1 DHCPAGENT(1M) Maintenance Commands DHCPAGENT(1M)
2
3
4
5 NAME
6 dhcpagent - Dynamic Host Configuration Protocol (DHCP) client daemon
7
8 SYNOPSIS
9 dhcpagent [-a] [ -d n] [-f] [-v]
10
11
12 DESCRIPTION
13 dhcpagent implements the client half of the Dynamic Host Configuration
14 Protocol (DHCP) for machines running illumos software.
15
16
17 The dhcpagent daemon obtains configuration parameters for the client
18 (local) machine's network interfaces from a DHCP server. These
19 parameters may include a lease on an IP address, which gives the client
20 machine use of the address for the period of the lease, which may be
21 infinite. If the client wishes to use the IP address for a period
22 longer than the lease, it must negotiate an extension using DHCP. For
23 this reason, dhcpagent must run as a daemon, terminating only when the
24 client machine powers down.
25
26
27 For IPv4, the dhcpagent daemon is controlled through ipadm(1M),
28 nwamcfg(1M), or ifconfig(1M) in much the same way that the init(1M)
29 daemon is controlled by telinit(1M). dhcpagent can be invoked as a user
30 process, albeit one requiring root privileges, but this is not
31 necessary, as ipadm(1M), nwamcfg(1M), or ifconfig(1M) will start
32 dhcpagent automatically.
33
34
35 For IPv6, the dhcpagent daemon is invoked automatically by in.ndpd(1M).
36 It can also be controlled through ifconfig(1M), if necessary.
37
38
39 When invoked, dhcpagent enters a passive state while it awaits
40 instructions from ipadm(1M), nwamcfg(1M), ifconfig(1M), or in.ndpd(1M).
41 When dhcpagent receives a command to configure an interface, dhcpagent
42 brings up the interface (if necessary) and starts DHCP. Once DHCP is
43 complete, dhcpagent can be queried for the values of the various
44 network parameters. In addition, if DHCP was used to obtain a lease on
45 an address for an interface, dhcpagent configures the address for use.
46 When a lease is obtained, it is automatically renewed as necessary. If
47 the lease cannot be renewed, dhcpagent will unconfigure the address,
48 but the interface will be left up, and dhcpagent will attempt to
49 acquire a new address lease.
50
51
52 dhcpagent monitors system suspend/resume events and will validate any
53 non-permanent leases with the DHCP server upon resume. Similarly,
54 dhcpagent monitors link up/down events and will validate any non-
55 permanent leases with the DHCP server when the downed link is brought
56 back up. The lease validation mechanism will restart DHCP if the server
57 indicates that the existing lease is no longer valid. If the server
58 cannot be contacted, then the existing lease will continue. This
59 behavior can be modified with the VERIFIED_LEASE_ONLY parameter in the
60 /etc/default/dhcpagent file. See the description of this parameter
61 below.
62
63
64 For IPv4, if the configured interface is found to be unplumbed, or to
65 have a different IP address, subnet mask, or broadcast address from
66 those obtained from DHCP, the interface is abandoned from DHCP control.
67
68
69 For IPv6, dhcpagent automatically plumbs and unplumbs logical
70 interfaces as necessary for the IPv6 addresses supplied by the server.
71 The IPv6 prefix length (netmask) is not set by the DHCPv6 protocol, but
72 is instead set by in.ndpd(1M) using prefix information obtained by
73 Router Advertisements. If any of the logical interfaces created by
74 dhcpagent is unplumbed, or configured with a different IP address, it
75 will be abandoned from DHCP control. If the link-local interface is
76 unplumbed, then all addresses configured by DHCP on that physical
77 interface will be removed.
78
79
80 In addition to DHCP, dhcpagent also supports BOOTP (IPv4 only). See RFC
81 951, Bootstrap Protocol. Configuration parameters obtained from a BOOTP
82 server are treated identically to those received from a DHCP server,
83 except that the IP address received from a BOOTP server always has an
84 infinite lease.
85
86
87 DHCP also acts as a mechanism to configure other information needed by
88 the client, for example, the domain name and addresses of routers.
89 Aside from the IP address, and for IPv4 alone, the netmask, broadcast
90 address, and default router, the agent does not directly configure the
91 workstation, but instead acts as a database which may be interrogated
92 by other programs, and in particular by dhcpinfo(1).
93
94
95 On clients with a single interface, this is quite straightforward.
96 Clients with multiple interfaces may present difficulties, as it is
97 possible that some information arriving on different interfaces may
98 need to be merged, or may be inconsistent. Furthermore, the
99 configuration of the interfaces is asynchronous, so requests may arrive
100 while some or all of the interfaces are still unconfigured. To handle
101 these cases, one interface may be designated as primary, which makes it
102 the authoritative source for the values of DHCP parameters in the case
103 where no specific interface is requested. See dhcpinfo(1) and
104 ifconfig(1M) for details.
105
106
107 For IPv4, the dhcpagent daemon can be configured to request a
108 particular Fully Qualified Domain Name (FQDN) or host name. See the
109 REQUEST_FQDN or REQUEST_HOSTNAME description in the FILES section. When
110 first configuring a client to request an FQDN or host name, you must
111 perform the following steps as root to ensure that the full DHCP
112 negotiation takes place:
113
114 # pkill dhcpagent
115 # rm /etc/dhcp/interface.dhc
116 # reboot
117
118
119
120
121 All DHCP packets sent by dhcpagent include a vendor class identifier
122 (RFC 2132, option code 60; RFC 3315, option code 16). This identifier
123 is the same as the platform name returned by the uname -i command,
124 except:
125
126 o Any commas in the platform name are changed to periods.
127
128 o If the name does not start with a stock symbol and a comma,
129 it is automatically prefixed with SUNW.
130
131 Messages
132 The dhcpagent daemon writes information and error messages in five
133 categories:
134
135 critical
136
137 Critical messages indicate severe conditions that prevent proper
138 operation.
139
140
141 errors
142
143 Error messages are important, sometimes unrecoverable events due to
144 resource exhaustion and other unexpected failure of system calls;
145 ignoring errors may lead to degraded functionality.
146
147
148 warnings
149
150 Warnings indicate less severe problems, and in most cases, describe
151 unusual or incorrect datagrams received from servers, or requests
152 for service that cannot be provided.
153
154
155 informational
156
157 Informational messages provide key pieces of information that can
158 be useful to debugging a DHCP configuration at a site.
159 Informational messages are generally controlled by the -v option.
160 However, certain critical pieces of information, such as the IP
161 address obtained, are always provided.
162
163
164 debug
165
166 Debugging messages, which may be generated at two different levels
167 of verbosity, are chiefly of benefit to persons having access to
168 source code, but may be useful as well in debugging difficult DHCP
169 configuration problems. Debugging messages are only generated when
170 using the -d option.
171
172
173
174 When dhcpagent is run without the -f option, all messages are sent to
175 the system logger syslog(3C) at the appropriate matching priority and
176 with a facility identifier LOG_DAEMON. When dhcpagent is run with the
177 -f option, all messages are directed to standard error.
178
179 DHCP Events and User-Defined Actions
180 If an executable (binary or script) is placed at /etc/dhcp/eventhook,
181 the dhcpagent daemon will automatically run that program when any of
182 the following events occur:
183
184 BOUND and BOUND6
185
186 These events occur during interface configuration. The event
187 program is invoked when dhcpagent receives the DHCPv4 ACK or DHCPv6
188 Reply message from the DHCP server for the lease request of an
189 address, indicating successful initial configuration of the
190 interface. (See also the INFORM and INFORM6 events, which occur
191 when configuration parameters are obtained without address leases.)
192
193
194 EXTEND and EXTEND6
195
196 These events occur during lease extension. The event program is
197 invoked just after dhcpagent receives the DHCPv4 ACK or DHCPv6
198 Reply from the DHCP server for the DHCPv4 REQUEST (renew) message
199 or the DHCPv6 Renew or Rebind message.
200
201 Note that with DHCPv6, the server might choose to remove some
202 addresses, add new address leases, and ignore (allow to expire)
203 still other addresses in a given Reply message. The EXTEND6 event
204 occurs when a Reply is received that leaves one or more address
205 leases still valid, even if the Reply message does not extend the
206 lease for any address. The event program is invoked just before any
207 addresses are removed, but just after any new addresses are added.
208 Those to be removed will be marked with the IFF_DEPRECATED flag.
209
210
211 EXPIRE and EXPIRE6
212
213 These events occur during lease expiration. For DHCPv4, the event
214 program is invoked just before the leased address is removed from
215 an interface. For DHCPv6, the event program is invoked just before
216 the last remaining leased addresses are removed from the interface.
217
218
219 DROP and DROP6
220
221 These events occur during the period when an interface is dropped.
222 The event program is invoked just before the interface is removed
223 from DHCP control. If the interface has been abandoned due the user
224 unplumbing the interface, then this event will occur after the
225 user's action has taken place. The interface might not be present.
226
227
228 INFORM and INFORM6
229
230 These events occur when an interface acquires new or updated
231 configuration information from a DHCP server by means of the DHCPv4
232 INFORM or the DHCPv6 Information-Request message. These messages
233 are sent using an ifconfig(1M) dhcp inform command or when the
234 DHCPv6 Router Advertisement O (letter 0) bit is set and the M bit
235 is not set. Thus, these events occur when the DHCP client does not
236 obtain an IP address lease from the server, and instead obtains
237 only configuration parameters.
238
239
240 LOSS6
241
242 This event occurs during lease expiration when one or more valid
243 leases still remain. The event program is invoked just before
244 expired addresses are removed. Those being removed will be marked
245 with the IFF_DEPRECATED flag.
246
247 Note that this event is not associated with the receipt of the
248 Reply message, which occurs only when one or more valid leases
249 remain, and occurs only with DHCPv6. If all leases have expired,
250 then the EXPIRE6 event occurs instead.
251
252
253 RELEASE and RELEASE6
254
255 This event occurs during the period when a leased address is
256 released. The event program is invoked just before dhcpagent
257 relinquishes the address on an interface and sends the DHCPv4
258 RELEASE or DHCPv6 Release packet to the DHCP server.
259
260
261
262 The system does not provide a default event program. The file
263 /etc/dhcp/eventhook is expected to be owned by root and have a mode of
264 755.
265
266
267 The event program will be passed two arguments, the interface name and
268 the event name, respectively. For DHCPv6, the interface name is the
269 name of the physical interface.
270
271
272 The event program can use the dhcpinfo(1) utility to fetch additional
273 information about the interface. While the event program is invoked on
274 every event defined above, it can ignore those events in which it is
275 not interested. The event program runs with the same privileges and
276 environment as dhcpagent itself, except that stdin, stdout, and stderr
277 are redirected to /dev/null. Note that this means that the event
278 program runs with root privileges.
279
280
281 If an invocation of the event program does not exit after 55 seconds,
282 it is sent a SIGTERM signal. If does not exit within the next three
283 seconds, it is terminated by a SIGKILL signal.
284
285
286 See EXAMPLES for an example event program.
287
288 OPTIONS
289 The following options are supported:
290
291 -a
292
293 Adopt a configured IPv4 interface. This option is for use with
294 diskless DHCP clients. In the case of diskless DHCP, DHCP has
295 already been performed on the network interface providing the
296 operating system image prior to running dhcpagent. This option
297 instructs the agent to take over control of the interface. It is
298 intended primarily for use in boot scripts.
299
300 The effect of this option depends on whether the interface is being
301 adopted.
302
303 If the interface is being adopted, the following conditions apply:
304
305 dhcpagent uses the client id specified in /chosen:<client_id>, as
306 published by the PROM or as specified on a boot(1M) command line.
307 If this value is not present, the client id is undefined. The DHCP
308 server then determines what to use as a client id. It is an error
309 condition if the interface is an Infiniband interface and the PROM
310 value is not present.
311
312 If the interface is not being adopted:
313
314 dhcpagent uses the value stored in /etc/default/dhcpagent. If this
315 value is not present, the client id is undefined. If the interface
316 is Infiniband and there is no value in /etc/default/dhcpagent, a
317 client id is generated as described by the draft document on DHCP
318 over Infiniband, available at:
319
320 http://www.ietf.org
321
322
323
324 -d n
325
326 Set debug level to n. Two levels of debugging are currently
327 available, 1 and 2; the latter is more verbose.
328
329
330 -f
331
332 Run in the foreground instead of as a daemon process. When this
333 option is used, messages are sent to standard error instead of to
334 syslog(3C).
335
336
337 -v
338
339 Provide verbose output useful for debugging site configuration
340 problems.
341
342
343 EXAMPLES
344 Example 1 Example Event Program
345
346
347 The following script is stored in the file /etc/dhcp/eventhook, owned
348 by root with a mode of 755. It is invoked upon the occurrence of the
349 events listed in the file.
350
351
352 #!/bin/sh
353
354 (
355 echo "Interface name: " $1
356 echo "Event: " $2
357
358 case $2 in
359 "BOUND")
360 echo "Address acquired from server "\
361 `/sbin/dhcpinfo -i $1 ServerID`
362 ;;
363 "BOUND6")
364 echo "Addresses acquired from server " \
365 `/sbin/dhcpinfo -v6 -i $1 ServerID`
366 ;;
367 "EXTEND")
368 echo "Lease extended for " \
369 `/sbin/dhcpinfo -i $1 LeaseTim`" seconds"
370 ;;
371 "EXTEND6")
372 echo "New lease information obtained on $i"
373 ;;
374 "EXPIRE" | "DROP" | "RELEASE")
375 ;;
376
377 esac
378 ) >/var/run/dhcp_eventhook_output 2>&1
379
380
381
382
383 Note the redirection of stdout and stderr to a file.
384
385
386 FILES
387 /etc/dhcp/if.dhc
388 /etc/dhcp/if.dh6
389
390 Contains the configuration for interface. The mere existence of
391 this file does not imply that the configuration is correct, since
392 the lease might have expired. On start-up, dhcpagent confirms the
393 validity of the address using REQUEST (for DHCPv4) or Confirm
394 (DHCPv6).
395
396
397 /etc/dhcp/duid
398 /etc/dhcp/iaid
399
400 Contains persistent storage for system-generated DUID (DHCP Unique
401 Identifier) and interface-specific IAID (Identity Association
402 Identifier) values which are used if no CLIENT_ID is defined (see
403 below). The format of these files is undocumented, and applications
404 should not read from or write to them. Instead, dhcpinfo(1) can be
405 used to query the dhcpagent for ClientID. For DHCPv6 interfaces,
406 the result will contain the DUID. For DHCPv4 interfaces with
407 V4_DEFAULT_IAID_DUID enabled (see below), the result will contain
408 the IAID and DUID.
409
410
411 /etc/default/dhcpagent
412
413 Contains default values for tunable parameters. All values may be
414 qualified with the interface they apply to by prepending the
415 interface name and a period (".") to the interface parameter name.
416 The parameters include: the interface parameter name.
417
418 To configure IPv6 parameters, place the string .v6 between the
419 interface name (if any) and the parameter name. For example, to set
420 the global IPv6 parameter request list, use .v6.PARAM_REQUEST_LIST.
421 To set the CLIENT_ID (DUID) on hme0, use hme0.v6.CLIENT_ID.
422
423 The parameters include:
424
425 VERIFIED_LEASE_ONLY
426
427 Indicates that a RELEASE rather than a DROP should be performed
428 on managed interfaces when the agent terminates. Release causes
429 the client to discard the lease, and the server to make the
430 address available again. Drop causes the client to record the
431 lease in /etc/dhcp/interface.dhc or /etc/dhcp/interface.dh6 for
432 later use. In addition, when the link status changes to up or
433 when the system is resumed after a suspend, the client will
434 verify the lease with the server. If the server is unreachable
435 for verification, then the old lease will be discarded (even if
436 it has time remaining) and a new one obtained.
437
438 Enabling this option is often desirable on mobile systems, such
439 as laptops, to allow the system to recover quickly from moves.
440
441 Default value of this option is no.
442
443
444 OFFER_WAIT
445
446 Indicates how long to wait in seconds between checking for
447 valid OFFERs after sending a DISCOVER. For DHCPv6, sets the
448 time to wait between checking for valid Advertisements after
449 sending a Solicit.
450
451 Default value of this option is 3.
452
453
454 CLIENT_ID
455
456 Indicates the value that should be used to uniquely identify
457 the client to the server. This value can take one of three
458 basic forms:
459
460 decimal,data...
461 0xHHHHH...
462 "string...."
463
464
465 The first form is an RFC 3315 DUID. This is legal for both IPv4
466 DHCP and DHCPv6. For IPv4, an RFC 4361 Client ID is constructed
467 from this value. In this first form, the format of data...
468 depends on the decimal value. The following formats are defined
469 for this first form:
470
471 1,hwtype,time,lla
472
473 Type 1, DUID-LLT. The hwtype value is an integer in the
474 range 0-65535, and indicates the type of hardware. The time
475 value is the number of seconds since midnight, January 1st,
476 2000 UTC, and can be omitted to use the current system
477 time. The lla value is either a colon-separated MAC address
478 or the name of a physical interface. If the name of an
479 interface is used, the hwtype value can be omitted. For
480 example: 1,,,hme0
481
482
483 2,enterprise,hex...
484
485 Type 2, DUID-EN. The enterprise value is an integer in the
486 range 0-4294967295 and represents the SMI Enterprise number
487 for an organization. The hex string is an even-length
488 sequence of hexadecimal digits.
489
490
491 3,hwtype,lla
492
493 Type 3, DUID-LL. This is the same as DUID-LLT (type 1),
494 except that a time stamp is not used.
495
496
497 *,hex
498
499 Any other type value (0 or 4-65535) can be used with an
500 even-length hexadecimal string.
501
502 The second and third forms of CLIENT_ID are legal for IPv4
503 only. These both represent raw Client ID (without RFC 4361), in
504 hex, or NVT ASCII string format. Thus, "Sun" and 0x53756E are
505 equivalent.
506
507
508 V4_DEFAULT_IAID_DUID
509
510 Indicates whether to use, when CLIENT_ID is not defined, a
511 system-managed, RFC 3315-style (i.e., DHCPv6-style) binding
512 identifier as documented in RFC 4361, "Node-specific Client
513 Identifiers for DHCPv4," for IPv4 interfaces which for purposes
514 of backward compatibility do not normally get default binding
515 identifiers.
516
517 An IPv4 interface that is not in an IP network multipathing
518 (IPMP) group, that is not IP over InfiniBand (IPoIB), and that
519 is not a logical interface does not normally get a default
520 binding identifier.
521
522 Default value of this option is no.
523
524
525 PARAM_REQUEST_LIST
526
527 Specifies a list of comma-separated integer values of options
528 for which the client would like values, or symbolic Site or
529 Option option names. Symbolic option names for IPv4 are
530 resolved through /etc/dhcp/inittab. Option names for IPv6 are
531 resolved by means of /etc/dhcp/inittab6.
532
533
534 PARAM_IGNORE_LIST
535
536 Specifies a list of options (constructed in the same manner as
537 PARAM_REQUEST_LIST) that the DHCP client will ignore. Ignored
538 options are treated as though the server did not return the
539 options specified. Ignored options are not visible using
540 dhcpinfo(1) or acted on by the client. This parameter can be
541 used, for example, to disable an unwanted client name or
542 default router.
543
544
545 REQUEST_FQDN
546
547 Indicates the client requests the DHCP server to map the
548 client's leased IPv4 address to the Fully Qualified Domain Name
549 (FQDN) associated with the network interface that performs DHCP
550 on the client and to collaborate with a compatible DNS server
551 to manage A and PTR resource records for the FQDN for the life
552 of the lease.
553
554 The hostname in the FQDN is determined from the following
555 possible configurations:
556
557 1. ipadm(1M): include the -1,--primary flag when creating an
558 address that uses DHCP so that nodename(4) is used as the
559 hostname.
560
561 2. ipadm(1M): include the -h,--reqhost hostname switch when
562 executing the create-addr -T dhcp subcommand, or use the set-
563 addrprop -p reqhost=hostname subcommand for any existing DHCP
564 address.
565
566 3. nwamcfg(1M): set a property, ip-primary=on, for an ncu ip
567 that uses DHCP so that nodename(4) is used as the hostname.
568
569 4. nwamcfg(1M): set a property, ip-reqhost=hostname, for an
570 ncu ip that uses DHCP.
571
572 The hostname value is either a Partially Qualified Domain Name
573 (PQDN) or an FQDN (i.e., a "rooted" domain name ending with a
574 '.' or one inferred to be an FQDN if it contains at least three
575 DNS labels such as srv.example.com). If a PQDN is specified,
576 then an FQDN is constructed if DNS_DOMAINNAME is defined or if
577 ADOPT_DOMAINNAME is set to yes and an eligible domain name (as
578 described below) is available.
579
580 If an FQDN is sent, REQUEST_HOSTNAME processing will not be
581 done, per RFC 4702 (3.1): "clients that send the Client FQDN
582 option in their messages MUST NOT also send the Host Name."
583
584 Default value of this option is yes.
585
586
587 DNS_DOMAINNAME
588
589 Indicates the value that should be appended to a PQDN specified
590 by the -h,--reqhost option of ipadm(1M), by the ncu ip-reqhost
591 property of nwamcfg(1M), or by nodename(4) to construct an FQDN
592 for REQUEST_FQDN processing. If the hostname value is already
593 an FQDN, then the value of this option is not used.
594
595
596 ADOPT_DOMAINNAME
597
598 Indicates that a domain name returned by the DHCP server or the
599 domain from resolv.conf(4) should be adopted if needed to
600 construct an FQDN from a PQDN specified by the -h,--reqhost
601 option of ipadm(1M), by the ncu ip-reqhost property of
602 nwamcfg(1M), or by nodename(4). If the hostname value is
603 already an FQDN, then the value of this option is not
604 applicable. The eligible DHCP option for domain name is DHCPv4
605 DNSdmain.
606
607 Default value of this option is no.
608
609
610 REQUEST_HOSTNAME
611
612 Indicates the client requests the DHCP server to map the
613 client's leased IPv4 address to the host name associated with
614 the network interface that performs DHCP on the client. The
615 host name must be specified as documented for a PQDN in
616 REQUEST_FQDN above or specified in the /etc/hostname.interface
617 file for the relevant interface on a line of the form
618
619 inet hostname
620
621
622 where hostname is the host name requested.
623
624 This option works with DHCPv4 only.
625
626 Default value of this option is yes.
627
628
629
630 /etc/dhcp/eventhook
631
632 Location of a DHCP event program.
633
634
635 ATTRIBUTES
636 See attributes(5) for descriptions of the following attributes:
637
638
639
640
641 +--------------------+-----------------+
642 | ATTRIBUTE TYPE | ATTRIBUTE VALUE |
643 +--------------------+-----------------+
644 |Interface Stability | Committed |
645 +--------------------+-----------------+
646
647 SEE ALSO
648 dhcpinfo(1), ifconfig(1M), init(1M), in.mpathd(1M), in.ndpd(1M),
649 ipadm(1M), nwamcfg(1M), syslog(3C), nodename(4), resolv.conf(4),
650 attributes(5), dhcp(5)
651
652
653
654
655 Croft, B. and Gilmore, J. RFC 951, Bootstrap Protocol (BOOTP), Network
656 Working Group, September 1985.
657
658
659 Droms, R. RFC 2131, Dynamic Host Configuration Protocol, Network
660 Working Group, March 1997.
661
662
663 Lemon, T. and B. Sommerfeld. RFC 4361, Node-specific Client Identifiers
664 for Dynamic Host Configuration Protocol Version Four (DHCPv4). Nominum
665 and Sun Microsystems. February 2006.
666
667
668 Droms, R. RFC 3315, Dynamic Host Configuration Protocol for IPv6
669 (DHCPv6). Cisco Systems. July 2003.
670
671 NOTES
672 The dhcpagent daemon can be used on IPv4 logical interfaces, just as
673 with physical interfaces. When used on a logical interface, the daemon
674 automatically constructs a Client ID value based on the DUID and IAID
675 values, according to RFC 4361. The /etc/default/dhcpagent CLIENT_ID
676 value, if any, overrides this automatic identifier.
677
678
679 As with physical IPv4 interfaces, the /etc/hostname.hme0:1 and
680 /etc/dhcp.hme0:1 files must also be created in order for hme0:1 to be
681 automatically plumbed and configured at boot. In addition, unlike
682 physical IPv4 interfaces, dhcpagent does not add or remove default
683 routes associated with logical interfaces.
684
685
686 DHCP can be performed on IPMP IP interfaces to acquire and maintain
687 IPMP data addresses. Because an IPMP IP interface has no hardware
688 address, the daemon automatically constructs a Client ID using the same
689 approach described above for IPv4 logical interfaces. In addition, the
690 lack of a hardware address means the daemon must set the "broadcast"
691 flag in all DISCOVER and REQUEST messages on IPMP IP interfaces. Some
692 DHCP servers may refuse such requests.
693
694
695 DHCP can be performed on IP interfaces that are part of an IPMP group
696 (to acquire and maintain test addresses). The daemon will automatically
697 set the NOFAILOVER and DEPRECATED flags on each test address.
698 Additionally, the daemon will not add or remove default routes in this
699 case. Note that the actual DHCP packet exchange may be performed over
700 any active IP interface in the IPMP group. It is strongly recommended
701 that test addresses have infinite leases. Otherwise, an extended
702 network outage detectable only by probes may cause test address leases
703 to expire, causing in.mpathd(1M) to revert to link-based failure
704 detection and trigger an erroneous repair.
705
706
707 With DHCPv6, the link-local interface must be configured using
708 /etc/hostname6.hme0 in order for DHCPv6 to run on hme0 at boot time.
709 The logical interfaces for each address are plumbed by dhcpagent
710 automatically.
711
712
713
714 February 13, 2020 DHCPAGENT(1M)