| blob | 5357cb56d8e402a1b6f1cacf4af10751c8890360 |
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30 .\" @(#)ifconfig.8 8.4 (Berkeley) 6/1/94
31 .\"
32 .Dd October 12, 2014
33 .Dt IFCONFIG 8
34 .Os
35 .Sh NAME
36 .Nm ifconfig
37 .Nd configure network interface parameters
38 .Sh SYNOPSIS
39 .Nm
40 .Op Fl N
41 .Ar interface address_family
42 .Oo
43 .Ar address
44 .Op Ar dest_address
45 .Oc
46 .Op Ar parameters
47 .Nm
48 .Op Fl hLmNvz
49 .Ar interface
50 .Op Ar protocol_family
51 .Nm
52 .Fl a
53 .Op Fl bdhLNmsuvz
54 .Op Ar protocol_family
55 .Nm
56 .Fl l
57 .Op Fl bdsu
58 .Nm
59 .Fl s
60 .Ar interface
61 .Nm
62 .Fl w
63 .Ar secs
64 .Nm
65 .Fl C
66 .Sh DESCRIPTION
67 .Nm
68 is used to assign an address
69 to a network interface and/or configure
70 network interface parameters.
71 .Nm
72 must be used at boot time to define the network address
73 of each interface present on a machine; it may also be used at
74 a later time to redefine an interface's address
75 or other operating parameters.
76 .Pp
77 Available operands for
78 .Nm :
79 .Bl -tag -width Ds
80 .It Ar address
81 For the
82 .Tn DARPA-Internet
83 family,
84 the address is either a host name present in the host name data
85 base,
86 .Xr hosts 5 ,
87 or a
88 .Tn DARPA
89 Internet address expressed in the Internet standard
90 .Dq dot notation .
91 For the Xerox Network Systems(tm) family,
92 addresses are
93 .Ar net:a.b.c.d.e.f ,
94 where
95 .Ar net
96 is the assigned network number
97 .Pq in decimal ,
98 and each of the six bytes of the host number,
99 .Ar a
100 through
101 .Ar f ,
102 are specified in hexadecimal.
103 The host number may be omitted on Ethernet interfaces,
104 which use the hardware physical address,
105 and on interfaces other than the first.
106 For the
107 .Tn ISO
108 family, addresses are specified as a long hexadecimal string,
109 as in the Xerox family.
110 However, two consecutive dots imply a zero
111 byte, and the dots are optional, if the user wishes to
112 .Pq carefully
113 count out long strings of digits in network byte order.
114 .It Ar address_family
115 Specifies the
116 .Ar address_family
117 which affects interpretation of the remaining parameters.
118 Since an interface can receive transmissions in differing protocols
119 with different naming schemes, specifying the address family is recommended.
120 The address or protocol families currently
121 supported are
122 .Dq inet ,
123 .Dq inet6 ,
124 .Dq atalk ,
125 .Dq iso ,
126 and
127 .Dq link .
128 .It Ar interface
129 The
130 .Ar interface
131 parameter is a string of the form
132 .Dq name unit ,
133 for example,
134 .Dq en0
135 .El
136 .Pp
137 The following parameters may be set with
138 .Nm :
139 .Bl -tag -width dest_addressxx
140 .It Cm active
141 This keyword applies when
142 .Nm
143 adds or modifies any link-layer address.
144 It indicates that
145 .Nm
146 should
147 .Dq activate
148 the address.
149 Activation makes an address the default source for transmissions
150 on the interface.
151 You may not delete the active address from an interface.
152 You must activate some other address, first.
153 .It Cm advbase Ar n
154 If the driver is a
155 .Xr carp 4
156 pseudo-device, set the base advertisement interval to
157 .Ar n
158 seconds.
159 This ia an 8-bit number; the default value is 1 second.
160 .It Cm advskew Ar n
161 If the driver is a
162 .Xr carp 4
163 pseudo-device, skew the advertisement interval by
164 .Ar n .
165 This is an 8-bit number; the default value is 0.
166 .Pp
167 Taken together the
168 .Cm advbase
169 indicate how frequently, in seconds, the host will advertise the fact that it
170 considers itself the master of the virtual host.
171 The formula is
172 .Cm advbase
173 +
174 .Pf ( Cm advskew
175 / 256).
176 If the master does not advertise within three times this interval, this host
177 will begin advertising as master.
178 .It Cm alias
179 Establish an additional network address for this interface.
180 This is sometimes useful when changing network numbers, and
181 one wishes to accept packets addressed to the old interface.
182 .It Fl alias
183 Remove the specified network address alias.
184 .It Cm arp
185 Enable the use of the Address Resolution Protocol in mapping
186 between network level addresses and link level addresses
187 .Pq default .
188 This is currently implemented for mapping between
189 .Tn DARPA
190 Internet
191 addresses and Ethernet addresses.
192 .It Fl arp
193 Disable the use of the Address Resolution Protocol.
194 .It Cm anycast
195 .Pq inet6 only
196 Set the IPv6 anycast address bit.
197 .It Fl anycast
198 .Pq inet6 only
199 Clear the IPv6 anycast address bit.
200 .It Cm broadcast Ar mask
201 .Pq Inet only
202 Specify the address to use to represent broadcasts to the
203 network.
204 The default broadcast address is the address with a host part of all 1's.
205 .It Cm carpdev Ar iface
206 If the driver is a
207 .Xr carp 4
208 pseudo-device, attach it to
209 .Ar iface .
210 If not specified, the kernel will attempt to select an interface with
211 a subnet matching that of the carp interface.
212 .It Cm debug
213 Enable driver dependent debugging code; usually, this turns on
214 extra console error logging.
215 .It Fl debug
216 Disable driver dependent debugging code.
217 .It Cm delete
218 Remove the network address specified.
219 This would be used if you incorrectly specified an alias, or it
220 was no longer needed.
221 If you have incorrectly set an NS address having the side effect
222 of specifying the host portion, removing all NS addresses will
223 allow you to respecify the host portion.
224 .Cm delete
225 does not work for IPv6 addresses.
226 Use
227 .Fl alias
228 with explicit IPv6 address instead.
229 .It Ar dest_address
230 Specify the address of the correspondent on the other end
231 of a point to point link.
232 .It Cm down
233 Mark an interface ``down''.
234 When an interface is
235 marked ``down'', the system will not attempt to
236 transmit messages through that interface.
237 If possible, the interface will be reset to disable reception as well.
238 This action does not automatically disable routes using the interface.
239 .It Cm ipdst
240 This is used to specify an Internet host who is willing to receive
241 ip packets encapsulating NS packets bound for a remote network.
242 An apparent point to point link is constructed, and
243 the address specified will be taken as the NS address and network
244 of the destination.
245 IP encapsulation of
246 .Tn CLNP
247 packets is done differently.
248 .It Cm media Ar type
249 Set the media type of the interface to
250 .Ar type .
251 Some interfaces support the mutually exclusive use of one of several
252 different physical media connectors.
253 For example, a 10Mb/s Ethernet
254 interface might support the use of either
255 .Tn AUI
256 or twisted pair connectors.
257 Setting the media type to
258 .Dq 10base5
259 or
260 .Dq AUI
261 would change the currently active connector to the AUI port.
262 Setting it to
263 .Dq 10baseT
264 or
265 .Dq UTP
266 would activate twisted pair.
267 Refer to the interfaces' driver
268 specific man page for a complete list of the available types
269 and the
270 .Xr ifmedia 4
271 manual page for a list of media types.
272 See the
273 .Fl m
274 flag below.
275 .It Cm mediaopt Ar opts
276 Set the specified media options on the interface.
277 .Ar opts
278 is a comma delimited list of options to apply to the interface.
279 Refer to the interfaces' driver specific man page for a complete
280 list of available options.
281 Also see the
282 .Xr ifmedia 4
283 manual page for a list of media options.
284 .It Fl mediaopt Ar opts
285 Disable the specified media options on the interface.
286 .It Cm mode Ar mode
287 If the driver supports the media selection system, set the specified
288 operating mode on the interface to
289 .Ar mode .
290 For IEEE 802.11 wireless interfaces that support multiple operating modes
291 this directive is used to select between 802.11a
292 .Pq Dq 11a ,
293 802.11b
294 .Pq Dq 11b ,
295 and 802.11g
296 .Pq Dq 11g
297 operating modes.
298 .It Cm instance Ar minst
299 Set the media instance to
300 .Ar minst .
301 This is useful for devices which have multiple physical layer interfaces
302 .Pq PHYs .
303 Setting the instance on such devices may not be strictly required
304 by the network interface driver as the driver may take care of this
305 automatically; see the driver's manual page for more information.
306 .It Cm metric Ar n
307 Set the routing metric of the interface to
308 .Ar n ,
309 default 0.
310 The routing metric is used by the routing protocol
311 .Pq Xr routed 8 .
312 Higher metrics have the effect of making a route
313 less favorable; metrics are counted as addition hops
314 to the destination network or host.
315 .It Cm mtu Ar n
316 Set the maximum transmission unit of the interface to
317 .Ar n .
318 Most interfaces don't support this option.
319 .It Cm netmask Ar mask
320 .Pq inet, inet6, and ISO
321 Specify how much of the address to reserve for subdividing
322 networks into sub-networks.
323 The mask includes the network part of the local address
324 and the subnet part, which is taken from the host field of the address.
325 The mask can be specified as a single hexadecimal number
326 with a leading 0x, with a dot-notation Internet address,
327 or with a pseudo-network name listed in the network table
328 .Xr networks 5 .
329 The mask contains 1's for the bit positions in the 32-bit address
330 which are to be used for the network and subnet parts,
331 and 0's for the host part.
332 The mask should contain at least the standard network portion,
333 and the subnet field should be contiguous with the network
334 portion.
335 .Pp
336 For INET and INET6 addresses, the netmask can also be given with
337 slash-notation after the address
338 .Pq e.g 192.168.17.3/24 .
339 .\" see
340 .\" Xr eon 5 .
341 .It Cm nsellength Ar n
342 .Pf ( Tn ISO
343 only)
344 This specifies a trailing number of bytes for a received
345 .Tn NSAP
346 used for local identification, the remaining leading part of which is
347 taken to be the
348 .Tn NET
349 .Pq Network Entity Title .
350 The default value is 1, which is conformant to US
351 .Tn GOSIP .
352 When an ISO address is set in an ifconfig command,
353 it is really the
354 .Tn NSAP
355 which is being specified.
356 For example, in
357 .Tn US GOSIP ,
358 20 hex digits should be
359 specified in the
360 .Tn ISO NSAP
361 to be assigned to the interface.
362 There is some evidence that a number different from 1 may be useful
363 for
364 .Tn AFI
365 37 type addresses.
366 .It Cm state Ar state
367 Explicitly force the
368 .Xr carp 4
369 pseudo-device to enter this state.
370 Valid states are
371 .Ar init ,
372 .Ar backup ,
373 and
374 .Ar master .
375 .It Cm frag Ar threshold
376 .Pq IEEE 802.11 devices only
377 Configure the fragmentation threshold for IEEE 802.11-based wireless
378 network interfaces.
379 .It Cm rts Ar threshold
380 .Pq IEEE 802.11 devices only
381 Configure the RTS/CTS threshold for IEEE 802.11-based wireless
382 network interfaces.
383 This controls the number of bytes used for the RTS/CTS handshake boundary.
384 The
385 .Ar threshold
386 can be any value between 0 and 2347.
387 The default is 2347, which indicates the RTS/CTS mechanism should not be used.
388 .It Cm ssid Ar id
389 .Pq IEEE 802.11 devices only
390 Configure the Service Set Identifier (a.k.a. the network name)
391 for IEEE 802.11-based wireless network interfaces.
392 The
393 .Ar id
394 can either be any text string up to 32 characters in length,
395 or a series of up to 64 hexadecimal digits preceded by
396 .Dq 0x .
397 Setting
398 .Ar id
399 to the empty string allows the interface to connect to any available
400 access point.
401 .It Cm nwid Ar id
402 Synonym for
403 .Dq ssid .
404 .It Cm hidessid
405 .Pq IEEE 802.11 devices only
406 When operating as an access point, do not broadcast the SSID
407 in beacon frames or respond to probe request frames unless
408 they are directed to the ap (i.e., they include the ap's SSID).
409 By default, the SSID is included in beacon frames and
410 undirected probe request frames are answered.
411 .It Fl hidessid
412 .Pq IEEE 802.11 devices only
413 When operating as an access point, broadcast the SSID
414 in beacon frames and answer and respond to undirected probe
415 request frames (default).
416 .It Cm nwkey Ar key
417 .Pq IEEE 802.11 devices only
418 Enable WEP encryption for IEEE 802.11-based wireless network interfaces
419 with the
420 .Ar key .
421 The
422 .Ar key
423 can either be a string, a series of hexadecimal digits preceded by
424 .Dq 0x ,
425 or a set of keys in the form
426 .Ar n:k1,k2,k3,k4 ,
427 where
428 .Ar n
429 specifies which of keys will be used for all transmitted packets,
430 and four keys,
431 .Ar k1
432 through
433 .Ar k4 ,
434 are configured as WEP keys.
435 Note that the order must be match within same network if multiple keys
436 are used.
437 For IEEE 802.11 wireless network, the length of each key is restricted to
438 40 bits, i.e. 5-character string or 10 hexadecimal digits,
439 while the WaveLAN/IEEE Gold cards accept the 104 bits
440 .Pq 13 characters
441 key.
442 .It Cm nwkey Cm persist
443 .Pq IEEE 802.11 devices only
444 Enable WEP encryption for IEEE 802.11-based wireless network interfaces
445 with the persistent key written in the network card.
446 .It Cm nwkey Cm persist: Ns Ar key
447 .Pq IEEE 802.11 devices only
448 Write the
449 .Ar key
450 to the persistent memory of the network card, and
451 enable WEP encryption for IEEE 802.11-based wireless network interfaces
452 with the
453 .Ar key .
454 .It Fl nwkey
455 .Pq IEEE 802.11 devices only
456 Disable WEP encryption for IEEE 802.11-based wireless network interfaces.
457 .It Cm apbridge
458 .Pq IEEE 802.11 devices only
459 When operating as an access point, pass packets between
460 wireless clients directly (default).
461 .It Fl apbridge
462 .Pq IEEE 802.11 devices only
463 When operating as an access point, pass packets through
464 the system so that they can be forwared using some other mechanism.
465 Disabling the internal bridging is useful when traffic
466 is to be processed with packet filtering.
467 .It Cm pass Ar passphrase
468 If the driver is a
469 .Xr carp 4
470 pseudo-device, set the authentication key to
471 .Ar passphrase .
472 There is no passphrase by default
473 .It Cm powersave
474 .Pq IEEE 802.11 devices only
475 Enable 802.11 power saving mode.
476 .It Fl powersave
477 .Pq IEEE 802.11 devices only
478 Disable 802.11 power saving mode.
479 .It Cm powersavesleep Ar duration
480 .Pq IEEE 802.11 devices only
481 Set the receiver sleep duration in milliseconds for 802.11 power saving mode.
482 .It Cm bssid Ar bssid
483 .Pq IEEE 802.11 devices only
484 Set the desired BSSID for IEEE 802.11-based wireless network interfaces.
485 .It Fl bssid
486 .Pq IEEE 802.11 devices only
487 Unset the desired BSSID for IEEE 802.11-based wireless network interfaces.
488 The interface will automatically select a BSSID in this mode, which is
489 the default.
490 .It Cm chan Ar chan
491 .Pq IEEE 802.11 devices only
492 Select the channel
493 .Pq radio frequency
494 to be used for IEEE 802.11-based wireless network interfaces.
495 .It Fl chan
496 .Pq IEEE 802.11 devices only
497 Unset the desired channel to be used
498 for IEEE 802.11-based wireless network interfaces.
499 It doesn't affect the channel to be created for IBSS or hostap mode.
500 .It Cm list scan
501 .Pq IEEE 802.11 devices only
502 Display the access points and/or ad-hoc neighbors
503 located in the vicinity.
504 The
505 .Fl v
506 flag may be used to display long SSIDs.
507 .Fl v
508 also causes received information elements to be displayed symbolically.
509 The interface must be up before any scanning operation.
510 Only the super-user can use this command.
511 .It Cm tunnel Ar src_addr Ns Oo Ar ,src_port Oc Ar dest_addr Ns Oo Ar ,dest_port
512 .Oc
513 .Pq IP tunnel devices only
514 Configure the physical source and destination address for IP tunnel
515 interfaces, including
516 .Xr gif 4 .
517 The arguments
518 .Ar src_addr
519 and
520 .Ar dest_addr
521 are interpreted as the outer source/destination for the encapsulating
522 IPv4/IPv6 header.
523 .Pp
524 On a
525 .Xr gre 4
526 interface in UDP mode, the arguments
527 .Ar src_port
528 and
529 .Ar dest_port
530 are interpreted as the outer source/destination port for the encapsulating
531 UDP header.
532 .It Cm deletetunnel
533 Unconfigure the physical source and destination address for IP tunnel
534 interfaces previously configured with
535 .Cm tunnel .
536 .It Cm create
537 Create the specified network pseudo-device.
538 .It Cm destroy
539 Destroy the specified network pseudo-device.
540 .It Cm pltime Ar n
541 .Pq inet6 only
542 Set preferred lifetime for the address.
543 .It Cm prefixlen Ar n
544 .Pq inet and inet6 only
545 Effect is similar to
546 .Cm netmask .
547 but you can specify by prefix length by digits.
548 .It Cm deprecated
549 .Pq inet6 only
550 Set the IPv6 deprecated address bit.
551 .It Fl deprecated
552 .Pq inet6 only
553 Clear the IPv6 deprecated address bit.
554 .It Cm eui64
555 .Pq inet6 only
556 Fill interface index
557 .Pq lowermost 64bit of an IPv6 address
558 automatically.
559 .It Cm link[0-2]
560 Enable special processing of the link level of the interface.
561 These three options are interface specific in actual effect, however,
562 they are in general used to select special modes of operation.
563 An example
564 of this is to enable SLIP compression, or to select the connector type
565 for some Ethernet cards.
566 Refer to the man page for the specific driver
567 for more information.
568 .It Fl link[0-2]
569 Disable special processing at the link level with the specified interface.
570 .It Cm linkstr
571 Set a link-level string parameter for the interface.
572 This functionality varies from interface to interface.
573 Refer to the man page for the specific driver
574 for more information.
575 .It Fl linkstr
576 Remove an interface link-level string parameter.
577 .It Cm up
578 Mark an interface ``up''.
579 This may be used to enable an interface after an ``ifconfig down.''
580 It happens automatically when setting the first address on an interface.
581 If the interface was reset when previously marked down,
582 the hardware will be re-initialized.
583 .It Cm vhid Ar n
584 If the driver is a
585 .Xr carp 4
586 pseudo-device, set the virtual host ID to
587 .Ar n .
588 Acceptable values are 1 to 255.
589 .It Cm vlan Ar vid
590 If the interface is a
591 .Xr vlan 4
592 pseudo-interface, set the VLAN identifier to
593 .Ar vid .
594 These are the first 12 bits (0-4095) from a 16-bit integer used
595 to create an 802.1Q VLAN header for packets sent from the
596 .Xr vlan 4
597 interface.
598 Note that
599 .Cm vlan
600 and
601 .Cm vlanif
602 must be set at the same time.
603 .It Cm vlanif Ar iface
604 If the interface is a
605 .Xr vlan 4
606 pseudo-interface, associate the physical interface
607 .Ar iface
608 with it.
609 Packets transmitted through the
610 .Xr vlan 4
611 interface will be diverted to the specified physical interface
612 .Ar iface
613 with 802.1Q VLAN encapsulation.
614 Packets with 802.1Q encapsulation received
615 by the physical interface with the correct VLAN tag will be diverted to the
616 associated
617 .Xr vlan 4
618 pseudo-interface.
619 The VLAN interface is assigned a copy of the physical
620 interface's flags and
621 .Tn Ethernet
622 address.
623 If the
624 .Xr vlan 4
625 interface already has a physical interface associated with it, this command
626 will fail.
627 To change the association to another physical interface, the
628 existing association must be cleared first.
629 Note that
630 .Cm vlanif
631 and
632 .Cm vlan
633 must be set at the same time.
634 .It Cm -vlanif Ar iface
635 Dissociate
636 .Ar iface
637 from the
638 .Xr vlan 4
639 interface.
640 .It Cm agrport Ar iface
641 Add
642 .Ar iface
643 to the
644 .Xr agr 4
645 interface.
646 .It Cm -agrport Ar iface
647 Remove
648 .Ar iface
649 from the
650 .Xr agr 4
651 interface.
652 .It Cm vltime Ar n
653 .Pq inet6 only
654 Set valid lifetime for the address.
655 .It Cm ip4csum
656 Shorthand of
657 .Dq ip4csum-tx ip4csum-rx
658 .It Cm -ip4csum
659 Shorthand of
660 .Dq -ip4csum-tx -ip4csum-rx
661 .It Cm tcp4csum
662 Shorthand of
663 .Dq tcp4csum-tx tcp4csum-rx
664 .It Cm -tcp4csum
665 Shorthand of
666 .Dq -tcp4csum-tx -tcp4csum-rx
667 .It Cm udp4csum
668 Shorthand of
669 .Dq udp4csum-tx udp4csum-rx
670 .It Cm -udp4csum
671 Shorthand of
672 .Dq -udp4csum-tx -udp4csum-rx
673 .It Cm tcp6csum
674 Shorthand of
675 .Dq tcp6csum-tx tcp6csum-rx
676 .It Cm -tcp6csum
677 Shorthand of
678 .Dq -tcp6csum-tx -tcp6csum-rx
679 .It Cm udp6csum
680 Shorthand of
681 .Dq udp6csum-tx udp6csum-rx
682 .It Cm -udp6csum
683 Shorthand of
684 .Dq -udp6csum-tx -udp6csum-rx
685 .It Cm ip4csum-tx
686 Enable hardware-assisted IPv4 header checksums for the out-bound direction.
687 .It Cm -ip4csum-tx
688 Disable hardware-assisted IPv4 header checksums for the out-bound direction.
689 .It Cm ip4csum-rx
690 Enable hardware-assisted IPv4 header checksums for the in-bound direction.
691 .It Cm -ip4csum-rx
692 Disable hardware-assisted IPv4 header checksums for the in-bound direction.
693 .It Cm tcp4csum-tx
694 Enable hardware-assisted TCP/IPv4 checksums for the out-bound direction.
695 .It Cm -tcp4csum-tx
696 Disable hardware-assisted TCP/IPv4 checksums for the out-bound direction.
697 .It Cm tcp4csum-rx
698 Enable hardware-assisted TCP/IPv4 checksums for the in-bound direction.
699 .It Cm -tcp4csum-rx
700 Disable hardware-assisted TCP/IPv4 checksums for the in-bound direction.
701 .It Cm udp4csum-tx
702 Enable hardware-assisted UDP/IPv4 checksums for the out-bound direction.
703 .It Cm -udp4csum-tx
704 Disable hardware-assisted UDP/IPv4 checksums for the out-bound direction.
705 .It Cm udp4csum-rx
706 Enable hardware-assisted UDP/IPv4 checksums for the in-bound direction.
707 .It Cm -udp4csum-rx
708 Disable hardware-assisted UDP/IPv4 checksums for the in-bound direction.
709 .It Cm tcp6csum-tx
710 Enable hardware-assisted TCP/IPv6 checksums for the out-bound direction.
711 .It Cm -tcp6csum-tx
712 Disable hardware-assisted TCP/IPv6 checksums for the out-bound direction.
713 .It Cm tcp6csum-rx
714 Enable hardware-assisted TCP/IPv6 checksums for the in-bound direction.
715 .It Cm -tcp6csum-rx
716 Disable hardware-assisted TCP/IPv6 checksums for the in-bound direction.
717 .It Cm udp6csum-tx
718 Enable hardware-assisted UDP/IPv6 checksums for the out-bound direction.
719 .It Cm -udp6csum-tx
720 Disable hardware-assisted UDP/IPv6 checksums for the out-bound direction.
721 .It Cm udp6csum-rx
722 Enable hardware-assisted UDP/IPv6 checksums for the in-bound direction.
723 .It Cm -udp6csum-rx
724 Disable hardware-assisted UDP/IPv6 checksums for the in-bound direction.
725 .It Cm tso4
726 Enable hardware-assisted TCP/IPv4 segmentation on interfaces that
727 support it.
728 .It Cm -tso4
729 Disable hardware-assisted TCP/IPv4 segmentation on interfaces that
730 support it.
731 .It Cm tso6
732 Enable hardware-assisted TCP/IPv6 segmentation on interfaces that
733 support it.
734 .It Cm -tso6
735 Disable hardware-assisted TCP/IPv6 segmentation on interfaces that
736 support it.
737 .It Cm maxupd Ar n
738 If the driver is a
739 .Xr pfsync 4
740 pseudo-device, indicate the maximum number
741 of updates for a single state which can be collapsed into one.
742 This is an 8-bit number; the default value is 128.
743 .It Cm syncdev Ar iface
744 If the driver is a
745 .Xr pfsync 4
746 pseudo-device, use the specified interface
747 to send and receive pfsync state synchronisation messages.
748 .It Fl syncdev
749 If the driver is a
750 .Xr pfsync 4
751 pseudo-device, stop sending pfsync state
752 synchronisation messages over the network.
753 .It Cm syncpeer Ar peer_address
754 If the driver is a
755 .Xr pfsync 4
756 pseudo-device, make the pfsync link point-to-point rather than using
757 multicast to broadcast the state synchronisation messages.
758 The peer_address is the IP address of the other host taking part in
759 the pfsync cluster.
760 With this option,
761 .Xr pfsync 4
762 traffic can be protected using
763 .Xr ipsec 4 .
764 .It Fl syncpeer
765 If the driver is a
766 .Xr pfsync 4
767 pseudo-device, broadcast the packets using multicast.
768 .El
769 .Pp
770 .Nm
771 displays the current configuration for a network interface
772 when no optional parameters are supplied.
773 If a protocol family is specified,
774 .Nm
775 will report only the details specific to that protocol
776 family.
777 .Pp
778 If the
779 .Fl s
780 flag is passed before an interface name,
781 .Nm
782 will attempt to query the interface for its media status.
783 If the
784 interface supports reporting media status, and it reports that it does
785 not appear to be connected to a network,
786 .Nm
787 will exit with status of 1
788 .Pq false ;
789 otherwise, it will exit with a
790 zero
791 .Pq true
792 exit status.
793 Not all interface drivers support media
794 status reporting.
795 .Pp
796 If the
797 .Fl m
798 flag is passed before an interface name,
799 .Nm
800 will display all of the supported media for the specified interface.
801 If the
802 .Fl L
803 flag is supplied, address lifetime is displayed for IPv6 addresses,
804 as time offset string.
805 .Pp
806 Optionally, the
807 .Fl a
808 flag may be used instead of an interface name.
809 This flag instructs
810 .Nm
811 to display information about all interfaces in the system.
812 This is also the default behaviour when no arguments are given to
813 .Nm
814 on the command line.
815 When
816 .Fl a
817 is used, the output can be modified by adding more flags:
818 .Fl d
819 limits this to interfaces that are down,
820 .Fl u
821 limits this to interfaces that are up,
822 .Fl b
823 limits this to broadcast interfaces, and
824 .Fl s
825 omits interfaces which appear not to be connected to a network.
826 .Pp
827 The
828 .Fl l
829 flag may be used to list all available interfaces on the system, with
830 no other additional information.
831 Use of this flag is mutually exclusive
832 with all other flags and commands, except for
833 .Fl d
834 .Pq only list interfaces that are down ,
835 .Fl u
836 .Pq only list interfaces that are up ,
837 .Fl s
838 .Pq only list interfaces that may be connected ,
839 .Fl b
840 .Pq only list broadcast interfaces .
841 .Pp
842 The
843 .Fl C
844 flag may be used to list all of the interface cloners available on
845 the system, with no additional information.
846 Use of this flag is
847 mutually exclusive with all other flags and commands.
848 .Pp
849 The
850 .Fl v
851 flag prints statistics on packets sent and received on the given
852 interface.
853 If
854 .Fl h
855 is used in conjunction with
856 .Fl v ,
857 the byte statistics will be printed in "human-readable" format.
858 The
859 .Fl z
860 flag is identical to the
861 .Fl v
862 flag except that it zeros the interface input and output statistics
863 after printing them.
864 .Pp
865 The
866 .Fl w
867 flag may be used to wait
868 .Ar seconds
869 seconds for the
870 .Cm tentative
871 flag to be removed from all addresses.
872 0 seconds means to wait indefinitely until all addresses no longer have the
873 .Cm tentative
874 flag.
875 .Pp
876 The
877 .Fl N
878 flag is just the opposite of the
879 .Fl n
880 flag in
881 .Xr netstat 1
882 or in
883 .Xr route 8 :
884 it tells
885 .Nm
886 to try to resolve numbers to hostnames or to service names.
887 The default
888 .Nm
889 behavior is to print numbers instead of names.
890 .Pp
891 Only the super-user may modify the configuration of a network interface.
892 .Sh EXAMPLES
893 Add a link-layer (MAC) address to an Ethernet:
894 .Pp
895 .Ic ifconfig sip0 link 00:11:22:33:44:55
896 .Pp
897 Add and activate a link-layer (MAC) address:
898 .Pp
899 .Ic ifconfig sip0 link 00:11:22:33:44:55 active
900 .Sh DIAGNOSTICS
901 Messages indicating the specified interface does not exist, the
902 requested address is unknown, or the user is not privileged and
903 tried to alter an interface's configuration.
904 .Sh SEE ALSO
905 .Xr netstat 1 ,
906 .Xr agr 4 ,
907 .Xr carp 4 ,
908 .Xr ifmedia 4 ,
909 .Xr netintro 4 ,
910 .Xr pfsync 4 ,
911 .Xr vlan 4 ,
912 .Xr ifconfig.if 5 ,
913 .\" .Xr eon 5 ,
914 .Xr rc 8 ,
915 .Xr routed 8
916 .Sh HISTORY
917 The
918 .Nm
919 command appeared in
920 .Bx 4.2 .