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3 | Network Working Group S. Alexander |
4 | INTERNET DRAFT Silicon Graphics, Inc. | |
10552a7c | 5 | Obsoletes: draft-ietf-dhc-options-1533update-05.txt R. Droms |
fc7afcec | 6 | Bucknell University |
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7 | December 1996 |
8 | Expires June 1997 | |
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9 | |
10 | ||
11 | DHCP Options and BOOTP Vendor Extensions | |
10552a7c | 12 | <draft-ietf-dhc-options-1533update-06.txt> |
fc7afcec TL |
13 | |
14 | Status of this memo | |
15 | ||
16 | This document is an Internet-Draft. Internet-Drafts are working | |
17 | documents of the Internet Engineering Task Force (IETF), its areas, | |
18 | and its working groups. Note that other groups may also distribute | |
19 | working documents as Internet-Drafts. | |
20 | ||
21 | Internet-Drafts are draft documents valid for a maximum of six months | |
22 | and may be updated, replaced, or obsoleted by other documents at any | |
23 | time. It is inappropriate to use Internet-Drafts as reference | |
24 | material or to cite them other than as ``work in progress.'' | |
25 | ||
26 | To learn the current status of any Internet-Draft, please check the | |
27 | ``1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow | |
28 | Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe), | |
29 | munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or | |
30 | ftp.isi.edu (US West Coast). | |
31 | ||
32 | Abstract | |
33 | ||
34 | The Dynamic Host Configuration Protocol (DHCP) [1] provides a | |
35 | framework for passing configuration information to hosts on a TCP/IP | |
36 | network. Configuration parameters and other control information are | |
37 | carried in tagged data items that are stored in the 'options' field | |
38 | of the DHCP message. The data items themselves are also called | |
39 | "options." | |
40 | ||
41 | This document specifies the current set of DHCP options. Future | |
42 | options will be specified in separate RFCs. The current list of | |
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43 | valid options is also available in |
44 | ftp://ftp.isi.edu/in-notes/iana/assignments [22]. | |
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45 | |
46 | All of the vendor information extensions defined in RFC 1497 [2] may | |
47 | be used as DHCP options. The definitions given in RFC 1497 are | |
48 | included in this document, which supersedes RFC 1497. All of the | |
49 | DHCP options defined in this document, except for those specific to | |
50 | DHCP as defined in section 9, may be used as BOOTP vendor information | |
51 | ||
52 | ||
53 | ||
54 | Alexander & Droms [Page 1] | |
55 | \f | |
10552a7c | 56 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
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57 | |
58 | ||
59 | extensions. | |
60 | ||
61 | Table of Contents | |
62 | ||
63 | 1. Introduction .............................................. 2 | |
64 | 2. BOOTP Extension/DHCP Option Field Format .................. 4 | |
65 | 3. RFC 1497 Vendor Extensions ................................ 5 | |
66 | 4. IP Layer Parameters per Host .............................. 12 | |
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67 | 5. IP Layer Parameters per Interface ........................ 15 |
68 | 6. Link Layer Parameters per Interface ....................... 19 | |
69 | 7. TCP Parameters ............................................ 20 | |
70 | 8. Application and Service Parameters ........................ 21 | |
71 | 9. DHCP Extensions ........................................... 29 | |
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72 | 10. Defining new extensions ................................... 35 |
73 | 11. Acknowledgements .......................................... 35 | |
74 | 12. References ................................................ 36 | |
75 | 13. Security Considerations ................................... 37 | |
76 | 14. Authors' Addresses ........................................ 37 | |
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77 | |
78 | 1. Introduction | |
79 | ||
80 | This document specifies options for use with both the Dynamic Host | |
81 | Configuration Protocol and the Bootstrap Protocol. | |
82 | ||
83 | The full description of DHCP packet formats may be found in the DHCP | |
84 | specification document [1], and the full description of BOOTP packet | |
85 | formats may be found in the BOOTP specification document [3]. This | |
86 | document defines the format of information in the last field of DHCP | |
87 | packets ('options') and of BOOTP packets ('vend'). The remainder of | |
88 | this section defines a generalized use of this area for giving | |
89 | information useful to a wide class of machines, operating systems and | |
90 | configurations. Sites with a single DHCP or BOOTP server that is | |
91 | shared among heterogeneous clients may choose to define other, site- | |
92 | specific formats for the use of the 'options' field. | |
93 | ||
94 | Section 2 of this memo describes the formats of DHCP options and | |
95 | BOOTP vendor extensions. Section 3 describes options defined in | |
96 | previous documents for use with BOOTP (all may also be used with | |
97 | DHCP). Sections 4-8 define new options intended for use with both | |
98 | DHCP and BOOTP. Section 9 defines options used only in DHCP. | |
99 | ||
100 | References further describing most of the options defined in sections | |
101 | 2-6 can be found in section 12. The use of the options defined in | |
102 | section 9 is described in the DHCP specification [1]. | |
103 | ||
104 | Information on registering new options is contained in section 10. | |
105 | ||
d172a5e2 | 106 | This document updates the definition of DHCP/BOOTP options that |
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107 | |
108 | ||
109 | ||
110 | Alexander & Droms [Page 2] | |
111 | \f | |
10552a7c | 112 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
d172a5e2 | 113 | |
fc7afcec | 114 | |
d172a5e2 | 115 | appears in RFC1533. The classing mechanism has been extended to |
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116 | include vendor classes as described in section 8.4 and 9.13. The new |
117 | procedure for defining new DHCP/BOOTP options in described in section | |
118 | 10. Several new options, including NIS+ domain and servers, Mobile | |
119 | IP home agent, SMTP server, TFTP server and Bootfile server, have | |
120 | been added. Text giving definitions used throughout the document has | |
121 | been added in section 1.1. Text emphasizing the need for uniqueness | |
122 | of client-identifiers has been added to section 9.14. | |
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123 | |
124 | 1.1 Requirements | |
125 | ||
126 | Throughout this document, the words that are used to define the | |
127 | significance of particular requirements are capitalized. These words | |
128 | are: | |
129 | ||
130 | o "MUST" | |
131 | ||
132 | This word or the adjective "REQUIRED" means that the | |
133 | item is an absolute requirement of this specification. | |
134 | ||
135 | o "MUST NOT" | |
136 | ||
137 | This phrase means that the item is an absolute prohibition | |
138 | of this specification. | |
139 | ||
140 | o "SHOULD" | |
141 | ||
142 | This word or the adjective "RECOMMENDED" means that there | |
143 | may exist valid reasons in particular circumstances to ignore | |
144 | this item, but the full implications should be understood and | |
145 | the case carefully weighed before choosing a different course. | |
146 | ||
147 | o "SHOULD NOT" | |
148 | ||
149 | This phrase means that there may exist valid reasons in | |
150 | particular circumstances when the listed behavior is acceptable | |
151 | or even useful, but the full implications should be understood | |
152 | and the case carefully weighed before implementing any behavior | |
153 | described with this label. | |
154 | ||
155 | o "MAY" | |
156 | ||
157 | This word or the adjective "OPTIONAL" means that this item is | |
158 | truly optional. One vendor may choose to include the item | |
159 | because a particular marketplace requires it or because it | |
160 | enhances the product, for example; another vendor may omit the | |
161 | same item. | |
162 | ||
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163 | |
164 | ||
10552a7c | 165 | |
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166 | Alexander & Droms [Page 3] |
167 | \f | |
10552a7c | 168 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
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169 | |
170 | ||
10552a7c | 171 | 1.2 Terminology |
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172 | |
173 | This document uses the following terms: | |
174 | ||
175 | o "DHCP client" | |
176 | ||
177 | A DHCP client or "client" is an Internet host using DHCP to obtain | |
178 | configuration parameters such as a network address. | |
179 | ||
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180 | o "DHCP server" |
181 | ||
182 | A DHCP server of "server"is an Internet host that returns | |
183 | configuration parameters to DHCP clients. | |
184 | ||
185 | o "binding" | |
186 | ||
187 | A binding is a collection of configuration parameters, including | |
188 | at least an IP address, associated with or "bound to" a DHCP | |
189 | client. Bindings are managed by DHCP servers. | |
190 | ||
191 | 2. BOOTP Extension/DHCP Option Field Format | |
192 | ||
193 | DHCP options have the same format as the BOOTP 'vendor extensions' | |
194 | defined in RFC 1497 [2]. Options may be fixed length or variable | |
195 | length. All options begin with a tag octet, which uniquely | |
196 | identifies the option. Fixed-length options without data consist of | |
197 | only a tag octet. Only options 0 and 255 are fixed length. All | |
198 | other options are variable-length with a length octet following the | |
199 | tag octet. The value of the length octet does not include the two | |
200 | octets specifying the tag and length. The length octet is followed | |
201 | by "length" octets of data. | |
202 | Options containing NVT ASCII data SHOULD NOT include a trailing NULL; | |
203 | however, the receiver of such options MUST be prepared to delete | |
204 | trailing nulls if they exist. | |
205 | The receiver MUST NOT | |
206 | require that a trailing null be included in the data. In the case | |
207 | of some variable-length | |
208 | options the length field is a constant but must still be specified. | |
209 | ||
210 | Any options defined subsequent to this document MUST contain a | |
211 | length octet even if the length is fixed or zero. | |
212 | ||
213 | All multi-octet quantities are in network byte-order. | |
214 | ||
215 | When used with BOOTP, the first four octets of the vendor information | |
216 | field have been assigned to the "magic cookie" (as suggested in RFC | |
217 | 951). This field identifies the mode in which the succeeding data is | |
218 | to be interpreted. The value of the magic cookie is the 4 octet | |
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219 | |
220 | ||
221 | ||
222 | Alexander & Droms [Page 4] | |
223 | \f | |
10552a7c | 224 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
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225 | |
226 | ||
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227 | dotted decimal 99.130.83.99 (or hexadecimal number 63.82.53.63) in |
228 | network byte order. | |
229 | ||
230 | All of the "vendor extensions" defined in RFC 1497 are also DHCP | |
231 | options. | |
232 | ||
233 | Option codes 128 to 254 (decimal) are reserved for site-specific | |
234 | options. | |
235 | ||
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236 | Except for the options in section 9, all options may be used with |
237 | either DHCP or BOOTP. | |
238 | ||
239 | Many of these options have their default values specified in other | |
240 | documents. In particular, RFC 1122 [4] specifies default values for | |
241 | most IP and TCP configuration parameters. | |
242 | ||
243 | Many options supply one or more 32-bit IP address. Use of IP | |
244 | addresses rather than fully-qualified Domain Names (FQDNs) may make | |
245 | future renumbering of IP hosts more difficult. Use of these addresses | |
246 | is discouraged at sites that may require renumbering. | |
247 | ||
248 | 3. RFC 1497 Vendor Extensions | |
249 | ||
250 | This section lists the vendor extensions as defined in RFC | |
251 | 1497. They are defined here for completeness. | |
252 | ||
253 | 3.1. Pad Option | |
254 | ||
255 | The pad option can be used to cause subsequent fields to align on | |
256 | word boundaries. | |
257 | ||
258 | The code for the pad option is 0, and its length is 1 octet. | |
259 | ||
260 | Code | |
261 | +-----+ | |
262 | | 0 | | |
263 | +-----+ | |
264 | ||
fc7afcec | 265 | |
fc7afcec | 266 | |
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267 | |
268 | ||
269 | ||
270 | ||
271 | ||
272 | ||
273 | ||
274 | ||
275 | ||
276 | ||
277 | ||
278 | Alexander & Droms [Page 5] | |
279 | \f | |
10552a7c | 280 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
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281 | |
282 | ||
283 | 3.2. End Option | |
284 | ||
285 | The end option marks the end of valid information in the vendor | |
286 | field. Subsequent octets should be filled with pad options. | |
287 | ||
288 | The code for the end option is 255, and its length is 1 octet. | |
fc7afcec | 289 | |
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290 | Code |
291 | +-----+ | |
292 | | 255 | | |
293 | +-----+ | |
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294 | |
295 | 3.3. Subnet Mask | |
296 | ||
297 | The subnet mask option specifies the client's subnet mask as per RFC | |
298 | 950 [5]. | |
299 | ||
300 | If both the subnet mask and the router option are specified in a DHCP | |
301 | reply, the subnet mask option MUST be first. | |
302 | ||
303 | The code for the subnet mask option is 1, and its length is 4 octets. | |
304 | ||
305 | Code Len Subnet Mask | |
306 | +-----+-----+-----+-----+-----+-----+ | |
307 | | 1 | 4 | m1 | m2 | m3 | m4 | | |
308 | +-----+-----+-----+-----+-----+-----+ | |
309 | ||
310 | 3.4. Time Offset | |
311 | ||
312 | The time offset field specifies the offset of the client's subnet in | |
313 | seconds from Coordinated Universal Time (UTC). The offset is | |
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314 | expressed as a two's complement 32-bit integer. A positive offset |
315 | indicates a location east of the zero meridian and a negative offset | |
316 | indicates a location west of the zero meridian. | |
317 | ||
318 | The code for the time offset option is 2, and its length is 4 octets. | |
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319 | |
320 | Code Len Time Offset | |
321 | +-----+-----+-----+-----+-----+-----+ | |
322 | | 2 | 4 | n1 | n2 | n3 | n4 | | |
323 | +-----+-----+-----+-----+-----+-----+ | |
324 | ||
fc7afcec | 325 | |
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326 | |
327 | ||
328 | ||
329 | ||
330 | ||
331 | ||
332 | ||
333 | ||
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334 | Alexander & Droms [Page 6] |
335 | \f | |
10552a7c | 336 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
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337 | |
338 | ||
339 | 3.5. Router Option | |
340 | ||
341 | The router option specifies a list of IP addresses for routers on the | |
342 | client's subnet. Routers SHOULD be listed in order of preference. | |
fc7afcec | 343 | |
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344 | The code for the router option is 3. The minimum length for the |
345 | router option is 4 octets, and the length MUST always be a multiple | |
346 | of 4. | |
347 | ||
348 | Code Len Address 1 Address 2 | |
349 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
350 | | 3 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
351 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
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352 | |
353 | 3.6. Time Server Option | |
354 | ||
355 | The time server option specifies a list of RFC 868 [6] time servers | |
356 | available to the client. Servers SHOULD be listed in order of | |
357 | preference. | |
358 | ||
359 | The code for the time server option is 4. The minimum length for | |
360 | this option is 4 octets, and the length MUST always be a multiple of | |
361 | 4. | |
362 | ||
363 | Code Len Address 1 Address 2 | |
364 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
365 | | 4 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
366 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
367 | ||
368 | 3.7. Name Server Option | |
369 | ||
370 | The name server option specifies a list of IEN 116 [7] name servers | |
371 | available to the client. Servers SHOULD be listed in order of | |
372 | preference. | |
373 | ||
374 | The code for the name server option is 5. The minimum length for | |
375 | this option is 4 octets, and the length MUST always be a multiple of | |
376 | 4. | |
377 | ||
378 | Code Len Address 1 Address 2 | |
379 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
380 | | 5 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
381 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
382 | ||
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383 | |
384 | ||
385 | ||
386 | ||
387 | ||
388 | ||
389 | ||
390 | Alexander & Droms [Page 7] | |
391 | \f | |
10552a7c | 392 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
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393 | |
394 | ||
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395 | 3.8. Domain Name Server Option |
396 | ||
397 | The domain name server option specifies a list of Domain Name System | |
398 | (STD 13, RFC 1035 [8]) name servers available to the client. Servers | |
399 | SHOULD be listed in order of preference. | |
400 | ||
401 | The code for the domain name server option is 6. The minimum length | |
402 | for this option is 4 octets, and the length MUST always be a multiple | |
403 | of 4. | |
404 | ||
405 | Code Len Address 1 Address 2 | |
406 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
407 | | 6 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
408 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
409 | ||
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410 | 3.9. Log Server Option |
411 | ||
412 | The log server option specifies a list of MIT-LCS UDP log servers | |
413 | available to the client. Servers SHOULD be listed in order of | |
414 | preference. | |
415 | ||
416 | The code for the log server option is 7. The minimum length for this | |
417 | option is 4 octets, and the length MUST always be a multiple of 4. | |
418 | ||
419 | Code Len Address 1 Address 2 | |
420 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
421 | | 7 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
422 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
423 | ||
424 | 3.10. Cookie Server Option | |
425 | ||
426 | The cookie server option specifies a list of RFC 865 [9] cookie | |
427 | servers available to the client. Servers SHOULD be listed in order | |
428 | of preference. | |
429 | ||
430 | The code for the log server option is 8. The minimum length for this | |
431 | option is 4 octets, and the length MUST always be a multiple of 4. | |
432 | ||
433 | Code Len Address 1 Address 2 | |
434 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
435 | | 8 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
436 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
437 | ||
fc7afcec | 438 | |
fc7afcec | 439 | |
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440 | |
441 | ||
442 | ||
443 | ||
444 | ||
445 | ||
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446 | Alexander & Droms [Page 8] |
447 | \f | |
10552a7c | 448 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
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449 | |
450 | ||
d172a5e2 | 451 | 3.11. LPR Server Option |
fc7afcec | 452 | |
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453 | The LPR server option specifies a list of RFC 1179 [10] line printer |
454 | servers available to the client. Servers SHOULD be listed in order | |
455 | of preference. | |
fc7afcec | 456 | |
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457 | The code for the LPR server option is 9. The minimum length for this |
458 | option is 4 octets, and the length MUST always be a multiple of 4. | |
fc7afcec | 459 | |
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460 | Code Len Address 1 Address 2 |
461 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
462 | | 9 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
463 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
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464 | |
465 | 3.12. Impress Server Option | |
466 | ||
467 | The Impress server option specifies a list of Imagen Impress servers | |
468 | available to the client. Servers SHOULD be listed in order of | |
469 | preference. | |
470 | ||
471 | The code for the Impress server option is 10. The minimum length for | |
472 | this option is 4 octets, and the length MUST always be a multiple of | |
473 | 4. | |
474 | ||
475 | Code Len Address 1 Address 2 | |
476 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
477 | | 10 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
478 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
479 | ||
480 | 3.13. Resource Location Server Option | |
481 | ||
482 | This option specifies a list of RFC 887 [11] Resource Location | |
483 | servers available to the client. Servers SHOULD be listed in order | |
484 | of preference. | |
485 | ||
486 | The code for this option is 11. The minimum length for this option | |
487 | is 4 octets, and the length MUST always be a multiple of 4. | |
488 | ||
489 | Code Len Address 1 Address 2 | |
490 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
491 | | 11 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
492 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
493 | ||
fc7afcec | 494 | |
fc7afcec | 495 | |
fc7afcec | 496 | |
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497 | |
498 | ||
499 | ||
500 | ||
501 | ||
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502 | Alexander & Droms [Page 9] |
503 | \f | |
10552a7c | 504 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
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505 | |
506 | ||
d172a5e2 | 507 | 3.14. Host Name Option |
fc7afcec | 508 | |
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509 | This option specifies the name of the client. The name may or may |
510 | not be qualified with the local domain name (see section 3.17 for the | |
511 | preferred way to retrieve the domain name). See RFC 1035 for | |
512 | character set restrictions. | |
fc7afcec | 513 | |
d172a5e2 | 514 | The code for this option is 12, and its minimum length is 1. |
fc7afcec | 515 | |
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516 | Code Len Host Name |
517 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
518 | | 12 | n | h1 | h2 | h3 | h4 | h5 | h6 | ... | |
519 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
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520 | |
521 | 3.15. Boot File Size Option | |
522 | ||
523 | This option specifies the length in 512-octet blocks of the default | |
524 | boot image for the client. The file length is specified as an | |
525 | unsigned 16-bit integer. | |
526 | ||
527 | The code for this option is 13, and its length is 2. | |
528 | ||
529 | Code Len File Size | |
530 | +-----+-----+-----+-----+ | |
531 | | 13 | 2 | l1 | l2 | | |
532 | +-----+-----+-----+-----+ | |
533 | ||
534 | 3.16. Merit Dump File | |
535 | ||
536 | This option specifies the path-name of a file to which the client's | |
537 | core image should be dumped in the event the client crashes. The | |
538 | path is formatted as a character string consisting of characters from | |
539 | the NVT ASCII character set. | |
540 | ||
541 | The code for this option is 14. Its minimum length is 1. | |
542 | ||
543 | Code Len Dump File Pathname | |
544 | +-----+-----+-----+-----+-----+-----+--- | |
545 | | 14 | n | n1 | n2 | n3 | n4 | ... | |
546 | +-----+-----+-----+-----+-----+-----+--- | |
547 | ||
fc7afcec | 548 | |
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549 | |
550 | ||
551 | ||
552 | ||
553 | ||
554 | ||
555 | ||
556 | ||
557 | ||
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558 | Alexander & Droms [Page 10] |
559 | \f | |
10552a7c | 560 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
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561 | |
562 | ||
d172a5e2 | 563 | 3.17. Domain Name |
fc7afcec | 564 | |
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565 | This option specifies the domain name that client should use when |
566 | resolving hostnames via the Domain Name System. | |
fc7afcec | 567 | |
d172a5e2 | 568 | The code for this option is 15. Its minimum length is 1. |
fc7afcec | 569 | |
d172a5e2 TL |
570 | Code Len Domain Name |
571 | +-----+-----+-----+-----+-----+-----+-- | |
572 | | 15 | n | d1 | d2 | d3 | d4 | ... | |
573 | +-----+-----+-----+-----+-----+-----+-- | |
fc7afcec TL |
574 | |
575 | 3.18. Swap Server | |
576 | ||
577 | This specifies the IP address of the client's swap server. | |
578 | ||
579 | The code for this option is 16 and its length is 4. | |
580 | ||
581 | Code Len Swap Server Address | |
582 | +-----+-----+-----+-----+-----+-----+ | |
583 | | 16 | n | a1 | a2 | a3 | a4 | | |
584 | +-----+-----+-----+-----+-----+-----+ | |
585 | ||
586 | 3.19. Root Path | |
587 | ||
588 | This option specifies the path-name that contains the client's root | |
589 | disk. The path is formatted as a character string consisting of | |
590 | characters from the NVT ASCII character set. | |
591 | ||
592 | The code for this option is 17. Its minimum length is 1. | |
593 | ||
594 | Code Len Root Disk Pathname | |
595 | +-----+-----+-----+-----+-----+-----+--- | |
596 | | 17 | n | n1 | n2 | n3 | n4 | ... | |
597 | +-----+-----+-----+-----+-----+-----+--- | |
598 | ||
d172a5e2 TL |
599 | |
600 | ||
601 | ||
602 | ||
603 | ||
604 | ||
605 | ||
606 | ||
607 | ||
608 | ||
609 | ||
610 | ||
611 | ||
612 | ||
613 | ||
614 | Alexander & Droms [Page 11] | |
615 | \f | |
10552a7c | 616 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
d172a5e2 TL |
617 | |
618 | ||
fc7afcec TL |
619 | 3.20. Extensions Path |
620 | ||
621 | A string to specify a file, retrievable via TFTP, which contains | |
622 | information which can be interpreted in the same way as the 64-octet | |
623 | vendor-extension field within the BOOTP response, with the following | |
624 | exceptions: | |
625 | ||
626 | - the length of the file is unconstrained; | |
627 | - all references to Tag 18 (i.e., instances of the | |
628 | BOOTP Extensions Path field) within the file are | |
629 | ignored. | |
630 | ||
631 | The code for this option is 18. Its minimum length is 1. | |
632 | ||
633 | Code Len Extensions Pathname | |
634 | +-----+-----+-----+-----+-----+-----+--- | |
635 | | 18 | n | n1 | n2 | n3 | n4 | ... | |
636 | +-----+-----+-----+-----+-----+-----+--- | |
637 | ||
fc7afcec TL |
638 | 4. IP Layer Parameters per Host |
639 | ||
640 | This section details the options that affect the operation of the IP | |
641 | layer on a per-host basis. | |
642 | ||
643 | 4.1. IP Forwarding Enable/Disable Option | |
644 | ||
645 | This option specifies whether the client should configure its IP | |
646 | layer for packet forwarding. A value of 0 means disable IP | |
647 | forwarding, and a value of 1 means enable IP forwarding. | |
648 | ||
649 | The code for this option is 19, and its length is 1. | |
650 | ||
651 | Code Len Value | |
652 | +-----+-----+-----+ | |
653 | | 19 | 1 | 0/1 | | |
654 | +-----+-----+-----+ | |
655 | ||
fc7afcec TL |
656 | |
657 | ||
658 | ||
659 | ||
660 | ||
661 | ||
662 | ||
663 | ||
664 | ||
665 | ||
666 | ||
667 | ||
668 | ||
669 | ||
d172a5e2 TL |
670 | Alexander & Droms [Page 12] |
671 | \f | |
10552a7c | 672 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
fc7afcec TL |
673 | |
674 | ||
d172a5e2 | 675 | 4.2. Non-Local Source Routing Enable/Disable Option |
fc7afcec | 676 | |
d172a5e2 TL |
677 | This option specifies whether the client should configure its IP |
678 | layer to allow forwarding of datagrams with non-local source routes | |
679 | (see Section 3.3.5 of [4] for a discussion of this topic). A value | |
680 | of 0 means disallow forwarding of such datagrams, and a value of 1 | |
681 | means allow forwarding. | |
fc7afcec | 682 | |
d172a5e2 | 683 | The code for this option is 20, and its length is 1. |
fc7afcec | 684 | |
d172a5e2 TL |
685 | Code Len Value |
686 | +-----+-----+-----+ | |
687 | | 20 | 1 | 0/1 | | |
688 | +-----+-----+-----+ | |
fc7afcec TL |
689 | |
690 | 4.3. Policy Filter Option | |
691 | ||
692 | This option specifies policy filters for non-local source routing. | |
693 | The filters consist of a list of IP addresses and masks which specify | |
694 | destination/mask pairs with which to filter incoming source routes. | |
695 | ||
696 | Any source routed datagram whose next-hop address does not match one | |
697 | of the filters should be discarded by the client. | |
698 | ||
699 | See [4] for further information. | |
700 | ||
701 | The code for this option is 21. The minimum length of this option is | |
702 | 8, and the length MUST be a multiple of 8. | |
703 | ||
704 | Code Len Address 1 Mask 1 | |
705 | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ | |
706 | | 21 | n | a1 | a2 | a3 | a4 | m1 | m2 | m3 | m4 | | |
707 | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ | |
708 | Address 2 Mask 2 | |
709 | +-----+-----+-----+-----+-----+-----+-----+-----+--- | |
710 | | a1 | a2 | a3 | a4 | m1 | m2 | m3 | m4 | ... | |
711 | +-----+-----+-----+-----+-----+-----+-----+-----+--- | |
712 | ||
fc7afcec | 713 | |
fc7afcec TL |
714 | |
715 | ||
716 | ||
717 | ||
718 | ||
719 | ||
720 | ||
721 | ||
722 | ||
723 | ||
724 | ||
725 | ||
d172a5e2 TL |
726 | Alexander & Droms [Page 13] |
727 | \f | |
10552a7c | 728 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
fc7afcec TL |
729 | |
730 | ||
d172a5e2 | 731 | 4.4. Maximum Datagram Reassembly Size |
fc7afcec | 732 | |
d172a5e2 TL |
733 | This option specifies the maximum size datagram that the client |
734 | should be prepared to reassemble. The size is specified as a 16-bit | |
735 | unsigned integer. The minimum value legal value is 576. | |
fc7afcec | 736 | |
d172a5e2 | 737 | The code for this option is 22, and its length is 2. |
fc7afcec | 738 | |
d172a5e2 TL |
739 | Code Len Size |
740 | +-----+-----+-----+-----+ | |
741 | | 22 | 2 | s1 | s2 | | |
742 | +-----+-----+-----+-----+ | |
fc7afcec TL |
743 | |
744 | 4.5. Default IP Time-to-live | |
745 | ||
746 | This option specifies the default time-to-live that the client should | |
747 | use on outgoing datagrams. The TTL is specified as an octet with a | |
748 | value between 1 and 255. | |
749 | ||
750 | The code for this option is 23, and its length is 1. | |
751 | ||
752 | Code Len TTL | |
753 | +-----+-----+-----+ | |
754 | | 23 | 1 | ttl | | |
755 | +-----+-----+-----+ | |
756 | ||
757 | 4.6. Path MTU Aging Timeout Option | |
758 | ||
759 | This option specifies the timeout (in seconds) to use when aging Path | |
760 | MTU values discovered by the mechanism defined in RFC 1191 [12]. The | |
761 | timeout is specified as a 32-bit unsigned integer. | |
762 | ||
763 | The code for this option is 24, and its length is 4. | |
764 | ||
765 | Code Len Timeout | |
766 | +-----+-----+-----+-----+-----+-----+ | |
767 | | 24 | 4 | t1 | t2 | t3 | t4 | | |
768 | +-----+-----+-----+-----+-----+-----+ | |
769 | ||
d172a5e2 TL |
770 | |
771 | ||
772 | ||
773 | ||
774 | ||
775 | ||
776 | ||
777 | ||
778 | ||
779 | ||
780 | ||
781 | ||
782 | Alexander & Droms [Page 14] | |
783 | \f | |
10552a7c | 784 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
d172a5e2 TL |
785 | |
786 | ||
fc7afcec TL |
787 | 4.7. Path MTU Plateau Table Option |
788 | ||
789 | This option specifies a table of MTU sizes to use when performing | |
790 | Path MTU Discovery as defined in RFC 1191. The table is formatted as | |
791 | a list of 16-bit unsigned integers, ordered from smallest to largest. | |
792 | The minimum MTU value cannot be smaller than 68. | |
793 | ||
794 | The code for this option is 25. Its minimum length is 2, and the | |
795 | length MUST be a multiple of 2. | |
796 | ||
797 | Code Len Size 1 Size 2 | |
798 | +-----+-----+-----+-----+-----+-----+--- | |
799 | | 25 | n | s1 | s2 | s1 | s2 | ... | |
800 | +-----+-----+-----+-----+-----+-----+--- | |
801 | ||
802 | 5. IP Layer Parameters per Interface | |
803 | ||
804 | This section details the options that affect the operation of the IP | |
805 | layer on a per-interface basis. It is expected that a client can | |
806 | issue multiple requests, one per interface, in order to configure | |
807 | interfaces with their specific parameters. | |
808 | ||
fc7afcec TL |
809 | 5.1. Interface MTU Option |
810 | ||
811 | This option specifies the MTU to use on this interface. The MTU is | |
812 | specified as a 16-bit unsigned integer. The minimum legal value for | |
813 | the MTU is 68. | |
814 | ||
815 | The code for this option is 26, and its length is 2. | |
816 | ||
817 | Code Len MTU | |
818 | +-----+-----+-----+-----+ | |
819 | | 26 | 2 | m1 | m2 | | |
820 | +-----+-----+-----+-----+ | |
821 | ||
d172a5e2 TL |
822 | |
823 | ||
824 | ||
825 | ||
826 | ||
827 | ||
828 | ||
829 | ||
830 | ||
831 | ||
832 | ||
833 | ||
834 | ||
835 | ||
836 | ||
837 | ||
838 | Alexander & Droms [Page 15] | |
839 | \f | |
10552a7c | 840 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
d172a5e2 TL |
841 | |
842 | ||
fc7afcec TL |
843 | 5.2. All Subnets are Local Option |
844 | ||
845 | This option specifies whether or not the client may assume that all | |
846 | subnets of the IP network to which the client is connected use the | |
847 | same MTU as the subnet of that network to which the client is | |
848 | directly connected. A value of 1 indicates that all subnets share | |
849 | the same MTU. A value of 0 means that the client should assume that | |
850 | some subnets of the directly connected network may have smaller MTUs. | |
851 | ||
852 | The code for this option is 27, and its length is 1. | |
853 | ||
854 | Code Len Value | |
855 | +-----+-----+-----+ | |
856 | | 27 | 1 | 0/1 | | |
857 | +-----+-----+-----+ | |
858 | ||
859 | 5.3. Broadcast Address Option | |
860 | ||
861 | This option specifies the broadcast address in use on the client's | |
862 | subnet. Legal values for broadcast addresses are specified in | |
863 | section 3.2.1.3 of [4]. | |
864 | ||
865 | The code for this option is 28, and its length is 4. | |
866 | ||
867 | Code Len Broadcast Address | |
868 | +-----+-----+-----+-----+-----+-----+ | |
869 | | 28 | 4 | b1 | b2 | b3 | b4 | | |
870 | +-----+-----+-----+-----+-----+-----+ | |
871 | ||
fc7afcec TL |
872 | 5.4. Perform Mask Discovery Option |
873 | ||
874 | This option specifies whether or not the client should perform subnet | |
875 | mask discovery using ICMP. A value of 0 indicates that the client | |
876 | should not perform mask discovery. A value of 1 means that the | |
877 | client should perform mask discovery. | |
878 | ||
879 | The code for this option is 29, and its length is 1. | |
880 | ||
881 | Code Len Value | |
882 | +-----+-----+-----+ | |
883 | | 29 | 1 | 0/1 | | |
884 | +-----+-----+-----+ | |
885 | ||
d172a5e2 TL |
886 | |
887 | ||
888 | ||
889 | ||
890 | ||
891 | ||
892 | ||
893 | ||
894 | Alexander & Droms [Page 16] | |
895 | \f | |
10552a7c | 896 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
d172a5e2 TL |
897 | |
898 | ||
fc7afcec TL |
899 | 5.5. Mask Supplier Option |
900 | ||
901 | This option specifies whether or not the client should respond to | |
902 | subnet mask requests using ICMP. A value of 0 indicates that the | |
903 | client should not respond. A value of 1 means that the client should | |
904 | respond. | |
905 | ||
906 | The code for this option is 30, and its length is 1. | |
907 | ||
908 | Code Len Value | |
909 | +-----+-----+-----+ | |
910 | | 30 | 1 | 0/1 | | |
911 | +-----+-----+-----+ | |
912 | ||
913 | 5.6. Perform Router Discovery Option | |
914 | ||
915 | This option specifies whether or not the client should solicit | |
916 | routers using the Router Discovery mechanism defined in RFC 1256 | |
917 | [13]. A value of 0 indicates that the client should not perform | |
918 | router discovery. A value of 1 means that the client should perform | |
919 | router discovery. | |
920 | ||
921 | The code for this option is 31, and its length is 1. | |
922 | ||
923 | Code Len Value | |
924 | +-----+-----+-----+ | |
925 | | 31 | 1 | 0/1 | | |
926 | +-----+-----+-----+ | |
927 | ||
d172a5e2 | 928 | 5.7. Router Solicitation Address Option |
fc7afcec | 929 | |
d172a5e2 TL |
930 | This option specifies the address to which the client should transmit |
931 | router solicitation requests. | |
fc7afcec | 932 | |
d172a5e2 | 933 | The code for this option is 32, and its length is 4. |
fc7afcec | 934 | |
d172a5e2 TL |
935 | Code Len Address |
936 | +-----+-----+-----+-----+-----+-----+ | |
937 | | 32 | 4 | a1 | a2 | a3 | a4 | | |
938 | +-----+-----+-----+-----+-----+-----+ | |
fc7afcec TL |
939 | |
940 | ||
941 | ||
942 | ||
943 | ||
fc7afcec TL |
944 | |
945 | ||
fc7afcec | 946 | |
fc7afcec | 947 | |
fc7afcec | 948 | |
d172a5e2 TL |
949 | |
950 | Alexander & Droms [Page 17] | |
951 | \f | |
10552a7c | 952 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
d172a5e2 | 953 | |
fc7afcec TL |
954 | |
955 | 5.8. Static Route Option | |
956 | ||
957 | This option specifies a list of static routes that the client should | |
958 | install in its routing cache. If multiple routes to the same | |
959 | destination are specified, they are listed in descending order of | |
960 | priority. | |
961 | ||
962 | The routes consist of a list of IP address pairs. The first address | |
963 | is the destination address, and the second address is the router for | |
964 | the destination. | |
965 | ||
966 | The default route (0.0.0.0) is an illegal destination for a static | |
967 | route. See section 3.5 for information about the router option. | |
968 | ||
969 | The code for this option is 33. The minimum length of this option is | |
970 | 8, and the length MUST be a multiple of 8. | |
971 | ||
972 | Code Len Destination 1 Router 1 | |
973 | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ | |
974 | | 33 | n | d1 | d2 | d3 | d4 | r1 | r2 | r3 | r4 | | |
975 | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ | |
976 | Destination 2 Router 2 | |
977 | +-----+-----+-----+-----+-----+-----+-----+-----+--- | |
978 | | d1 | d2 | d3 | d4 | r1 | r2 | r3 | r4 | ... | |
979 | +-----+-----+-----+-----+-----+-----+-----+-----+--- | |
980 | ||
981 | ||
982 | ||
983 | ||
984 | ||
985 | ||
986 | ||
987 | ||
988 | ||
989 | ||
990 | ||
991 | ||
992 | ||
993 | ||
d172a5e2 TL |
994 | |
995 | ||
996 | ||
997 | ||
998 | ||
999 | ||
1000 | ||
1001 | ||
1002 | ||
1003 | ||
1004 | ||
1005 | ||
1006 | Alexander & Droms [Page 18] | |
fc7afcec | 1007 | \f |
10552a7c | 1008 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
fc7afcec TL |
1009 | |
1010 | ||
1011 | 6. Link Layer Parameters per Interface | |
1012 | ||
1013 | This section lists the options that affect the operation of the data | |
1014 | link layer on a per-interface basis. | |
1015 | ||
1016 | 6.1. Trailer Encapsulation Option | |
1017 | ||
1018 | This option specifies whether or not the client should negotiate the | |
1019 | use of trailers (RFC 893 [14]) when using the ARP protocol. A value | |
1020 | of 0 indicates that the client should not attempt to use trailers. A | |
1021 | value of 1 means that the client should attempt to use trailers. | |
1022 | ||
1023 | The code for this option is 34, and its length is 1. | |
1024 | ||
1025 | Code Len Value | |
1026 | +-----+-----+-----+ | |
1027 | | 34 | 1 | 0/1 | | |
1028 | +-----+-----+-----+ | |
1029 | ||
1030 | 6.2. ARP Cache Timeout Option | |
1031 | ||
1032 | This option specifies the timeout in seconds for ARP cache entries. | |
1033 | The time is specified as a 32-bit unsigned integer. | |
1034 | ||
1035 | The code for this option is 35, and its length is 4. | |
1036 | ||
1037 | Code Len Time | |
1038 | +-----+-----+-----+-----+-----+-----+ | |
1039 | | 35 | 4 | t1 | t2 | t3 | t4 | | |
1040 | +-----+-----+-----+-----+-----+-----+ | |
1041 | ||
1042 | 6.3. Ethernet Encapsulation Option | |
1043 | ||
1044 | This option specifies whether or not the client should use Ethernet | |
1045 | Version 2 (RFC 894 [15]) or IEEE 802.3 (RFC 1042 [16]) encapsulation | |
1046 | if the interface is an Ethernet. A value of 0 indicates that the | |
1047 | client should use RFC 894 encapsulation. A value of 1 means that the | |
1048 | client should use RFC 1042 encapsulation. | |
1049 | ||
1050 | The code for this option is 36, and its length is 1. | |
1051 | ||
1052 | Code Len Value | |
1053 | +-----+-----+-----+ | |
1054 | | 36 | 1 | 0/1 | | |
1055 | +-----+-----+-----+ | |
1056 | ||
1057 | ||
1058 | ||
1059 | ||
1060 | ||
1061 | ||
d172a5e2 | 1062 | Alexander & Droms [Page 19] |
fc7afcec | 1063 | \f |
10552a7c | 1064 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
fc7afcec TL |
1065 | |
1066 | ||
1067 | 7. TCP Parameters | |
1068 | ||
1069 | This section lists the options that affect the operation of the TCP | |
1070 | layer on a per-interface basis. | |
1071 | ||
1072 | 7.1. TCP Default TTL Option | |
1073 | ||
1074 | This option specifies the default TTL that the client should use when | |
1075 | sending TCP segments. The value is represented as an 8-bit unsigned | |
1076 | integer. The minimum value is 1. | |
1077 | ||
1078 | The code for this option is 37, and its length is 1. | |
1079 | ||
1080 | Code Len TTL | |
1081 | +-----+-----+-----+ | |
1082 | | 37 | 1 | n | | |
1083 | +-----+-----+-----+ | |
1084 | ||
1085 | 7.2. TCP Keepalive Interval Option | |
1086 | ||
1087 | This option specifies the interval (in seconds) that the client TCP | |
1088 | should wait before sending a keepalive message on a TCP connection. | |
1089 | The time is specified as a 32-bit unsigned integer. A value of zero | |
1090 | indicates that the client should not generate keepalive messages on | |
1091 | connections unless specifically requested by an application. | |
1092 | ||
1093 | The code for this option is 38, and its length is 4. | |
1094 | ||
1095 | Code Len Time | |
1096 | +-----+-----+-----+-----+-----+-----+ | |
1097 | | 38 | 4 | t1 | t2 | t3 | t4 | | |
1098 | +-----+-----+-----+-----+-----+-----+ | |
1099 | ||
1100 | 7.3. TCP Keepalive Garbage Option | |
1101 | ||
1102 | This option specifies the whether or not the client should send TCP | |
1103 | keepalive messages with a octet of garbage for compatibility with | |
1104 | older implementations. A value of 0 indicates that a garbage octet | |
1105 | should not be sent. A value of 1 indicates that a garbage octet | |
1106 | should be sent. | |
1107 | ||
1108 | The code for this option is 39, and its length is 1. | |
1109 | ||
1110 | Code Len Value | |
1111 | +-----+-----+-----+ | |
1112 | | 39 | 1 | 0/1 | | |
1113 | +-----+-----+-----+ | |
1114 | ||
1115 | ||
1116 | ||
1117 | ||
d172a5e2 | 1118 | Alexander & Droms [Page 20] |
fc7afcec | 1119 | \f |
10552a7c | 1120 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
fc7afcec TL |
1121 | |
1122 | ||
1123 | 8. Application and Service Parameters | |
1124 | ||
1125 | This section details some miscellaneous options used to configure | |
1126 | miscellaneous applications and services. | |
1127 | ||
1128 | 8.1. Network Information Service Domain Option | |
1129 | ||
1130 | This option specifies the name of the client's NIS [17] domain. The | |
1131 | domain is formatted as a character string consisting of characters | |
1132 | from the NVT ASCII character set. | |
1133 | ||
1134 | The code for this option is 40. Its minimum length is 1. | |
1135 | ||
1136 | Code Len NIS Domain Name | |
1137 | +-----+-----+-----+-----+-----+-----+--- | |
1138 | | 40 | n | n1 | n2 | n3 | n4 | ... | |
1139 | +-----+-----+-----+-----+-----+-----+--- | |
1140 | ||
1141 | 8.2. Network Information Servers Option | |
1142 | ||
1143 | This option specifies a list of IP addresses indicating NIS servers | |
1144 | available to the client. Servers SHOULD be listed in order of | |
1145 | preference. | |
1146 | ||
1147 | The code for this option is 41. Its minimum length is 4, and the | |
1148 | length MUST be a multiple of 4. | |
1149 | ||
1150 | Code Len Address 1 Address 2 | |
1151 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1152 | | 41 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
1153 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1154 | ||
1155 | 8.3. Network Time Protocol Servers Option | |
1156 | ||
1157 | This option specifies a list of IP addresses indicating NTP [18] | |
1158 | servers available to the client. Servers SHOULD be listed in order | |
1159 | of preference. | |
1160 | ||
1161 | The code for this option is 42. Its minimum length is 4, and the | |
1162 | length MUST be a multiple of 4. | |
1163 | ||
1164 | Code Len Address 1 Address 2 | |
1165 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1166 | | 42 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
1167 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1168 | ||
1169 | ||
1170 | ||
1171 | ||
1172 | ||
1173 | ||
d172a5e2 | 1174 | Alexander & Droms [Page 21] |
fc7afcec | 1175 | \f |
10552a7c | 1176 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 |
fc7afcec TL |
1177 | |
1178 | ||
1179 | 8.4. Vendor Specific Information | |
1180 | ||
1181 | This option is used by clients and servers to exchange vendor- | |
1182 | specific information. The information is an opaque object of n | |
1183 | octets, presumably interpreted by vendor-specific code on the clients | |
1184 | and servers. The definition of this information is vendor specific. | |
1185 | The vendor is indicated in the vendor class identifier option. | |
1186 | Servers not equipped to interpret the vendor-specific information | |
1187 | sent by a client MUST ignore it (although it may be reported). | |
1188 | Clients which do not receive desired vendor-specific information | |
1189 | SHOULD make an attempt to operate without it, although they may do so | |
1190 | (and announce they are doing so) in a degraded mode. | |
1191 | ||
1192 | If a vendor potentially encodes more than one item of information in | |
1193 | this option, then the vendor SHOULD encode the option using | |
1194 | "Encapsulated vendor-specific options" as described below: | |
1195 | ||
1196 | The Encapsulated vendor-specific options field SHOULD be encoded as a | |
1197 | sequence of code/length/value fields of identical syntax to the DHCP | |
1198 | options field with the following exceptions: | |
1199 | ||
1200 | 1) There SHOULD NOT be a "magic cookie" field in the encapsulated | |
1201 | vendor-specific extensions field. | |
1202 | ||
1203 | 2) Codes other than 0 or 255 MAY be redefined by the vendor within | |
1204 | the encapsulated vendor-specific extensions field, but SHOULD | |
1205 | conform to the tag-length-value syntax defined in section 2. | |
1206 | ||
1207 | 3) Code 255 (END), if present, signifies the end of the | |
1208 | encapsulated vendor extensions, not the end of the vendor | |
1209 | extensions field. If no code 255 is present, then the end of | |
1210 | the enclosing vendor-specific information field is taken as the | |
1211 | end of the encapsulated vendor-specific extensions field. | |
1212 | ||
1213 | The code for this option is 43 and its minimum length is 1. | |
1214 | ||
1215 | Code Len Vendor-specific information | |
1216 | +-----+-----+-----+-----+--- | |
1217 | | 43 | n | i1 | i2 | ... | |
1218 | +-----+-----+-----+-----+--- | |
1219 | ||
1220 | When encapsulated vendor-specific extensions are used, the | |
1221 | information bytes 1-n have the following format: | |
1222 | ||
1223 | Code Len Data item Code Len Data item Code | |
1224 | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ | |
1225 | | T1 | n | d1 | d2 | ... | T2 | n | D1 | D2 | ... | ... | | |
1226 | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ | |
1227 | ||
1228 | ||
1229 | ||
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1233 | |
1234 | ||
1235 | 8.5. NetBIOS over TCP/IP Name Server Option | |
1236 | ||
1237 | The NetBIOS name server (NBNS) option specifies a list of RFC | |
1238 | 1001/1002 [19] [20] NBNS name servers listed in order of preference. | |
1239 | ||
1240 | The code for this option is 44. The minimum length of the option is | |
1241 | 4 octets, and the length must always be a multiple of 4. | |
1242 | ||
1243 | Code Len Address 1 Address 2 | |
1244 | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+---- | |
1245 | | 44 | n | a1 | a2 | a3 | a4 | b1 | b2 | b3 | b4 | ... | |
1246 | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+---- | |
1247 | ||
1248 | 8.6. NetBIOS over TCP/IP Datagram Distribution Server Option | |
1249 | ||
1250 | The NetBIOS datagram distribution server (NBDD) option specifies a | |
1251 | list of RFC 1001/1002 NBDD servers listed in order of preference. The | |
1252 | code for this option is 45. The minimum length of the option is 4 | |
1253 | octets, and the length must always be a multiple of 4. | |
1254 | ||
1255 | Code Len Address 1 Address 2 | |
1256 | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+---- | |
1257 | | 45 | n | a1 | a2 | a3 | a4 | b1 | b2 | b3 | b4 | ... | |
1258 | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+---- | |
1259 | ||
1260 | 8.7. NetBIOS over TCP/IP Node Type Option | |
1261 | ||
1262 | The NetBIOS node type option allows NetBIOS over TCP/IP clients which | |
1263 | are configurable to be configured as described in RFC 1001/1002. The | |
1264 | value is specified as a single octet which identifies the client type | |
1265 | as follows: | |
1266 | ||
1267 | Value Node Type | |
1268 | ----- --------- | |
1269 | 0x1 B-node | |
1270 | 0x2 P-node | |
1271 | 0x4 M-node | |
1272 | 0x8 H-node | |
1273 | ||
1274 | In the above chart, the notation '0x' indicates a number in base-16 | |
1275 | (hexadecimal). | |
1276 | ||
1277 | ||
1278 | ||
1279 | ||
1280 | ||
1281 | ||
1282 | ||
1283 | ||
1284 | ||
1285 | ||
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1289 | |
1290 | ||
1291 | The code for this option is 46. The length of this option is always | |
1292 | 1. | |
1293 | ||
1294 | Code Len Node Type | |
1295 | +-----+-----+-----------+ | |
1296 | | 46 | 1 | see above | | |
1297 | +-----+-----+-----------+ | |
1298 | ||
1299 | 8.8. NetBIOS over TCP/IP Scope Option | |
1300 | ||
1301 | The NetBIOS scope option specifies the NetBIOS over TCP/IP scope | |
1302 | parameter for the client as specified in RFC 1001/1002. See [19], | |
1303 | [20], and [8] for character-set restrictions. | |
1304 | ||
1305 | The code for this option is 47. The minimum length of this option is | |
1306 | 1. | |
1307 | ||
1308 | Code Len NetBIOS Scope | |
1309 | +-----+-----+-----+-----+-----+-----+---- | |
1310 | | 47 | n | s1 | s2 | s3 | s4 | ... | |
1311 | +-----+-----+-----+-----+-----+-----+---- | |
1312 | ||
1313 | 8.9. X Window System Font Server Option | |
1314 | ||
1315 | This option specifies a list of X Window System [21] Font servers | |
1316 | available to the client. Servers SHOULD be listed in order of | |
1317 | preference. | |
1318 | ||
1319 | The code for this option is 48. The minimum length of this option is | |
1320 | 4 octets, and the length MUST be a multiple of 4. | |
1321 | ||
1322 | Code Len Address 1 Address 2 | |
1323 | +-----+-----+-----+-----+-----+-----+-----+-----+--- | |
1324 | | 48 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
1325 | +-----+-----+-----+-----+-----+-----+-----+-----+--- | |
1326 | ||
1327 | ||
1328 | ||
1329 | ||
1330 | ||
1331 | ||
1332 | ||
1333 | ||
1334 | ||
1335 | ||
1336 | ||
1337 | ||
1338 | ||
1339 | ||
1340 | ||
1341 | ||
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1345 | |
1346 | ||
1347 | 8.10. X Window System Display Manager Option | |
1348 | ||
1349 | This option specifies a list of IP addresses of systems that are | |
1350 | running the X Window System Display Manager and are available to the | |
1351 | client. | |
1352 | ||
1353 | Addresses SHOULD be listed in order of preference. | |
1354 | ||
1355 | The code for the this option is 49. The minimum length of this option | |
1356 | is 4, and the length MUST be a multiple of 4. | |
1357 | ||
1358 | Code Len Address 1 Address 2 | |
1359 | ||
1360 | +-----+-----+-----+-----+-----+-----+-----+-----+--- | |
1361 | | 49 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
1362 | +-----+-----+-----+-----+-----+-----+-----+-----+--- | |
1363 | ||
1364 | 8.11. Network Information Service+ Domain Option | |
1365 | ||
1366 | This option specifies the name of the client's NIS+ [17] domain. The | |
1367 | domain is formatted as a character string consisting of characters | |
1368 | from the NVT ASCII character set. | |
1369 | ||
1370 | The code for this option is 64. Its minimum length is 1. | |
1371 | ||
1372 | Code Len NIS Client Domain Name | |
1373 | +-----+-----+-----+-----+-----+-----+--- | |
1374 | | 64 | n | n1 | n2 | n3 | n4 | ... | |
1375 | +-----+-----+-----+-----+-----+-----+--- | |
1376 | ||
1377 | 8.12. Network Information Service+ Servers Option | |
1378 | ||
1379 | This option specifies a list of IP addresses indicating NIS+ servers | |
1380 | available to the client. Servers SHOULD be listed in order of | |
1381 | preference. | |
1382 | ||
1383 | The code for this option is 65. Its minimum length is 4, and the | |
1384 | length MUST be a multiple of 4. | |
1385 | ||
1386 | Code Len Address 1 Address 2 | |
1387 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1388 | | 65 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
1389 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1390 | ||
1391 | ||
1392 | ||
1393 | ||
1394 | ||
1395 | ||
1396 | ||
1397 | ||
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1401 | |
1402 | ||
1403 | 8.13. Mobile IP Home Agent option | |
1404 | ||
1405 | This option specifies a list of IP addresses indicating mobile IP | |
1406 | home agents available to the client. Agents SHOULD be listed in | |
1407 | order of preference. | |
1408 | ||
1409 | The code for this option is 68. Its minimum length is 0 (indicating | |
1410 | no home agents are available) and the length MUST be a multiple of 4. | |
1411 | It is expected that the usual length will be four octets, containing | |
1412 | a single home agent's address. | |
1413 | ||
1414 | Code Len Home Agent Addresses (zero or more) | |
1415 | +-----+-----+-----+-----+-----+-----+-- | |
1416 | | 68 | n | a1 | a2 | a3 | a4 | ... | |
1417 | +-----+-----+-----+-----+-----+-----+-- | |
1418 | ||
1419 | 8.14. Simple Mail Transport Protocol (SMTP) Server Option | |
1420 | ||
1421 | The SMTP server option specifies a list of SMTP servers available to | |
1422 | the client. Servers SHOULD be listed in order of preference. | |
1423 | ||
1424 | The code for the SMTP server option is 69. The minimum length for | |
1425 | this option is 4 octets, and the length MUST always be a multiple of | |
1426 | 4. | |
1427 | ||
1428 | Code Len Address 1 Address 2 | |
1429 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1430 | | 69 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
1431 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1432 | ||
1433 | 8.15. Post Office Protocol (POP3) Server Option | |
1434 | ||
1435 | The POP3 server option specifies a list of POP3 available to the | |
1436 | client. Servers SHOULD be listed in order of preference. | |
1437 | ||
1438 | The code for the POP3 server option is 70. The minimum length for | |
1439 | this option is 4 octets, and the length MUST always be a multiple of | |
1440 | 4. | |
1441 | ||
1442 | Code Len Address 1 Address 2 | |
1443 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1444 | | 70 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
1445 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1446 | ||
1447 | ||
1448 | ||
1449 | ||
1450 | ||
1451 | ||
1452 | ||
1453 | ||
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1457 | |
1458 | ||
1459 | 8.16. Network News Transport Protocol (NNTP) Server Option | |
1460 | ||
1461 | The NNTP server option specifies a list of NNTP available to the | |
1462 | client. Servers SHOULD be listed in order of preference. | |
1463 | ||
1464 | The code for the NNTP server option is 71. The minimum length for | |
1465 | this option is 4 octets, and the length MUST always be a multiple of | |
1466 | 4. | |
1467 | ||
1468 | Code Len Address 1 Address 2 | |
1469 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1470 | | 71 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
1471 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1472 | ||
1473 | 8.17. Default World Wide Web (WWW) Server Option | |
1474 | ||
1475 | The WWW server option specifies a list of WWW available to the | |
1476 | client. Servers SHOULD be listed in order of preference. | |
1477 | ||
1478 | The code for the WWW server option is 72. The minimum length for | |
1479 | this option is 4 octets, and the length MUST always be a multiple of | |
1480 | 4. | |
1481 | ||
1482 | Code Len Address 1 Address 2 | |
1483 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1484 | | 72 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
1485 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1486 | ||
1487 | 8.18. Default Finger Server Option | |
1488 | ||
1489 | The Finger server option specifies a list of Finger available to the | |
1490 | client. Servers SHOULD be listed in order of preference. | |
1491 | ||
1492 | The code for the Finger server option is 73. The minimum length for | |
1493 | this option is 4 octets, and the length MUST always be a multiple of | |
1494 | 4. | |
1495 | ||
1496 | Code Len Address 1 Address 2 | |
1497 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1498 | | 73 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
1499 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1500 | ||
1501 | ||
1502 | ||
1503 | ||
1504 | ||
1505 | ||
1506 | ||
1507 | ||
1508 | ||
1509 | ||
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1513 | |
1514 | ||
1515 | 8.19. Default Internet Relay Chat (IRC) Server Option | |
1516 | ||
1517 | The IRC server option specifies a list of IRC available to the | |
1518 | client. Servers SHOULD be listed in order of preference. | |
1519 | ||
1520 | The code for the IRC server option is 74. The minimum length for | |
1521 | this option is 4 octets, and the length MUST always be a multiple of | |
1522 | 4. | |
1523 | ||
1524 | Code Len Address 1 Address 2 | |
1525 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1526 | | 74 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
1527 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1528 | ||
1529 | 8.20. StreetTalk Server Option | |
1530 | ||
1531 | The StreetTalk server option specifies a list of StreetTalk servers | |
1532 | available to the client. Servers SHOULD be listed in order of | |
1533 | preference. | |
1534 | ||
1535 | The code for the StreetTalk server option is 75. The minimum length | |
1536 | for this option is 4 octets, and the length MUST always be a multiple | |
1537 | of 4. | |
1538 | ||
1539 | Code Len Address 1 Address 2 | |
1540 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1541 | | 75 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
1542 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1543 | ||
1544 | 8.21. StreetTalk Directory Assistance (STDA) Server Option | |
1545 | ||
1546 | The StreetTalk Directory Assistance (STDA) server option specifies a | |
1547 | list of STDA servers available to the client. Servers SHOULD be | |
1548 | listed in order of preference. | |
1549 | ||
1550 | The code for the StreetTalk Directory Assistance server option is 76. | |
1551 | The minimum length for this option is 4 octets, and the length MUST | |
1552 | always be a multiple of 4. | |
1553 | ||
1554 | Code Len Address 1 Address 2 | |
1555 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1556 | | 76 | n | a1 | a2 | a3 | a4 | a1 | a2 | ... | |
1557 | +-----+-----+-----+-----+-----+-----+-----+-----+-- | |
1558 | ||
1559 | ||
1560 | ||
1561 | ||
1562 | ||
1563 | ||
1564 | ||
1565 | ||
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1569 | |
1570 | ||
1571 | 9. DHCP Extensions | |
1572 | ||
1573 | This section details the options that are specific to DHCP. | |
1574 | ||
1575 | 9.1. Requested IP Address | |
1576 | ||
1577 | This option is used in a client request (DHCPDISCOVER) to allow the | |
1578 | client to request that a particular IP address be assigned. | |
1579 | ||
1580 | The code for this option is 50, and its length is 4. | |
1581 | ||
1582 | Code Len Address | |
1583 | +-----+-----+-----+-----+-----+-----+ | |
1584 | | 50 | 4 | a1 | a2 | a3 | a4 | | |
1585 | +-----+-----+-----+-----+-----+-----+ | |
1586 | ||
1587 | 9.2. IP Address Lease Time | |
1588 | ||
1589 | This option is used in a client request (DHCPDISCOVER or DHCPREQUEST) | |
1590 | to allow the client to request a lease time for the IP address. In a | |
1591 | server reply (DHCPOFFER), a DHCP server uses this option to specify | |
1592 | the lease time it is willing to offer. | |
1593 | ||
1594 | The time is in units of seconds, and is specified as a 32-bit | |
1595 | unsigned integer. | |
1596 | ||
1597 | The code for this option is 51, and its length is 4. | |
1598 | ||
1599 | Code Len Lease Time | |
1600 | +-----+-----+-----+-----+-----+-----+ | |
1601 | | 51 | 4 | t1 | t2 | t3 | t4 | | |
1602 | +-----+-----+-----+-----+-----+-----+ | |
1603 | ||
1604 | 9.3. Option Overload | |
1605 | ||
1606 | This option is used to indicate that the DHCP 'sname' or 'file' | |
1607 | fields are being overloaded by using them to carry DHCP options. A | |
1608 | DHCP server inserts this option if the returned parameters will | |
1609 | exceed the usual space allotted for options. | |
1610 | ||
1611 | If this option is present, the client interprets the specified | |
1612 | additional fields after it concludes interpretation of the standard | |
1613 | option fields. | |
1614 | ||
1615 | ||
1616 | ||
1617 | ||
1618 | ||
1619 | ||
1620 | ||
1621 | ||
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1625 | |
1626 | ||
1627 | The code for this option is 52, and its length is 1. Legal values | |
1628 | for this option are: | |
1629 | ||
1630 | Value Meaning | |
1631 | ----- -------- | |
1632 | 1 the 'file' field is used to hold options | |
1633 | 2 the 'sname' field is used to hold options | |
1634 | 3 both fields are used to hold options | |
1635 | ||
1636 | Code Len Value | |
1637 | +-----+-----+-----+ | |
1638 | | 52 | 1 |1/2/3| | |
1639 | +-----+-----+-----+ | |
1640 | ||
1641 | 9.4 TFTP server name | |
1642 | ||
1643 | This option is used to identify a TFTP server when the 'sname' | |
1644 | field in the DHCP header has been used for DHCP options. | |
1645 | ||
1646 | The code for this option is 66, and its minimum length is 1. | |
1647 | ||
1648 | Code Len TFTP server | |
1649 | +-----+-----+-----+-----+-----+--- | |
1650 | | 66 | n | c1 | c2 | c3 | ... | |
1651 | +-----+-----+-----+-----+-----+--- | |
1652 | ||
1653 | 9.5 Bootfile name | |
1654 | ||
1655 | This option is used to identify a bootfile when the 'file' field in | |
1656 | the DHCP header has been used for DHCP options. | |
1657 | ||
1658 | The code for this option is 67, and its minimum length is 1. | |
1659 | ||
1660 | Code Len Bootfile name | |
1661 | +-----+-----+-----+-----+-----+--- | |
1662 | | 67 | n | c1 | c2 | c3 | ... | |
1663 | +-----+-----+-----+-----+-----+--- | |
1664 | ||
1665 | ||
1666 | ||
1667 | ||
1668 | ||
1669 | ||
1670 | ||
1671 | ||
1672 | ||
1673 | ||
1674 | ||
1675 | ||
1676 | ||
1677 | ||
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1681 | |
1682 | ||
1683 | 9.6. DHCP Message Type | |
1684 | ||
1685 | This option is used to convey the type of the DHCP message. The code | |
1686 | for this option is 53, and its length is 1. Legal values for this | |
1687 | option are: | |
1688 | ||
1689 | Value Message Type | |
1690 | ----- ------------ | |
1691 | 1 DHCPDISCOVER | |
1692 | 2 DHCPOFFER | |
1693 | 3 DHCPREQUEST | |
1694 | 4 DHCPDECLINE | |
1695 | 5 DHCPACK | |
1696 | 6 DHCPNAK | |
1697 | 7 DHCPRELEASE | |
1698 | 8 DHCPINFORM | |
1699 | ||
1700 | Code Len Type | |
1701 | +-----+-----+-----+ | |
1702 | | 53 | 1 | 1-9 | | |
1703 | +-----+-----+-----+ | |
1704 | ||
1705 | 9.7. Server Identifier | |
1706 | ||
1707 | This option is used in DHCPOFFER and DHCPREQUEST messages, and may | |
1708 | optionally be included in the DHCPACK and DHCPNAK messages. DHCP | |
1709 | servers include this option in the DHCPOFFER in order to allow the | |
10552a7c TL |
1710 | client to distinguish between lease offers. DHCP clients use the |
1711 | contents of the 'server identifier' field as the destination address | |
1712 | for any DHCP messages unicast to the DHCP server. DHCP clients also | |
1713 | indicate which of several lease offers is being accepted by including | |
1714 | this option in a DHCPREQUEST message. | |
fc7afcec TL |
1715 | |
1716 | The identifier is the IP address of the selected server. | |
1717 | ||
1718 | The code for this option is 54, and its length is 4. | |
1719 | ||
1720 | Code Len Address | |
1721 | +-----+-----+-----+-----+-----+-----+ | |
1722 | | 54 | 4 | a1 | a2 | a3 | a4 | | |
1723 | +-----+-----+-----+-----+-----+-----+ | |
1724 | ||
1725 | ||
1726 | ||
1727 | ||
1728 | ||
1729 | ||
1730 | ||
1731 | ||
1732 | ||
1733 | ||
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1737 | |
1738 | ||
1739 | 9.8. Parameter Request List | |
1740 | ||
1741 | This option is used by a DHCP client to request values for specified | |
1742 | configuration parameters. The list of requested parameters is | |
1743 | specified as n octets, where each octet is a valid DHCP option code | |
1744 | as defined in this document. | |
1745 | ||
1746 | The client MAY list the options in order of preference. The DHCP | |
1747 | server is not required to return the options in the requested order, | |
1748 | but MUST try to insert the requested options in the order requested | |
1749 | by the client. | |
1750 | ||
1751 | The code for this option is 55. Its minimum length is 1. | |
1752 | ||
1753 | Code Len Option Codes | |
1754 | +-----+-----+-----+-----+--- | |
1755 | | 55 | n | c1 | c2 | ... | |
1756 | +-----+-----+-----+-----+--- | |
1757 | ||
1758 | 9.9. Message | |
1759 | ||
1760 | This option is used by a DHCP server to provide an error message to a | |
1761 | DHCP client in a DHCPNAK message in the event of a failure. A client | |
1762 | may use this option in a DHCPDECLINE message to indicate the why the | |
1763 | client declined the offered parameters. The message consists of n | |
1764 | octets of NVT ASCII text, which the client may display on an | |
1765 | available output device. | |
1766 | ||
1767 | The code for this option is 56 and its minimum length is 1. | |
1768 | ||
1769 | Code Len Text | |
1770 | +-----+-----+-----+-----+--- | |
1771 | | 56 | n | c1 | c2 | ... | |
1772 | +-----+-----+-----+-----+--- | |
1773 | ||
1774 | ||
1775 | ||
1776 | ||
1777 | ||
1778 | ||
1779 | ||
1780 | ||
1781 | ||
1782 | ||
1783 | ||
1784 | ||
1785 | ||
1786 | ||
1787 | ||
1788 | ||
1789 | ||
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1793 | |
1794 | ||
1795 | 9.10. Maximum DHCP Message Size | |
1796 | ||
1797 | This option specifies the maximum length DHCP message that it is | |
1798 | willing to accept. The length is specified as an unsigned 16-bit | |
1799 | integer. A client may use the maximum DHCP message size option in | |
1800 | DHCPDISCOVER or DHCPREQUEST messages, but should not use the option | |
1801 | in DHCPDECLINE messages. | |
1802 | ||
1803 | The code for this option is 57, and its length is 2. The minimum | |
1804 | legal value is 576 octets. | |
1805 | ||
1806 | Code Len Length | |
1807 | +-----+-----+-----+-----+ | |
1808 | | 57 | 2 | l1 | l2 | | |
1809 | +-----+-----+-----+-----+ | |
1810 | ||
1811 | 9.11. Renewal (T1) Time Value | |
1812 | ||
1813 | This option specifies the time interval from address assignment until | |
1814 | the client transitions to the RENEWING state. | |
1815 | ||
1816 | The value is in units of seconds, and is specified as a 32-bit | |
1817 | unsigned integer. | |
1818 | ||
1819 | The code for this option is 58, and its length is 4. | |
1820 | ||
1821 | Code Len T1 Interval | |
1822 | +-----+-----+-----+-----+-----+-----+ | |
1823 | | 58 | 4 | t1 | t2 | t3 | t4 | | |
1824 | +-----+-----+-----+-----+-----+-----+ | |
1825 | ||
1826 | 9.12. Rebinding (T2) Time Value | |
1827 | ||
1828 | This option specifies the time interval from address assignment until | |
1829 | the client transitions to the REBINDING state. | |
1830 | ||
1831 | The value is in units of seconds, and is specified as a 32-bit | |
1832 | unsigned integer. | |
1833 | ||
1834 | The code for this option is 59, and its length is 4. | |
1835 | ||
1836 | Code Len T2 Interval | |
1837 | +-----+-----+-----+-----+-----+-----+ | |
1838 | | 59 | 4 | t1 | t2 | t3 | t4 | | |
1839 | +-----+-----+-----+-----+-----+-----+ | |
1840 | ||
1841 | ||
1842 | ||
1843 | ||
1844 | ||
1845 | ||
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1849 | |
1850 | ||
1851 | 9.13. Vendor class identifier | |
1852 | ||
1853 | This option is used by DHCP clients to optionally identify the vendor | |
1854 | type and configuration of a DHCP client. The information is a string | |
1855 | of n octets, interpreted by servers. Vendors may choose to define | |
1856 | specific vendor class identifiers to convey particular configuration | |
1857 | or other identification information about a client. For example, the | |
1858 | identifier may encode the client's hardware configuration. Servers | |
1859 | not equipped to interpret the class-specific information sent by a | |
1860 | client MUST ignore it (although it may be reported). Servers that | |
1861 | respond SHOULD only use option 43 to return the vendor-specific | |
1862 | information to the client. | |
1863 | ||
1864 | The code for this option is 60, and its minimum length is 1. | |
1865 | ||
1866 | Code Len Vendor class Identifier | |
1867 | +-----+-----+-----+-----+--- | |
1868 | | 60 | n | i1 | i2 | ... | |
1869 | +-----+-----+-----+-----+--- | |
1870 | ||
1871 | 9.14. Client-identifier | |
1872 | ||
1873 | This option is used by DHCP clients to specify their unique | |
1874 | identifier. DHCP servers use this value to index their database of | |
1875 | address bindings. This value is expected to be unique for all | |
1876 | clients in an administrative domain. | |
1877 | ||
1878 | Identifiers SHOULD be treated as opaque objects by DHCP servers. | |
1879 | ||
1880 | The client identifier MAY consist of type-value pairs similar to the | |
1881 | 'htype'/'chaddr' fields defined in [3]. For instance, it MAY consist | |
1882 | of a hardware type and hardware address. In this case the type field | |
1883 | SHOULD be one of the ARP hardware types defined in STD2 [22]. A | |
1884 | hardware type of 0 (zero) should be used when the value field | |
1885 | contains an identifier other than a hardware address (e.g. a fully | |
1886 | qualified domain name). | |
1887 | ||
1888 | For correct identification of clients, each client's client- | |
1889 | identifier MUST be unique among the client-identifiers used on the | |
1890 | subnet to which the client is attached. Vendors and system | |
1891 | administrators are responsible for choosing client-identifiers that | |
1892 | meet this requirement for uniqueness. | |
1893 | ||
1894 | ||
1895 | ||
1896 | ||
1897 | ||
1898 | ||
1899 | ||
1900 | ||
1901 | ||
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1905 | |
1906 | ||
1907 | The code for this option is 61, and its minimum length is 2. | |
1908 | ||
1909 | Code Len Type Client-Identifier | |
1910 | +-----+-----+-----+-----+-----+--- | |
1911 | | 61 | n | t1 | i1 | i2 | ... | |
1912 | +-----+-----+-----+-----+-----+--- | |
1913 | ||
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1914 | |
1915 | 10. Defining new extensions | |
1916 | ||
1917 | The author of a new DHCP option will follow these steps to obtain | |
1918 | acceptance of the option as a part of the DHCP Internet Standard: | |
1919 | ||
1920 | 1. The author devises the new option. | |
1921 | 2. The author requests a number for the new option from IANA by | |
1922 | contacting: | |
1923 | Internet Assigned Numbers Authority (IANA) | |
1924 | USC/Information Sciences Institute | |
1925 | 4676 Admiralty Way | |
1926 | Marina del Rey, California 90292-6695 | |
1927 | ||
1928 | or by email as: iana@isi.edu | |
1929 | ||
1930 | 3. The author documents the new option, using the newly obtained | |
1931 | option number, as an Internet Draft. | |
1932 | 4. The author submits the Internet Draft for review through the IETF | |
1933 | standards process as defined in "Internet Official Protocol | |
1934 | Standards" (STD 1). The new option will be submitted for eventual | |
1935 | acceptance as an Internet Standard. | |
1936 | 5. The new option progresses through the IETF standards process; the | |
1937 | new option will be reviewed by the Dynamic Host Configuration | |
1938 | Working Group (if that group still exists), or as an Internet | |
1939 | Draft not submitted by an IETF working group. | |
1940 | 6. If the new option fails to gain acceptance as an Internet | |
1941 | Standard, the assigned option number will be returned to IANA for | |
1942 | reassignment. | |
1943 | ||
1944 | This procedure for defining new extensions will ensure that: | |
1945 | ||
1946 | * allocation of new option numbers is coordinated from a single | |
1947 | authority, | |
1948 | * new options are reviewed for technical correctness and | |
1949 | appropriateness, and | |
1950 | * documentation for new options is complete and published. | |
1951 | ||
1952 | 11. Acknowledgements | |
1953 | ||
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1954 | The author thanks the many (and too numerous to mention!) |
1955 | ||
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fc7afcec | 1957 | |
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1958 | Alexander & Droms [Page 35] |
1959 | \f | |
1960 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 | |
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1961 | |
1962 | ||
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1963 | members of the DHC WG for their tireless and ongoing efforts in |
1964 | the development of DHCP and this document. | |
fc7afcec | 1965 | |
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1966 | |
1967 | The efforts of J Allard, Mike Carney, Dave Lapp, Fred Lien and | |
1968 | John Mendonca in organizing DHCP interoperability testing | |
1969 | sessions are gratefully acknowledged. | |
1970 | ||
1971 | The development of this document was supported in part by grants | |
1972 | from the Corporation for National Research Initiatives (CNRI), | |
1973 | Bucknell University and Sun Microsystems. | |
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1974 | |
1975 | ||
1976 | 12. References | |
1977 | ||
1978 | [1] Droms, R., "Dynamic Host Configuration Protocol", RFC 1531, | |
1979 | Bucknell University, October 1993. | |
1980 | ||
1981 | [2] Reynolds, J., "BOOTP Vendor Information Extensions", RFC 1497, | |
1982 | USC/Information Sciences Institute, August 1993. | |
1983 | ||
1984 | [3] Croft, W., and J. Gilmore, "Bootstrap Protocol", RFC 951, | |
1985 | Stanford University and Sun Microsystems, September 1985. | |
1986 | ||
1987 | [4] Braden, R., Editor, "Requirements for Internet Hosts - | |
1988 | Communication Layers", STD 3, RFC 1122, USC/Information Sciences | |
1989 | Institute, October 1989. | |
1990 | ||
1991 | [5] Mogul, J., and J. Postel, "Internet Standard Subnetting | |
1992 | Procedure", STD 5, RFC 950, USC/Information Sciences Institute, | |
1993 | August 1985. | |
1994 | ||
1995 | [6] Postel, J., and K. Harrenstien, "Time Protocol", STD 26, RFC | |
1996 | 868, USC/Information Sciences Institute, SRI, May 1983. | |
1997 | ||
1998 | [7] Postel, J., "Name Server", IEN 116, USC/Information Sciences | |
1999 | Institute, August 1979. | |
2000 | ||
2001 | [8] Mockapetris, P., "Domain Names - Implementation and | |
2002 | Specification", STD 13, RFC 1035, USC/Information Sciences | |
2003 | Institute, November 1987. | |
2004 | ||
2005 | [9] Postel, J., "Quote of the Day Protocol", STD 23, RFC 865, | |
2006 | USC/Information Sciences Institute, May 1983. | |
2007 | ||
2008 | [10] McLaughlin, L., "Line Printer Daemon Protocol", RFC 1179, The | |
2009 | Wollongong Group, August 1990. | |
2010 | ||
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2011 | |
2012 | ||
2013 | ||
2014 | Alexander & Droms [Page 36] | |
2015 | \f | |
2016 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 | |
2017 | ||
2018 | ||
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2019 | [11] Accetta, M., "Resource Location Protocol", RFC 887, CMU, |
2020 | December 1983. | |
2021 | ||
2022 | [12] Mogul, J. and S. Deering, "Path MTU Discovery", RFC 1191, | |
2023 | DECWRL, Stanford University, November 1990. | |
2024 | ||
2025 | [13] Deering, S., "ICMP Router Discovery Messages", RFC 1256, | |
2026 | Xerox PARC, September 1991. | |
2027 | ||
2028 | [14] Leffler, S. and M. Karels, "Trailer Encapsulations", RFC 893, | |
2029 | U. C. Berkeley, April 1984. | |
2030 | ||
2031 | [15] Hornig, C., "Standard for the Transmission of IP Datagrams over | |
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2032 | Ethernet Networks", RFC 894, Symbolics, April 1984. |
2033 | ||
2034 | [16] Postel, J. and J. Reynolds, "Standard for the Transmission of | |
2035 | IP Datagrams Over IEEE 802 Networks", RFC 1042, USC/Information | |
2036 | Sciences Institute, February 1988. | |
2037 | ||
2038 | [17] Sun Microsystems, "System and Network Administration", March | |
2039 | 1990. | |
2040 | ||
2041 | [18] Mills, D., "Internet Time Synchronization: The Network Time | |
2042 | Protocol", RFC 1305, UDEL, March 1992. | |
2043 | ||
2044 | [19] NetBIOS Working Group, "Protocol Standard for a NetBIOS Service | |
2045 | on a TCP/UDP transport: Concepts and Methods", STD 19, RFC 1001, | |
2046 | March 1987. | |
2047 | ||
2048 | [20] NetBIOS Working Group, "Protocol Standard for a NetBIOS Service | |
2049 | on a TCP/UDP transport: Detailed Specifications", STD 19, RFC | |
2050 | 1002, March 1987. | |
2051 | ||
2052 | [21] Scheifler, R., "FYI On the X Window System", FYI 6, RFC 1198, | |
2053 | MIT Laboratory for Computer Science, January 1991. | |
2054 | ||
2055 | [22] Reynolds, J., and J. Postel, "Assigned Numbers", STD 2, RFC 1700, | |
2056 | USC/Information Sciences Institute, July 1992. | |
2057 | ||
2058 | 13. Security Considerations | |
2059 | ||
2060 | Security issues are not discussed in this memo. | |
2061 | ||
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2062 | 14. Authors' Addresses |
2063 | ||
2064 | Steve Alexander | |
2065 | Silicon Graphics, Inc. | |
2066 | 2011 N. Shoreline Boulevard | |
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2067 | |
2068 | ||
2069 | ||
2070 | Alexander & Droms [Page 37] | |
2071 | \f | |
2072 | DRAFT DHCP Options and BOOTP Vendor Extensions December 1996 | |
2073 | ||
2074 | ||
fc7afcec TL |
2075 | Mailstop 510 |
2076 | Mountain View, CA 94043-1389 | |
2077 | ||
2078 | Phone: (415) 933-6172 | |
2079 | EMail: sca@engr.sgi.com | |
2080 | ||
2081 | Ralph Droms | |
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2082 | Bucknell University |
2083 | Lewisburg, PA 17837 | |
2084 | ||
2085 | Phone: (717) 524-1145 | |
2086 | EMail: droms@bucknell.edu | |
2087 | ||
2088 | ||
2089 | ||
2090 | ||
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