
! 939: declaration.
! 940: .RE
! 941: .PP
! 942: .B option \fBsubnet-selection\fR \fIstring\fR\fB;\fR
! 943: .RS 0.25i
! 944: .PP
! 945: Sent by the client if an address is required in a subnet other than the one
! 946: that would normally be selected (based on the relaying address of the
! 947: connected subnet the request is obtained from). See RFC3011. Note that the
! 948: option number used by this server is 118; this has not always been the
! 949: defined number, and some clients may use a different value. Use of this
! 950: option should be regarded as slightly experimental!
! 951: .RE
! 952: .PP
! 953: This option is not user configurable in the server.
! 954: .PP
! 955: .PP
! 956: .B option \fBswap-server\fR \fIip-address\fR\fB;\fR
! 957: .RS 0.25i
! 958: .PP
! 959: This specifies the IP address of the client's swap server.
! 960: .RE
! 961: .PP
! 962: .B option \fBtcp-keepalive-garbage\fR \fIflag\fR\fB;\fR
! 963: .RS 0.25i
! 964: .PP
! 965: This option specifies whether or not the client should send TCP
! 966: keepalive messages with an octet of garbage for compatibility with
! 967: older implementations. A value of false indicates that a garbage octet
! 968: should not be sent. A value of true indicates that a garbage octet
! 969: should be sent.
! 970: .RE
! 971: .PP
! 972: .B option \fBtcp-keepalive-interval\fR \fIuint32\fR\fB;\fR
! 973: .RS 0.25i
! 974: .PP
! 975: This option specifies the interval (in seconds) that the client TCP
! 976: should wait before sending a keepalive message on a TCP connection.
! 977: The time is specified as a 32-bit unsigned integer. A value of zero
! 978: indicates that the client should not generate keepalive messages on
! 979: connections unless specifically requested by an application.
! 980: .RE
! 981: .PP
! 982: .B option \fBtftp-server-name\fR \fItext\fR\fB;\fR
! 983: .RS 0.25i
! 984: .PP
! 985: This option is used to identify a TFTP server and, if supported by the
! 986: client, should have the same effect as the \fBserver-name\fR
! 987: declaration. BOOTP clients are unlikely to support this option.
! 988: Some DHCP clients will support it, and others actually require it.
! 989: .RE
! 990: .PP
! 991: .B option time-offset \fIint32\fR\fB;\fR
! 992: .RS 0.25i
! 993: .PP
! 994: The time-offset option specifies the offset of the client's subnet in
! 995: seconds from Coordinated Universal Time (UTC).
! 996: .RE
! 997: .PP
! 998: .B option time-servers \fIip-address\fR [, \fIip-address\fR...
! 999: ]\fB;\fR
! 1000: .RS 0.25i
! 1001: .PP
! 1002: The time-server option specifies a list of RFC 868 time servers
! 1003: available to the client. Servers should be listed in order of
! 1004: preference.
! 1005: .RE
! 1006: .PP
! 1007: .B option \fBtrailer-encapsulation\fR \fIflag\fR\fB;\fR
! 1008: .RS 0.25i
! 1009: .PP
! 1010: This option specifies whether or not the client should negotiate the
! 1011: use of trailers (RFC 893 [14]) when using the ARP protocol. A value
! 1012: of false indicates that the client should not attempt to use trailers. A
! 1013: value of true means that the client should attempt to use trailers.
! 1014: .RE
! 1015: .PP
! 1016: .B option \fBuap-servers\fR \fItext\fR\fB;\fR
! 1017: .RS 0.25i
! 1018: .PP
! 1019: This option specifies a list of URLs, each pointing to a user
! 1020: authentication service that is capable of processing authentication
! 1021: requests encapsulated in the User Authentication Protocol (UAP). UAP
! 1022: servers can accept either HTTP 1.1 or SSLv3 connections. If the list
! 1023: includes a URL that does not contain a port component, the normal
! 1024: default port is assumed (i.e., port 80 for http and port 443 for
! 1025: https). If the list includes a URL that does not contain a path
! 1026: component, the path /uap is assumed. If more than one URL is
! 1027: specified in this list, the URLs are separated by spaces.
! 1028: .RE
! 1029: .PP
! 1030: .B option \fBuser-class\fR \fIstring\fR\fB;\fR
! 1031: .RS 0.25i
! 1032: .PP
! 1033: This option is used by some DHCP clients as a way for users to
! 1034: specify identifying information to the client. This can be used in a
! 1035: similar way to the vendor-class-identifier option, but the value of
! 1036: the option is specified by the user, not the vendor. Most recent
! 1037: DHCP clients have a way in the user interface to specify the value for
! 1038: this identifier, usually as a text string.
! 1039: .RE
! 1040: .PP
! 1041: .B option \fBvendor-class-identifier\fR \fIstring\fR\fB;\fR
! 1042: .RS 0.25i
! 1043: .PP
! 1044: This option is used by some DHCP clients to identify the vendor
! 1045: type and possibly the configuration of a DHCP client. The information
! 1046: is a string of bytes whose contents are specific to the vendor and are
! 1047: not specified in a standard. To see what vendor class identifier
! 1048: clients are sending, you can write the following in your DHCP server
! 1049: configuration file:
! 1050: .nf
! 1051: .PP
! 1052: set vendor-string = option vendor-class-identifier;
! 1053: .fi
! 1054: .PP
! 1055: This will result in all entries in the DHCP server lease database file
! 1056: for clients that sent vendor-class-identifier options having a set
! 1057: statement that looks something like this:
! 1058: .nf
! 1059: .PP
! 1060: set vendor-string = "SUNW.Ultra-5_10";
! 1061: .fi
! 1062: .PP
! 1063: The vendor-class-identifier option is normally used by the DHCP server
! 1064: to determine the options that are returned in the
! 1065: .B vendor-encapsulated-options
! 1066: option. Please see the VENDOR ENCAPSULATED OPTIONS section later in this
! 1067: manual page for further information.
! 1068: .RE
! 1069: .PP
! 1070: .B option \fBvendor-encapsulated-options\fR \fIstring\fR\fB;\fR
! 1071: .RS 0.25i
! 1072: .PP
! 1073: The \fBvendor-encapsulated-options\fR option can contain either a
! 1074: single vendor-specific value or one or more vendor-specific
! 1075: suboptions. This option is not normally specified in the DHCP server
! 1076: configuration file - instead, a vendor class is defined for each
! 1077: vendor, vendor class suboptions are defined, values for those
! 1078: suboptions are defined, and the DHCP server makes up a response on
! 1079: that basis.
! 1080: .PP
! 1081: Some default behaviours for well-known DHCP client vendors (currently,
! 1082: the Microsoft Windows 2000 DHCP client) are configured automatically,
! 1083: but otherwise this must be configured manually - see the VENDOR
! 1084: ENCAPSULATED OPTIONS section later in this manual page for details.
! 1085: .RE
! 1086: .PP
! 1087: .B option \fBvivso\fR \fIstring\fR\fB;\fR
! 1088: .RS 0.25i
! 1089: .PP
! 1090: The \fBvivso\fR option can contain multiple separate options, one for
! 1091: each 32-bit Enterprise ID. Each Enterprise-ID discriminated option then
! 1092: contains additional options whose format is defined by the vendor who
! 1093: holds that ID. This option is usually not configured manually, but
! 1094: rather is configured via intervening option definitions. Please also
! 1095: see the VENDOR ENCAPSULATED OPTIONS section later in this manual page
! 1096: for details.
! 1097: .RE
! 1098: .PP
! 1099: .B option \fBwww-server\fR \fIip-address\fR [\fB,\fR
! 1100: \fIip-address\fR... ]\fB;\fR
! 1101: .RS 0.25i
! 1102: .PP
! 1103: The WWW server option specifies a list of WWW servers available
! 1104: to the client. Servers should be listed in order of preference.
! 1105: .RE
! 1106: .PP
! 1107: .B option \fBx-display-manager\fR \fIip-address\fR [\fB,\fR \fIip-address\fR...
! 1108: ]\fB;\fR
! 1109: .RS 0.25i
! 1110: .PP
! 1111: This option specifies a list of systems that are running the X Window
! 1112: System Display Manager and are available to the client. Addresses
! 1113: should be listed in order of preference.
! 1114: .RE
! 1115: .SH RELAY AGENT INFORMATION OPTION
! 1116: An IETF draft, draft-ietf-dhc-agent-options-11.txt, defines a series
! 1117: of encapsulated options that a relay agent can add to a DHCP packet
! 1118: when relaying it to the DHCP server. The server can then make
! 1119: address allocation decisions (or whatever other decisions it wants)
! 1120: based on these options. The server also returns these options in any
! 1121: replies it sends through the relay agent, so that the relay agent can
! 1122: use the information in these options for delivery or accounting
! 1123: purposes.
! 1124: .PP
! 1125: The current draft defines two options. To reference
! 1126: these options in the dhcp server, specify the option space name,
! 1127: "agent", followed by a period, followed by the option name. It is
! 1128: not normally useful to define values for these options in the server,
! 1129: although it is permissible. These options are not supported in the
! 1130: client.
! 1131: .PP
! 1132: .B option \fBagent.circuit-id\fR \fIstring\fR\fB;\fR
! 1133: .RS 0.25i
! 1134: .PP
! 1135: The circuit-id suboption encodes an agent-local identifier of the
! 1136: circuit from which a DHCP client-to-server packet was received. It is
! 1137: intended for use by agents in relaying DHCP responses back to the
! 1138: proper circuit. The format of this option is currently defined to be
! 1139: vendor-dependent, and will probably remain that way, although the
! 1140: current draft allows for for the possibility of standardizing the
! 1141: format in the future.
! 1142: .RE
! 1143: .PP
! 1144: .B option \fBagent.remote-id\fR \fIstring\fR\fB;\fR
! 1145: .RS 0.25i
! 1146: .PP
! 1147: The remote-id suboption encodes information about the remote host end
! 1148: of a circuit. Examples of what it might contain include caller ID
! 1149: information, username information, remote ATM address, cable modem ID,
! 1150: and similar things. In principal, the meaning is not well-specified,
! 1151: and it should generally be assumed to be an opaque object that is
! 1152: administratively guaranteed to be unique to a particular remote end of
! 1153: a circuit.
! 1154: .RE
! 1155: .PP
! 1156: .B option \fBagent.DOCSIS-device-class\fR \fIuint32\fR\fB;\fR
! 1157: .RS 0.25i
! 1158: .PP
! 1159: The DOCSIS-device-class suboption is intended to convey information about
! 1160: the host endpoint, hardware, and software, that either the host operating
! 1161: system or the DHCP server may not otherwise be aware of (but the relay is
! 1162: able to distinguish). This is implemented as a 32-bit field (4 octets),
! 1163: each bit representing a flag describing the host in one of these ways.
! 1164: So far, only bit zero (being the least significant bit) is defined in
! 1165: RFC3256. If this bit is set to one, the host is considered a CPE
! 1166: Controlled Cable Modem (CCCM). All other bits are reserved.
! 1167: .RE
! 1168: .PP
! 1169: .B option \fBagent.link-selection\fR \fIip-address\fR\fB;\fR
! 1170: .RS 0.25i
! 1171: .PP
! 1172: The link-selection suboption is provided by relay agents to inform servers
! 1173: what subnet the client is actually attached to. This is useful in those
! 1174: cases where the giaddr (where responses must be sent to the relay agent)
! 1175: is not on the same subnet as the client. When this option is present in
! 1176: a packet from a relay agent, the DHCP server will use its contents to find
! 1177: a subnet declared in configuration, and from here take one step further
! 1178: backwards to any shared-network the subnet may be defined within...the
! 1179: client may be given any address within that shared network, as normally
! 1180: appropriate.
! 1181: .RE
! 1182: .SH THE CLIENT FQDN SUBOPTIONS
! 1183: The Client FQDN option, currently defined in the Internet Draft
! 1184: draft-ietf-dhc-fqdn-option-00.txt is not a standard yet, but is in
! 1185: sufficiently wide use already that we have implemented it. Due to
! 1186: the complexity of the option format, we have implemented it as a
! 1187: suboption space rather than a single option. In general this
! 1188: option should not be configured by the user - instead it should be
! 1189: used as part of an automatic DNS update system.
! 1190: .PP
! 1191: .B option fqdn.no-client-update \fIflag\fB;
! 1192: .RS 0.25i
! 1193: .PP
! 1194: When the client sends this, if it is true, it means the client will not
! 1195: attempt to update its A record. When sent by the server to the client,
! 1196: it means that the client \fIshould not\fR update its own A record.
! 1197: .RE
! 1198: .PP
! 1199: .B option fqdn.server-update \fIflag\fB;
! 1200: .RS 0.25i
! 1201: .PP
! 1202: When the client sends this to the server, it is requesting that the server
! 1203: update its A record. When sent by the server, it means that the server
! 1204: has updated (or is about to update) the client's A record.
! 1205: .RE
! 1206: .PP
! 1207: .B option fqdn.encoded \fIflag\fB;
! 1208: .RS 0.25i
! 1209: .PP
! 1210: If true, this indicates that the domain name included in the option is
! 1211: encoded in DNS wire format, rather than as plain ASCII text. The client
! 1212: normally sets this to false if it doesn't support DNS wire format in the
! 1213: FQDN option. The server should always send back the same value that the
! 1214: client sent. When this value is set on the configuration side, it controls
! 1215: the format in which the \fIfqdn.fqdn\fR suboption is encoded.
! 1216: .RE
! 1217: .PP
! 1218: .B option fqdn.rcode1 \fIflag\fB;
! 1219: .PP
! 1220: .B option fqdn.rcode2 \fIflag\fB;
! 1221: .RS 0.25i
! 1222: .PP
! 1223: These options specify the result of the updates of the A and PTR records,
! 1224: respectively, and are only sent by the DHCP server to the DHCP client.
! 1225: The values of these fields are those defined in the DNS protocol specification.
! 1226: .RE
! 1227: .PP
! 1228: .B option fqdn.fqdn \fItext\fB;
! 1229: .RS 0.25i
! 1230: .PP
! 1231: Specifies the domain name that the client wishes to use. This can be a
! 1232: fully-qualified domain name, or a single label. If there is no trailing
! 1233: \'.\' character in the name, it is not fully-qualified, and the server will
! 1234: generally update that name in some locally-defined domain.
! 1235: .RE
! 1236: .PP
! 1237: .B option fqdn.hostname \fI--never set--\fB;
! 1238: .RS 0.25i
! 1239: .PP
! 1240: This option should never be set, but it can be read back using the \fBoption\fR
! 1241: and \fBconfig-option\fR operators in an expression, in which case it returns
! 1242: the first label in the \fBfqdn.fqdn\fR suboption - for example, if
! 1243: the value of \fBfqdn.fqdn\fR is "foo.example.com.", then \fBfqdn.hostname\fR
! 1244: will be "foo".
! 1245: .RE
! 1246: .PP
! 1247: .B option fqdn.domainname \fI--never set--\fB;
! 1248: .RS 0.25i
! 1249: .PP
! 1250: This option should never be set, but it can be read back using the \fBoption\fR
! 1251: and \fBconfig-option\fR operators in an expression, in which case it returns
! 1252: all labels after the first label in the \fBfqdn.fqdn\fR suboption - for
! 1253: example, if the value of \fBfqdn.fqdn\fR is "foo.example.com.",
! 1254: then \fBfqdn.hostname\fR will be "example.com.". If this suboption value
! 1255: is not set, it means that an unqualified name was sent in the fqdn option,
! 1256: or that no fqdn option was sent at all.
! 1257: .RE
! 1258: .PP
! 1259: If you wish to use any of these suboptions, we strongly recommend that you
! 1260: refer to the Client FQDN option draft (or standard, when it becomes a
! 1261: standard) - the documentation here is sketchy and incomplete in comparison,
! 1262: and is just intended for reference by people who already understand the
! 1263: Client FQDN option specification.
! 1264: .SH THE NETWARE/IP SUBOPTIONS
! 1265: RFC2242 defines a set of encapsulated options for Novell NetWare/IP
! 1266: clients. To use these options in the dhcp server, specify the option
! 1267: space name, "nwip", followed by a period, followed by the option name.
! 1268: The following options can be specified:
! 1269: .PP
! 1270: .B option \fBnwip.nsq-broadcast\fR \fIflag\fR\fB;\fR
! 1271: .RS 0.25i
! 1272: .PP
! 1273: If true, the client should use the NetWare Nearest Server Query to
! 1274: locate a NetWare/IP server. The behaviour of the Novell client if
! 1275: this suboption is false, or is not present, is not specified.
! 1276: .PP
! 1277: .RE
! 1278: .B option \fBnwip.preferred-dss\fR \fIip-address\fR [\fB,\fR \fIip-address\fR... ]\fR\fB;\fR
! 1279: .RS 0.25i
! 1280: .PP
! 1281: This suboption specifies a list of up to five IP addresses, each of
! 1282: which should be the IP address of a NetWare Domain SAP/RIP server
! 1283: (DSS).
! 1284: .RE
! 1285: .PP
! 1286: .B option \fBnwip.nearest-nwip-server\fR \fI\fIip-address\fR
! 1287: [\fB,\fR \fIip-address\fR...]\fR\fB;\fR
! 1288: .RS 0.25i
! 1289: .PP
! 1290: This suboption specifies a list of up to five IP addresses, each of
! 1291: which should be the IP address of a Nearest NetWare IP server.
! 1292: .RE
! 1293: .PP
! 1294: .B option \fBnwip.autoretries\fR \fIuint8\fR\fB;\fR
! 1295: .RS 0.25i
! 1296: .PP
! 1297: Specifies the number of times that a NetWare/IP client should attempt
! 1298: to communicate with a given DSS server at startup.
! 1299: .RE
! 1300: .PP
! 1301: .B option \fBnwip.autoretry-secs\fR \fIuint8\fR\fB;\fR
! 1302: .RS 0.25i
! 1303: .PP
! 1304: Specifies the number of seconds that a Netware/IP client should wait
! 1305: between retries when attempting to establish communications with a DSS
! 1306: server at startup.
! 1307: .RE
! 1308: .PP
! 1309: .B option \fBnwip.nwip-1-1\fR \fIuint8\fR\fB;\fR
! 1310: .RS 0.25i
! 1311: .PP
! 1312: If true, the NetWare/IP client should support NetWare/IP version 1.1
! 1313: compatibility. This is only needed if the client will be contacting
! 1314: Netware/IP version 1.1 servers.
! 1315: .RE
! 1316: .PP
! 1317: .B option \fBnwip.primary-dss\fR \fIip-address\fR\fB;\fR
! 1318: .RS 0.25i
! 1319: .PP
! 1320: Specifies the IP address of the Primary Domain SAP/RIP Service server
! 1321: (DSS) for this NetWare/IP domain. The NetWare/IP administration
! 1322: utility uses this value as Primary DSS server when configuring a
! 1323: secondary DSS server.
! 1324: .RE
! 1325: .SH STANDARD DHCPV6 OPTIONS
! 1326: DHCPv6 options differ from DHCPv4 options partially due to using
! 1327: 16-bit code and length tags, but semantically zero-length options
! 1328: are legal in DHCPv6, and multiple options are treated differently.
! 1329: Whereas in DHCPv4 multiple options would be concatenated to form one
! 1330: option, in DHCPv6 they are expected to be individual instantiations.
! 1331: Understandably, many options are not "allowed" to have multiple
! 1332: instances in a packet - normally these are options which are digested
! 1333: by the DHCP protocol software, and not by users or applications.
! 1334: .PP
! 1335: .B option \fBdhcp6.client-id\fR \fIstring\fR\fB;\fR
! 1336: .RS 0.25i
! 1337: .PP
! 1338: This option specifies the client's DUID identifier. DUIDs are similar
! 1339: but different from DHCPv4 client identifiers - there are documented duid
! 1340: types:
! 1341: .PP
! 1342: .I duid-llt
! 1343: .PP
! 1344: .I duid-en
! 1345: .PP
! 1346: .I duid-ll
! 1347: .PP
! 1348: This value should not be configured, but rather is provided by clients
! 1349: and treated as an opaque identifier key blob by servers.
! 1350: .RE
! 1351: .PP
! 1352: .B option \fBdhcp6.server-id\fR \fIstring\fR\fB;\fR
! 1353: .RS 0.25i
! 1354: .PP
! 1355: This option specifies the server's DUID identifier. One may use this
! 1356: option to configure an opaque binary blob for your server's identifier.
! 1357: .RE
! 1358: .PP
! 1359: .B option \fBdhcp6.ia-na\fR \fIstring\fR\fB;\fR
! 1360: .RS 0.25i
! 1361: .PP
! 1362: The Identity Association for Non-temporary Addresses (ia-na) carries
! 1363: assigned addresses that are not temporary addresses for use by the
! 1364: DHCPv6 client. This option is produced by the DHCPv6 server software,
! 1365: and should not be configured.
! 1366: .RE
! 1367: .PP
! 1368: .B option \fBdhcp6.ia-ta\fR \fIstring\fR\fB;\fR
! 1369: .RS 0.25i
! 1370: .PP
! 1371: The Identity Association for Temporary Addresses (ia-ta) carries
! 1372: temporary addresses, which may change upon every renewal. There is
! 1373: no support for this in the current DHCPv6 software.
! 1374: .RE
! 1375: .PP
! 1376: .B option \fBdhcp6.ia-addr\fR \fIstring\fR\fB;\fR
! 1377: .RS 0.25i
! 1378: .PP
! 1379: The Identity Association Address option is encapsulated inside ia-na
! 1380: or ia-ta options in order to represent addresses associated with those
! 1381: IA's. These options are manufactured by the software, so should not
! 1382: be configured.
! 1383: .RE
! 1384: .PP
! 1385: .B option \fBdhcp6.oro\fR \fIuint16\fR [ \fB,\fR \fIuint16\fR\fB,\fR ... ]\fB;\fR
! 1386: .RS 0.25i
! 1387: .PP
! 1388: The Option Request Option ("ORO") is the DHCPv6 equivalent of the
! 1389: parameter-request-list. Clients supply this option to ask servers
! 1390: to reply with options relevant to their needs and use. This option
! 1391: must not be directly configured, the request syntax in dhclient.conf (5)
! 1392: should be used instead.
! 1393: .RE
! 1394: .PP
! 1395: .B option \fBdhcp6.preference\fR \fIuint8\fR\fB;\fR
! 1396: .RS 0.25i
! 1397: .PP
! 1398: The \fBpreference\fR option informs a DHCPv6 client which server is
! 1399: \'preferred\' for use on a given subnet. This preference is only
! 1400: applied during the initial stages of configuration - once a client
! 1401: is bound to an IA, it will remain bound to that IA until it is no
! 1402: longer valid or has expired. This value may be configured on the
! 1403: server, and is digested by the client software.
! 1404: .RE
! 1405: .PP
! 1406: .B option \fBdhcp6.elapsed-time\fR \fIuint16\fR\fB;\fR
! 1407: .RS 0.25i
! 1408: .PP
! 1409: The \fBelapsed-time\fR option is constructed by the DHCPv6 client
! 1410: software, and is potentially consumed by intermediaries. This
! 1411: option should not be configured.
! 1412: .RE
! 1413: .PP
! 1414: .B option \fBdhcp6.relay-msg\fR \fIstring\fR\fB;\fR
! 1415: .RS 0.25i
! 1416: .PP
! 1417: The \fBrelay-msg\fR option is constructed by intervening DHCPv6
! 1418: relay agent software. This option is entirely used by protocol
! 1419: software, and is not meant for user configuration.
! 1420: .RE
! 1421: .PP
! 1422: .B option \fBdhcp6.unicast\fR \fIip6-address\fR\fB;\fR
! 1423: .RS 0.25i
! 1424: .PP
! 1425: The \fBunicast\fR option is provided by DHCPv6 servers which are
! 1426: willing (or prefer) to receive Renew packets from their clients
! 1427: by exchanging UDP unicasts with them. Normally, DHCPv6 clients
! 1428: will multicast their Renew messages. This may be configured on
! 1429: the server, and should be configured as an address the server
! 1430: is ready to reply to.
! 1431: .RE
! 1432: .PP
! 1433: .B option \fBdhcp6.status-code\fR \fIstatus-code\fR [ \fIstring\fR ] \fB;\fR
! 1434: .RS 0.25i
! 1435: .PP
! 1436: The \fBstatus-code\fR option is provided by DHCPv6 servers to inform
! 1437: clients of error conditions during protocol communication. This option
! 1438: is manufactured and digested by protocol software, and should not be
! 1439: configured.
! 1440: .RE
! 1441: .PP
! 1442: .B option \fBdhcp6.rapid-commit\fR \fB;\fR
! 1443: .RS 0.25i
! 1444: .PP
! 1445: The \fBrapid-commit\fR option is a zero-length option that clients use
! 1446: to indicate their desire to enter into rapid-commit with the server. This
! 1447: option is not supported by the client at this time, and is digested by
! 1448: the server when present, so should not be configured.
! 1449: .RE
! 1450: .PP
! 1451: .B option \fBdhcp6.vendor-opts\fR \fIstring\fR\fB;\fR
! 1452: .RS 0.25i
! 1453: .PP
! 1454: The \fBvendor-opts\fR option is actually an encapsulated sub-option space,
! 1455: in which each Vendor-specific Information Option (VSIO) is identified by
! 1456: a 32-bit Enterprise-ID number. The encapsulated option spaces within these
! 1457: options are defined by the vendors.
! 1458: .PP
! 1459: To make use of this option, the best way is to examine the section
! 1460: titled VENDOR ENCAPSULATED OPTIONS below, in particular the bits about
! 1461: the "vsio" option space.
! 1462: .RE
! 1463: .PP
! 1464: .B option \fBdhcp6.interface-id\fR \fIstring\fR\fB;\fR
! 1465: .RS 0.25i
! 1466: .PP
! 1467: The \fBinterface-id\fR option is manufactured by relay agents, and may
! 1468: be used to guide configuration differentiating clients by the interface
! 1469: they are remotely attached to. It does not make sense to configure a
! 1470: value for this option, but it may make sense to inspect its contents.
! 1471: .RE
! 1472: .PP
! 1473: .B option \fBdhcp6.reconf-msg\fR \fIdhcpv6-message\fR\fB;\fR
! 1474: .RS 0.25i
! 1475: .PP
! 1476: The \fBreconf-msg\fR option is manufactured by servers, and sent to
! 1477: clients in Reconfigure messages to inform them of what message
! 1478: the client should Reconfigure using. There is no support for
! 1479: DHCPv6 Reconfigure extensions, and this option is documented
! 1480: informationally only.
! 1481: .RE
! 1482: .PP
! 1483: .B option \fBdhcp6.reconf-accept ;\fR
! 1484: .RS 0.25i
! 1485: .PP
! 1486: The \fBreconf-accept\fR option is included by DHCPv6 clients that
! 1487: support the Reconfigure extentions, advertising that they will
! 1488: respond if the server were to ask them to Reconfigure. There is
! 1489: no support for DHCPv6 Reconfigure extensions, and this option is
! 1490: documented informationally only.
! 1491: .RE
! 1492: .PP
! 1493: .B option \fBdhcp6.sip-servers-names\fR \fIdomain-list\fR\fB;\fR
! 1494: .RS 0.25i
! 1495: .PP
! 1496: The \fBsip-servers-names\fR option allows SIP clients to locate a
! 1497: local SIP server that is to be used for all outbound SIP requests, a
! 1498: so-called"outbound proxy server." If you wish to use manually entered
! 1499: IPv6 addresses instead, please see the \fBsip-servers-addresses\fR option
! 1500: below.
! 1501: .RE
! 1502: .PP
! 1503: .B option
! 1504: .B dhcp6.sip-servers-addresses
! 1505: .I ip6-address \fR[\fB,\fR
! 1506: .I ip6-address \fR... ]
! 1507: .B ;
! 1508: .RS 0.25i
! 1509: .PP
! 1510: The \fBsip-servers-addresses\fR option allows SIP clients to locate
! 1511: a local SIP server that is to be used for all outbound SIP requests,
! 1512: a so-called "outbound proxy servers." If you wish to use domain names
! 1513: rather than IPv6 addresses, please see the \fBsip-servers-names\fR option
! 1514: above.
! 1515: .RE
! 1516: .PP
! 1517: .B option
! 1518: .B dhcp6.name-servers
! 1519: .I ip6-address \fR[\fB,\fR
! 1520: .I ip6-address \fR... ]
! 1521: .B ;
! 1522: .RS 0.25i
! 1523: .PP
! 1524: The \fBname-servers\fR option instructs clients about locally available
! 1525: recursive DNS servers. It is easiest to describe this as the "nameserver"
! 1526: line in /etc/resolv.conf.
! 1527: .RE
! 1528: .PP
! 1529: .B option \fBdhcp6.domain-search\fR \fIdomain-list\fR\fB;\fR
! 1530: .RS 0.25i
! 1531: .PP
! 1532: The \fBdomain-search\fR option specifies the client's domain search path
! 1533: to be applied to recursive DNS queries. It is easiest to describe this as
! 1534: the "search" line in /etc/resolv.conf.
! 1535: .RE
! 1536: .PP
! 1537: .B option \fBdhcp6.ia-pd\fR \fIstring\fR\fB;\fR
! 1538: .RS 0.25i
! 1539: .PP
! 1540: The \fBia-pd\fR option is manufactured by clients and servers to create a
! 1541: Prefix Delegation binding - to delegate an IPv6 prefix to the client. It is
! 1542: not directly edited in dhcpd.conf(5) or dhclient.conf(5), but rather is
! 1543: manufactured and consumed by the software.
! 1544: .RE
! 1545: .PP
! 1546: .B option \fBdhcp6.ia-prefix\fR \fIstring\fR\fB;\fR
! 1547: .RS 0.25i
! 1548: .PP
! 1549: The \fBia-prefix\fR option is placed inside \fBia-pd\fR options in order
! 1550: to identify the prefix(es) allocated to the client. It is not directly
! 1551: edited in dhcpd.conf(5) or dhclient.conf(5), but rather is
! 1552: manufactured and consumed by the software.
! 1553: .RE
! 1554: .PP
! 1555: .B option
! 1556: .B dhcp6.nis-servers
! 1557: .I ip6-address \fR[\fB,
! 1558: .I ip6-address \fR... ]
! 1559: .B ;
! 1560: .RS 0.25i
! 1561: .PP
! 1562: The \fBnis-servers\fR option identifies, in order, NIS servers available
! 1563: to the client.
! 1564: .RE
! 1565: .PP
! 1566: .B option
! 1567: .B dhcp6.nisp-servers
! 1568: .I ip6-address \fR[\fB,
! 1569: .I ip6-address \fR... ]
! 1570: .B ;
! 1571: .RS 0.25i
! 1572: .PP
! 1573: The \fBnisp-servers\fR option identifies, in order, NIS+ servers available
! 1574: to the client.
! 1575: .RE
! 1576: .PP
! 1577: .B option \fBnis-domain-name\fR \fIdomain-list\fR\fB;\fR
! 1578: .RS 0.25i
! 1579: .PP
! 1580: The \fBnis-domain-name\fR option specifies the NIS domain name the client is
! 1581: expected to use, and is related to the \fBnis-servers\fR option.
! 1582: .RE
! 1583: .PP
! 1584: .B option \fBnisp-domain-name\fR \fIdomain-list\fR\fB;\fR
! 1585: .RS 0.25i
! 1586: .PP
! 1587: The \fBnisp-domain-name\fR option specifies the NIS+ domain name the client
! 1588: is expected to use, and is related to the \fBnisp-servers\fR option.
! 1589: .RE
! 1590: .PP
! 1591: .B option
! 1592: .B dhcp6.sntp-servers
! 1593: .I ip6-address \fR[\fB,
! 1594: .I ip6-address \fR... ]
! 1595: .B ;
! 1596: .RS 0.25i
! 1597: .PP
! 1598: The \fBsntp-servers\fR option specifies a list of local SNTP servers
! 1599: available for the client to synchronize their clocks.
! 1600: .RE
! 1601: .PP
! 1602: .B option \fBdhcp6.info-refresh-time\fR \fIuint32\fR\fB;\fR
! 1603: .RS 0.25i
! 1604: .PP
! 1605: The \fBinfo-refresh-time\fR option gives DHCPv6 clients using
! 1606: Information-request messages a hint as to how long they should between
! 1607: refreshing the information they were given. Note that this option will
! 1608: only be delivered to the client, and be likely to affect the client's
! 1609: behaviour, if the client requested the option.
! 1610: .RE
! 1611: .PP
! 1612: .B option \fBdhcp6.bcms-server-d\fR \fIdomain-list\fR\fB;\fR
! 1613: .RS 0.25i
! 1614: .PP
! 1615: The \fBbcms-server-d\fR option contains the domain names of local BCMS
! 1616: (Broadcast and Multicast Control Services) controllers which the client
! 1617: may use.
! 1618: .RE
! 1619: .PP
! 1620: .B option
! 1621: .B dhcp6.bcms-server-a
! 1622: .I ip6-address \fR[\fB,
! 1623: .I ip6-address \fR... ]
! 1624: .B ;
! 1625: .RS 0.25i
! 1626: .PP
! 1627: The \fBbcms-server-a\fR option contains the IPv6 addresses of local BCMS
! 1628: (Broadcast and Multicast Control Services) controllers which the client
! 1629: may use.
! 1630: .RE
! 1631: .PP
! 1632: .B option \fBdhcp6.remote-id\fR \fIstring\fR\fB;\fR
! 1633: .RS 0.25i
! 1634: .PP
! 1635: The \fBremote-id\fR option is constructed by relay agents, to inform the
! 1636: server of details pertaining to what the relay knows about the client (such
! 1637: as what port it is attached to, and so forth). The contents of this option
! 1638: have some vendor-specific structure (similar to VSIO), but we have chosen
! 1639: to treat this option as an opaque field.
! 1640: .RE
! 1641: .PP
! 1642: .B option \fBdhcp6.subscriber-id\fR\fB;\fR
! 1643: .RS 0.25i
! 1644: .PP
! 1645: The \fBsubscriber-id\fR option is an opaque field provided by the relay agent,
! 1646: which provides additional information about the subscriber in question. The
! 1647: exact contents of this option depend upon the vendor and/or the operator's
! 1648: configuration of the remote device, and as such is an opaque field.
! 1649: .RE
! 1650: .PP
! 1651: .B option \fBdhcp6.fqdn\fR \fIstring\fR\fB;\fR
! 1652: .RS 0.25i
! 1653: .PP
! 1654: The \fBfqdn\fR option is normally constructed by the client or server,
! 1655: and negotiates the client's Fully Qualified Domain Name, as well as which
! 1656: party is responsible for Dynamic DNS Updates. See the section on the
! 1657: Client FQDN SubOptions for full details (the DHCPv4 and DHCPv6 FQDN options
! 1658: use the same "fqdn." encapsulated space, so are in all ways identical).
! 1659: .RE
! 1660: .PP
! 1661: .B option \fBdhcp6.lq-query\fR \fIstring\fR\fB;\fR
! 1662: .RS 0.25i
! 1663: .PP
! 1664: The \fBlq-query\fR option is used internally by for lease query.
! 1665: .RE
! 1666: .PP
! 1667: .B option \fBdhcp6.client-data\fR \fIstring\fR\fB;\fR
! 1668: .RS 0.25i
! 1669: .PP
! 1670: The \fBclient-data\fR option is used internally by for lease query.
! 1671: .RE
! 1672: .PP
! 1673: .B option \fBdhcp6.clt-time\fR \fIuint32\fR\fB;\fR
! 1674: .RS 0.25i
! 1675: .PP
! 1676: The \fBclt-time\fR option is used internally by for lease query.
! 1677: .RE
! 1678: .PP
! 1679: .B option \fBdhcp6.lq-relay-data\fR \fIip6-address string\fR\fB;\fR
! 1680: .RS 0.25i
! 1681: .PP
! 1682: The \fBlq-relay-data\fR option is used internally by for lease query.
! 1683: .RE
! 1684: .PP
! 1685: .B option
! 1686: .B dhcp6.lq-client-link
! 1687: .I ip6-address \fR[\fB,\fR
! 1688: .I ip6-address \fR... ]
! 1689: .B ;
! 1690: .RS 0.25i
! 1691: .PP
! 1692: The \fBlq-client-link\fR option is used internally by for lease query.
! 1693: .RE
! 1694: .PP
! 1695: .RE
! 1696: .SH DEFINING NEW OPTIONS
! 1697: The Internet Systems Consortium DHCP client and server provide the
! 1698: capability to define new options. Each DHCP option has a name, a
! 1699: code, and a structure. The name is used by you to refer to the
! 1700: option. The code is a number, used by the DHCP server and client to
! 1701: refer to an option. The structure describes what the contents of an
! 1702: option looks like.
! 1703: .PP
! 1704: To define a new option, you need to choose a name for it that is not
! 1705: in use for some other option - for example, you can't use "host-name"
! 1706: because the DHCP protocol already defines a host-name option, which is
! 1707: documented earlier in this manual page. If an option name doesn't
! 1708: appear in this manual page, you can use it, but it's probably a good
! 1709: idea to put some kind of unique string at the beginning so you can be
! 1710: sure that future options don't take your name. For example, you
! 1711: might define an option, "local-host-name", feeling some confidence
! 1712: that no official DHCP option name will ever start with "local".
! 1713: .PP
! 1714: Once you have chosen a name, you must choose a code. All codes between
! 1715: 224 and 254 are reserved as \'site-local\' DHCP options, so you can pick
! 1716: any one of these for your site (not for your product/application). In
! 1717: RFC3942, site-local space was moved from starting at 128 to starting at
! 1718: 224. In practice, some vendors have interpreted the protocol rather
! 1719: loosely and have used option code values greater than 128 themselves.
! 1720: There's no real way to avoid this problem, and it was thought to be
! 1721: unlikely to cause too much trouble in practice. If you come across
! 1722: a vendor-documented option code in either the new or old site-local
! 1723: spaces, please contact your vendor and inform them about rfc3942.
! 1724: .PP
! 1725: The structure of an option is simply the format in which the option
! 1726: data appears. The ISC DHCP server currently supports a few simple
! 1727: types, like integers, booleans, strings and IP addresses, and it also
! 1728: supports the ability to define arrays of single types or arrays of
! 1729: fixed sequences of types.
! 1730: .PP
! 1731: New options are declared as follows:
! 1732: .PP
! 1733: .B option
! 1734: .I new-name
! 1735: .B code
! 1736: .I new-code
! 1737: .B =
! 1738: .I definition
! 1739: .B ;
! 1740: .PP
! 1741: The values of
! 1742: .I new-name
! 1743: and
! 1744: .I new-code
! 1745: should be the name you have chosen for the new option and the code you
! 1746: have chosen. The
! 1747: .I definition
! 1748: should be the definition of the structure of the option.
! 1749: .PP
! 1750: The following simple option type definitions are supported:
! 1751: .PP
! 1752: .B BOOLEAN
! 1753: .PP
! 1754: .B option
! 1755: .I new-name
! 1756: .B code
! 1757: .I new-code
! 1758: .B =
! 1759: .B boolean
! 1760: .B ;
! 1761: .PP
! 1762: An option of type boolean is a flag with a value of either on or off
! 1763: (or true or false). So an example use of the boolean type would be:
! 1764: .nf
! 1765:
! 1766: option use-zephyr code 180 = boolean;
! 1767: option use-zephyr on;
! 1768:
! 1769: .fi
! 1770: .B INTEGER
! 1771: .PP
! 1772: .B option
! 1773: .I new-name
! 1774: .B code
! 1775: .I new-code
! 1776: .B =
! 1777: .I sign
! 1778: .B integer
! 1779: .I width
! 1780: .B ;
! 1781: .PP
! 1782: The \fIsign\fR token should either be blank, \fIunsigned\fR
! 1783: or \fIsigned\fR. The width can be either 8, 16 or 32, and refers to
! 1784: the number of bits in the integer. So for example, the following two
! 1785: lines show a definition of the sql-connection-max option and its use:
! 1786: .nf
! 1787:
! 1788: option sql-connection-max code 192 = unsigned integer 16;
! 1789: option sql-connection-max 1536;
! 1790:
! 1791: .fi
! 1792: .B IP-ADDRESS
! 1793: .PP
! 1794: .B option
! 1795: .I new-name
! 1796: .B code
! 1797: .I new-code
! 1798: .B =
! 1799: .B ip-address
! 1800: .B ;
! 1801: .PP
! 1802: An option whose structure is an IP address can be expressed either as
! 1803: a domain name or as a dotted quad. So the following is an example use
! 1804: of the ip-address type:
! 1805: .nf
! 1806:
! 1807: option sql-server-address code 193 = ip-address;
! 1808: option sql-server-address sql.example.com;
! 1809:
! 1810: .fi
! 1811: .B IP6-ADDRESS
! 1812: .PP
! 1813: .B option
! 1814: .I new-name
! 1815: .B code
! 1816: .I new-code
! 1817: .B =
! 1818: .B ip6-address
! 1819: .B ;
! 1820: .PP
! 1821: An option whose structure is an IPv6 address must be expressed as
! 1822: a valid IPv6 address. The following is an example use of the
! 1823: ip6-address type:
! 1824: .nf
! 1825:
! 1826: option dhcp6.some-server code 1234 = array of ip6-address;
! 1827: option dhcp6.some-server 3ffe:bbbb:aaaa:aaaa::1, 3ffe:bbbb:aaaa:aaaa::2;
! 1828:
! 1829: .fi
! 1830: .PP
! 1831: .B TEXT
! 1832: .PP
! 1833: .B option
! 1834: .I new-name
! 1835: .B code
! 1836: .I new-code
! 1837: .B =
! 1838: .B text
! 1839: .B ;
! 1840: .PP
! 1841: An option whose type is text will encode an ASCII text string. For
! 1842: example:
! 1843: .nf
! 1844:
! 1845: option sql-default-connection-name code 194 = text;
! 1846: option sql-default-connection-name "PRODZA";
! 1847:
! 1848: .fi
! 1849: .PP
! 1850: .B DATA STRING
! 1851: .PP
! 1852: .B option
! 1853: .I new-name
! 1854: .B code
! 1855: .I new-code
! 1856: .B =
! 1857: .B string
! 1858: .B ;
! 1859: .PP
! 1860: An option whose type is a data string is essentially just a collection
! 1861: of bytes, and can be specified either as quoted text, like the text
! 1862: type, or as a list of hexadecimal contents separated by colons whose
! 1863: values must be between 0 and FF. For example:
! 1864: .nf
! 1865:
! 1866: option sql-identification-token code 195 = string;
! 1867: option sql-identification-token 17:23:19:a6:42:ea:99:7c:22;
! 1868:
! 1869: .fi
! 1870: .PP
! 1871: .B DOMAIN-LIST
! 1872: .PP
! 1873: .B option
! 1874: .I new-name
! 1875: .B code
! 1876: .I new-code
! 1877: .B =
! 1878: .B domain-list
! 1879: .B [compressed]
! 1880: .B ;
! 1881: .PP
! 1882: An option whose type is \fBdomain-list\fR is an RFC1035 formatted (on the
! 1883: wire, "DNS Format") list of domain names, separated by root labels. The
! 1884: optional \fBcompressed\fR keyword indicates if the option should be
! 1885: compressed relative to the start of the option contents (not the packet
! 1886: contents).
! 1887: .PP
! 1888: When in doubt, omit the \fBcompressed\fR keyword. When the software recieves
! 1889: an option that is compressed and the \fBcompressed\fR keyword is omitted, it
! 1890: will still decompress the option (relative to the option contents field). The
! 1891: keyword only controls whether or not transmitted packets are compressed.
! 1892: .PP
! 1893: Note that when
! 1894: .B domain-list
! 1895: formatted options are output as environment variables to
! 1896: .B dhclient-script(8),
! 1897: the standard DNS \-escape mechanism is used: they are decimal. This is
! 1898: appropriate for direct use in eg /etc/resolv.conf.
! 1899: .nf
! 1900:
! 1901: .fi
! 1902: .PP
! 1903: .B ENCAPSULATION
! 1904: .PP
! 1905: .B option
! 1906: .I new-name
! 1907: .B code
! 1908: .I new-code
! 1909: .B =
! 1910: .B encapsulate
! 1911: .I identifier
! 1912: .B ;
! 1913: .PP
! 1914: An option whose type is \fBencapsulate\fR will encapsulate the
! 1915: contents of the option space specified in \fIidentifier\fR. Examples
! 1916: of encapsulated options in the DHCP protocol as it currently exists
! 1917: include the vendor-encapsulated-options option, the netware-suboptions
! 1918: option and the relay-agent-information option.
! 1919: .nf
! 1920:
! 1921: option space local;
! 1922: option local.demo code 1 = text;
! 1923: option local-encapsulation code 197 = encapsulate local;
! 1924: option local.demo "demo";
! 1925:
! 1926: .fi
! 1927: .PP
! 1928: .B ARRAYS
! 1929: .PP
! 1930: Options can contain arrays of any of the above types except for the
! 1931: text and data string types, which aren't currently supported in
! 1932: arrays. An example of an array definition is as follows:
! 1933: .nf
! 1934:
! 1935: option kerberos-servers code 200 = array of ip-address;
! 1936: option kerberos-servers 10.20.10.1, 10.20.11.1;
! 1937:
! 1938: .fi
! 1939: .B RECORDS
! 1940: .PP
! 1941: Options can also contain data structures consisting of a sequence of
! 1942: data types, which is sometimes called a record type. For example:
! 1943: .nf
! 1944:
! 1945: option contrived-001 code 201 = { boolean, integer 32, text };
! 1946: option contrived-001 on 1772 "contrivance";
! 1947:
! 1948: .fi
! 1949: It's also possible to have options that are arrays of records, for
! 1950: example:
! 1951: .nf
! 1952:
! 1953: option new-static-routes code 201 = array of {
! 1954: ip-address, ip-address, ip-address, integer 8 };
! 1955: option static-routes
! 1956: 10.0.0.0 255.255.255.0 net-0-rtr.example.com 1,
! 1957: 10.0.1.0 255.255.255.0 net-1-rtr.example.com 1,
! 1958: 10.2.0.0 255.255.224.0 net-2-0-rtr.example.com 3;
! 1959:
! 1960: .fi
! 1961: .SH VENDOR ENCAPSULATED OPTIONS
! 1962: The DHCP protocol defines the \fBvendor-encapsulated-options\fR
! 1963: option, which allows vendors to define their own options that will be
! 1964: sent encapsulated in a standard DHCP option. It also defines
! 1965: the \fBVendor Identified Vendor Sub Options\fR option ("VIVSO"), and the
! 1966: DHCPv6 protocol defines the \fBVendor-specific Information Option\fR
! 1967: ("VSIO"). The format of all of these options is usually internally a
! 1968: string of options, similarly to other normal DHCP options. The VIVSO
! 1969: and VSIO options differ in that that they contain options that correspond
! 1970: to vendor Enterprise-ID numbers (assigned by IANA), which then contain
! 1971: options according to each Vendor's specifications. You will need to refer
! 1972: to your vendor's documentation in order to form options to their
! 1973: specification.
! 1974: .PP
! 1975: The value of these options can be set in one of two ways. The first
! 1976: way is to simply specify the data directly, using a text string or a
! 1977: colon-separated list of hexadecimal values. For help in forming these
! 1978: strings, please refer to \fBRFC2132\fR for the DHCPv4 \fBVendor Specific
! 1979: Information Option\fR, \fBRFC3925\fR for the DHCPv4 \fBVendor Identified Vendor
! 1980: Sub Options\fR, or \fBRFC3315\fR for the DHCPv6 \fBVendor-specific Information
! 1981: Option\fR. For example:
! 1982: .PP
! 1983: .nf
! 1984: option vendor-encapsulated-options
! 1985: 2:4:
! 1986: AC:11:41:1:
! 1987: 3:12:
! 1988: 73:75:6e:64:68:63:70:2d:73:65:72:76:65:72:31:37:2d:31:
! 1989: 4:12:
! 1990: 2f:65:78:70:6f:72:74:2f:72:6f:6f:74:2f:69:38:36:70:63;
! 1991: option vivso
! 1992: 00:00:09:bf:0E:
! 1993: 01:0c:
! 1994: 48:65:6c:6c:6f:20:77:6f:72:6c:64:21;
! 1995: option dhcp6.vendor-opts
! 1996: 00:00:09:bf:
! 1997: 00:01:00:0c:
! 1998: 48:65:6c:6c:6f:20:77:6f:72:6c:64:21;
! 1999: .fi
! 2000: .PP
! 2001: The second way of setting the value of these options is to have the DHCP
! 2002: server generate a vendor-specific option buffer. To do this, you
! 2003: must do four things: define an option space, define some options in
! 2004: that option space, provide values for them, and specify that that
! 2005: option space should be used to generate the relevant option.
! 2006: .PP
! 2007: To define a new option space in which vendor options can be stored,
! 2008: use the \fRoption space\fP statement:
! 2009: .PP
! 2010: .B option
! 2011: .B space
! 2012: .I name
! 2013: .B [ [ code width
! 2014: .I number
! 2015: .B ] [ length width
! 2016: .I number
! 2017: .B ] [ hash size
! 2018: .I number
! 2019: .B ] ] ;
! 2020: .PP
! 2021: Where the numbers following \fBcode width\fR, \fBlength width\fR,
! 2022: and \fBhash size\fR respectively identify the number of bytes used to
! 2023: describe option codes, option lengths, and the size in buckets of the
! 2024: hash tables to hold options in this space (most DHCPv4 option spaces
! 2025: use 1 byte codes and lengths, which is the default, whereas most
! 2026: DHCPv6 option spaces use 2 byte codes and lengths).
! 2027: .PP
! 2028: The code and length widths are used in DHCP protocol - you must configure
! 2029: these numbers to match the applicable option space you are configuring.
! 2030: They each default to 1. Valid values for code widths are 1, 2 or 4.
! 2031: Valid values for length widths are 0, 1 or 2. Most DHCPv4 option spaces
! 2032: use 1 byte codes and lengths, which is the default, whereas most DHCPv6
! 2033: option spaces use 2 byte codes and lengths. A zero-byte length produces
! 2034: options similar to the DHCPv6 Vendor-specific Information Option - but
! 2035: not their contents!
! 2036: .PP
! 2037: The hash size defaults depend upon the \fBcode width\fR selected, and
! 2038: may be 254 or 1009. Valid values range between 1 and 65535. Note
! 2039: that the higher you configure this value, the more memory will be used. It
! 2040: is considered good practice to configure a value that is slightly larger
! 2041: than the estimated number of options you plan to configure within the
! 2042: space. Previous versions of ISC DHCP (up to and including DHCP 3.0.*),
! 2043: this value was fixed at 9973.
! 2044: .PP
! 2045: The name can then be used in option definitions, as described earlier in
! 2046: this document. For example:
! 2047: .nf
! 2048:
! 2049: option space SUNW code width 1 length width 1 hash size 3;
! 2050: option SUNW.server-address code 2 = ip-address;
! 2051: option SUNW.server-name code 3 = text;
! 2052: option SUNW.root-path code 4 = text;
! 2053:
! 2054: option space ISC code width 1 length width 1 hash size 3;
! 2055: option ISC.sample code 1 = text;
! 2056: option vendor.ISC code 2495 = encapsulate vivso-sample;
! 2057: option vendor-class.ISC code 2495 = text;
! 2058:
! 2059: option ISC.sample "configuration text here";
! 2060: option vendor-class.ISC "vendor class here";
! 2061:
! 2062: option space docsis code width 2 length width 2 hash size 17;
! 2063: option docsis.tftp-servers code 32 = array of ip6-address;
! 2064: option docsis.cablelabs-configuration-file code 33 = text;
! 2065: option docsis.cablelabs-syslog-servers code 34 = array of ip6-address;
! 2066: option docsis.device-id code 36 = string;
! 2067: option docsis.time-servers code 37 = array of ip6-address;
! 2068: option docsis.time-offset code 38 = signed integer 32;
! 2069: option vsio.docsis code 4491 = encapsulate docsis;
! 2070:
! 2071: .fi
! 2072: Once you have defined an option space and the format of some options,
! 2073: you can set up scopes that define values for those options, and you
! 2074: can say when to use them. For example, suppose you want to handle
! 2075: two different classes of clients. Using the option space definition
! 2076: shown in the previous example, you can send different option values to
! 2077: different clients based on the vendor-class-identifier option that the
! 2078: clients send, as follows:
! 2079: .PP
! 2080: .nf
! 2081: class "vendor-classes" {
! 2082: match option vendor-class-identifier;
! 2083: }
! 2084:
! 2085: subclass "vendor-classes" "SUNW.Ultra-5_10" {
! 2086: vendor-option-space SUNW;
! 2087: option SUNW.root-path "/export/root/sparc";
! 2088: }
! 2089:
! 2090: subclass "vendor-classes" "SUNW.i86pc" {
! 2091: vendor-option-space SUNW;
! 2092: option SUNW.root-path "/export/root/i86pc";
! 2093: }
! 2094:
! 2095: option SUNW.server-address 172.17.65.1;
! 2096: option SUNW.server-name "sundhcp-server17-1";
! 2097:
! 2098: option vivso-sample.sample "Hello world!";
! 2099:
! 2100: option docsis.tftp-servers ::1;
! 2101:
! 2102: .fi
! 2103: .PP
! 2104: As you can see in the preceding example, regular scoping rules apply,
! 2105: so you can define values that are global in the global scope, and only
! 2106: define values that are specific to a particular class in the local
! 2107: scope. The \fBvendor-option-space\fR declaration tells the DHCP
! 2108: server to use options in the SUNW option space to construct the DHCPv4
! 2109: .B vendor-encapsulated-options
! 2110: option. This is a limitation of that option - the DHCPv4 VIVSO and the
! 2111: DHCPv6 VSIO options can have multiple vendor definitions all at once (even
! 2112: transmitted to the same client), so it is not necessary to configure this.
! 2113: .SH SEE ALSO
! 2114: dhcpd.conf(5), dhcpd.leases(5), dhclient.conf(5), dhcp-eval(5), dhcpd(8),
! 2115: dhclient(8), RFC2132, RFC2131, RFC3046, RFC3315.
! 2116: .SH AUTHOR
! 2117: The Internet Systems Consortium DHCP Distribution was written by Ted
! 2118: Lemon under a contract with Vixie Labs. Funding for
! 2119: this project was provided through Internet Systems Consortium.
! 2120: Information about Internet Systems Consortium can be found at
! 2121: .B https://www.isc.org.
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