xref: /freebsd/sbin/ifconfig/ifconfig.8 (revision 4a5216a6dc0c3ce4cf5f2d3ee8af0c3ff3402c4f)
1.\" Copyright (c) 1983, 1991, 1993
2.\"	The Regents of the University of California.  All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\"    notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\"    notice, this list of conditions and the following disclaimer in the
11.\"    documentation and/or other materials provided with the distribution.
12.\" 4. Neither the name of the University nor the names of its contributors
13.\"    may be used to endorse or promote products derived from this software
14.\"    without specific prior written permission.
15.\"
16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26.\" SUCH DAMAGE.
27.\"
28.\"     From: @(#)ifconfig.8	8.3 (Berkeley) 1/5/94
29.\" $FreeBSD$
30.\"
31.Dd September 5, 2008
32.Dt IFCONFIG 8
33.Os
34.Sh NAME
35.Nm ifconfig
36.Nd configure network interface parameters
37.Sh SYNOPSIS
38.Nm
39.Op Fl L
40.Op Fl k
41.Op Fl m
42.Op Fl n
43.Ar interface
44.Op Cm create
45.Op Ar address_family
46.Oo
47.Ar address
48.Op Ar dest_address
49.Oc
50.Op Ar parameters
51.Nm
52.Ar interface
53.Cm destroy
54.Nm
55.Fl a
56.Op Fl L
57.Op Fl d
58.Op Fl m
59.Op Fl u
60.Op Fl v
61.Op Ar address_family
62.Nm
63.Fl l
64.Op Fl d
65.Op Fl u
66.Op Ar address_family
67.Nm
68.Op Fl L
69.Op Fl d
70.Op Fl k
71.Op Fl m
72.Op Fl u
73.Op Fl v
74.Op Fl C
75.Nm
76.Op Fl g Ar groupname
77.Sh DESCRIPTION
78The
79.Nm
80utility is used to assign an address
81to a network interface and/or configure
82network interface parameters.
83The
84.Nm
85utility must be used at boot time to define the network address
86of each interface present on a machine; it may also be used at
87a later time to redefine an interface's address
88or other operating parameters.
89.Pp
90The following options are available:
91.Bl -tag -width indent
92.It Ar address
93For the
94.Tn DARPA Ns -Internet
95family,
96the address is either a host name present in the host name data
97base,
98.Xr hosts 5 ,
99or a
100.Tn DARPA
101Internet address expressed in the Internet standard
102.Dq dot notation .
103.Pp
104It is also possible to use the CIDR notation (also known as the
105slash notation) to include the netmask.
106That is, one can specify an address like
107.Li 192.168.0.1/16 .
108.Pp
109For
110.Dq inet6
111family, it is also possible to specify the prefix length using the slash
112notation, like
113.Li ::1/128 .
114See the
115.Cm prefixlen
116parameter below for more information.
117.\" For the Xerox Network Systems(tm) family,
118.\" addresses are
119.\" .Ar net:a.b.c.d.e.f ,
120.\" where
121.\" .Ar net
122.\" is the assigned network number (in decimal),
123.\" and each of the six bytes of the host number,
124.\" .Ar a
125.\" through
126.\" .Ar f ,
127.\" are specified in hexadecimal.
128.\" The host number may be omitted on IEEE 802 protocol
129.\" (Ethernet, FDDI, and Token Ring) interfaces,
130.\" which use the hardware physical address,
131.\" and on interfaces other than the first.
132.\" For the
133.\" .Tn ISO
134.\" family, addresses are specified as a long hexadecimal string,
135.\" as in the Xerox family.
136.\" However, two consecutive dots imply a zero
137.\" byte, and the dots are optional, if the user wishes to (carefully)
138.\" count out long strings of digits in network byte order.
139.Pp
140The link-level
141.Pq Dq link
142address
143is specified as a series of colon-separated hex digits.
144This can be used to
145e.g.\& set a new MAC address on an ethernet interface, though the
146mechanism used is not ethernet-specific.
147If the interface is already
148up when this option is used, it will be briefly brought down and
149then brought back up again in order to ensure that the receive
150filter in the underlying ethernet hardware is properly reprogrammed.
151.It Ar address_family
152Specify the
153address family
154which affects interpretation of the remaining parameters.
155Since an interface can receive transmissions in differing protocols
156with different naming schemes, specifying the address family is recommended.
157The address or protocol families currently
158supported are
159.Dq inet ,
160.Dq inet6 ,
161.Dq atalk ,
162.Dq ipx ,
163.\" .Dq iso ,
164and
165.Dq link .
166.\" and
167.\" .Dq ns .
168The default is
169.Dq inet .
170.Dq ether
171and
172.Dq lladdr
173are synonyms for
174.Dq link .
175.It Ar dest_address
176Specify the address of the correspondent on the other end
177of a point to point link.
178.It Ar interface
179This
180parameter is a string of the form
181.Dq name unit ,
182for example,
183.Dq Li ed0 .
184.It Ar groupname
185List the interfaces in the given group.
186.El
187.Pp
188The following parameters may be set with
189.Nm :
190.Bl -tag -width indent
191.It Cm add
192Another name for the
193.Cm alias
194parameter.
195Introduced for compatibility
196with
197.Bsx .
198.It Cm alias
199Establish an additional network address for this interface.
200This is sometimes useful when changing network numbers, and
201one wishes to accept packets addressed to the old interface.
202If the address is on the same subnet as the first network address
203for this interface, a non-conflicting netmask must be given.
204Usually
205.Li 0xffffffff
206is most appropriate.
207.It Fl alias
208Remove the network address specified.
209This would be used if you incorrectly specified an alias, or it
210was no longer needed.
211If you have incorrectly set an NS address having the side effect
212of specifying the host portion, removing all NS addresses will
213allow you to respecify the host portion.
214.It Cm anycast
215(Inet6 only.)
216Specify that the address configured is an anycast address.
217Based on the current specification,
218only routers may configure anycast addresses.
219Anycast address will not be used as source address of any of outgoing
220IPv6 packets.
221.It Cm arp
222Enable the use of the Address Resolution Protocol
223.Pq Xr arp 4
224in mapping
225between network level addresses and link level addresses (default).
226This is currently implemented for mapping between
227.Tn DARPA
228Internet
229addresses and
230.Tn IEEE
231802 48-bit MAC addresses (Ethernet, FDDI, and Token Ring addresses).
232.It Fl arp
233Disable the use of the Address Resolution Protocol
234.Pq Xr arp 4 .
235.It Cm staticarp
236If the Address Resolution Protocol is enabled,
237the host will only reply to requests for its addresses,
238and will never send any requests.
239.It Fl staticarp
240If the Address Resolution Protocol is enabled,
241the host will perform normally,
242sending out requests and listening for replies.
243.It Cm broadcast
244(Inet only.)
245Specify the address to use to represent broadcasts to the
246network.
247The default broadcast address is the address with a host part of all 1's.
248.It Cm debug
249Enable driver dependent debugging code; usually, this turns on
250extra console error logging.
251.It Fl debug
252Disable driver dependent debugging code.
253.It Cm promisc
254Put interface into permanently promiscuous mode.
255.It Fl promisc
256Disable permanently promiscuous mode.
257.It Cm delete
258Another name for the
259.Fl alias
260parameter.
261.It Cm down
262Mark an interface
263.Dq down .
264When an interface is marked
265.Dq down ,
266the system will not attempt to
267transmit messages through that interface.
268If possible, the interface will be reset to disable reception as well.
269This action does not automatically disable routes using the interface.
270.It Cm group Ar group-name
271Assign the interface to a
272.Dq group .
273Any interface can be in multiple groups.
274.Pp
275Cloned interfaces are members of their interface family group by default.
276For example, a PPP interface such as
277.Em ppp0
278is a member of the PPP interface family group,
279.Em ppp .
280.\" The interface(s) the default route(s) point to are members of the
281.\" .Em egress
282.\" interface group.
283.It Cm -group Ar group-name
284Remove the interface from the given
285.Dq group .
286.It Cm eui64
287(Inet6 only.)
288Fill interface index
289(lowermost 64bit of an IPv6 address)
290automatically.
291.It Cm ipdst
292This is used to specify an Internet host who is willing to receive
293IP packets encapsulating IPX packets bound for a remote network.
294An apparent point to point link is constructed, and
295the address specified will be taken as the IPX address and network
296of the destination.
297.It Cm maclabel Ar label
298If Mandatory Access Control support is enabled in the kernel,
299set the MAC label to
300.Ar label .
301.\" (see
302.\" .Xr maclabel 7 ) .
303.It Cm media Ar type
304If the driver supports the media selection system, set the media type
305of the interface to
306.Ar type .
307Some interfaces support the mutually exclusive use of one of several
308different physical media connectors.
309For example, a 10Mbit/s Ethernet
310interface might support the use of either
311.Tn AUI
312or twisted pair connectors.
313Setting the media type to
314.Cm 10base5/AUI
315would change the currently active connector to the AUI port.
316Setting it to
317.Cm 10baseT/UTP
318would activate twisted pair.
319Refer to the interfaces' driver
320specific documentation or man page for a complete list of the
321available types.
322.It Cm mediaopt Ar opts
323If the driver supports the media selection system, set the specified
324media options on the interface.
325The
326.Ar opts
327argument
328is a comma delimited list of options to apply to the interface.
329Refer to the interfaces' driver specific man page for a complete
330list of available options.
331.It Fl mediaopt Ar opts
332If the driver supports the media selection system, disable the
333specified media options on the interface.
334.It Cm mode Ar mode
335If the driver supports the media selection system, set the specified
336operating mode on the interface to
337.Ar mode .
338For IEEE 802.11 wireless interfaces that support multiple operating modes
339this directive is used to select between 802.11a
340.Pq Cm 11a ,
341802.11b
342.Pq Cm 11b ,
343and 802.11g
344.Pq Cm 11g
345operating modes.
346.It Cm inst Ar minst , Cm instance Ar minst
347Set the media instance to
348.Ar minst .
349This is useful for devices which have multiple physical layer interfaces
350.Pq PHYs .
351.It Cm name Ar name
352Set the interface name to
353.Ar name .
354.It Cm rxcsum , txcsum
355If the driver supports user-configurable checksum offloading,
356enable receive (or transmit) checksum offloading on the interface.
357Some drivers may not be able to enable these flags independently
358of each other, so setting one may also set the other.
359The driver will offload as much checksum work as it can reliably
360support, the exact level of offloading varies between drivers.
361.It Fl rxcsum , txcsum
362If the driver supports user-configurable checksum offloading,
363disable receive (or transmit) checksum offloading on the interface.
364These settings may not always be independent of each other.
365.It Cm tso
366If the driver supports
367.Xr tcp 4
368segmentation offloading, enable TSO on the interface.
369Some drivers may not be able to support TSO for
370.Xr ip 4
371and
372.Xr ip6 4
373packets, so they may enable only one of them.
374.It Fl tso
375If the driver supports
376.Xr tcp 4
377segmentation offloading, disable TSO on the interface.
378It will always disable TSO for
379.Xr ip 4
380and
381.Xr ip6 4 .
382.It Cm lro
383If the driver supports
384.Xr tcp 4
385large receive offloading, enable LRO on the interface.
386.It Fl lro
387If the driver supports
388.Xr tcp 4
389large receive offloading, disable LRO on the interface.
390.It Cm wol , wol_ucast , wol_mcast , wol_magic
391Enable Wake On Lan (WOL) support, if available.
392WOL is a facility whereby a machine in a low power state may be woken
393in response to a received packet.
394There are three types of packets that may wake a system:
395ucast (directed solely to the machine's mac address),
396mcast (directed to a broadcast or multicast address),
397or
398magic (unicast or multicast frames with a ``magic contents'').
399Not all devices support WOL, those that do indicate the mechanisms
400they support in their capabilities.
401.Cm wol
402is a synonym for enabling all available WOL mechanisms.
403To disable WOL use
404.Fl wol .
405.It Cm vlanmtu , vlanhwtag, vlanhwfilter
406If the driver offers user-configurable VLAN support, enable
407reception of extended frames, tag processing in hardware, or
408frame filtering in hardware,
409respectively.
410Note that this must be issued on a physical interface associated with
411.Xr vlan 4 ,
412not on a
413.Xr vlan 4
414interface itself.
415.It Fl vlanmtu , vlanhwtag, vlanhwfilter
416If the driver offers user-configurable VLAN support, disable
417reception of extended frames, tag processing in hardware, or
418frame filtering in hardware,
419respectively.
420.It Cm polling
421Turn on
422.Xr polling 4
423feature and disable interrupts on the interface, if driver supports
424this mode.
425.It Fl polling
426Turn off
427.Xr polling 4
428feature and enable interrupt mode on the interface.
429.It Cm create
430Create the specified network pseudo-device.
431If the interface is given without a unit number, try to create a new
432device with an arbitrary unit number.
433If creation of an arbitrary device is successful, the new device name is
434printed to standard output unless the interface is renamed or destroyed
435in the same
436.Nm
437invocation.
438.It Cm destroy
439Destroy the specified network pseudo-device.
440.It Cm plumb
441Another name for the
442.Cm create
443parameter.
444Included for
445.Tn Solaris
446compatibility.
447.It Cm unplumb
448Another name for the
449.Cm destroy
450parameter.
451Included for
452.Tn Solaris
453compatibility.
454.It Cm metric Ar n
455Set the routing metric of the interface to
456.Ar n ,
457default 0.
458The routing metric is used by the routing protocol
459.Pq Xr routed 8 .
460Higher metrics have the effect of making a route
461less favorable; metrics are counted as additional hops
462to the destination network or host.
463.It Cm mtu Ar n
464Set the maximum transmission unit of the interface to
465.Ar n ,
466default is interface specific.
467The MTU is used to limit the size of packets that are transmitted on an
468interface.
469Not all interfaces support setting the MTU, and some interfaces have
470range restrictions.
471.It Cm netmask Ar mask
472.\" (Inet and ISO.)
473(Inet only.)
474Specify how much of the address to reserve for subdividing
475networks into sub-networks.
476The mask includes the network part of the local address
477and the subnet part, which is taken from the host field of the address.
478The mask can be specified as a single hexadecimal number
479with a leading
480.Ql 0x ,
481with a dot-notation Internet address,
482or with a pseudo-network name listed in the network table
483.Xr networks 5 .
484The mask contains 1's for the bit positions in the 32-bit address
485which are to be used for the network and subnet parts,
486and 0's for the host part.
487The mask should contain at least the standard network portion,
488and the subnet field should be contiguous with the network
489portion.
490.Pp
491The netmask can also be specified in CIDR notation after the address.
492See the
493.Ar address
494option above for more information.
495.It Cm prefixlen Ar len
496(Inet6 only.)
497Specify that
498.Ar len
499bits are reserved for subdividing networks into sub-networks.
500The
501.Ar len
502must be integer, and for syntactical reason it must be between 0 to 128.
503It is almost always 64 under the current IPv6 assignment rule.
504If the parameter is omitted, 64 is used.
505.Pp
506The prefix can also be specified using the slash notation after the address.
507See the
508.Ar address
509option above for more information.
510.\" see
511.\" Xr eon 5 .
512.\" .It Cm nsellength Ar n
513.\" .Pf ( Tn ISO
514.\" only)
515.\" This specifies a trailing number of bytes for a received
516.\" .Tn NSAP
517.\" used for local identification, the remaining leading part of which is
518.\" taken to be the
519.\" .Tn NET
520.\" (Network Entity Title).
521.\" The default value is 1, which is conformant to US
522.\" .Tn GOSIP .
523.\" When an ISO address is set in an ifconfig command,
524.\" it is really the
525.\" .Tn NSAP
526.\" which is being specified.
527.\" For example, in
528.\" .Tn US GOSIP ,
529.\" 20 hex digits should be
530.\" specified in the
531.\" .Tn ISO NSAP
532.\" to be assigned to the interface.
533.\" There is some evidence that a number different from 1 may be useful
534.\" for
535.\" .Tn AFI
536.\" 37 type addresses.
537.It Cm range Ar netrange
538Under appletalk, set the interface to respond to a
539.Ar netrange
540of the form
541.Ar startnet Ns - Ns Ar endnet .
542Appletalk uses this scheme instead of
543netmasks though
544.Fx
545implements it internally as a set of netmasks.
546.It Cm remove
547Another name for the
548.Fl alias
549parameter.
550Introduced for compatibility
551with
552.Bsx .
553.It Cm phase
554The argument following this specifies the version (phase) of the
555Appletalk network attached to the interface.
556Values of 1 or 2 are permitted.
557.Sm off
558.It Cm link Op Cm 0 No - Cm 2
559.Sm on
560Enable special processing of the link level of the interface.
561These three options are interface specific in actual effect, however,
562they are in general used to select special modes of operation.
563An example
564of this is to enable SLIP compression, or to select the connector type
565for some Ethernet cards.
566Refer to the man page for the specific driver
567for more information.
568.Sm off
569.It Fl link Op Cm 0 No - Cm 2
570.Sm on
571Disable special processing at the link level with the specified interface.
572.It Cm monitor
573Put the interface in monitor mode.
574No packets are transmitted, and received packets are discarded after
575.Xr bpf 4
576processing.
577.It Fl monitor
578Take the interface out of monitor mode.
579.It Cm up
580Mark an interface
581.Dq up .
582This may be used to enable an interface after an
583.Dq Nm Cm down .
584It happens automatically when setting the first address on an interface.
585If the interface was reset when previously marked down,
586the hardware will be re-initialized.
587.El
588.Pp
589The following parameters are specific to cloning
590IEEE 802.11 wireless interfaces with the
591.Cm create
592request:
593.Bl -tag -width indent
594.It Cm wlandev Ar device
595Use
596.Ar device
597as the parent for the cloned device.
598.It Cm wlanmode Ar mode
599Specify the operating mode for this cloned device.
600.Ar mode
601is one of
602.Cm sta ,
603.Cm ahdemo
604(or
605.Cm adhoc-demo ),
606.Cm ibss ,
607(or
608.Cm adhoc ),
609.Cm ap ,
610(or
611.Cm hostap ),
612.Cm wds ,
613and
614.Cm monitor .
615The operating mode of a cloned interface cannot be changed.
616.It Cm wlanbssid Ar bssid
617The 802.11 mac address to use for the bssid.
618This must be specified at create time for a legacy
619.Cm wds
620device.
621.It Cm wlanaddr Ar address
622The local mac address.
623If this is not specified then a mac address will automatically be assigned
624to the cloned device.
625Typically this address is the same as the address of the parent device
626but if the
627.Cm bssid
628parameter is specified then the driver will craft a unique address for
629the device (if supported).
630.It Cm wdslegacy
631Mark a
632.Cm wds
633device as operating in ``legacy mode''.
634Legacy
635.Cm wds
636devices have a fixed peer relationship and do not, for example, roam
637if their peer stops communicating.
638For completeness a Dynamic WDS (DWDS) interface may marked as
639.Fl wdslegacy .
640.It Cm bssid
641Request a unique local mac address for the cloned device.
642This is only possible if the device supports multiple mac addresses.
643To force use of the parent's mac address use
644.Fl bssid .
645.It Cm beacons
646Mark the cloned interface as depending on hardware support to
647track received beacons.
648To have beacons tracked in software use
649.Fl beacons .
650For
651.Cm hostap
652mode
653.Fl beacons
654can also be used to indicate no beacons should
655be transmitted; this can be useful when creating a WDS configuration but
656.Cm wds
657interfaces can only be created as companions to an access point.
658.El
659.Pp
660The following parameters are specific to IEEE 802.11 wireless interfaces
661cloned with a
662.Cm create
663operation:
664.Bl -tag -width indent
665.It Cm ampdu
666Enable sending and receiving AMPDU frames when using 802.11n (default).
667The 802.11n specification states a compliant station must be capable
668of receiving AMPDU frames but transmision is optional.
669Use
670.Fl ampdu
671to disable all use of AMPDU with 802.11n.
672For testing and/or to work around interoperability problems one can use
673.Cm ampdutx
674and
675.Cm ampdurx
676to control use of AMPDU in one direction.
677.It Cm ampdudensity Ar density
678Set the AMPDU density parameter used when operating with 802.11n.
679This parameter controls the inter-packet gap for AMPDU frames.
680The sending device normally controls this setting but a receiving station
681may request wider gaps.
682Legal values for
683.Ar density
684are 0, .25, .5, 1, 2, 4, 8, and 16 (microseconds).
685A value of
686.Cm -
687is treated the same as 0.
688.It Cm ampdulimit Ar limit
689Set the limit on packet size for receiving AMPDU frames when operating
690with 802.11n.
691Legal values for
692.Ar limit
693are 8192, 16384, 32768, and 65536 but one can also specify
694just the unique prefix: 8, 16, 32, 64.
695Note the sender may limit the size of AMPDU frames to be less
696than the maximum specified by the receiving station.
697.It Cm amsdu
698Enable sending and receiving AMSDU frames when using 802.11n.
699By default AMSDU is received but not transmitted.
700Use
701.Fl amsdu
702to disable all use of AMSDU with 802.11n.
703For testing and/or to work around interoperability problems one can use
704.Cm amsdutx
705and
706.Cm amsdurx
707to control use of AMSDU in one direction.
708.It Cm amsdulimit Ar limit
709Set the limit on packet size for sending and receiving AMSDU frames
710when operating with 802.11n.
711Legal values for
712.Ar limit
713are 7935 and 3839 (bytes).
714Note the sender may limit the size of AMSDU frames to be less
715than the maximum specified by the receiving station.
716Note also that devices are not required to support the 7935 limit,
717only 3839 is required by the specification and the larger value
718may require more memory to be dedicated to support functionality
719that is rarely used.
720.It Cm apbridge
721When operating as an access point, pass packets between
722wireless clients directly (default).
723To instead let them pass up through the
724system and be forwarded using some other mechanism, use
725.Fl apbridge .
726Disabling the internal bridging
727is useful when traffic is to be processed with
728packet filtering.
729.It Cm authmode Ar mode
730Set the desired authentication mode in infrastructure mode.
731Not all adapters support all modes.
732The set of
733valid modes is
734.Cm none , open , shared
735(shared key),
736.Cm 8021x
737(IEEE 802.1x),
738and
739.Cm wpa
740(IEEE WPA/WPA2/802.11i).
741The
742.Cm 8021x
743and
744.Cm wpa
745modes are only useful when using an authentication service
746(a supplicant for client operation or an authenticator when
747operating as an access point).
748Modes are case insensitive.
749.It Cm bgscan
750Enable background scanning when operating as a station.
751Background scanning is a technique whereby a station associated to
752an access point will temporarily leave the channel to scan for
753neighboring stations.
754This allows a station to maintain a cache of nearby access points
755so that roaming between access points can be done without
756a lengthy scan operation.
757Background scanning is done only when a station is not busy and
758any outbound traffic will cancel a scan operation.
759Background scanning should never cause packets to be lost though
760there may be some small latency if outbound traffic interrupts a
761scan operation.
762By default background scanning is enabled if the device is capable.
763To disable background scanning, use
764.Fl bgscan .
765Background scanning is controlled by the
766.Cm bgscanidle
767and
768.Cm bgscanintvl
769parameters.
770Background scanning must be enabled for roaming; this is an artifact
771of the current implementation and may not be required in the future.
772.It Cm bgscanidle Ar idletime
773Set the minimum time a station must be idle (not transmitting or
774receiving frames) before a background scan is initiated.
775The
776.Ar idletime
777parameter is specified in milliseconds.
778By default a station must be idle at least 250 milliseconds before
779a background scan is initiated.
780The idle time may not be set to less than 100 milliseconds.
781.It Cm bgscanintvl Ar interval
782Set the interval at which background scanning is attempted.
783The
784.Ar interval
785parameter is specified in seconds.
786By default a background scan is considered every 300 seconds (5 minutes).
787The
788.Ar interval
789may not be set to less than 15 seconds.
790.It Cm bintval Ar interval
791Set the interval at which beacon frames are sent when operating in
792ad-hoc or ap mode.
793The
794.Ar interval
795parameter is specified in TU's (1024 usecs).
796By default beacon frames are transmitted every 100 TU's.
797.It Cm bmissthreshold Ar count
798Set the number of consecutive missed beacons at which the station
799will attempt to roam (i.e., search for a new access point).
800The
801.Ar count
802parameter must be in the range 1 to 255; though the
803upper bound may be reduced according to device capabilities.
804The default threshold is 7 consecutive missed beacons; but
805this may be overridden by the device driver.
806Another name for the
807.Cm bmissthreshold
808parameter is
809.Cm bmiss .
810.It Cm bssid Ar address
811Specify the MAC address of the access point to use when operating
812as a station in a BSS network.
813This overrides any automatic selection done by the system.
814To disable a previously selected access point, supply
815.Cm any , none ,
816or
817.Cm -
818for the address.
819This option is useful when more than one access point uses the same SSID.
820Another name for the
821.Cm bssid
822parameter is
823.Cm ap .
824.It Cm burst
825Enable packet bursting.
826Packet bursting is a transmission technique whereby the wireless
827medium is acquired once to send multiple frames and the interframe
828spacing is reduced.
829This technique can significantly increase throughput by reducing
830transmission overhead.
831Packet bursting is supported by the 802.11e QoS specification
832and some devices that do not support QoS may still be capable.
833By default packet bursting is enabled if a device is capable
834of doing it.
835To disable packet bursting, use
836.Fl burst .
837.It Cm chanlist Ar channels
838Set the desired channels to use when scanning for access
839points, neighbors in an IBSS network, or looking for unoccupied
840channels when operating as an access point.
841The set of channels is specified as a comma-separated list with
842each element in the list representing either a single channel number or a range
843of the form
844.Dq Li a-b .
845Channel numbers must be in the range 1 to 255 and be permissible
846according to the operating characteristics of the device.
847.It Cm channel Ar number
848Set a single desired channel.
849Channels range from 1 to 255, but the exact selection available
850depends on the region your adaptor was manufactured for.
851Setting
852the channel to
853.Li any ,
854or
855.Cm -
856will clear any desired channel and, if the device is marked up,
857force a scan for a channel to operate on.
858Alternatively the frequency, in megahertz, may be specified
859instead of the channel number.
860.Pp
861When there are several ways to use a channel the channel
862number/frequency may be appended with attributes to clarify.
863For example, if a device is capable of operating on channel 6
864with 802.11n and 802.11g then one can specify that g-only use
865should be used by specifying ``6:g''.
866Similarly the channel width can be specified by appending it
867with ``/''; e.g. ``6/40'' specifies a 40MHz wide channel,
868These attributes can be combined as in: ``6:ht/40''.
869The full set of flags specified following a `:'' are:
870.Cm a
871(802.11a),
872.Cm b
873(802.11b),
874.Cm d
875(Atheros Dynamic Turbo mode),
876.Cm g
877(802.11g),
878.Cm h
879or
880.Cm n
881(802.11n aka HT),
882.Cm s
883(Atheros Static Turbo mode),
884and
885.Cm t
886(Atheros Dynamic Turbo mode, or appended to ``st'' and ``dt'').
887The full set of channel widths following a '/' are:
888.Cm 5
889(5MHz aka quarter-rate channel),
890.Cm 10
891(10MHz aka half-rate channel),
892.Cm 20
893(20MHz mostly for use in specifying ht20),
894and
895.Cm 40
896(40MHz mostly for use in specifying ht40),
897In addition,
898a 40MHz HT channel specification may include the location
899of the extension channel by appending ``+'' or ``-'' for above and below,
900respectively; e.g. ``2437:ht/40+'' specifies 40MHz wide HT operation
901with the center channel at frequency 2437 and the extension channel above.
902.It Cm country Ar name
903Set the country code to use in calculating the regulatory constraints
904for operation.
905In particular the set of available channels, how the wireless device
906will operation on the channels, and the maximum transmit power that
907can be used on a channel are defined by this setting.
908Country/Region codes are specified as a 2-character abbreviation
909defined by ISO 3166 or using a longer, but possibly ambiguous, spelling;
910e.g. "ES" and "Spain".
911The set of country codes are taken from /etc/regdomain.xml and can also
912be viewed with the ``list countries'' request.
913Note that not all devices support changing the country code from a default
914setting; typically stored in EEPROM.
915See also
916.Cm regdomain ,
917.Cm indoor ,
918.Cm outdoor ,
919and
920.Cm anywhere .
921.It Cm dfs
922Enable Dynamic Frequency Selection (DFS) as specified in 802.11h.
923DFS embodies several facilities including detection of overlapping
924radar signals, dynamic transmit power control, and channel selection
925according to a least-congested criteria.
926DFS support is mandatory for some 5Ghz frequencies in certain
927locales (e.g. ETSI).
928By default DFS is enabled according to the regulatory definitions
929specified in /etc/regdomain.xml and the curent country code, regdomain,
930and channel.
931Note the underlying device (and driver) must support radar detection
932for full DFS support to work.
933To be fully compliant with the local regulatory agency frequencies that
934require DFS should not be used unless it is fully supported.
935Use
936.Fl dfs
937to disable this functionality for testing.
938.It Cm dotd
939Enable support for the 802.11d specification (default).
940When this support is enabled in station mode, beacon frames that advertise
941a country code different than the currently configured country code will
942cause an event to be dispatched to user applications.
943This event can be used by the station to adopt that country code and
944operate according to the associated regulatory constraints.
945When operating as an access point with 802.11d enabled the beacon and
946probe response frames transmitted will advertise the current regulatory
947domain settings.
948To disable 802.11d use
949.Fl dotd .
950.It Cm doth
951Enable 802.11h support including spectrum management.
952When 802.11h is enabled beacon and probe response frames will have
953the SpectrumMgt bit set in the capabilities field and
954country and power constraint information elements will be present.
955802.11h support also includes handling Channel Switch Announcements (CSA)
956which are a mechanism to coordinate channel changes by an access point.
957By default 802.11h is enabled if the device is capable.
958To disable 802.11h use
959.Fl doth .
960.It Cm deftxkey Ar index
961Set the default key to use for transmission.
962Typically this is only set when using WEP encryption.
963Note that you must set a default transmit key
964for the system to know which key to use in encrypting outbound traffic.
965The
966.Cm weptxkey
967is an alias for this request; it is provided for backwards compatibility.
968.It Cm dtimperiod Ar period
969Set the
970DTIM
971period for transmitting buffered multicast data frames when
972operating in ap mode.
973The
974.Ar period
975specifies the number of beacon intervals between DTIM
976and must be in the range 1 to 15.
977By default DTIM is 1 (i.e., DTIM occurs at each beacon).
978.It Cm dturbo
979Enable the use of Atheros Dynamic Turbo mode when communicating with
980another Dynamic Turbo-capable station.
981Dynamic Turbo mode is an Atheros-specific mechanism by which
982stations switch between normal 802.11 operation and a ``boosted''
983mode in which a 40MHz wide channel is used for communication.
984Stations using Dynamic Turbo mode operate boosted only when the
985channel is free of non-dturbo stations; when a non-dturbo station
986is identified on the channel all stations will automatically drop
987back to normal operation.
988By default, Dynamic Turbo mode is not enabled, even if the device is capable.
989Note that turbo mode (dynamic or static) is only allowed on some
990channels depending on the regulatory constraints; use the
991.Cm list chan
992command to identify the channels where turbo mode may be used.
993To disable Dynamic Turbo mode use
994.Fl dturbo .
995.It Cm dwds
996Enable Dynamic WDS (DWDS) support.
997DWDS is a facility by which 4-address traffic can be carried between
998stations operating in infrastructure mode.
999A station first associates to an access point and authenticates using
1000normal procedures (e.g. WPA).
1001Then 4-address frames are passed to carry traffic for stations
1002operating on either side of the wireless link.
1003DWDS extends the normal WDS mechanism by leveraging existing security
1004protocols and eliminating static binding.
1005.Pp
1006When DWDS is enabled on an access point 4-address frames received from
1007an authorized station will generate a ``DWDS discovery'' event to user
1008applications.
1009This event should be used to create a WDS interface that is bound
1010to the remote station (and usually plumbed into a bridge).
1011Once the WDS interface is up and running 4-address traffic then logically
1012flows through that interface.
1013.Pp
1014When DWDS is enabled on a station, traffic with a destination address
1015different from the peer station are encapsulated in a 4-address frame
1016and transmitted to the peer.
1017All 4-address traffic uses the security information of the stations
1018(e.g. cryptographic keys).
1019A station is associated using 802.11n facilities may transport
10204-address traffic using these same mechanisms; this depends on available
1021resources and capabilities of the device.
1022The DWDS implementation guards against layer 2 routing loops of
1023multicast traffic.
1024.It Cm ff
1025Enable the use of Atheros Fast Frames when communicating with
1026another Fast Frames-capable station.
1027Fast Frames are an encapsulation technique by which two 802.3
1028frames are transmitted in a single 802.11 frame.
1029This can noticeably improve throughput but requires that the
1030receiving station understand how to decapsulate the frame.
1031Fast frame use is negotiated using the Atheros 802.11 vendor-specific
1032protocol extension so enabling use is safe when communicating with
1033non-Atheros devices.
1034By default, use of fast frames is enabled if the device is capable.
1035To explicitly disable fast frames, use
1036.Fl ff .
1037.It Cm fragthreshold Ar length
1038Set the threshold for which transmitted frames are broken into fragments.
1039The
1040.Ar length
1041argument is the frame size in bytes and must be in the range 256 to 2346.
1042Setting
1043.Ar length
1044to
1045.Li 2346 ,
1046.Cm any ,
1047or
1048.Cm -
1049disables transmit fragmentation.
1050Not all adapters honor the fragmentation threshold.
1051.It Cm hidessid
1052When operating as an access point, do not broadcast the SSID
1053in beacon frames or respond to probe request frames unless
1054they are directed to the ap (i.e., they include the ap's SSID).
1055By default, the SSID is included in beacon frames and
1056undirected probe request frames are answered.
1057To re-enable the broadcast of the SSID etc., use
1058.Fl hidessid .
1059.It Cm ht
1060Enable use of High Throughput (HT) when using 802.11n (default).
1061The 802.11n specification includes mechanisms for operation
1062on 20MHz and 40MHz wide channels using different signalling mechanisms
1063than specified in 802.11b, 802.11g, and 802.11a.
1064Stations negotiate use of these facilities, termed HT20 and HT40,
1065when they associate.
1066To disable all use of 802.11n use
1067.Fl ht .
1068To disable use of HT20 (e.g. to force only HT40 use) use
1069.Fl ht20 .
1070To disable use of HT40 use
1071.Fl ht40 .
1072.Pp
1073HT configuration is used to ``auto promote'' operation
1074when several choices are available.
1075For example, if a station associates to an 11n-capable access point
1076it controls whether the station uses legacy operation, HT20, or HT40.
1077When an 11n-capable device is setup as an access point and
1078Auto Channel Selection is used to locate a channel to operate on,
1079HT configuration controls whether legacy, HT20, or HT40 operation is setup
1080on the selected channel.
1081If a fixed channel is specified for a station then HT configuration can
1082be given as part of the channel specification; e.g. 6:ht/20 to setup
1083HT20 operation on channel 6.
1084.It Cm htcompat
1085Enable use of compatibility support for pre-802.11n devices (default).
1086The 802.11n protocol specification went through several incompatible iterations.
1087Some vendors implemented 11n support to older specifications that
1088will not interoperate with a purely 11n-compliant station.
1089In particular the information elements included in management frames
1090for old devices are different.
1091When compatibility support is enabled both standard and compatible data
1092will be provided.
1093Stations that associate using the compatiblity mechanisms are flagged
1094in ``list sta''.
1095To disable compatiblity support use
1096.Fl htcompat .
1097.It Cm htprotmode Ar technique
1098For interfaces operating in 802.11n, use the specified
1099.Ar technique
1100for protecting HT frames in a mixed legacy/HT network.
1101The set of valid techniques is
1102.Cm off ,
1103and
1104.Cm rts
1105(RTS/CTS, default).
1106Technique names are case insensitive.
1107.It Cm inact
1108Enable inactivity processing for stations associated to an
1109access point (default).
1110When operating as an access point the 802.11 layer monitors
1111the activity of each associated station.
1112When a station is inactive for 5 minutes it will send several
1113``probe frames'' to see if the station is still present.
1114If no response is received then the station is deauthenticated.
1115Applications that prefer to handle this work can disable this
1116facility by using
1117.Fl inact .
1118.It Cm indoor
1119Set the location to use in calculating regulatory constraints.
1120The location is also advertised in beacon and probe response frames
1121when 802.11d is enabled with
1122.Cm dotd .
1123See also
1124.Cm outdoor ,
1125.Cm anywhere ,
1126.Cm country ,
1127and
1128.Cm regdomain .
1129.It Cm list active
1130Display the list of channels available for use taking into account
1131any restrictions set with the
1132.Cm chanlist
1133directive.
1134See the description of
1135.Cm list chan
1136for more information.
1137.It Cm list caps
1138Display the adaptor's capabilities, including the operating
1139modes supported.
1140.It Cm list chan
1141Display the list of channels available for use.
1142Channels are shown with their IEEE channel number, equivalent
1143frequency, and usage modes.
1144Channels identified as
1145.Ql 11g
1146are also usable in
1147.Ql 11b
1148mode.
1149Channels identified as
1150.Ql 11a Turbo
1151may be used only for Atheros' Static Turbo mode
1152(specified with
1153. Cm mediaopt turbo ) .
1154Channels marked with a
1155.Ql *
1156have a regulatory constraint that they be passively scanned.
1157This means a station is not permitted to transmit on the channel until
1158it identifies the channel is being used for 802.11 communication;
1159typically by hearing a beacon frame from an access point operating
1160on the channel.
1161.Cm list freq
1162is another way of requesting this information.
1163By default a compacted list of channels is displayed; if the
1164.Fl v
1165option is specified then all channels are shown.
1166.It Cm list countries
1167Display the set of country codes and regulatory domains that can be
1168used in regulatory configuration.
1169.It Cm list mac
1170Display the current MAC Access Control List state.
1171Each address is prefixed with a character that indicates the
1172current policy applied to it:
1173.Ql +
1174indicates the address is allowed access,
1175.Ql -
1176indicates the address is denied access,
1177.Ql *
1178indicates the address is present but the current policy open
1179(so the ACL is not consulted).
1180.It Cm list regdomain
1181Display the current regulatory settings including the available channels
1182and transmit power caps.
1183.It Cm list roam
1184Display the parameters that govern roaming operation.
1185.It Cm list txparam
1186Display the parameters that govern transmit operation.
1187.It Cm list txpower
1188Display the transmit power caps for each channel.
1189.It Cm list scan
1190Display the access points and/or ad-hoc neighbors
1191located in the vicinity.
1192This information may be updated automatically by the adapter
1193with a
1194.Cm scan
1195request or through background scanning.
1196Depending on the capabilities of the stations the following
1197flags can be included in the output:
1198.Bl -tag -width 3n
1199.It Li A
1200Authorized.
1201Indicates that the station is permitted to send/receive data frames.
1202.It Li E
1203Extended Rate Phy (ERP).
1204Indicates that the station is operating in an 802.11g network
1205using extended transmit rates.
1206.It Li H
1207High Throughput (HT).
1208Indicates that the station is using HT transmit rates.
1209If a `+' follows immediately after then the station associated
1210using deprecated mechanisms supported only when
1211.Cm htcompat
1212is enabled.
1213.It Li P
1214Power Save.
1215Indicates that the station is operating in power save mode.
1216.It Li Q
1217Quality of Service (QoS).
1218Indicates that the station is using QoS encapsulation for
1219data frame.
1220QoS encapsulation is enabled only when WME mode is enabled.
1221.It Li T
1222Transitional Security Network (TSN).
1223Indicates that the station associated using TSN; see also
1224.Cm tsn
1225below.
1226.It Li W
1227Wi-Fi Protected Setup (WPS).
1228Indicates that the station associated using WPS.
1229.El
1230.Pp
1231By default interesting information elements captured from the neighboring
1232stations are displayed at the end of each row.
1233Possible elements include:
1234.Cm WME
1235(station supports WME),
1236.Cm WPA
1237(station supports WPA),
1238.Cm WPS
1239(station supports WPS),
1240.Cm RSN
1241(station supports 802.11i/RSN),
1242.Cm HTCAP
1243(station supports 802.11n/HT communication),
1244.Cm ATH
1245(station supports Atheros protocol extensions),
1246.Cm VEN
1247(station supports unknown vendor-specific extensions).
1248If the
1249.Fl v
1250flag is used all the information elements and their
1251contents will be shown.
1252Specifying The
1253.Fl v
1254flag also enables display of long SSIDs.
1255.Cm list ap
1256is another way of requesting this information.
1257.It Cm list sta
1258When operating as an access point display the stations that are
1259currently associated.
1260When operating in ad-hoc mode display stations identified as
1261neighbors in the IBSS.
1262When operating in station mode display the access point.
1263Capabilities advertised by the stations are described under
1264the
1265.Cm scan
1266request.
1267Depending on the capabilities of the stations the following
1268flags can be included in the output:
1269.Bl -tag -width 3n
1270.It Li A
1271Authorized.
1272Indicates that the station is permitted to send/receive data frames.
1273.It Li E
1274Extended Rate Phy (ERP).
1275Indicates that the station is operating in an 802.11g network
1276using extended transmit rates.
1277.It Li H
1278High Throughput (HT).
1279Indicates that the station is using HT transmit rates.
1280If a `+' follows immediately after then the station associated
1281using deprecated mechanisms supported only when
1282.Cm htcompat
1283is enabled.
1284.It Li P
1285Power Save.
1286Indicates that the station is operating in power save mode.
1287.It Li Q
1288Quality of Service (QoS).
1289Indicates that the station is using QoS encapsulation for
1290data frame.
1291QoS encapsulation is enabled only when WME mode is enabled.
1292.It Li T
1293Transitional Security Network (TSN).
1294Indicates that the station associated using TSN; see also
1295.Cm tsn
1296below.
1297.It Li W
1298Wi-Fi Protected Setup (WPS).
1299Indicates that the station associated using WPS.
1300.El
1301.Pp
1302By default information elements received from associated stations
1303are displayed in a short form; the
1304.Fl v
1305flag causes this information to be displayed symbolically.
1306.It Cm list wme
1307Display the current channel parameters to use when operating in WME mode.
1308If the
1309.Fl v
1310option is specified then both channel and BSS parameters are displayed
1311for each AC (first channel, then BSS).
1312When WME mode is enabled for an adaptor this information will be
1313displayed with the regular status; this command is mostly useful
1314for examining parameters when WME mode is disabled.
1315See the description of the
1316.Cm wme
1317directive for information on the various parameters.
1318.It Cm maxretry Ar count
1319Set the maximum number of tries to use in sending unicast frames.
1320The default setting is 6 but drivers may override this with a value
1321they choose.
1322.It Cm mcastrate Ar rate
1323Set the rate for transmitting multicast/broadcast frames.
1324Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s.
1325This rate should be valid for the current operating conditions;
1326if an invalid rate is specified drivers are free to chose an
1327appropriate rate.
1328.It Cm mgtrate Ar rate
1329Set the rate for transmitting management and/or control frames.
1330Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s.
1331.It Cm outdoor
1332Set the location to use in calculating regulatory constraints.
1333The location is also advertised in beacon and probe response frames
1334when 802.11d is enabled with
1335.Cm dotd .
1336See also
1337.Cm anywhere ,
1338.Cm country ,
1339.Cm indoor ,
1340and
1341.Cm regdomain .
1342.It Cm powersave
1343Enable powersave operation.
1344When operating as a client, the station will conserve power by
1345periodically turning off the radio and listening for
1346messages from the access point telling it there are packets waiting.
1347The station must then retrieve the packets.
1348Not all devices support power save operation as a client.
1349The 802.11 specification requires that all access points support
1350power save but some drivers do not.
1351Use
1352.Fl powersave
1353to disable powersave operation when operating as a client.
1354.It Cm powersavesleep Ar sleep
1355Set the desired max powersave sleep time in TU's (1024 usecs).
1356By default the max powersave sleep time is 100 TU's.
1357.It Cm protmode Ar technique
1358For interfaces operating in 802.11g, use the specified
1359.Ar technique
1360for protecting OFDM frames in a mixed 11b/11g network.
1361The set of valid techniques is
1362.Cm off , cts
1363(CTS to self),
1364and
1365.Cm rtscts
1366(RTS/CTS).
1367Technique names are case insensitive.
1368Not all devices support
1369.Cm cts
1370as a protection technique.
1371.It Cm pureg
1372When operating as an access point in 802.11g mode allow only
137311g-capable stations to associate (11b-only stations are not
1374permitted to associate).
1375To allow both 11g and 11b-only stations to associate, use
1376.Fl pureg .
1377.It Cm puren
1378When operating as an access point in 802.11n mode allow only
1379HT-capable stations to associate (legacy stations are not
1380permitted to associate).
1381To allow both HT and legacy stations to associate, use
1382.Fl puren .
1383.It Cm regdomain Ar sku
1384Set the regulatory domain to use in calculating the regulatory constraints
1385for operation.
1386In particular the set of available channels, how the wireless device
1387will operation on the channels, and the maximum transmit power that
1388can be used on a channel are defined by this setting.
1389Regdomain codes (SKU's) are taken from /etc/regdomain.xml and can also
1390be viewed with the ``list countries'' request.
1391Note that not all devices support changing the regdomain from a default
1392setting; typically stored in EEPROM.
1393See also
1394.Cm country ,
1395.Cm indoor ,
1396.Cm outdoor ,
1397and
1398.Cm anywhere .
1399.It Cm rifs
1400Enable use of Reduced InterFrame Spacing (RIFS) when operating in 802.11n
1401on an HT channel.
1402Note that RIFS must be supported by both the station and access point
1403for it to be used.
1404To disable RIFS use
1405.Fl rifs .
1406.It Cm roam:rate Ar rate
1407Set the threshold for controlling roaming when operating in a BSS.
1408The
1409.Ar rate
1410parameter specifies the transmit rate in megabits
1411at which roaming should be considered.
1412If the current transmit rate drops below this setting and background scanning
1413is enabled, then the system will check if a more desirable access point is
1414available and switch over to it.
1415The current scan cache contents are used if they are considered
1416valid according to the
1417.Cm scanvalid
1418parameter; otherwise a background scan operation is triggered before
1419any selection occurs.
1420Each channel type has a separate rate threshold; the default values are:
142112 Mb/s (11a), 2 Mb/s (11b), 2 Mb/s (11g), MCS 1 (11na, 11ng).
1422.It Cm roam:rssi Ar rssi
1423Set the threshold for controlling roaming when operating in a BSS.
1424The
1425.Ar rssi
1426parameter specifies the receive signal strength in dBm units
1427at which roaming should be considered.
1428If the current rssi drops below this setting and background scanning
1429is enabled, then the system will check if a more desirable access point is
1430available and switch over to it.
1431The current scan cache contents are used if they are considered
1432valid according to the
1433.Cm scanvalid
1434parameter; otherwise a background scan operation is triggered before
1435any selection occurs.
1436Each channel type has a separate rssi threshold; the default values are
1437all 7 dBm.
1438.It Cm roaming Ar mode
1439When operating as a station, control how the system will
1440behave when communication with the current access point
1441is broken.
1442The
1443.Ar mode
1444argument may be one of
1445.Cm device
1446(leave it to the hardware device to decide),
1447.Cm auto
1448(handle either in the device or the operating system\[em]as appropriate),
1449.Cm manual
1450(do nothing until explicitly instructed).
1451By default, the device is left to handle this if it is
1452capable; otherwise, the operating system will automatically
1453attempt to reestablish communication.
1454Manual mode is used by applications such as
1455.Xr wpa_supplicant 8
1456that want to control the selection of an access point.
1457.It Cm rtsthreshold Ar length
1458Set the threshold for which
1459transmitted frames are preceded by transmission of an
1460RTS
1461control frame.
1462The
1463.Ar length
1464argument
1465is the frame size in bytes and must be in the range 1 to 2346.
1466Setting
1467.Ar length
1468to
1469.Li 2346 ,
1470.Cm any ,
1471or
1472.Cm -
1473disables transmission of RTS frames.
1474Not all adapters support setting the RTS threshold.
1475.It Cm scan
1476Initiate a scan of neighboring stations, wait for it to complete, and
1477display all stations found.
1478Only the super-user can initiate a scan.
1479See
1480.Cm list scan
1481for information on the display.
1482By default a background scan is done; otherwise a foreground
1483scan is done and the station may roam to a different access point.
1484The
1485.Cm list scan
1486request can be used to show recent scan results without
1487initiating a new scan.
1488.It Cm scanvalid Ar threshold
1489Set the maximum time the scan cache contents are considered valid;
1490i.e. will be used without first triggering a scan operation to
1491refresh the data.
1492The
1493.Ar threshold
1494parameter is specified in seconds and defaults to 60 seconds.
1495The minimum setting for
1496.Ar threshold
1497is 10 seconds.
1498One should take care setting this threshold; if it is set too low
1499then attempts to roam to another access point may trigger unnecessary
1500background scan operations.
1501.It Cm shortgi
1502Enable use of Short Guard Interval when operating in 802.11n
1503on an HT channel.
1504NB: this currently enables Short GI on both HT40 and HT20 channels.
1505To disable Short GI use
1506.Fl shortgi .
1507.It Cm smps
1508Enable use of Static Spatial Multiplexing Power Save (SMPS)
1509when operating in 802.11n.
1510A station operating with Static SMPS maintains only a single
1511receive chain active (this can significantly reduce power consumption).
1512To disable SMPS use
1513.Fl smps .
1514.It Cm smpsdyn
1515Enable use of Dynamic Spatial Multiplexing Power Save (SMPS)
1516when operating in 802.11n.
1517A station operating with Dynamic SMPS maintains only a single
1518receive chain active but switches to multiple receive chains when it
1519receives an RTS frame (this can significantly reduce power consumption).
1520Note that stations cannot distinguish between RTS/CTS intended to
1521enable multiple receive chains and those used for other purposes.
1522To disable SMPS use
1523.Fl smps .
1524.It Cm ssid Ar ssid
1525Set the desired Service Set Identifier (aka network name).
1526The SSID is a string up to 32 characters
1527in length and may be specified as either a normal string or in
1528hexadecimal when preceded by
1529.Ql 0x .
1530Additionally, the SSID may be cleared by setting it to
1531.Ql - .
1532.It Cm tsn
1533When operating as an access point with WPA/802.11i allow legacy
1534stations to associate using static key WEP and open authentication.
1535To disallow legacy station use of WEP, use
1536.Fl tsn .
1537.It Cm txpower Ar power
1538Set the power used to transmit frames.
1539The
1540.Ar power
1541argument is specified in .5 dBm units.
1542Out of range values are truncated.
1543Typically only a few discreet power settings are available and
1544the driver will use the setting closest to the specified value.
1545Not all adapters support changing the transmit power.
1546.It Cm ucastrate Ar rate
1547Set a fixed rate for transmitting unicast frames.
1548Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s.
1549This rate should be valid for the current operating conditions;
1550if an invalid rate is specified drivers are free to chose an
1551appropriate rate.
1552.It Cm wepmode Ar mode
1553Set the desired WEP mode.
1554Not all adapters support all modes.
1555The set of valid modes is
1556.Cm off , on ,
1557and
1558.Cm mixed .
1559The
1560.Cm mixed
1561mode explicitly tells the adaptor to allow association with access
1562points which allow both encrypted and unencrypted traffic.
1563On these adapters,
1564.Cm on
1565means that the access point must only allow encrypted connections.
1566On other adapters,
1567.Cm on
1568is generally another name for
1569.Cm mixed .
1570Modes are case insensitive.
1571.It Cm weptxkey Ar index
1572Set the WEP key to be used for transmission.
1573This is the same as setting the default transmission key with
1574.Cm deftxkey .
1575.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key
1576Set the selected WEP key.
1577If an
1578.Ar index
1579is not given, key 1 is set.
1580A WEP key will be either 5 or 13
1581characters (40 or 104 bits) depending of the local network and the
1582capabilities of the adaptor.
1583It may be specified either as a plain
1584string or as a string of hexadecimal digits preceded by
1585.Ql 0x .
1586For maximum portability, hex keys are recommended;
1587the mapping of text keys to WEP encryption is usually driver-specific.
1588In particular, the
1589.Tn Windows
1590drivers do this mapping differently to
1591.Fx .
1592A key may be cleared by setting it to
1593.Ql - .
1594If WEP is supported then there are at least four keys.
1595Some adapters support more than four keys.
1596If that is the case, then the first four keys
1597(1-4) will be the standard temporary keys and any others will be adaptor
1598specific keys such as permanent keys stored in NVRAM.
1599.Pp
1600Note that you must set a default transmit key with
1601.Cm deftxkey
1602for the system to know which key to use in encrypting outbound traffic.
1603.It Cm wme
1604Enable Wireless Multimedia Extensions (WME) support, if available,
1605for the specified interface.
1606WME is a subset of the IEEE 802.11e standard to support the
1607efficient communication of realtime and multimedia data.
1608To disable WME support, use
1609.Fl wme .
1610Another name for this parameter is
1611.Cm wmm .
1612.Pp
1613The following parameters are meaningful only when WME support is in use.
1614Parameters are specified per-AC (Access Category) and
1615split into those that are used by a station when acting
1616as an access point and those for client stations in the BSS.
1617The latter are received from the access point and may not be changed
1618(at the station).
1619The following Access Categories are recognized:
1620.Pp
1621.Bl -tag -width ".Cm AC_BK" -compact
1622.It Cm AC_BE
1623(or
1624.Cm BE )
1625best effort delivery,
1626.It Cm AC_BK
1627(or
1628.Cm BK )
1629background traffic,
1630.It Cm AC_VI
1631(or
1632.Cm VI )
1633video traffic,
1634.It Cm AC_VO
1635(or
1636.Cm VO )
1637voice traffic.
1638.El
1639.Pp
1640AC parameters are case-insensitive.
1641Traffic classification is done in the operating system using the
1642vlan priority associated with data frames or the
1643ToS (Type of Service) indication in IP-encapsulated frames.
1644If neither information is present, traffic is assigned to the
1645Best Effort (BE) category.
1646.Bl -tag -width indent
1647.It Cm ack Ar ac
1648Set the ACK policy for QoS transmissions by the local station;
1649this controls whether or not data frames transmitted by a station
1650require an ACK response from the receiving station.
1651To disable waiting for an ACK use
1652.Fl ack .
1653This parameter is applied only to the local station.
1654.It Cm acm Ar ac
1655Enable the Admission Control Mandatory (ACM) mechanism
1656for transmissions by the local station.
1657To disable the ACM use
1658.Fl acm .
1659On stations in a BSS this parameter is read-only and indicates
1660the setting received from the access point.
1661NB: ACM is not supported right now.
1662.It Cm aifs Ar ac Ar count
1663Set the Arbitration Inter Frame Spacing (AIFS)
1664channel access parameter to use for transmissions
1665by the local station.
1666On stations in a BSS this parameter is read-only and indicates
1667the setting received from the access point.
1668.It Cm cwmin Ar ac Ar count
1669Set the CWmin channel access parameter to use for transmissions
1670by the local station.
1671On stations in a BSS this parameter is read-only and indicates
1672the setting received from the access point.
1673.It Cm cwmax Ar ac Ar count
1674Set the CWmax channel access parameter to use for transmissions
1675by the local station.
1676On stations in a BSS this parameter is read-only and indicates
1677the setting received from the access point.
1678.It Cm txoplimit Ar ac Ar limit
1679Set the Transmission Opportunity Limit channel access parameter
1680to use for transmissions by the local station.
1681This parameter defines an interval of time when a WME station
1682has the right to initiate transmissions onto the wireless medium.
1683On stations in a BSS this parameter is read-only and indicates
1684the setting received from the access point.
1685.It Cm bss:aifs Ar ac Ar count
1686Set the AIFS channel access parameter to send to stations in a BSS.
1687This parameter is meaningful only when operating in ap mode.
1688.It Cm bss:cwmin Ar ac Ar count
1689Set the CWmin channel access parameter to send to stations in a BSS.
1690This parameter is meaningful only when operating in ap mode.
1691.It Cm bss:cwmax Ar ac Ar count
1692Set the CWmax channel access parameter to send to stations in a BSS.
1693This parameter is meaningful only when operating in ap mode.
1694.It Cm bss:txoplimit Ar ac Ar limit
1695Set the TxOpLimit channel access parameter to send to stations in a BSS.
1696This parameter is meaningful only when operating in ap mode.
1697.El
1698.It Cm wps
1699Enable Wireless Privacy Subscriber support.
1700Note that WPS support requires a WPS-capable supplicant.
1701To disable this function use
1702.Fl wps .
1703.El
1704.Pp
1705The following parameters support an optional access control list
1706feature available with some adapters when operating in ap mode; see
1707.Xr wlan_acl 4 .
1708This facility allows an access point to accept/deny association
1709requests based on the MAC address of the station.
1710Note that this feature does not significantly enhance security
1711as MAC address spoofing is easy to do.
1712.Bl -tag -width indent
1713.It Cm mac:add Ar address
1714Add the specified MAC address to the database.
1715Depending on the policy setting association requests from the
1716specified station will be allowed or denied.
1717.It Cm mac:allow
1718Set the ACL policy to permit association only by
1719stations registered in the database.
1720.It Cm mac:del Ar address
1721Delete the specified MAC address from the database.
1722.It Cm mac:deny
1723Set the ACL policy to deny association only by
1724stations registered in the database.
1725.It Cm mac:kick Ar address
1726Force the specified station to be deauthenticated.
1727This typically is done to block a station after updating the
1728address database.
1729.It Cm mac:open
1730Set the ACL policy to allow all stations to associate.
1731.It Cm mac:flush
1732Delete all entries in the database.
1733.It Cm mac:radius
1734Set the ACL policy to permit association only by
1735stations approved by a RADIUS server.
1736Note that this feature requires the
1737.Xr hostapd 8
1738program be configured to do the right thing
1739as it handles the RADIUS processing
1740(and marks stations as authorized).
1741.El
1742.Pp
1743The following parameters are for compatibility with other systems:
1744.Bl -tag -width indent
1745.It Cm nwid Ar ssid
1746Another name for the
1747.Cm ssid
1748parameter.
1749Included for
1750.Nx
1751compatibility.
1752.It Cm stationname Ar name
1753Set the name of this station.
1754The station name is not part of the IEEE 802.11
1755protocol though some interfaces support it.
1756As such it only
1757seems to be meaningful to identical or virtually identical equipment.
1758Setting the station name is identical in syntax to setting the SSID.
1759One can also use
1760.Cm station
1761for
1762.Bsx
1763compatibility.
1764.It Cm wep
1765Another way of saying
1766.Cm wepmode on .
1767Included for
1768.Bsx
1769compatibility.
1770.It Fl wep
1771Another way of saying
1772.Cm wepmode off .
1773Included for
1774.Bsx
1775compatibility.
1776.It Cm nwkey key
1777Another way of saying:
1778.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" .
1779Included for
1780.Nx
1781compatibility.
1782.It Cm nwkey Xo
1783.Sm off
1784.Ar n : k1 , k2 , k3 , k4
1785.Sm on
1786.Xc
1787Another way of saying
1788.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" .
1789Included for
1790.Nx
1791compatibility.
1792.It Fl nwkey
1793Another way of saying
1794.Cm wepmode off .
1795Included for
1796.Nx
1797compatibility.
1798.El
1799.Pp
1800The following parameters are specific to bridge interfaces:
1801.Bl -tag -width indent
1802.It Cm addm Ar interface
1803Add the interface named by
1804.Ar interface
1805as a member of the bridge.
1806The interface is put into promiscuous mode
1807so that it can receive every packet sent on the network.
1808.It Cm deletem Ar interface
1809Remove the interface named by
1810.Ar interface
1811from the bridge.
1812Promiscuous mode is disabled on the interface when
1813it is removed from the bridge.
1814.It Cm maxaddr Ar size
1815Set the size of the bridge address cache to
1816.Ar size .
1817The default is 100 entries.
1818.It Cm timeout Ar seconds
1819Set the timeout of address cache entries to
1820.Ar seconds
1821seconds.
1822If
1823.Ar seconds
1824is zero, then address cache entries will not be expired.
1825The default is 240 seconds.
1826.It Cm addr
1827Display the addresses that have been learned by the bridge.
1828.It Cm static Ar interface-name Ar address
1829Add a static entry into the address cache pointing to
1830.Ar interface-name .
1831Static entries are never aged out of the cache or re-placed, even if the
1832address is seen on a different interface.
1833.It Cm deladdr Ar address
1834Delete
1835.Ar address
1836from the address cache.
1837.It Cm flush
1838Delete all dynamically-learned addresses from the address cache.
1839.It Cm flushall
1840Delete all addresses, including static addresses, from the address cache.
1841.It Cm discover Ar interface
1842Mark an interface as a
1843.Dq discovering
1844interface.
1845When the bridge has no address cache entry
1846(either dynamic or static)
1847for the destination address of a packet,
1848the bridge will forward the packet to all
1849member interfaces marked as
1850.Dq discovering .
1851This is the default for all interfaces added to a bridge.
1852.It Cm -discover Ar interface
1853Clear the
1854.Dq discovering
1855attribute on a member interface.
1856For packets without the
1857.Dq discovering
1858attribute, the only packets forwarded on the interface are broadcast
1859or multicast packets and packets for which the destination address
1860is known to be on the interface's segment.
1861.It Cm learn Ar interface
1862Mark an interface as a
1863.Dq learning
1864interface.
1865When a packet arrives on such an interface, the source
1866address of the packet is entered into the address cache as being a
1867destination address on the interface's segment.
1868This is the default for all interfaces added to a bridge.
1869.It Cm -learn Ar interface
1870Clear the
1871.Dq learning
1872attribute on a member interface.
1873.It Cm sticky Ar interface
1874Mark an interface as a
1875.Dq sticky
1876interface.
1877Dynamically learned address entries are treated at static once entered into
1878the cache.
1879Sticky entries are never aged out of the cache or replaced, even if the
1880address is seen on a different interface.
1881.It Cm -sticky Ar interface
1882Clear the
1883.Dq sticky
1884attribute on a member interface.
1885.It Cm private Ar interface
1886Mark an interface as a
1887.Dq private
1888interface.
1889A private interface does not forward any traffic to any other port that is also
1890a private interface.
1891.It Cm -private Ar interface
1892Clear the
1893.Dq private
1894attribute on a member interface.
1895.It Cm span Ar interface
1896Add the interface named by
1897.Ar interface
1898as a span port on the bridge.
1899Span ports transmit a copy of every frame received by the bridge.
1900This is most useful for snooping a bridged network passively on
1901another host connected to one of the span ports of the bridge.
1902.It Cm -span Ar interface
1903Delete the interface named by
1904.Ar interface
1905from the list of span ports of the bridge.
1906.It Cm stp Ar interface
1907Enable Spanning Tree protocol on
1908.Ar interface .
1909The
1910.Xr if_bridge 4
1911driver has support for the IEEE 802.1D Spanning Tree protocol (STP).
1912Spanning Tree is used to detect and remove loops in a network topology.
1913.It Cm -stp Ar interface
1914Disable Spanning Tree protocol on
1915.Ar interface .
1916This is the default for all interfaces added to a bridge.
1917.It Cm edge Ar interface
1918Set
1919.Ar interface
1920as an edge port.
1921An edge port connects directly to end stations cannot create bridging
1922loops in the network, this allows it to transition straight to forwarding.
1923.It Cm -edge Ar interface
1924Disable edge status on
1925.Ar interface .
1926.It Cm autoedge Ar interface
1927Allow
1928.Ar interface
1929to automatically detect edge status.
1930This is the default for all interfaces added to a bridge.
1931.It Cm -autoedge Ar interface
1932Disable automatic edge status on
1933.Ar interface .
1934.It Cm ptp Ar interface
1935Set the
1936.Ar interface
1937as a point to point link.
1938This is required for straight transitions to forwarding and
1939should be enabled on a direct link to another RSTP capable switch.
1940.It Cm -ptp Ar interface
1941Disable point to point link status on
1942.Ar interface .
1943This should be disabled for a half duplex link and for an interface
1944connected to a shared network segment,
1945like a hub or a wireless network.
1946.It Cm autoptp Ar interface
1947Automatically detect the point to point status on
1948.Ar interface
1949by checking the full duplex link status.
1950This is the default for interfaces added to the bridge.
1951.It Cm -autoptp Ar interface
1952Disable automatic point to point link detection on
1953.Ar interface .
1954.It Cm maxage Ar seconds
1955Set the time that a Spanning Tree protocol configuration is valid.
1956The default is 20 seconds.
1957The minimum is 6 seconds and the maximum is 40 seconds.
1958.It Cm fwddelay Ar seconds
1959Set the time that must pass before an interface begins forwarding
1960packets when Spanning Tree is enabled.
1961The default is 15 seconds.
1962The minimum is 4 seconds and the maximum is 30 seconds.
1963.It Cm hellotime Ar seconds
1964Set the time between broadcasting of Spanning Tree protocol
1965configuration messages.
1966The hello time may only be changed when operating in legacy stp mode.
1967The default is 2 seconds.
1968The minimum is 1 second and the maximum is 2 seconds.
1969.It Cm priority Ar value
1970Set the bridge priority for Spanning Tree.
1971The default is 32768.
1972The minimum is 0 and the maximum is 61440.
1973.It Cm proto Ar value
1974Set the Spanning Tree protocol.
1975The default is rstp.
1976The available options are stp and rstp.
1977.It Cm holdcnt Ar value
1978Set the transmit hold count for Spanning Tree.
1979This is the number of packets transmitted before being rate limited.
1980The default is 6.
1981The minimum is 1 and the maximum is 10.
1982.It Cm ifpriority Ar interface Ar value
1983Set the Spanning Tree priority of
1984.Ar interface
1985to
1986.Ar value .
1987The default is 128.
1988The minimum is 0 and the maximum is 240.
1989.It Cm ifpathcost Ar interface Ar value
1990Set the Spanning Tree path cost of
1991.Ar interface
1992to
1993.Ar value .
1994The default is calculated from the link speed.
1995To change a previously selected path cost back to automatic, set the
1996cost to 0.
1997The minimum is 1 and the maximum is 200000000.
1998.It Cm ifmaxaddr Ar interface Ar size
1999Set the maximum number of hosts allowed from an interface, packets with unknown
2000source addresses are dropped until an existing host cache entry expires or is
2001removed.
2002Set to 0 to disable.
2003.El
2004.Pp
2005The following parameters are specific to lagg interfaces:
2006.Bl -tag -width indent
2007.It Cm laggport Ar interface
2008Add the interface named by
2009.Ar interface
2010as a port of the aggregation interface.
2011.It Cm -laggport Ar interface
2012Remove the interface named by
2013.Ar interface
2014from the aggregation interface.
2015.It Cm laggproto Ar proto
2016Set the aggregation protocol.
2017The default is failover.
2018The available options are failover, fec, lacp, loadbalance, roundrobin and
2019none.
2020.El
2021.Pp
2022The following parameters are specific to IP tunnel interfaces,
2023.Xr gif 4 :
2024.Bl -tag -width indent
2025.It Cm tunnel Ar src_addr dest_addr
2026Configure the physical source and destination address for IP tunnel
2027interfaces.
2028The arguments
2029.Ar src_addr
2030and
2031.Ar dest_addr
2032are interpreted as the outer source/destination for the encapsulating
2033IPv4/IPv6 header.
2034.It Fl tunnel
2035Unconfigure the physical source and destination address for IP tunnel
2036interfaces previously configured with
2037.Cm tunnel .
2038.It Cm deletetunnel
2039Another name for the
2040.Fl tunnel
2041parameter.
2042.El
2043.Pp
2044The following parameters are specific to GRE tunnel interfaces,
2045.Xr gre 4 :
2046.Bl -tag -width indent
2047.It Cm grekey Ar key
2048Configure the GRE key to be used for outgoing packets.
2049Note that
2050.Xr gre 4 will always accept GRE packets with invalid or absent keys.
2051This command will result in a four byte MTU reduction on the interface.
2052.El
2053.Pp
2054The following parameters are specific to
2055.Xr pfsync 4
2056interfaces:
2057.Bl -tag -width indent
2058.It Cm maxupd Ar n
2059Set the maximum number of updates for a single state which
2060can be collapsed into one.
2061This is an 8-bit number; the default value is 128.
2062.El
2063.Pp
2064The following parameters are specific to
2065.Xr vlan 4
2066interfaces:
2067.Bl -tag -width indent
2068.It Cm vlan Ar vlan_tag
2069Set the VLAN tag value to
2070.Ar vlan_tag .
2071This value is a 16-bit number which is used to create an 802.1Q
2072VLAN header for packets sent from the
2073.Xr vlan 4
2074interface.
2075Note that
2076.Cm vlan
2077and
2078.Cm vlandev
2079must both be set at the same time.
2080.It Cm vlandev Ar iface
2081Associate the physical interface
2082.Ar iface
2083with a
2084.Xr vlan 4
2085interface.
2086Packets transmitted through the
2087.Xr vlan 4
2088interface will be
2089diverted to the specified physical interface
2090.Ar iface
2091with 802.1Q VLAN encapsulation.
2092Packets with 802.1Q encapsulation received
2093by the parent interface with the correct VLAN tag will be diverted to
2094the associated
2095.Xr vlan 4
2096pseudo-interface.
2097The
2098.Xr vlan 4
2099interface is assigned a
2100copy of the parent interface's flags and the parent's ethernet address.
2101The
2102.Cm vlandev
2103and
2104.Cm vlan
2105must both be set at the same time.
2106If the
2107.Xr vlan 4
2108interface already has
2109a physical interface associated with it, this command will fail.
2110To
2111change the association to another physical interface, the existing
2112association must be cleared first.
2113.Pp
2114Note: if the hardware tagging capability
2115is set on the parent interface, the
2116.Xr vlan 4
2117pseudo
2118interface's behavior changes:
2119the
2120.Xr vlan 4
2121interface recognizes that the
2122parent interface supports insertion and extraction of VLAN tags on its
2123own (usually in firmware) and that it should pass packets to and from
2124the parent unaltered.
2125.It Fl vlandev Op Ar iface
2126If the driver is a
2127.Xr vlan 4
2128pseudo device, disassociate the parent interface from it.
2129This breaks the link between the
2130.Xr vlan 4
2131interface and its parent,
2132clears its VLAN tag, flags and its link address and shuts the interface down.
2133The
2134.Ar iface
2135argument is useless and hence deprecated.
2136.El
2137.Pp
2138The following parameters are specific to
2139.Xr carp 4
2140interfaces:
2141.Bl -tag -width indent
2142.It Cm advbase Ar seconds
2143Specifies the base of the advertisement interval in seconds.
2144The acceptable values are 1 to 255.
2145The default value is 1.
2146.\" The default value is
2147.\" .Dv CARP_DFLTINTV .
2148.It Cm advskew Ar interval
2149Specifies the skew to add to the base advertisement interval to
2150make one host advertise slower than another host.
2151It is specified in 1/256 of seconds.
2152The acceptable values are 1 to 254.
2153The default value is 0.
2154.It Cm pass Ar phrase
2155Set the authentication key to
2156.Ar phrase .
2157.It Cm vhid Ar n
2158Set the virtual host ID.
2159This is a required setting.
2160Acceptable values are 1 to 255.
2161.El
2162.Pp
2163The
2164.Nm
2165utility displays the current configuration for a network interface
2166when no optional parameters are supplied.
2167If a protocol family is specified,
2168.Nm
2169will report only the details specific to that protocol family.
2170.Pp
2171If the
2172.Fl m
2173flag is passed before an interface name,
2174.Nm
2175will display the capability list and all
2176of the supported media for the specified interface.
2177If
2178.Fl L
2179flag is supplied, address lifetime is displayed for IPv6 addresses,
2180as time offset string.
2181.Pp
2182Optionally, the
2183.Fl a
2184flag may be used instead of an interface name.
2185This flag instructs
2186.Nm
2187to display information about all interfaces in the system.
2188The
2189.Fl d
2190flag limits this to interfaces that are down, and
2191.Fl u
2192limits this to interfaces that are up.
2193When no arguments are given,
2194.Fl a
2195is implied.
2196.Pp
2197The
2198.Fl l
2199flag may be used to list all available interfaces on the system, with
2200no other additional information.
2201Use of this flag is mutually exclusive
2202with all other flags and commands, except for
2203.Fl d
2204(only list interfaces that are down)
2205and
2206.Fl u
2207(only list interfaces that are up).
2208.Pp
2209The
2210.Fl v
2211flag may be used to get more verbose status for an interface.
2212.Pp
2213The
2214.Fl C
2215flag may be used to list all of the interface cloners available on
2216the system, with no additional information.
2217Use of this flag is mutually exclusive with all other flags and commands.
2218.Pp
2219The
2220.Fl k
2221flag causes keying information for the interface, if available, to be
2222printed.
2223For example, the values of 802.11 WEP keys will be printed, if accessible to
2224the current user.
2225This information is not printed by default, as it may be considered
2226sensitive.
2227.Pp
2228If the network interface driver is not present in the kernel then
2229.Nm
2230will attempt to load it.
2231The
2232.Fl n
2233flag disables this behavior.
2234.Pp
2235Only the super-user may modify the configuration of a network interface.
2236.Sh NOTES
2237The media selection system is relatively new and only some drivers support
2238it (or have need for it).
2239.Sh EXAMPLES
2240Assign the IPv4 address
2241.Li 192.0.2.10 ,
2242with a network mask of
2243.Li 255.255.255.0 ,
2244to the interface
2245.Li fxp0 :
2246.Dl # ifconfig fxp0 inet 192.0.2.10 netmask 255.255.255.0
2247.Pp
2248Add the IPv4 address
2249.Li 192.0.2.45 ,
2250with the CIDR network prefix
2251.Li /28 ,
2252to the interface
2253.Li ed0 ,
2254using
2255.Cm add
2256as a synonym for the canonical form of the option
2257.Cm alias :
2258.Dl # ifconfig ed0 inet 192.0.2.45/28 add
2259.Pp
2260Remove the IPv4 address
2261.Li 192.0.2.45
2262from the interface
2263.Li ed0 :
2264.Dl # ifconfig ed0 inet 192.0.2.45 -alias
2265.Pp
2266Add the IPv6 address
2267.Li 2001:DB8:DBDB::123/48
2268to the interface
2269.Li em0 :
2270.Dl # ifconfig em0 inet6 2001:db8:bdbd::123 prefixlen 48 alias
2271Note that lower case hexadecimal IPv6 addresses are acceptable.
2272.Pp
2273Remove the IPv6 address added in the above example,
2274using the
2275.Li /
2276character as shorthand for the network prefix,
2277and using
2278.Cm delete
2279as a synonym for the canonical form of the option
2280.Fl alias :
2281.Dl # ifconfig em0 inet6 2001:db8:bdbd::123/48 delete
2282.Pp
2283Configure the interface
2284.Li xl0 ,
2285to use 100baseTX, full duplex Ethernet media options:
2286.Dl # ifconfig xl0 media 100baseTX mediaopt full-duplex
2287.Pp
2288Create the software network interface
2289.Li gif1 :
2290.Dl # ifconfig gif1 create
2291.Pp
2292Destroy the software network interface
2293.Li gif1 :
2294.Dl # ifconfig gif1 destroy
2295.Sh DIAGNOSTICS
2296Messages indicating the specified interface does not exist, the
2297requested address is unknown, or the user is not privileged and
2298tried to alter an interface's configuration.
2299.Sh SEE ALSO
2300.Xr netstat 1 ,
2301.Xr carp 4 ,
2302.Xr netintro 4 ,
2303.Xr pfsync 4 ,
2304.Xr polling 4 ,
2305.Xr vlan 4 ,
2306.\" .Xr eon 5 ,
2307.Xr rc 8 ,
2308.Xr routed 8 ,
2309.Xr sysctl 8
2310.Sh HISTORY
2311The
2312.Nm
2313utility appeared in
2314.Bx 4.2 .
2315.Sh BUGS
2316Basic IPv6 node operation requires a link-local address on each
2317interface configured for IPv6.
2318Normally, such an address is automatically configured by the
2319kernel on each interface added to the system; this behaviour may
2320be disabled by setting the sysctl MIB variable
2321.Va net.inet6.ip6.auto_linklocal
2322to 0.
2323.Pp
2324If you delete such an address using
2325.Nm ,
2326the kernel may act very odd.
2327Do this at your own risk.
2328