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7 .TH DHCPAGENT 1M "Jun 30, 2017"
8 .SH NAME
9 dhcpagent \- Dynamic Host Configuration Protocol (DHCP) client daemon
10 .SH SYNOPSIS
11 .LP
12 .nf
13 \fBdhcpagent\fR [\fB-a\fR] [ \fB-d\fR \fIn\fR] [\fB-f\fR] [\fB-v\fR]
14 .fi
15
16 .SH DESCRIPTION
17 .LP
18 \fBdhcpagent\fR implements the client half of the Dynamic Host Configuration
19 Protocol \fB(DHCP)\fR for machines running illumos software.
20 .sp
21 .LP
22 The \fBdhcpagent\fR daemon obtains configuration parameters for the client
23 (local) machine's network interfaces from a \fBDHCP\fR server. These parameters
24 may include a lease on an \fBIP\fR address, which gives the client machine use
25 of the address for the period of the lease, which may be infinite. If the
26 client wishes to use the \fBIP\fR address for a period longer than the lease,
27 it must negotiate an extension using \fBDHCP\fR. For this reason,
28 \fBdhcpagent\fR must run as a daemon, terminating only when the client machine
29 powers down.
30 .sp
31 .LP
32 For IPv4, the \fBdhcpagent\fR daemon is controlled through \fBipadm\fR(1M),
33 \fBnwamcfg\fR(1M), or \fBifconfig\fR(1M) in much the same way that the
34 \fBinit\fR(1M) daemon is controlled by \fBtelinit\fR(1M). \fBdhcpagent\fR can
35 be invoked as a user process, albeit one requiring root privileges, but this is
36 not necessary, as \fBipadm\fR(1M), \fBnwamcfg\fR(1M), or \fBifconfig\fR(1M)
37 will start \fBdhcpagent\fR automatically.
38 .sp
39 .LP
40 For IPv6, the \fBdhcpagent\fR daemon is invoked automatically by
41 \fBin.ndpd\fR(1M). It can also be controlled through \fBifconfig\fR(1M), if
42 necessary.
43 .sp
44 .LP
45 When invoked, \fBdhcpagent\fR enters a passive state while it awaits
46 instructions from \fBipadm\fR(1M), \fBnwamcfg\fR(1M), \fBifconfig\fR(1M), or
47 \fBin.ndpd\fR(1M). When \fBdhcpagent\fR receives a command to configure an
48 interface, \fBdhcpagent\fR brings up the interface (if necessary) and starts
49 DHCP. Once DHCP is complete, \fBdhcpagent\fR can be queried for the values of
50 the various network parameters. In addition, if DHCP was used to obtain a lease
51 on an address for an interface, \fBdhcpagent\fR configures the address for use.
52 When a lease is obtained, it is automatically renewed as necessary. If the
53 lease cannot be renewed, \fBdhcpagent\fR will unconfigure the address, but the
54 interface will be left up, and \fBdhcpagent\fR will attempt to acquire a new
55 address lease.
56 .sp
57 .LP
58 \fBdhcpagent\fR monitors system suspend/resume events and will validate any
59 non-permanent leases with the DHCP server upon resume. Similarly,
60 \fBdhcpagent\fR monitors link up/down events and will validate any
61 non-permanent leases with the DHCP server when the downed link is brought back
62 up. The lease validation mechanism will restart DHCP if the server indicates
63 that the existing lease is no longer valid. If the server cannot be contacted,
64 then the existing lease will continue. This behavior can be modified with the
65 \fBVERIFIED_LEASE_ONLY\fR parameter in the \fB/etc/default/dhcpagent\fR file.
66 See the description of this parameter below.
67 .sp
68 .LP
69 For IPv4, if the configured interface is found to be unplumbed, or to have a
70 different IP address, subnet mask, or broadcast address from those obtained
71 from DHCP, the interface is abandoned from DHCP control.
72 .sp
73 .LP
74 For IPv6, \fBdhcpagent\fR automatically plumbs and unplumbs logical interfaces
75 as necessary for the IPv6 addresses supplied by the server. The IPv6 prefix
76 length (netmask) is not set by the DHCPv6 protocol, but is instead set by
77 \fBin.ndpd\fR(1M) using prefix information obtained by Router Advertisements.
78 If any of the logical interfaces created by \fBdhcpagent\fR is unplumbed, or
79 configured with a different IP address, it will be abandoned from DHCP control.
80 If the link-local interface is unplumbed, then all addresses configured by DHCP
81 on that physical interface will be removed.
82 .sp
83 .LP
84 In addition to \fBDHCP\fR, \fBdhcpagent\fR also supports \fBBOOTP\fR (IPv4
85 only). See \fIRFC 951, Bootstrap Protocol\fR. Configuration parameters obtained
86 from a \fBBOOTP\fR server are treated identically to those received from a
87 \fBDHCP\fR server, except that the \fBIP\fR address received from a \fBBOOTP\fR
88 server always has an infinite lease.
89 .sp
90 .LP
91 \fBDHCP\fR also acts as a mechanism to configure other information needed by
92 the client, for example, the domain name and addresses of routers. Aside from
93 the IP address, and for IPv4 alone, the netmask, broadcast address, and default
94 router, the agent does not directly configure the workstation, but instead acts
95 as a database which may be interrogated by other programs, and in particular by
96 \fBdhcpinfo\fR(1).
97 .sp
98 .LP
99 On clients with a single interface, this is quite straightforward. Clients with
100 multiple interfaces may present difficulties, as it is possible that some
101 information arriving on different interfaces may need to be merged, or may be
102 inconsistent. Furthermore, the configuration of the interfaces is asynchronous,
103 so requests may arrive while some or all of the interfaces are still
104 unconfigured. To handle these cases, one interface may be designated as
105 primary, which makes it the authoritative source for the values of \fBDHCP\fR
106 parameters in the case where no specific interface is requested. See
107 \fBdhcpinfo\fR(1) and \fBifconfig\fR(1M) for details.
108 .sp
109 .LP
110 For IPv4, the \fBdhcpagent\fR daemon can be configured to request a particular
111 Fully Qualified Domain Name (FQDN) or host name. See the \fBREQUEST_FQDN\fR or
112 \fBREQUEST_HOSTNAME\fR description in the \fBFILES\fR section. When first
113 configuring a client to request an FQDN or host name, you must perform the
114 following steps as root to ensure that the full DHCP negotiation takes place:
115 .sp
116 .in +2
117 .nf
118 # pkill dhcpagent
119 # rm /etc/dhcp/\fIinterface\fR.dhc
120 # reboot
121 .fi
122 .in -2
123 .sp
124
125 .sp
126 .LP
127 All DHCP packets sent by \fBdhcpagent\fR include a vendor class identifier (RFC
128 2132, option code 60; RFC 3315, option code 16). This identifier is the same as
129 the platform name returned by the \fBuname\fR \fB-i\fR command, except:
130 .RS +4
131 .TP
132 .ie t \(bu
133 .el o
134 Any commas in the platform name are changed to periods.
135 .RE
136 .RS +4
137 .TP
138 .ie t \(bu
139 .el o
140 If the name does not start with a stock symbol and a comma, it is automatically
141 prefixed with \fBSUNW\fR.
142 .RE
143 .SS "Messages"
144 .LP
145 The \fBdhcpagent\fR daemon writes information and error messages in five
146 categories:
147 .sp
148 .ne 2
149 .na
150 \fBcritical\fR
151 .ad
152 .sp .6
153 .RS 4n
154 Critical messages indicate severe conditions that prevent proper operation.
155 .RE
156
157 .sp
158 .ne 2
159 .na
160 \fBerrors\fR
161 .ad
162 .sp .6
163 .RS 4n
164 Error messages are important, sometimes unrecoverable events due to resource
165 exhaustion and other unexpected failure of system calls; ignoring errors may
166 lead to degraded functionality.
167 .RE
168
169 .sp
170 .ne 2
171 .na
172 \fBwarnings\fR
173 .ad
174 .sp .6
175 .RS 4n
176 Warnings indicate less severe problems, and in most cases, describe unusual or
177 incorrect datagrams received from servers, or requests for service that cannot
178 be provided.
179 .RE
180
181 .sp
182 .ne 2
183 .na
184 \fBinformational\fR
185 .ad
186 .sp .6
187 .RS 4n
188 Informational messages provide key pieces of information that can be useful to
189 debugging a \fBDHCP\fR configuration at a site. Informational messages are
190 generally controlled by the \fB-v\fR option. However, certain critical pieces
191 of information, such as the IP address obtained, are always provided.
192 .RE
193
194 .sp
195 .ne 2
196 .na
197 \fBdebug\fR
198 .ad
199 .sp .6
200 .RS 4n
201 Debugging messages, which may be generated at two different levels of
202 verbosity, are chiefly of benefit to persons having access to source code, but
203 may be useful as well in debugging difficult DHCP configuration problems.
204 Debugging messages are only generated when using the \fB-d\fR option.
205 .RE
206
207 .sp
208 .LP
209 When \fBdhcpagent\fR is run without the \fB-f\fR option, all messages are sent
210 to the system logger \fBsyslog\fR(3C) at the appropriate matching priority and
211 with a facility identifier \fBLOG_DAEMON\fR. When \fBdhcpagent\fR is run with
212 the \fB-f\fR option, all messages are directed to standard error.
213 .SS "DHCP Events and User-Defined Actions"
214 .LP
215 If an executable (binary or script) is placed at \fB/etc/dhcp/eventhook\fR, the
216 \fBdhcpagent\fR daemon will automatically run that program when any of the
217 following events occur:
218 .sp
219 .ne 2
220 .na
221 \fB\fBBOUND\fR and \fBBOUND6\fR\fR
222 .ad
223 .sp .6
224 .RS 4n
225 These events occur during interface configuration. The event program is invoked
226 when \fBdhcpagent\fR receives the DHCPv4 ACK or DHCPv6 Reply message from the
227 DHCP server for the lease request of an address, indicating successful initial
228 configuration of the interface. (See also the \fBINFORM\fR and \fBINFORM6\fR
229 events, which occur when configuration parameters are obtained without address
230 leases.)
231 .RE
232
233 .sp
234 .ne 2
235 .na
236 \fB\fBEXTEND\fR and \fBEXTEND6\fR\fR
237 .ad
238 .sp .6
239 .RS 4n
240 These events occur during lease extension. The event program is invoked just
241 after \fBdhcpagent\fR receives the DHCPv4 ACK or DHCPv6 Reply from the DHCP
242 server for the DHCPv4 REQUEST (renew) message or the DHCPv6 Renew or Rebind
243 message.
244 .sp
245 Note that with DHCPv6, the server might choose to remove some addresses, add
246 new address leases, and ignore (allow to expire) still other addresses in a
247 given Reply message. The \fBEXTEND6\fR event occurs when a Reply is received
248 that leaves one or more address leases still valid, even if the Reply message
249 does not extend the lease for any address. The event program is invoked just
250 before any addresses are removed, but just after any new addresses are added.
251 Those to be removed will be marked with the \fBIFF_DEPRECATED\fR flag.
252 .RE
253
254 .sp
255 .ne 2
256 .na
257 \fB\fBEXPIRE\fR and \fBEXPIRE6\fR\fR
258 .ad
259 .sp .6
260 .RS 4n
261 These events occur during lease expiration. For DHCPv4, the event program is
262 invoked just before the leased address is removed from an interface. For
263 DHCPv6, the event program is invoked just before the last remaining leased
264 addresses are removed from the interface.
265 .RE
266
267 .sp
268 .ne 2
269 .na
270 \fB\fBDROP\fR and \fBDROP6\fR\fR
271 .ad
272 .sp .6
273 .RS 4n
274 These events occur during the period when an interface is dropped. The event
275 program is invoked just before the interface is removed from DHCP control. If
276 the interface has been abandoned due the user unplumbing the interface, then
277 this event will occur after the user's action has taken place. The interface
278 might not be present.
279 .RE
280
281 .sp
282 .ne 2
283 .na
284 \fB\fBINFORM\fR and \fBINFORM6\fR\fR
285 .ad
286 .sp .6
287 .RS 4n
288 These events occur when an interface acquires new or updated configuration
289 information from a DHCP server by means of the DHCPv4 \fBINFORM\fR or the
290 DHCPv6 Information-Request message. These messages are sent using an
291 \fBifconfig\fR(1M) \fBdhcp inform\fR command or when the DHCPv6 Router
292 Advertisement \fBO\fR (letter 0) bit is set and the \fBM\fR bit is not set.
293 Thus, these events occur when the DHCP client does not obtain an IP address
294 lease from the server, and instead obtains only configuration parameters.
295 .RE
296
297 .sp
298 .ne 2
299 .na
300 \fB\fBLOSS6\fR\fR
301 .ad
302 .sp .6
303 .RS 4n
304 This event occurs during lease expiration when one or more valid leases still
305 remain. The event program is invoked just before expired addresses are removed.
306 Those being removed will be marked with the \fBIFF_DEPRECATED\fR flag.
307 .sp
308 Note that this event is not associated with the receipt of the Reply message,
309 which occurs only when one or more valid leases remain, and occurs only with
310 DHCPv6. If all leases have expired, then the EXPIRE6 event occurs instead.
311 .RE
312
313 .sp
314 .ne 2
315 .na
316 \fB\fBRELEASE\fR and \fBRELEASE6\fR\fR
317 .ad
318 .sp .6
319 .RS 4n
320 This event occurs during the period when a leased address is released. The
321 event program is invoked just before \fBdhcpagent\fR relinquishes the address
322 on an interface and sends the DHCPv4 \fBRELEASE\fR or DHCPv6 Release packet to
323 the DHCP server.
324 .RE
325
326 .sp
327 .LP
328 The system does not provide a default event program. The file
329 \fB/etc/dhcp/eventhook\fR is expected to be owned by root and have a mode of
330 755.
331 .sp
332 .LP
333 The event program will be passed two arguments, the interface name and the
334 event name, respectively. For DHCPv6, the interface name is the name of the
335 physical interface.
336 .sp
337 .LP
338 The event program can use the \fBdhcpinfo\fR(1) utility to fetch additional
339 information about the interface. While the event program is invoked on every
340 event defined above, it can ignore those events in which it is not interested.
341 The event program runs with the same privileges and environment as
342 \fBdhcpagent\fR itself, except that \fBstdin\fR, \fBstdout\fR, and \fBstderr\fR
343 are redirected to \fB/dev/null\fR. Note that this means that the event program
344 runs with root privileges.
345 .sp
346 .LP
347 If an invocation of the event program does not exit after 55 seconds, it is
348 sent a \fBSIGTERM\fR signal. If does not exit within the next three seconds, it
349 is terminated by a \fBSIGKILL\fR signal.
350 .sp
351 .LP
352 See EXAMPLES for an example event program.
353 .SH OPTIONS
354 .LP
355 The following options are supported:
356 .sp
357 .ne 2
358 .na
359 \fB\fB-a\fR\fR
360 .ad
361 .sp .6
362 .RS 4n
363 Adopt a configured IPv4 interface. This option is for use with diskless
364 \fBDHCP\fR clients. In the case of diskless \fBDHCP\fR, \fBDHCP\fR has already
365 been performed on the network interface providing the operating system image
366 prior to running \fBdhcpagent\fR. This option instructs the agent to take over
367 control of the interface. It is intended primarily for use in boot scripts.
368 .sp
369 The effect of this option depends on whether the interface is being adopted.
370 .sp
371 If the interface is being adopted, the following conditions apply:
372 .sp
373 \fBdhcpagent\fR uses the client id specified in
374 \fB/chosen\fR:\fI<client_id>\fR, as published by the PROM or as specified on a
375 \fBboot\fR(1M) command line. If this value is not present, the client id is
376 undefined. The DHCP server then determines what to use as a client id. It is an
377 error condition if the interface is an Infiniband interface and the PROM value
378 is not present.
379 .sp
380 If the interface is not being adopted:
381 .sp
382 \fBdhcpagent\fR uses the value stored in \fB/etc/default/dhcpagent\fR. If this
383 value is not present, the client id is undefined. If the interface is
384 Infiniband and there is no value in \fB/etc/default/dhcpagent\fR, a client id
385 is generated as described by the draft document on DHCP over Infiniband,
386 available at:
387 .sp
388 .in +2
389 .nf
390 http://www.ietf.org
391 .fi
392 .in -2
393
394 .RE
395
396 .sp
397 .ne 2
398 .na
399 \fB\fB-d\fR \fIn\fR\fR
400 .ad
401 .sp .6
402 .RS 4n
403 Set debug level to \fIn\fR. Two levels of debugging are currently available, 1
404 and 2; the latter is more verbose.
405 .RE
406
407 .sp
408 .ne 2
409 .na
410 \fB\fB-f\fR\fR
411 .ad
412 .sp .6
413 .RS 4n
414 Run in the foreground instead of as a daemon process. When this option is used,
415 messages are sent to standard error instead of to \fBsyslog\fR(3C).
416 .RE
417
418 .sp
419 .ne 2
420 .na
421 \fB\fB-v\fR\fR
422 .ad
423 .sp .6
424 .RS 4n
425 Provide verbose output useful for debugging site configuration problems.
426 .RE
427
428 .SH EXAMPLES
429 .LP
430 \fBExample 1 \fRExample Event Program
431 .sp
432 .LP
433 The following script is stored in the file \fB/etc/dhcp/eventhook\fR, owned by
434 root with a mode of 755. It is invoked upon the occurrence of the events listed
435 in the file.
436
437 .sp
438 .in +2
439 .nf
440 #!/bin/sh
441
442 (
443 echo "Interface name: " $1
444 echo "Event: " $2
445
446 case $2 in
447 "BOUND")
448 echo "Address acquired from server "\e
449 `/sbin/dhcpinfo -i $1 ServerID`
450 ;;
451 "BOUND6")
452 echo "Addresses acquired from server " \e
453 `/sbin/dhcpinfo -v6 -i $1 ServerID`
454 ;;
455 "EXTEND")
456 echo "Lease extended for " \e
457 `sbin/dhcpinfo -i $1 LeaseTim`" seconds"
458 ;;
459 "EXTEND6")
460 echo "New lease information obtained on $i"
461 ;;
462 "EXPIRE" | "DROP" | "RELEASE")
463 ;;
464
465 esac
466 ) >/var/run/dhcp_eventhook_output 2>&1
467 .fi
468 .in -2
469 .sp
470
471 .sp
472 .LP
473 Note the redirection of stdout and stderr to a file.
474
475 .SH FILES
476 .ne 2
477 .na
478 \fB\fB/etc/dhcp/\fIif\fR.dhc\fR\fR
479 .ad
480 .br
481 .na
482 \fB\fB/etc/dhcp/\fIif\fR.dh6\fR\fR
483 .ad
484 .sp .6
485 .RS 4n
486 Contains the configuration for interface. The mere existence of this file does
487 not imply that the configuration is correct, since the lease might have
488 expired. On start-up, \fBdhcpagent\fR confirms the validity of the address
489 using REQUEST (for DHCPv4) or Confirm (DHCPv6).
490 .RE
491
492 .sp
493 .ne 2
494 .na
495 \fB\fB/etc/dhcp/duid\fR\fR
496 .ad
497 .br
498 .na
499 \fB\fB/etc/dhcp/iaid\fR\fR
500 .ad
501 .sp .6
502 .RS 4n
503 Contains persistent storage for system-generated DUID (DHCP Unique Identifier)
504 and interface-specific IAID (Identity Association Identifier) values which are
505 used if no \fBCLIENT_ID\fR is defined (see below). The format of these files is
506 undocumented, and applications should not read from or write to them. Instead,
507 \fBdhcpinfo\fR(1) can be used to query the \fBdhcpagent\fR for \fIClientID\fR.
508 For DHCPv6 interfaces, the result will contain the DUID. For DHCPv4 interfaces
509 with \fBV4_DEFAULT_IAID_DUID\fR enabled (see below), the result will contain
510 the IAID and DUID.
511 .RE
512
513 .sp
514 .ne 2
515 .na
516 \fB\fB/etc/default/dhcpagent\fR\fR
517 .ad
518 .sp .6
519 .RS 4n
520 Contains default values for tunable parameters. All values may be qualified
521 with the interface they apply to by prepending the interface name and a period
522 (".") to the interface parameter name. The parameters include: the interface
523 parameter name.
524 .sp
525 To configure IPv6 parameters, place the string \fB\&.v6\fR between the
526 interface name (if any) and the parameter name. For example, to set the global
527 IPv6 parameter request list, use \fB\&.v6.PARAM_REQUEST_LIST\fR. To set the
528 \fBCLIENT_ID\fR (\fBDUID\fR) on \fBhme0\fR, use \fBhme0.v6.CLIENT_ID\fR.
529 .sp
530 The parameters include:
531 .sp
532 .ne 2
533 .na
534 \fB\fBVERIFIED_LEASE_ONLY\fR\fR
535 .ad
536 .sp .6
537 .RS 4n
538 Indicates that a \fBRELEASE\fR rather than a \fBDROP\fR should be performed on
539 managed interfaces when the agent terminates. Release causes the client to
540 discard the lease, and the server to make the address available again. Drop
541 causes the client to record the lease in \fB/etc/dhcp/\fIinterface\fR.dhc\fR or
542 \fB/etc/dhcp/\fIinterface\fR.dh6\fR for later use. In addition, when the link
543 status changes to \fBup\fR or when the system is resumed after a suspend, the
544 client will verify the lease with the server. If the server is unreachable for
545 verification, then the old lease will be discarded (even if it has time
546 remaining) and a new one obtained.
547 .sp
548 Enabling this option is often desirable on mobile systems, such as laptops, to
549 allow the system to recover quickly from moves.
550 .sp
551 Default value of this option is \fIno\fR.
552 .RE
553
554 .sp
555 .ne 2
556 .na
557 \fB\fBOFFER_WAIT\fR\fR
558 .ad
559 .sp .6
560 .RS 4n
561 Indicates how long to wait in seconds between checking for valid
562 \fBOFFER\fRs after sending a \fBDISCOVER\fR. For DHCPv6, sets the time to
563 wait between checking for valid Advertisements after sending a Solicit.
564 .sp
565 Default value of this option is \fI3\fR.
566 .RE
567
568 .sp
569 .ne 2
570 .na
571 \fB\fBCLIENT_ID\fR\fR
572 .ad
573 .sp .6
574 .RS 4n
575 Indicates the value that should be used to uniquely identify the client to the
576 server. This value can take one of three basic forms:
577 .sp
578 .in +2
579 .nf
580 \fIdecimal\fR,\fIdata\fR...
581 0xHHHHH...
582 "\fIstring\fR...."
583 .fi
584 .in -2
585 .sp
586
587 The first form is an RFC 3315 DUID. This is legal for both IPv4 DHCP and
588 DHCPv6. For IPv4, an RFC 4361 Client ID is constructed from this value. In this
589 first form, the format of \fIdata\fR... depends on the decimal value. The
590 following formats are defined for this first form:
591 .sp
592 .ne 2
593 .na
594 \fB1,\fIhwtype\fR,\fItime\fR,\fIlla\fR\fR
595 .ad
596 .sp .6
597 .RS 4n
598 Type 1, DUID-LLT. The \fIhwtype\fR value is an integer in the range 0-65535,
599 and indicates the type of hardware. The \fItime\fR value is the number of
600 seconds since midnight, January 1st, 2000 UTC, and can be omitted to use the
601 current system time. The \fIlla\fR value is either a colon-separated MAC
602 address or the name of a physical interface. If the name of an interface is
603 used, the \fIhwtype\fR value can be omitted. For example: \fB1,,,hme0\fR
604 .RE
605
606 .sp
607 .ne 2
608 .na
609 \fB2,\fIenterprise\fR,\fIhex\fR...\fR
610 .ad
611 .sp .6
612 .RS 4n
613 Type 2, DUID-EN. The \fIenterprise\fR value is an integer in the range
614 0-4294967295 and represents the SMI Enterprise number for an organization. The
615 \fIhex\fR string is an even-length sequence of hexadecimal digits.
616 .RE
617
618 .sp
619 .ne 2
620 .na
621 \fB3,\fIhwtype\fR,\fIlla\fR\fR
622 .ad
623 .sp .6
624 .RS 4n
625 Type 3, DUID-LL. This is the same as DUID-LLT (type 1), except that a time
626 stamp is not used.
627 .RE
628
629 .sp
630 .ne 2
631 .na
632 \fB*,\fIhex\fR\fR
633 .ad
634 .sp .6
635 .RS 4n
636 Any other type value (0 or 4-65535) can be used with an even-length hexadecimal
637 string.
638 .RE
639
640 The second and third forms of \fBCLIENT_ID\fR are legal for IPv4 only. These
641 both represent raw Client ID (without RFC 4361), in hex, or NVT ASCII string
642 format. Thus, "\fBSun\fR" and \fB0x53756E\fR are equivalent.
643 .RE
644
645 .sp
646 .ne 2
647 .na
648 \fB\fBV4_DEFAULT_IAID_DUID\fR\fR
649 .ad
650 .sp .6
651 .RS 4n
652 Indicates whether to use, when CLIENT_ID is not defined, a system-managed,
653 RFC 3315-style (i.e., DHCPv6-style) binding identifier as documented in
654 RFC 4361, "Node-specific Client Identifiers for DHCPv4," for IPv4
655 interfaces which for purposes of backward compatibility do not normally get
656 default binding identifiers.
657 .sp
658 An IPv4 interface that is not in an IP network multipathing (IPMP) group,
659 that is not IP over InfiniBand (IPoIB), and that is not a logical interface
660 does not normally get a default binding identifier.
661 .sp
662 Default value of this option is \fIno\fR.
663 .RE
664
665 .sp
666 .ne 2
667 .na
668 \fB\fBPARAM_REQUEST_LIST\fR\fR
669 .ad
670 .sp .6
671 .RS 4n
672 Specifies a list of comma-separated integer values of options for which the
673 client would like values, or symbolic \fBSite\fR or \fBOption\fR option names.
674 Symbolic option names for IPv4 are resolved through \fB/etc/dhcp/inittab\fR.
675 Option names for IPv6 are resolved by means of \fB/etc/dhcp/inittab6\fR.
676 .RE
677
678 .sp
679 .ne 2
680 .na
681 \fB\fBPARAM_IGNORE_LIST\fR\fR
682 .ad
683 .sp .6
684 .RS 4n
685 Specifies a list of options (constructed in the same manner as
686 \fBPARAM_REQUEST_LIST\fR) that the DHCP client will ignore. Ignored options are
687 treated as though the server did not return the options specified. Ignored
688 options are not visible using \fBdhcpinfo\fR(1) or acted on by the client. This
689 parameter can be used, for example, to disable an unwanted client name or
690 default router.
691 .RE
692
693 .sp
694 .ne 2
695 .na
696 \fB\fBREQUEST_FQDN\fR\fR
697 .ad
698 .sp .6
699 .RS 4n
700 Indicates the client requests the DHCP server to map the client's leased
701 IPv4 address to the Fully Qualified Domain Name (FQDN) associated with the
702 network interface that performs DHCP on the client and to collaborate with
703 a compatible DNS server to manage A and PTR resource records for the FQDN
704 for the life of the lease.
705 .sp .6
706 The \fIhostname\fR in the FQDN is determined from the following possible
707 configurations:
708 .sp
709 .ne 2
710 .na
711 1. \fBipadm\fR(1M): include the \fB-1,--primary\fR flag when creating an
712 address that uses DHCP so that \fBnodename\fR(4) is used as the
713 \fIhostname\fR.
714 .ad
715 .sp
716 .ne 2
717 .na
718 2. \fBipadm\fR(1M): include the \fB-h,--reqhost\fR \fIhostname\fR switch
719 when executing the \fBcreate-addr -T dhcp\fR subcommand, or use the
720 \fBset-addrprop -p reqhost=\fR\fIhostname\fR subcommand for any existing
721 DHCP address.
722 .ad
723 .sp
724 .ne 2
725 .na
726 3. \fBnwamcfg\fR(1M): set a property,
727 \fBip-primary=\fR\fIon\fR, for an ncu ip that uses DHCP so that
728 \fBnodename\fR(4) is used as the \fIhostname\fR.
729 .ad
730 .sp
731 .ne 2
732 .na
733 4. \fBnwamcfg\fR(1M): set a property,
734 \fBip-reqhost=\fR\fIhostname\fR, for an ncu ip that uses DHCP.
735 .ad
736 .sp
737 The \fIhostname\fR value is either a Partially Qualified Domain Name (PQDN)
738 or an FQDN (i.e., a "rooted" domain name ending with a '.' or one inferred
739 to be an FQDN if it contains at least three DNS labels such as
740 srv.example.com). If a PQDN is specified, then an FQDN is constructed if
741 \fBDNS_DOMAINNAME\fR is defined or if \fBADOPT_DOMAINNAME\fR is set to
742 \fIyes\fR and an eligible domain name (as described below) is available.
743 .sp
744 If an FQDN is sent, \fBREQUEST_HOSTNAME\fR processing will not be done,
745 per RFC 4702 (3.1): "clients that send the Client FQDN option in their
746 messages MUST NOT also send the Host Name."
747 .sp
748 Default value of this option is \fIyes\fR.
749 .RE
750
751 .sp
752 .ne 2
753 .na
754 \fB\fBDNS_DOMAINNAME\fR\fR
755 .ad
756 .sp .6
757 .RS 4n
758 Indicates the value that should be appended to a PQDN specified by the
759 \fB-h,--reqhost\fR option of \fBipadm\fR(1M), by the ncu \fBip-reqhost\fR
760 property of \fBnwamcfg\fR(1M), or by \fBnodename\fR(4) to construct an FQDN
761 for \fBREQUEST_FQDN\fR processing.
762 If the \fIhostname\fR value is already an FQDN, then the value of this
763 option is not used.
764 .RE
765
766 .sp
767 .ne 2
768 .na
769 \fB\fBADOPT_DOMAINNAME\fR\fR
770 .ad
771 .sp .6
772 .RS 4n
773 Indicates that a domain name returned by the DHCP server or the \fBdomain\fR
774 from \fBresolv.conf\fR(4) should be adopted if needed to construct an FQDN
775 from a PQDN specified by the \fB-h,--reqhost\fR option of \fBipadm\fR(1M),
776 by the ncu \fBip-reqhost\fR property of \fBnwamcfg\fR(1M), or by
777 \fBnodename\fR(4).
778 If the \fIhostname\fR value is already an FQDN, then the value of this
779 option is not applicable.
780 The eligible DHCP option for domain name is DHCPv4 \fBDNSdmain\fR.
781 .sp
782 Default value of this option is \fIno\fR.
783 .RE
784
785 .sp
786 .ne 2
787 .na
788 \fB\fBREQUEST_HOSTNAME\fR\fR
789 .ad
790 .sp .6
791 .RS 4n
792 Indicates the client requests the DHCP server to map the client's leased IPv4
793 address to the host name associated with the network interface that performs
794 DHCP on the client. The host name must be specified as documented for a
795 PQDN in \fBREQUEST_FQDN\fR above or specified in the
796 \fB/etc/hostname.\fIinterface\fR\fR file for the relevant interface on a line
797 of the form
798 .sp
799 .in +2
800 .nf
801 inet \fIhostname\fR
802 .fi
803 .in -2
804 .sp
805
806 where \fIhostname\fR is the host name requested.
807 .sp
808 This option works with DHCPv4 only.
809 .sp
810 Default value of this option is \fIyes\fR.
811 .RE
812
813 .RE
814
815 .sp
816 .ne 2
817 .na
818 \fB\fB/etc/dhcp/eventhook\fR\fR
819 .ad
820 .sp .6
821 .RS 4n
822 Location of a DHCP event program.
823 .RE
824
825 .SH ATTRIBUTES
826 .LP
827 See \fBattributes\fR(5) for descriptions of the following attributes:
828 .sp
829
830 .sp
831 .TS
832 box;
833 c | c
834 l | l .
835 ATTRIBUTE TYPE ATTRIBUTE VALUE
836 _
837 Interface Stability Committed
838 .TE
839
840 .SH SEE ALSO
841 .LP
842 \fBdhcpinfo\fR(1), \fBifconfig\fR(1M), \fBinit\fR(1M), \fBin.mpathd\fR(1M),
843 \fBin.ndpd\fR(1M), \fBipadm\fR(1M), \fBnwamcfg\fR(1M), \fBsyslog\fR(3C),
844 \fBnodename\fR(4), \fBresolv.conf\fR(4), \fBattributes\fR(5), \fBdhcp\fR(5)
845 .sp
846 .LP
847 \fI\fR
848 .sp
849 .LP
850 Croft, B. and Gilmore, J. \fIRFC 951, Bootstrap Protocol (BOOTP)\fR, Network
851 Working Group, September 1985.
852 .sp
853 .LP
854 Droms, R. \fIRFC 2131, Dynamic Host Configuration Protocol\fR, Network Working
855 Group, March 1997.
856 .sp
857 .LP
858 Lemon, T. and B. Sommerfeld. \fIRFC 4361, Node-specific Client Identifiers for
859 Dynamic Host Configuration Protocol Version Four (DHCPv4)\fR. Nominum and Sun
860 Microsystems. February 2006.
861 .sp
862 .LP
863 Droms, R. \fIRFC 3315, Dynamic Host Configuration Protocol for IPv6
864 (DHCPv6)\fR. Cisco Systems. July 2003.
865 .SH NOTES
866 .LP
867 The \fBdhcpagent\fR daemon can be used on IPv4 logical interfaces, just as with
868 physical interfaces. When used on a logical interface, the daemon automatically
869 constructs a Client ID value based on the DUID and IAID values, according to
870 RFC 4361. The \fB/etc/default/dhcpagent\fR \fBCLIENT_ID\fR value, if any,
871 overrides this automatic identifier.
872 .sp
873 .LP
874 As with physical IPv4 interfaces, the \fB/etc/hostname.hme0:1\fR and
875 \fB/etc/dhcp.hme0:1\fR files must also be created in order for \fBhme0:1\fR to
876 be automatically plumbed and configured at boot. In addition, unlike physical
877 IPv4 interfaces, \fBdhcpagent\fR does not add or remove default routes
878 associated with logical interfaces.
879 .sp
880 .LP
881 DHCP can be performed on IPMP IP interfaces to acquire and maintain IPMP data
882 addresses. Because an IPMP IP interface has no hardware address, the daemon
883 automatically constructs a Client ID using the same approach described above
884 for IPv4 logical interfaces. In addition, the lack of a hardware address means
885 the daemon must set the "broadcast" flag in all \fBDISCOVER\fR and
886 \fBREQUEST\fR messages on IPMP IP interfaces. Some DHCP servers may refuse such
887 requests.
888 .sp
889 .LP
890 DHCP can be performed on IP interfaces that are part of an IPMP group (to
891 acquire and maintain test addresses). The daemon will automatically set the
892 \fBNOFAILOVER\fR and \fBDEPRECATED\fR flags on each test address. Additionally,
893 the daemon will not add or remove default routes in this case. Note that the
894 actual DHCP packet exchange may be performed over any active IP interface in
895 the IPMP group. It is strongly recommended that test addresses have infinite
896 leases. Otherwise, an extended network outage detectable only by probes may
897 cause test address leases to expire, causing \fBin.mpathd\fR(1M) to revert to
898 link-based failure detection and trigger an erroneous repair.
899 .sp
900 .LP
901 With DHCPv6, the link-local interface must be configured using
902 \fB/etc/hostname6.hme0\fR in order for DHCPv6 to run on \fBhme0\fR at boot
903 time. The logical interfaces for each address are plumbed by \fBdhcpagent\fR
904 automatically.