1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
|
.\" Copyright (c) 1983, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\" must display the following acknowledgment:
.\" This product includes software developed by the University of
.\" California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\" may be used to endorse or promote products derived from this software
.\" without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" From: @(#)ifconfig.8 8.3 (Berkeley) 1/5/94
.\" $FreeBSD$
.\"
.Dd July 2, 2001
.Dt IFCONFIG 8
.Os
.Sh NAME
.Nm ifconfig
.Nd configure network interface parameters
.Sh SYNOPSIS
.Nm
.Op Fl L
.Op Fl m
.Ar interface
.Op Cm create
.Op Ar address_family
.Oo
.Ar address
.Op Ar dest_address
.Oc
.Op Ar parameters
.Nm
.Ar interface
.Cm destroy
.Nm
.Fl a
.Op Fl L
.Op Fl d
.Op Fl m
.Op Fl u
.Op Ar address_family
.Nm
.Fl l
.Op Fl d
.Op Fl u
.Op Ar address_family
.Nm
.Op Fl L
.Op Fl d
.Op Fl m
.Op Fl u
.Op Fl C
.Sh DESCRIPTION
.Nm Ifconfig
is used to assign an address
to a network interface and/or configure
network interface parameters.
.Nm Ifconfig
must be used at boot time to define the network address
of each interface present on a machine; it may also be used at
a later time to redefine an interface's address
or other operating parameters.
.Pp
The following options are available:
.Bl -tag -width indent
.It Ar address
For the
.Tn DARPA Ns -Internet
family,
the address is either a host name present in the host name data
base,
.Xr hosts 5 ,
or a
.Tn DARPA
Internet address expressed in the Internet standard
.Dq dot notation .
.Pp
It is also possible to use the CIDR notation (also known as the
slash notation) to include the netmask.
That is, one can specify an address like
.Li 192.168.0.1/16 .
.Pp
For
.Dq inet6
family, it is also possible to specify the prefix length using the slash
notation, like
.Li ::1/128 .
See the
.Cm prefixlen
parameter below for more information.
.\" For the Xerox Network Systems(tm) family,
.\" addresses are
.\" .Ar net:a.b.c.d.e.f ,
.\" where
.\" .Ar net
.\" is the assigned network number (in decimal),
.\" and each of the six bytes of the host number,
.\" .Ar a
.\" through
.\" .Ar f ,
.\" are specified in hexadecimal.
.\" The host number may be omitted on IEEE 802 protocol
.\" (Ethernet, FDDI, and Token Ring) interfaces,
.\" which use the hardware physical address,
.\" and on interfaces other than the first.
.\" For the
.\" .Tn ISO
.\" family, addresses are specified as a long hexadecimal string,
.\" as in the Xerox family.
.\" However, two consecutive dots imply a zero
.\" byte, and the dots are optional, if the user wishes to (carefully)
.\" count out long strings of digits in network byte order.
.It Ar address_family
Specify the
address family
which affects interpretation of the remaining parameters.
Since an interface can receive transmissions in differing protocols
with different naming schemes, specifying the address family is recommended.
The address or protocol families currently
supported are
.Dq inet ,
.Dq inet6 ,
.Dq atalk ,
.Dq ether ,
.\" .Dq iso ,
and
.Dq ipx .
.\" and
.\" .Dq ns .
The default is
.Dq inet .
.It Ar dest_address
Specify the address of the correspondent on the other end
of a point to point link.
.It Ar interface
This
parameter is a string of the form
.Dq name unit ,
for example,
.Dq Li ed0 .
.El
.Pp
The following parameters may be set with
.Nm :
.Bl -tag -width indent
.It Cm add
Another name for the
.Cm alias
parameter.
Introduced for compatibility
with
.Bsx .
.It Cm alias
Establish an additional network address for this interface.
This is sometimes useful when changing network numbers, and
one wishes to accept packets addressed to the old interface.
If the address is on the same subnet as the first network address
for this interface, a netmask of
.Li 0xffffffff
has to be specified.
.It Fl alias
Remove the network address specified.
This would be used if you incorrectly specified an alias, or it
was no longer needed.
If you have incorrectly set an NS address having the side effect
of specifying the host portion, removing all NS addresses will
allow you to respecify the host portion.
.It Cm anycast
(Inet6 only.)
Specify that the address configured is an anycast address.
Based on the current specification,
only routers may configure anycast addresses.
Anycast address will not be used as source address of any of outgoing
IPv6 packets.
.It Cm arp
Enable the use of the Address Resolution Protocol
.Pq Xr arp 4
in mapping
between network level addresses and link level addresses (default).
This is currently implemented for mapping between
.Tn DARPA
Internet
addresses and
.Tn IEEE
802 48-bit MAC addresses (Ethernet, FDDI, and Token Ring addresses).
.It Fl arp
Disable the use of the Address Resolution Protocol
.Pq Xr arp 4 .
.It Cm broadcast
(Inet only.)
Specify the address to use to represent broadcasts to the
network.
The default broadcast address is the address with a host part of all 1's.
.It Cm debug
Enable driver dependent debugging code; usually, this turns on
extra console error logging.
.It Fl debug
Disable driver dependent debugging code.
.It Cm delete
Another name for the
.Fl alias
parameter.
.It Cm down
Mark an interface
.Dq down .
When an interface is marked
.Dq down ,
the system will not attempt to
transmit messages through that interface.
If possible, the interface will be reset to disable reception as well.
This action does not automatically disable routes using the interface.
.It Cm ether
Another name for the
.Cm lladdr
parameter.
.\" .It Cm ipdst
.\" This is used to specify an Internet host who is willing to receive
.\" ip packets encapsulating NS packets bound for a remote network.
.\" An apparent point to point link is constructed, and
.\" the address specified will be taken as the NS address and network
.\" of the destination.
.\" IP encapsulation of
.\" .Tn CLNP
.\" packets is done differently.
.It Cm lladdr Ar addr
Set the link-level address on an interface.
This can be used to
e.g. set a new MAC address on an ethernet interface, though the
mechanism used is not ethernet-specific.
The address
.Ar addr
is specified as a series of colon-separated hex digits.
If the interface is already
up when this option is used, it will be briefly brought down and
then brought back up again in order to ensure that the receive
filter in the underlying ethernet hardware is properly reprogrammed.
.It Cm media Ar type
If the driver supports the media selection system, set the media type
of the interface to
.Ar type .
Some interfaces support the mutually exclusive use of one of several
different physical media connectors.
For example, a 10Mb/s Ethernet
interface might support the use of either
.Tn AUI
or twisted pair connectors.
Setting the media type to
.Dq 10base5/AUI
would change the currently active connector to the AUI port.
Setting it to
.Dq 10baseT/UTP
would activate twisted pair.
Refer to the interfaces' driver
specific documentation or man page for a complete list of the
available types.
.It Cm mediaopt Ar opts
If the driver supports the media selection system, set the specified
media options on the interface.
The
.Ar opts
argument
is a comma delimited list of options to apply to the interface.
Refer to the interfaces' driver specific man page for a complete
list of available options.
.It Fl mediaopt Ar opts
If the driver supports the media selection system, disable the
specified media options on the interface.
.It Cm tunnel Ar src_addr dest_addr
(IP tunnel devices only.)
Configure the physical source and destination address for IP tunnel
interfaces
.Pq Xr gif 4 .
The arguments
.Ar src_addr
and
.Ar dest_addr
are interpreted as the outer source/destination for the encapsulating
IPv4/IPv6 header.
.It Cm deletetunnel
Unconfigure the physical source and destination address for IP tunnel
interfaces previously configured with
.Cm tunnel .
.It Cm create
Create the specified network pseudo-device.
If the interface is given without a unit number, try to create a new
device with an arbitrary unit number.
If creation of an arbitrary device is successful, the new device name is
printed to standard output.
.It Cm destroy
Destroy the specified network pseudo-device.
.It Cm plumb
Another name for the
.Cm create
parameter.
Included for
.Tn Solaris
compatibility.
.It Cm unplumb
Another name for the
.Cm destroy
parameter.
Included for
.Tn Solaris
compatibility.
.It Cm vlan Ar vlan_tag
If the interface is a vlan pseudo interface, set the vlan tag value
to
.Ar vlan_tag .
This value is a 16-bit number which is used to create an 802.1Q
vlan header for packets sent from the vlan interface.
Note that
.Cm vlan
and
.Cm vlandev
must both be set at the same time.
.It Cm vlandev Ar iface
If the interface is a vlan pseudo device, associate physical interface
.Ar iface
with it.
Packets transmitted through the vlan interface will be
diverted to the specified physical interface
.Ar iface
with 802.1Q vlan encapsulation.
Packets with 802.1Q encapsulation received
by the parent interface with the correct vlan tag will be diverted to
the associated vlan pseudo-interface.
The vlan interface is assigned a
copy of the parent interface's flags and the parent's ethernet address.
The
.Cm vlandev
and
.Cm vlan
must both be set at the same time.
If the vlan interface already has
a physical interface associated with it, this command will fail.
To
change the association to another physical interface, the existing
association must be cleared first.
.Pp
Note: if the
.Cm link0
flag is set on the vlan interface, the vlan pseudo
interface's behavior changes: the
.Cm link0
tells the vlan interface that the
parent interface supports insertion and extraction of vlan tags on its
own (usually in firmware) and that it should pass packets to and from
the parent unaltered.
.It Fl vlandev Ar iface
If the driver is a vlan pseudo device, disassociate the physical interface
.Ar iface
from it.
This breaks the link between the vlan interface and its parent,
clears its vlan tag, flags and its link address and shuts the interface down.
.It Cm metric Ar n
Set the routing metric of the interface to
.Ar n ,
default 0.
The routing metric is used by the routing protocol
.Pq Xr routed 8 .
Higher metrics have the effect of making a route
less favorable; metrics are counted as addition hops
to the destination network or host.
.It Cm mtu Ar n
Set the maximum transmission unit of the interface to
.Ar n ,
default is interface specific.
The MTU is used to limit the size of packets that are transmitted on an
interface.
Not all interfaces support setting the MTU, and some interfaces have
range restrictions.
.It Cm netmask Ar mask
.\" (Inet and ISO.)
(Inet only.)
Specify how much of the address to reserve for subdividing
networks into sub-networks.
The mask includes the network part of the local address
and the subnet part, which is taken from the host field of the address.
The mask can be specified as a single hexadecimal number
with a leading
.Ql 0x ,
with a dot-notation Internet address,
or with a pseudo-network name listed in the network table
.Xr networks 5 .
The mask contains 1's for the bit positions in the 32-bit address
which are to be used for the network and subnet parts,
and 0's for the host part.
The mask should contain at least the standard network portion,
and the subnet field should be contiguous with the network
portion.
.Pp
The netmask can also be specified in CIDR notation after the address.
See the
.Ar address
option above for more information.
.It Cm prefixlen Ar len
(Inet6 only.)
Specify that
.Ar len
bits are reserved for subdividing networks into sub-networks.
The
.Ar len
must be integer, and for syntactical reason it must be between 0 to 128.
It is almost always 64 under the current IPv6 assignment rule.
If the parameter is omitted, 64 is used.
.Pp
The prefix can also be specified using the slash notation after the address.
See the
.Ar address
option above for more information.
.\" see
.\" Xr eon 5 .
.\" .It Cm nsellength Ar n
.\" .Pf ( Tn ISO
.\" only)
.\" This specifies a trailing number of bytes for a received
.\" .Tn NSAP
.\" used for local identification, the remaining leading part of which is
.\" taken to be the
.\" .Tn NET
.\" (Network Entity Title).
.\" The default value is 1, which is conformant to US
.\" .Tn GOSIP .
.\" When an ISO address is set in an ifconfig command,
.\" it is really the
.\" .Tn NSAP
.\" which is being specified.
.\" For example, in
.\" .Tn US GOSIP ,
.\" 20 hex digits should be
.\" specified in the
.\" .Tn ISO NSAP
.\" to be assigned to the interface.
.\" There is some evidence that a number different from 1 may be useful
.\" for
.\" .Tn AFI
.\" 37 type addresses.
.It Cm range Ar netrange
Under appletalk, set the interface to respond to a
.Ar netrange
of the form
.Ar startnet Ns - Ns Ar endnet .
Appletalk uses this scheme instead of
netmasks though
.Fx
implements it internally as a set of netmasks.
.It Cm remove
Another name for the
.Fl alias
parameter.
Introduced for compatibility
with
.Bsx .
.It Cm phase
The argument following this specifies the version (phase) of the
Appletalk network attached to the interface.
Values of 1 or 2 are permitted.
.Sm off
.It Cm link Op Cm 0 No - Cm 2
.Sm on
Enable special processing of the link level of the interface.
These three options are interface specific in actual effect, however,
they are in general used to select special modes of operation.
An example
of this is to enable SLIP compression, or to select the connector type
for some Ethernet cards.
Refer to the man page for the specific driver
for more information.
.Sm off
.It Fl link Op Cm 0 No - Cm 2
.Sm on
Disable special processing at the link level with the specified interface.
.It Cm up
Mark an interface
.Dq up .
This may be used to enable an interface after an
.Dq Nm Cm down .
It happens automatically when setting the first address on an interface.
If the interface was reset when previously marked down,
the hardware will be re-initialized.
.It Cm ssid Ar ssid
For IEEE 802.11 wireless interfaces, set the desired Service Set
Identifier (aka network name).
The SSID is a string up to 32 characters
in length and may be specified as either a normal string or in
hexadecimal when proceeded by
.Ql 0x .
Additionally, the SSID may be cleared by setting it to
.Ql - .
.It Cm nwid Ar ssid
Another name for the
.Cm ssid
parameter.
Included for
.Nx
compatibility.
.It Cm stationname Ar name
For IEEE 802.11 wireless interfaces, set the name of this station.
It appears that the station name is not really part of the IEEE 802.11
protocol though all interfaces seem to support it.
As such it only
seems to be meaningful to identical or virtually identical equipment.
Setting the station name is identical in syntax to setting the SSID.
.It Cm station Ar name
Another name for the
.Cm stationname
parameter.
Included for
.Bsx
compatibility.
.It Cm channel Ar number
For IEEE 802.11 wireless interfaces, set the desired channel.
Channels range from 1 to 14, but the exact selection available
depends on the region your adaptor was manufactured for.
Setting
the channel to 0 will give you the default for your adaptor.
Many
adaptors ignore this setting unless you are in ad-hoc mode.
.It Cm authmode Ar mode
For IEEE 802.11 wireless interfaces, set the desired authentication mode
in infrastructure mode.
Not all adaptors support all modes.
The set of
valid modes is
.Dq none ,
.Dq open ,
and
.Dq shared .
Modes are case insensitive.
.It Cm powersave
For IEEE 802.11 wireless interfaces, enable powersave mode.
.It Fl powersave
For IEEE 802.11 wireless interfaces, disable powersave mode.
.It Cm powersavesleep Ar sleep
For IEEE 802.11 wireless interfaces, set the desired max powersave sleep
time in milliseconds.
.It Cm wepmode Ar mode
For IEEE 802.11 wireless interfaces, set the desired WEP mode.
Not all adaptors support all modes.
The set of valid modes is
.Dq off ,
.Dq on ,
and
.Dq mixed .
.Dq Mixed
mode explicitly tells the adaptor to allow association with access
points which allow both encrypted and unencrypted traffic.
On these adaptors,
.Dq on
means that the access point must only allow encrypted connections.
On other adaptors,
.Dq on
is generally another name for
.Dq mixed .
Modes are case insensitive.
.It Cm weptxkey Ar index
For IEEE 802.11 wireless interfaces, set the WEP key to be used for
transmission.
.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key
For IEEE 802.11 wireless interfaces, set the selected WEP key.
If an
.Ar index
is not given, key 1 is set.
A WEP key will be either 5 or 13
characters (40 or 104 bits) depending of the local network and the
capabilities of the adaptor.
It may be specified either as a plain
string or as a string of hexadecimal digits proceeded by
.Ql 0x .
A key may be cleared by setting it to
.Ql - .
If WEP is supported then there are at least four keys.
Some adaptors support more than four keys.
If that is the case, then the first four keys
(1-4) will be the standard temporary keys and any others will be adaptor
specific keys such as permanent keys stored in NVRAM.
.It Cm wep
Another way of saying
.Cm wepmode on .
Included for
.Bsx
compatibility.
.It Fl wep
Another way of saying
.Cm wepmode off .
Included for
.Bsx
compatibility.
.It Cm nwkey key
Another way of saying:
.Pp
.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" .
.Pp
Included for
.Nx
compatibility.
.It Cm nwkey Xo
.Sm off
.Ar n : k1 , k2 , k3 , k4
.Sm on
.Xc
Another way of saying
.Pp
.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" .
.Pp
Included for
.Nx
compatibility.
.It Fl nwkey
Another way of saying
.Cm wepmode off .
.Pp
Included for
.Nx
compatibility.
.El
.Pp
.Nm Ifconfig
displays the current configuration for a network interface
when no optional parameters are supplied.
If a protocol family is specified,
.Nm
will report only the details specific to that protocol family.
.Pp
If the driver does supports the media selection system, the supported
media list will be included in the output.
.Pp
If the
.Fl m
flag is passed before an interface name,
.Nm
will display all
of the supported media for the specified interface.
If
.Fl L
flag is supplied, address lifetime is displayed for IPv6 addresses,
as time offset string.
.Pp
Optionally, the
.Fl a
flag may be used instead of an interface name.
This flag instructs
.Nm
to display information about all interfaces in the system.
The
.Fl d
flag limits this to interfaces that are down, and
.Fl u
limits this to interfaces that are up.
When no arguments are given,
.Fl a
is implied.
.Pp
The
.Fl l
flag may be used to list all available interfaces on the system, with
no other additional information.
Use of this flag is mutually exclusive
with all other flags and commands, except for
.Fl d
(only list interfaces that are down)
and
.Fl u
(only list interfaces that are up).
.Pp
The
.Fl C
flag may be used to list all of the interface cloners available on
the system, with no additional information.
Use of this flag is mutually exclusive with all other flags and commands.
.Pp
Only the super-user may modify the configuration of a network interface.
.Sh NOTES
The media selection system is relatively new and only some drivers support
it (or have need for it).
.Sh DIAGNOSTICS
Messages indicating the specified interface does not exist, the
requested address is unknown, or the user is not privileged and
tried to alter an interface's configuration.
.Sh BUGS
IPv6 link-local addresses are required for several basic communication
between IPv6 node.
If they are deleted by
.Nm
manually, the kernel might show very strange behavior.
So, such manual deletions are strongly discouraged.
.Sh SEE ALSO
.Xr netstat 1 ,
.Xr netintro 4 ,
.\" .Xr eon 5 ,
.Xr rc 8 ,
.Xr routed 8
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.2 .
|