xref: /freebsd/sbin/ifconfig/ifconfig.8 (revision 271c3a9060f2ee55607ebe146523f888e1db2654)
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28.\"     From: @(#)ifconfig.8	8.3 (Berkeley) 1/5/94
29.\" $FreeBSD$
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31.Dd August 8, 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
406If the driver offers user-configurable VLAN support, enable
407reception of extended frames or tag processing in hardware,
408respectively.
409Note that this must be issued on a physical interface associated with
410.Xr vlan 4 ,
411not on a
412.Xr vlan 4
413interface itself.
414.It Fl vlanmtu , vlanhwtag
415If the driver offers user-configurable VLAN support, disable
416reception of extended frames or tag processing in hardware,
417respectively.
418.It Cm polling
419Turn on
420.Xr polling 4
421feature and disable interrupts on the interface, if driver supports
422this mode.
423.It Fl polling
424Turn off
425.Xr polling 4
426feature and enable interrupt mode on the interface.
427.It Cm create
428Create the specified network pseudo-device.
429If the interface is given without a unit number, try to create a new
430device with an arbitrary unit number.
431If creation of an arbitrary device is successful, the new device name is
432printed to standard output unless the interface is renamed or destroyed
433in the same
434.Nm
435invocation.
436.It Cm destroy
437Destroy the specified network pseudo-device.
438.It Cm plumb
439Another name for the
440.Cm create
441parameter.
442Included for
443.Tn Solaris
444compatibility.
445.It Cm unplumb
446Another name for the
447.Cm destroy
448parameter.
449Included for
450.Tn Solaris
451compatibility.
452.It Cm metric Ar n
453Set the routing metric of the interface to
454.Ar n ,
455default 0.
456The routing metric is used by the routing protocol
457.Pq Xr routed 8 .
458Higher metrics have the effect of making a route
459less favorable; metrics are counted as additional hops
460to the destination network or host.
461.It Cm mtu Ar n
462Set the maximum transmission unit of the interface to
463.Ar n ,
464default is interface specific.
465The MTU is used to limit the size of packets that are transmitted on an
466interface.
467Not all interfaces support setting the MTU, and some interfaces have
468range restrictions.
469.It Cm netmask Ar mask
470.\" (Inet and ISO.)
471(Inet only.)
472Specify how much of the address to reserve for subdividing
473networks into sub-networks.
474The mask includes the network part of the local address
475and the subnet part, which is taken from the host field of the address.
476The mask can be specified as a single hexadecimal number
477with a leading
478.Ql 0x ,
479with a dot-notation Internet address,
480or with a pseudo-network name listed in the network table
481.Xr networks 5 .
482The mask contains 1's for the bit positions in the 32-bit address
483which are to be used for the network and subnet parts,
484and 0's for the host part.
485The mask should contain at least the standard network portion,
486and the subnet field should be contiguous with the network
487portion.
488.Pp
489The netmask can also be specified in CIDR notation after the address.
490See the
491.Ar address
492option above for more information.
493.It Cm prefixlen Ar len
494(Inet6 only.)
495Specify that
496.Ar len
497bits are reserved for subdividing networks into sub-networks.
498The
499.Ar len
500must be integer, and for syntactical reason it must be between 0 to 128.
501It is almost always 64 under the current IPv6 assignment rule.
502If the parameter is omitted, 64 is used.
503.Pp
504The prefix can also be specified using the slash notation after the address.
505See the
506.Ar address
507option above for more information.
508.\" see
509.\" Xr eon 5 .
510.\" .It Cm nsellength Ar n
511.\" .Pf ( Tn ISO
512.\" only)
513.\" This specifies a trailing number of bytes for a received
514.\" .Tn NSAP
515.\" used for local identification, the remaining leading part of which is
516.\" taken to be the
517.\" .Tn NET
518.\" (Network Entity Title).
519.\" The default value is 1, which is conformant to US
520.\" .Tn GOSIP .
521.\" When an ISO address is set in an ifconfig command,
522.\" it is really the
523.\" .Tn NSAP
524.\" which is being specified.
525.\" For example, in
526.\" .Tn US GOSIP ,
527.\" 20 hex digits should be
528.\" specified in the
529.\" .Tn ISO NSAP
530.\" to be assigned to the interface.
531.\" There is some evidence that a number different from 1 may be useful
532.\" for
533.\" .Tn AFI
534.\" 37 type addresses.
535.It Cm range Ar netrange
536Under appletalk, set the interface to respond to a
537.Ar netrange
538of the form
539.Ar startnet Ns - Ns Ar endnet .
540Appletalk uses this scheme instead of
541netmasks though
542.Fx
543implements it internally as a set of netmasks.
544.It Cm remove
545Another name for the
546.Fl alias
547parameter.
548Introduced for compatibility
549with
550.Bsx .
551.It Cm phase
552The argument following this specifies the version (phase) of the
553Appletalk network attached to the interface.
554Values of 1 or 2 are permitted.
555.Sm off
556.It Cm link Op Cm 0 No - Cm 2
557.Sm on
558Enable special processing of the link level of the interface.
559These three options are interface specific in actual effect, however,
560they are in general used to select special modes of operation.
561An example
562of this is to enable SLIP compression, or to select the connector type
563for some Ethernet cards.
564Refer to the man page for the specific driver
565for more information.
566.Sm off
567.It Fl link Op Cm 0 No - Cm 2
568.Sm on
569Disable special processing at the link level with the specified interface.
570.It Cm monitor
571Put the interface in monitor mode.
572No packets are transmitted, and received packets are discarded after
573.Xr bpf 4
574processing.
575.It Fl monitor
576Take the interface out of monitor mode.
577.It Cm up
578Mark an interface
579.Dq up .
580This may be used to enable an interface after an
581.Dq Nm Cm down .
582It happens automatically when setting the first address on an interface.
583If the interface was reset when previously marked down,
584the hardware will be re-initialized.
585.El
586.Pp
587The following parameters are specific to cloning
588IEEE 802.11 wireless interfaces with the
589.Cm create
590request:
591.Bl -tag -width indent
592.It Cm wlandev Ar device
593Use
594.Ar device
595as the parent for the cloned device.
596.It Cm wlanmode Ar mode
597Specify the operating mode for this cloned device.
598.Ar mode
599is one of
600.Cm sta ,
601.Cm ahdemo
602(or
603.Cm adhoc-demo ),
604.Cm ibss ,
605(or
606.Cm adhoc ),
607.Cm ap ,
608(or
609.Cm hostap ),
610.Cm wds ,
611and
612.Cm monitor .
613The operating mode of a cloned interface cannot be changed.
614.It Cm wlanbssid Ar bssid
615The 802.11 mac address to use for the bssid.
616This must be specified at create time for a legacy
617.Cm wds
618device.
619.It Cm wlanaddr Ar address
620The local mac address.
621If this is not specified then a mac address will automatically be assigned
622to the cloned device.
623Typically this address is the same as the address of the parent device
624but if the
625.Cm bssid
626parameter is specified then the driver will craft a unique address for
627the device (if supported).
628.It Cm wdslegacy
629Mark a
630.Cm wds
631device as operating in ``legacy mode''.
632Legacy
633.Cm wds
634devices have a fixed peer relationship and do not, for example, roam
635if their peer stops communicating.
636For completeness a Dynamic WDS (DWDS) interface may marked as
637.Fl wdslegacy .
638.It Cm bssid
639Request a unique local mac address for the cloned device.
640This is only possible if the device supports multiple mac addresses.
641To force use of the parent's mac address use
642.Fl bssid .
643.It Cm beacons
644Mark the cloned interface as depending on hardware support to
645track received beacons.
646To have beacons tracked in software use
647.Fl beacons .
648For
649.Cm hostap
650mode
651.Fl beacons
652can also be used to indicate no beacons should
653be transmitted; this can be useful when creating a WDS configuration but
654.Cm wds
655interfaces can only be created as companions to an access point.
656.El
657.Pp
658The following parameters are specific to IEEE 802.11 wireless interfaces
659cloned with a
660.Cm create
661operation:
662.Bl -tag -width indent
663.It Cm ampdu
664Enable sending and receiving AMPDU frames when using 802.11n (default).
665The 802.11n specification states a compliant station must be capable
666of receiving AMPDU frames but transmision is optional.
667Use
668.Fl ampdu
669to disable all use of AMPDU with 802.11n.
670For testing and/or to work around interoperability problems one can use
671.Cm ampdutx
672and
673.Cm ampdurx
674to control use of AMPDU in one direction.
675.It Cm ampdudensity Ar density
676Set the AMPDU density parameter used when operating with 802.11n.
677This parameter controls the inter-packet gap for AMPDU frames.
678The sending device normally controls this setting but a receiving station
679may request wider gaps.
680Legal values for
681.Ar density
682are 0, .25, .5, 1, 2, 4, 8, and 16 (microseconds).
683A value of
684.Cm -
685is treated the same as 0.
686.It Cm ampdulimit Ar limit
687Set the limit on packet size for receiving AMPDU frames when operating
688with 802.11n.
689Legal values for
690.Ar limit
691are 8192, 16384, 32768, and 65536 but one can also specify
692just the unique prefix: 8, 16, 32, 64.
693Note the sender may limit the size of AMPDU frames to be less
694than the maximum specified by the receiving station.
695.It Cm amsdu
696Enable sending and receiving AMSDU frames when using 802.11n.
697By default AMSDU is received but not transmitted.
698Use
699.Fl amsdu
700to disable all use of AMSDU with 802.11n.
701For testing and/or to work around interoperability problems one can use
702.Cm amsdutx
703and
704.Cm amsdurx
705to control use of AMSDU in one direction.
706.It Cm amsdulimit Ar limit
707Set the limit on packet size for sending and receiving AMSDU frames
708when operating with 802.11n.
709Legal values for
710.Ar limit
711are 7935 and 3839 (bytes).
712Note the sender may limit the size of AMSDU frames to be less
713than the maximum specified by the receiving station.
714Note also that devices are not required to support the 7935 limit,
715only 3839 is required by the specification and the larger value
716may require more memory to be dedicated to support functionality
717that is rarely used.
718.It Cm apbridge
719When operating as an access point, pass packets between
720wireless clients directly (default).
721To instead let them pass up through the
722system and be forwarded using some other mechanism, use
723.Fl apbridge .
724Disabling the internal bridging
725is useful when traffic is to be processed with
726packet filtering.
727.It Cm authmode Ar mode
728Set the desired authentication mode in infrastructure mode.
729Not all adapters support all modes.
730The set of
731valid modes is
732.Cm none , open , shared
733(shared key),
734.Cm 8021x
735(IEEE 802.1x),
736and
737.Cm wpa
738(IEEE WPA/WPA2/802.11i).
739The
740.Cm 8021x
741and
742.Cm wpa
743modes are only useful when using an authentication service
744(a supplicant for client operation or an authenticator when
745operating as an access point).
746Modes are case insensitive.
747.It Cm bgscan
748Enable background scanning when operating as a station.
749Background scanning is a technique whereby a station associated to
750an access point will temporarily leave the channel to scan for
751neighboring stations.
752This allows a station to maintain a cache of nearby access points
753so that roaming between access points can be done without
754a lengthy scan operation.
755Background scanning is done only when a station is not busy and
756any outbound traffic will cancel a scan operation.
757Background scanning should never cause packets to be lost though
758there may be some small latency if outbound traffic interrupts a
759scan operation.
760By default background scanning is enabled if the device is capable.
761To disable background scanning, use
762.Fl bgscan .
763Background scanning is controlled by the
764.Cm bgscanidle
765and
766.Cm bgscanintvl
767parameters.
768Background scanning must be enabled for roaming; this is an artifact
769of the current implementation and may not be required in the future.
770.It Cm bgscanidle Ar idletime
771Set the minimum time a station must be idle (not transmitting or
772receiving frames) before a background scan is initiated.
773The
774.Ar idletime
775parameter is specified in milliseconds.
776By default a station must be idle at least 250 milliseconds before
777a background scan is initiated.
778The idle time may not be set to less than 100 milliseconds.
779.It Cm bgscanintvl Ar interval
780Set the interval at which background scanning is attempted.
781The
782.Ar interval
783parameter is specified in seconds.
784By default a background scan is considered every 300 seconds (5 minutes).
785The
786.Ar interval
787may not be set to less than 15 seconds.
788.It Cm bintval Ar interval
789Set the interval at which beacon frames are sent when operating in
790ad-hoc or ap mode.
791The
792.Ar interval
793parameter is specified in TU's (1024 usecs).
794By default beacon frames are transmitted every 100 TU's.
795.It Cm bmissthreshold Ar count
796Set the number of consecutive missed beacons at which the station
797will attempt to roam (i.e., search for a new access point).
798The
799.Ar count
800parameter must be in the range 1 to 255; though the
801upper bound may be reduced according to device capabilities.
802The default threshold is 7 consecutive missed beacons; but
803this may be overridden by the device driver.
804Another name for the
805.Cm bmissthreshold
806parameter is
807.Cm bmiss .
808.It Cm bssid Ar address
809Specify the MAC address of the access point to use when operating
810as a station in a BSS network.
811This overrides any automatic selection done by the system.
812To disable a previously selected access point, supply
813.Cm any , none ,
814or
815.Cm -
816for the address.
817This option is useful when more than one access point uses the same SSID.
818Another name for the
819.Cm bssid
820parameter is
821.Cm ap .
822.It Cm burst
823Enable packet bursting.
824Packet bursting is a transmission technique whereby the wireless
825medium is acquired once to send multiple frames and the interframe
826spacing is reduced.
827This technique can significantly increase throughput by reducing
828transmission overhead.
829Packet bursting is supported by the 802.11e QoS specification
830and some devices that do not support QoS may still be capable.
831By default packet bursting is enabled if a device is capable
832of doing it.
833To disable packet bursting, use
834.Fl burst .
835.It Cm chanlist Ar channels
836Set the desired channels to use when scanning for access
837points, neighbors in an IBSS network, or looking for unoccupied
838channels when operating as an access point.
839The set of channels is specified as a comma-separated list with
840each element in the list representing either a single channel number or a range
841of the form
842.Dq Li a-b .
843Channel numbers must be in the range 1 to 255 and be permissible
844according to the operating characteristics of the device.
845.It Cm channel Ar number
846Set a single desired channel.
847Channels range from 1 to 255, but the exact selection available
848depends on the region your adaptor was manufactured for.
849Setting
850the channel to
851.Li any ,
852or
853.Cm -
854will clear any desired channel and, if the device is marked up,
855force a scan for a channel to operate on.
856Alternatively the frequency, in megahertz, may be specified
857instead of the channel number.
858.Pp
859When there are several ways to use a channel the channel
860number/frequency may be appended with attributes to clarify.
861For example, if a device is capable of operating on channel 6
862with 802.11n and 802.11g then one can specify that g-only use
863should be used by specifying ``6:g''.
864Similarly the channel width can be specified by appending it
865with ``/''; e.g. ``6/40'' specifies a 40MHz wide channel,
866These attributes can be combined as in: ``6:ht/40''.
867The full set of flags specified following a `:'' are:
868.Cm a
869(802.11a),
870.Cm b
871(802.11b),
872.Cm d
873(Atheros Dynamic Turbo mode),
874.Cm g
875(802.11g),
876.Cm h
877or
878.Cm n
879(802.11n aka HT),
880.Cm s
881(Atheros Static Turbo mode),
882and
883.Cm t
884(Atheros Dynamic Turbo mode, or appended to ``st'' and ``dt'').
885The full set of channel widths following a '/' are:
886.Cm 5
887(5MHz aka quarter-rate channel),
888.Cm 10
889(10MHz aka half-rate channel),
890.Cm 20
891(20MHz mostly for use in specifying ht20),
892and
893.Cm 40
894(40MHz mostly for use in specifying ht40),
895In addition,
896a 40MHz HT channel specification may include the location
897of the extension channel by appending ``+'' or ``-'' for above and below,
898respectively; e.g. ``2437:ht/40+'' specifies 40MHz wide HT operation
899with the center channel at frequency 2437 and the extension channel above.
900.It Cm country Ar name
901Set the country code to use in calculating the regulatory constraints
902for operation.
903In particular the set of available channels, how the wireless device
904will operation on the channels, and the maximum transmit power that
905can be used on a channel are defined by this setting.
906Country/Region codes are specified as a 2-character abbreviation
907defined by ISO 3166 or using a longer, but possibly ambiguous, spelling;
908e.g. "ES" and "Spain".
909The set of country codes are taken from /etc/regdomain.xml and can also
910be viewed with the ``list countries'' request.
911Note that not all devices support changing the country code from a default
912setting; typically stored in EEPROM.
913See also
914.Cm regdomain ,
915.Cm indoor ,
916.Cm outdoor ,
917and
918.Cm anywhere .
919.It Cm dfs
920Enable Dynamic Frequency Selection (DFS) as specified in 802.11h.
921DFS embodies several facilities including detection of overlapping
922radar signals, dynamic transmit power control, and channel selection
923according to a least-congested criteria.
924DFS support is mandatory for some 5Ghz frequencies in certain
925locales (e.g. ETSI).
926By default DFS is enabled according to the regulatory definitions
927specified in /etc/regdomain.xml and the curent country code, regdomain,
928and channel.
929Note the underlying device (and driver) must support radar detection
930for full DFS support to work.
931To be fully compliant with the local regulatory agency frequencies that
932require DFS should not be used unless it is fully supported.
933Use
934.Fl dfs
935to disable this functionality for testing.
936.It Cm dotd
937Enable support for the 802.11d specification (default).
938When this support is enabled in station mode, beacon frames that advertise
939a country code different than the currently configured country code will
940cause an event to be dispatched to user applications.
941This event can be used by the station to adopt that country code and
942operate according to the associated regulatory constraints.
943When operating as an access point with 802.11d enabled the beacon and
944probe response frames transmitted will advertise the current regulatory
945domain settings.
946To disable 802.11d use
947.Fl dotd .
948.It Cm doth
949Enable 802.11h support including spectrum management.
950When 802.11h is enabled beacon and probe response frames will have
951the SpectrumMgt bit set in the capabilities field and
952country and power constraint information elements will be present.
953802.11h support also includes handling Channel Switch Announcements (CSA)
954which are a mechanism to coordinate channel changes by an access point.
955By default 802.11h is enabled if the device is capable.
956To disable 802.11h use
957.Fl doth .
958.It Cm deftxkey Ar index
959Set the default key to use for transmission.
960Typically this is only set when using WEP encryption.
961Note that you must set a default transmit key
962for the system to know which key to use in encrypting outbound traffic.
963The
964.Cm weptxkey
965is an alias for this request; it is provided for backwards compatibility.
966.It Cm dtimperiod Ar period
967Set the
968DTIM
969period for transmitting buffered multicast data frames when
970operating in ap mode.
971The
972.Ar period
973specifies the number of beacon intervals between DTIM
974and must be in the range 1 to 15.
975By default DTIM is 1 (i.e., DTIM occurs at each beacon).
976.It Cm dturbo
977Enable the use of Atheros Dynamic Turbo mode when communicating with
978another Dynamic Turbo-capable station.
979Dynamic Turbo mode is an Atheros-specific mechanism by which
980stations switch between normal 802.11 operation and a ``boosted''
981mode in which a 40MHz wide channel is used for communication.
982Stations using Dynamic Turbo mode operate boosted only when the
983channel is free of non-dturbo stations; when a non-dturbo station
984is identified on the channel all stations will automatically drop
985back to normal operation.
986By default, Dynamic Turbo mode is not enabled, even if the device is capable.
987Note that turbo mode (dynamic or static) is only allowed on some
988channels depending on the regulatory constraints; use the
989.Cm list chan
990command to identify the channels where turbo mode may be used.
991To disable Dynamic Turbo mode use
992.Fl dturbo .
993.It Cm dwds
994Enable Dynamic WDS (DWDS) support.
995DWDS is a facility by which 4-address traffic can be carried between
996stations operating in infrastructure mode.
997A station first associates to an access point and authenticates using
998normal procedures (e.g. WPA).
999Then 4-address frames are passed to carry traffic for stations
1000operating on either side of the wireless link.
1001DWDS extends the normal WDS mechanism by leveraging existing security
1002protocols and eliminating static binding.
1003.Pp
1004When DWDS is enabled on an access point 4-address frames received from
1005an authorized station will generate a ``DWDS discovery'' event to user
1006applications.
1007This event should be used to create a WDS interface that is bound
1008to the remote station (and usually plumbed into a bridge).
1009Once the WDS interface is up and running 4-address traffic then logically
1010flows through that interface.
1011.Pp
1012When DWDS is enabled on a station, traffic with a destination address
1013different from the peer station are encapsulated in a 4-address frame
1014and transmitted to the peer.
1015All 4-address traffic uses the security information of the stations
1016(e.g. cryptographic keys).
1017A station is associated using 802.11n facilities may transport
10184-address traffic using these same mechanisms; this depends on available
1019resources and capabilities of the device.
1020The DWDS implementation guards against layer 2 routing loops of
1021multicast traffic.
1022.It Cm ff
1023Enable the use of Atheros Fast Frames when communicating with
1024another Fast Frames-capable station.
1025Fast Frames are an encapsulation technique by which two 802.3
1026frames are transmitted in a single 802.11 frame.
1027This can noticeably improve throughput but requires that the
1028receiving station understand how to decapsulate the frame.
1029Fast frame use is negotiated using the Atheros 802.11 vendor-specific
1030protocol extension so enabling use is safe when communicating with
1031non-Atheros devices.
1032By default, use of fast frames is enabled if the device is capable.
1033To explicitly disable fast frames, use
1034.Fl ff .
1035.It Cm fragthreshold Ar length
1036Set the threshold for which transmitted frames are broken into fragments.
1037The
1038.Ar length
1039argument is the frame size in bytes and must be in the range 256 to 2346.
1040Setting
1041.Ar length
1042to
1043.Li 2346 ,
1044.Cm any ,
1045or
1046.Cm -
1047disables transmit fragmentation.
1048Not all adapters honor the fragmentation threshold.
1049.It Cm hidessid
1050When operating as an access point, do not broadcast the SSID
1051in beacon frames or respond to probe request frames unless
1052they are directed to the ap (i.e., they include the ap's SSID).
1053By default, the SSID is included in beacon frames and
1054undirected probe request frames are answered.
1055To re-enable the broadcast of the SSID etc., use
1056.Fl hidessid .
1057.It Cm ht
1058Enable use of High Throughput (HT) when using 802.11n (default).
1059The 802.11n specification includes mechanisms for operation
1060on 20MHz and 40MHz wide channels using different signalling mechanisms
1061than specified in 802.11b, 802.11g, and 802.11a.
1062Stations negotiate use of these facilities, termed HT20 and HT40,
1063when they associate.
1064To disable all use of 802.11n use
1065.Fl ht .
1066To disable use of HT20 (e.g. to force only HT40 use) use
1067.Fl ht20 .
1068To disable use of HT40 use
1069.Fl ht40 .
1070.Pp
1071HT configuration is used to ``auto promote'' operation
1072when several choices are available.
1073For example, if a station associates to an 11n-capable access point
1074it controls whether the station uses legacy operation, HT20, or HT40.
1075When an 11n-capable device is setup as an access point and
1076Auto Channel Selection is used to locate a channel to operate on,
1077HT configuration controls whether legacy, HT20, or HT40 operation is setup
1078on the selected channel.
1079If a fixed channel is specified for a station then HT configuration can
1080be given as part of the channel specification; e.g. 6:ht/20 to setup
1081HT20 operation on channel 6.
1082.It Cm htcompat
1083Enable use of compatibility support for pre-802.11n devices (default).
1084The 802.11n protocol specification went through several incompatible iterations.
1085Some vendors implemented 11n support to older specifications that
1086will not interoperate with a purely 11n-compliant station.
1087In particular the information elements included in management frames
1088for old devices are different.
1089When compatibility support is enabled both standard and compatible data
1090will be provided.
1091Stations that associate using the compatiblity mechanisms are flagged
1092in ``list sta''.
1093To disable compatiblity support use
1094.Fl htcompat .
1095.It Cm htprotmode Ar technique
1096For interfaces operating in 802.11n, use the specified
1097.Ar technique
1098for protecting HT frames in a mixed legacy/HT network.
1099The set of valid techniques is
1100.Cm off ,
1101and
1102.Cm rts
1103(RTS/CTS, default).
1104Technique names are case insensitive.
1105.It Cm inact
1106Enable inactivity processing for stations associated to an
1107access point (default).
1108When operating as an access point the 802.11 layer monitors
1109the activity of each associated station.
1110When a station is inactive for 5 minutes it will send several
1111``probe frames'' to see if the station is still present.
1112If no response is received then the station is deauthenticated.
1113Applications that prefer to handle this work can disable this
1114facility by using
1115.Fl inact .
1116.It Cm indoor
1117Set the location to use in calculating regulatory constraints.
1118The location is also advertised in beacon and probe response frames
1119when 802.11d is enabled with
1120.Cm dotd .
1121See also
1122.Cm outdoor ,
1123.Cm anywhere ,
1124.Cm country ,
1125and
1126.Cm regdomain .
1127.It Cm list active
1128Display the list of channels available for use taking into account
1129any restrictions set with the
1130.Cm chanlist
1131directive.
1132See the description of
1133.Cm list chan
1134for more information.
1135.It Cm list caps
1136Display the adaptor's capabilities, including the operating
1137modes supported.
1138.It Cm list chan
1139Display the list of channels available for use.
1140Channels are shown with their IEEE channel number, equivalent
1141frequency, and usage modes.
1142Channels identified as
1143.Ql 11g
1144are also usable in
1145.Ql 11b
1146mode.
1147Channels identified as
1148.Ql 11a Turbo
1149may be used only for Atheros' Static Turbo mode
1150(specified with
1151. Cm mediaopt turbo ) .
1152Channels marked with a
1153.Ql *
1154have a regulatory constraint that they be passively scanned.
1155This means a station is not permitted to transmit on the channel until
1156it identifies the channel is being used for 802.11 communication;
1157typically by hearing a beacon frame from an access point operating
1158on the channel.
1159.Cm list freq
1160is another way of requesting this information.
1161By default a compacted list of channels is displayed; if the
1162.Fl v
1163option is specified then all channels are shown.
1164.It Cm list countries
1165Display the set of country codes and regulatory domains that can be
1166used in regulatory configuration.
1167.It Cm list mac
1168Display the current MAC Access Control List state.
1169Each address is prefixed with a character that indicates the
1170current policy applied to it:
1171.Ql +
1172indicates the address is allowed access,
1173.Ql -
1174indicates the address is denied access,
1175.Ql *
1176indicates the address is present but the current policy open
1177(so the ACL is not consulted).
1178.It Cm list regdomain
1179Display the current regulatory settings including the available channels
1180and transmit power caps.
1181.It Cm list roam
1182Display the parameters that govern roaming operation.
1183.It Cm list txparam
1184Display the parameters that govern transmit operation.
1185.It Cm list txpower
1186Display the transmit power caps for each channel.
1187.It Cm list scan
1188Display the access points and/or ad-hoc neighbors
1189located in the vicinity.
1190This information may be updated automatically by the adapter
1191with a
1192.Cm scan
1193request or through background scanning.
1194Depending on the capabilities of the stations the following
1195flags can be included in the output:
1196.Bl -tag -width 3n
1197.It Li A
1198Authorized.
1199Indicates that the station is permitted to send/receive data frames.
1200.It Li E
1201Extended Rate Phy (ERP).
1202Indicates that the station is operating in an 802.11g network
1203using extended transmit rates.
1204.It Li H
1205High Throughput (HT).
1206Indicates that the station is using HT transmit rates.
1207If a `+' follows immediately after then the station associated
1208using deprecated mechanisms supported only when
1209.Cm htcompat
1210is enabled.
1211.It Li P
1212Power Save.
1213Indicates that the station is operating in power save mode.
1214.It Li Q
1215Quality of Service (QoS).
1216Indicates that the station is using QoS encapsulation for
1217data frame.
1218QoS encapsulation is enabled only when WME mode is enabled.
1219.It Li T
1220Transitional Security Network (TSN).
1221Indicates that the station associated using TSN; see also
1222.Cm tsn
1223below.
1224.It Li W
1225Wi-Fi Protected Setup (WPS).
1226Indicates that the station associated using WPS.
1227.El
1228.Pp
1229By default interesting information elements captured from the neighboring
1230stations are displayed at the end of each row.
1231Possible elements include:
1232.Cm WME
1233(station supports WME),
1234.Cm WPA
1235(station supports WPA),
1236.Cm WPS
1237(station supports WPS),
1238.Cm RSN
1239(station supports 802.11i/RSN),
1240.Cm HTCAP
1241(station supports 802.11n/HT communication),
1242.Cm ATH
1243(station supoprts Atheros protocol extensions),
1244.Cm VEN
1245(station supports unknown vendor-specific extensions).
1246If the
1247.Fl v
1248flag is used all the information elements and their
1249contents will be shown.
1250Specifying The
1251.Fl v
1252flag also enables display of long SSIDs.
1253.Cm list ap
1254is another way of requesting this information.
1255.It Cm list sta
1256When operating as an access point display the stations that are
1257currently associated.
1258When operating in ad-hoc mode display stations identified as
1259neighbors in the IBSS.
1260When operating in station mode display the access point.
1261Capabilities advertised by the stations are described under
1262the
1263.Cm scan
1264request.
1265Depending on the capabilities of the stations the following
1266flags can be included in the output:
1267.Bl -tag -width 3n
1268.It Li A
1269Authorized.
1270Indicates that the station is permitted to send/receive data frames.
1271.It Li E
1272Extended Rate Phy (ERP).
1273Indicates that the station is operating in an 802.11g network
1274using extended transmit rates.
1275.It Li H
1276High Throughput (HT).
1277Indicates that the station is using HT transmit rates.
1278If a `+' follows immediately after then the station associated
1279using deprecated mechanisms supported only when
1280.Cm htcompat
1281is enabled.
1282.It Li P
1283Power Save.
1284Indicates that the station is operating in power save mode.
1285.It Li Q
1286Quality of Service (QoS).
1287Indicates that the station is using QoS encapsulation for
1288data frame.
1289QoS encapsulation is enabled only when WME mode is enabled.
1290.It Li T
1291Transitional Security Network (TSN).
1292Indicates that the station associated using TSN; see also
1293.Cm tsn
1294below.
1295.It Li W
1296Wi-Fi Protected Setup (WPS).
1297Indicates that the station associated using WPS.
1298.El
1299.Pp
1300By default information elements received from associated stations
1301are displayed in a short form; the
1302.Fl v
1303flag causes this information to be displayed symbolicaly.
1304.It Cm list wme
1305Display the current channel parameters to use when operating in WME mode.
1306If the
1307.Fl v
1308option is specified then both channel and BSS parameters are displayed
1309for each AC (first channel, then BSS).
1310When WME mode is enabled for an adaptor this information will be
1311displayed with the regular status; this command is mostly useful
1312for examining parameters when WME mode is disabled.
1313See the description of the
1314.Cm wme
1315directive for information on the various parameters.
1316.It Cm maxretry Ar count
1317Set the maximum number of tries to use in sending unicast frames.
1318The default setting is 6 but drivers may override this with a value
1319they choose.
1320.It Cm mcastrate Ar rate
1321Set the rate for transmitting multicast/broadcast frames.
1322Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s.
1323This rate should be valid for the current operating conditions;
1324if an invalid rate is specified drivers are free to chose an
1325appropriate rate.
1326.It Cm mgtrate Ar rate
1327Set the rate for transmitting management and/or control frames.
1328Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s.
1329.It Cm outdoor
1330Set the location to use in calculating regulatory constraints.
1331The location is also advertised in beacon and probe response frames
1332when 802.11d is enabled with
1333.Cm dotd .
1334See also
1335.Cm anywhere ,
1336.Cm country ,
1337.Cm indoor ,
1338and
1339.Cm regdomain .
1340.It Cm powersave
1341Enable powersave operation.
1342When operating as a client, the station will conserve power by
1343periodically turning off the radio and listening for
1344messages from the access point telling it there are packets waiting.
1345The station must then retrieve the packets.
1346Not all devices support power save operation as a client.
1347The 802.11 specification requires that all access points support
1348power save but some drivers do not.
1349Use
1350.Fl powersave
1351to disable powersave operation when operating as a client.
1352.It Cm powersavesleep Ar sleep
1353Set the desired max powersave sleep time in TU's (1024 usecs).
1354By default the max powersave sleep time is 100 TU's.
1355.It Cm protmode Ar technique
1356For interfaces operating in 802.11g, use the specified
1357.Ar technique
1358for protecting OFDM frames in a mixed 11b/11g network.
1359The set of valid techniques is
1360.Cm off , cts
1361(CTS to self),
1362and
1363.Cm rtscts
1364(RTS/CTS).
1365Technique names are case insensitive.
1366Not all devices support
1367.Cm cts
1368as a protection technique.
1369.It Cm pureg
1370When operating as an access point in 802.11g mode allow only
137111g-capable stations to associate (11b-only stations are not
1372permitted to associate).
1373To allow both 11g and 11b-only stations to associate, use
1374.Fl pureg .
1375.It Cm puren
1376When operating as an access point in 802.11n mode allow only
1377HT-capable stations to associate (legacy stations are not
1378permitted to associate).
1379To allow both HT and legacy stations to associate, use
1380.Fl puren .
1381.It Cm regdomain Ar sku
1382Set the regulatory domain to use in calculating the regulatory constraints
1383for operation.
1384In particular the set of available channels, how the wireless device
1385will operation on the channels, and the maximum transmit power that
1386can be used on a channel are defined by this setting.
1387Regdomain codes (SKU's) are taken from /etc/regdomain.xml and can also
1388be viewed with the ``list countries'' request.
1389Note that not all devices support changing the regdomain from a default
1390setting; typically stored in EEPROM.
1391See also
1392.Cm country ,
1393.Cm indoor ,
1394.Cm outdoor ,
1395and
1396.Cm anywhere .
1397.It Cm roam:rate Ar rate
1398Set the threshold for controlling roaming when operating in a BSS.
1399The
1400.Ar rate
1401parameter specifies the transmit rate in megabits
1402at which roaming should be considered.
1403If the current transmit rate drops below this setting and background scanning
1404is enabled, then the system will check if a more desirable access point is
1405available and switch over to it.
1406The current scan cache contents are used if they are considered
1407valid according to the
1408.Cm scanvalid
1409parameter; otherwise a background scan operation is triggered before
1410any selection occurs.
1411Each channel type has a separate rate threshold; the default values are:
141212 Mb/s (11a), 2 Mb/s (11b), 2 Mb/s (11g), MCS 1 (11na, 11ng).
1413.It Cm roam:rssi Ar rssi
1414Set the threshold for controlling roaming when operating in a BSS.
1415The
1416.Ar rssi
1417parameter specifies the receive signal strength in dBm units
1418at which roaming should be considered.
1419If the current rssi drops below this setting and background scanning
1420is enabled, then the system will check if a more desirable access point is
1421available and switch over to it.
1422The current scan cache contents are used if they are considered
1423valid according to the
1424.Cm scanvalid
1425parameter; otherwise a background scan operation is triggered before
1426any selection occurs.
1427Rach channel type has a separate rssi threshold; the default values are
1428all 7 dBm.
1429.It Cm roaming Ar mode
1430When operating as a station, control how the system will
1431behave when communication with the current access point
1432is broken.
1433The
1434.Ar mode
1435argument may be one of
1436.Cm device
1437(leave it to the hardware device to decide),
1438.Cm auto
1439(handle either in the device or the operating system\[em]as appropriate),
1440.Cm manual
1441(do nothing until explicitly instructed).
1442By default, the device is left to handle this if it is
1443capable; otherwise, the operating system will automatically
1444attempt to reestablish communication.
1445Manual mode is used by applications such as
1446.Xr wpa_supplicant 8
1447that want to control the selection of an access point.
1448.It Cm rtsthreshold Ar length
1449Set the threshold for which
1450transmitted frames are preceded by transmission of an
1451RTS
1452control frame.
1453The
1454.Ar length
1455argument
1456is the frame size in bytes and must be in the range 1 to 2346.
1457Setting
1458.Ar length
1459to
1460.Li 2346 ,
1461.Cm any ,
1462or
1463.Cm -
1464disables transmission of RTS frames.
1465Not all adapters support setting the RTS threshold.
1466.It Cm scan
1467Initiate a scan of neighboring stations, wait for it to complete, and
1468display all stations found.
1469Only the super-user can initiate a scan.
1470See
1471.Cm list scan
1472for information on the display.
1473By default a background scan is done; otherwise a foreground
1474scan is done and the station may roam to a different access point.
1475The
1476.Cm list scan
1477request can be used to show recent scan results without
1478initiating a new scan.
1479.It Cm scanvalid Ar threshold
1480Set the maximum time the scan cache contents are considered valid;
1481i.e. will be used without first triggering a scan operation to
1482refresh the data.
1483The
1484.Ar threshold
1485parameter is specified in seconds and defaults to 60 seconds.
1486The minimum setting for
1487.Ar threshold
1488is 10 seconds.
1489One should take care setting this threshold; if it is set too low
1490then attempts to roam to another access point may trigger unnecessary
1491background scan operations.
1492.It Cm shortgi
1493Enable use of Short Guard Interval when operating in 802.11n
1494on an HT channel.
1495NB: this currently enables Short GI on both HT40 and HT20 channels.
1496To disable Short GI use
1497.Fl shortgi .
1498.It Cm ssid Ar ssid
1499Set the desired Service Set Identifier (aka network name).
1500The SSID is a string up to 32 characters
1501in length and may be specified as either a normal string or in
1502hexadecimal when preceded by
1503.Ql 0x .
1504Additionally, the SSID may be cleared by setting it to
1505.Ql - .
1506.It Cm tsn
1507When operating as an access point with WPA/802.11i allow legacy
1508stations to associate using static key WEP and open authentication.
1509To disallow legacy station use of WEP, use
1510.Fl tsn .
1511.It Cm txpower Ar power
1512Set the power used to transmit frames.
1513The
1514.Ar power
1515argument is specified in .5 dBm units.
1516Out of range values are truncated.
1517Typically only a few discreet power settings are available and
1518the driver will use the setting closest to the specified value.
1519Not all adapters support changing the transmit power.
1520.It Cm ucastrate Ar rate
1521Set a fixed rate for transmitting unicast frames.
1522Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s.
1523This rate should be valid for the current operating conditions;
1524if an invalid rate is specified drivers are free to chose an
1525appropriate rate.
1526.It Cm wepmode Ar mode
1527Set the desired WEP mode.
1528Not all adapters support all modes.
1529The set of valid modes is
1530.Cm off , on ,
1531and
1532.Cm mixed .
1533The
1534.Cm mixed
1535mode explicitly tells the adaptor to allow association with access
1536points which allow both encrypted and unencrypted traffic.
1537On these adapters,
1538.Cm on
1539means that the access point must only allow encrypted connections.
1540On other adapters,
1541.Cm on
1542is generally another name for
1543.Cm mixed .
1544Modes are case insensitive.
1545.It Cm weptxkey Ar index
1546Set the WEP key to be used for transmission.
1547This is the same as setting the default transmission key with
1548.Cm deftxkey .
1549.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key
1550Set the selected WEP key.
1551If an
1552.Ar index
1553is not given, key 1 is set.
1554A WEP key will be either 5 or 13
1555characters (40 or 104 bits) depending of the local network and the
1556capabilities of the adaptor.
1557It may be specified either as a plain
1558string or as a string of hexadecimal digits preceded by
1559.Ql 0x .
1560For maximum portability, hex keys are recommended;
1561the mapping of text keys to WEP encryption is usually driver-specific.
1562In particular, the
1563.Tn Windows
1564drivers do this mapping differently to
1565.Fx .
1566A key may be cleared by setting it to
1567.Ql - .
1568If WEP is supported then there are at least four keys.
1569Some adapters support more than four keys.
1570If that is the case, then the first four keys
1571(1-4) will be the standard temporary keys and any others will be adaptor
1572specific keys such as permanent keys stored in NVRAM.
1573.Pp
1574Note that you must set a default transmit key with
1575.Cm deftxkey
1576for the system to know which key to use in encrypting outbound traffic.
1577.It Cm wme
1578Enable Wireless Multimedia Extensions (WME) support, if available,
1579for the specified interface.
1580WME is a subset of the IEEE 802.11e standard to support the
1581efficient communication of realtime and multimedia data.
1582To disable WME support, use
1583.Fl wme .
1584Another name for this parameter is
1585.Cm wmm .
1586.Pp
1587The following parameters are meaningful only when WME support is in use.
1588Parameters are specified per-AC (Access Category) and
1589split into those that are used by a station when acting
1590as an access point and those for client stations in the BSS.
1591The latter are received from the access point and may not be changed
1592(at the station).
1593The following Access Categories are recognized:
1594.Pp
1595.Bl -tag -width ".Cm AC_BK" -compact
1596.It Cm AC_BE
1597(or
1598.Cm BE )
1599best effort delivery,
1600.It Cm AC_BK
1601(or
1602.Cm BK )
1603background traffic,
1604.It Cm AC_VI
1605(or
1606.Cm VI )
1607video traffic,
1608.It Cm AC_VO
1609(or
1610.Cm VO )
1611voice traffic.
1612.El
1613.Pp
1614AC parameters are case-insensitive.
1615Traffic classification is done in the operating system using the
1616vlan priority associated with data frames or the
1617ToS (Type of Service) indication in IP-encapsulated frames.
1618If neither information is present, traffic is assigned to the
1619Best Effort (BE) category.
1620.Bl -tag -width indent
1621.It Cm ack Ar ac
1622Set the ACK policy for QoS transmissions by the local station;
1623this controls whether or not data frames transmitted by a station
1624require an ACK response from the receiving station.
1625To disable waiting for an ACK use
1626.Fl ack .
1627This parameter is applied only to the local station.
1628.It Cm acm Ar ac
1629Enable the Admission Control Mandatory (ACM) mechanism
1630for transmissions by the local station.
1631To disable the ACM use
1632.Fl acm .
1633On stations in a BSS this parameter is read-only and indicates
1634the setting received from the access point.
1635NB: ACM is not supported right now.
1636.It Cm aifs Ar ac Ar count
1637Set the Arbitration Inter Frame Spacing (AIFS)
1638channel access parameter to use for transmissions
1639by the local station.
1640On stations in a BSS this parameter is read-only and indicates
1641the setting received from the access point.
1642.It Cm cwmin Ar ac Ar count
1643Set the CWmin channel access parameter to use for transmissions
1644by the local station.
1645On stations in a BSS this parameter is read-only and indicates
1646the setting received from the access point.
1647.It Cm cwmax Ar ac Ar count
1648Set the CWmax channel access parameter to use for transmissions
1649by the local station.
1650On stations in a BSS this parameter is read-only and indicates
1651the setting received from the access point.
1652.It Cm txoplimit Ar ac Ar limit
1653Set the Transmission Opportunity Limit channel access parameter
1654to use for transmissions by the local station.
1655This parameter defines an interval of time when a WME station
1656has the right to initiate transmissions onto the wireless medium.
1657On stations in a BSS this parameter is read-only and indicates
1658the setting received from the access point.
1659.It Cm bss:aifs Ar ac Ar count
1660Set the AIFS channel access parameter to send to stations in a BSS.
1661This parameter is meaningful only when operating in ap mode.
1662.It Cm bss:cwmin Ar ac Ar count
1663Set the CWmin channel access parameter to send to stations in a BSS.
1664This parameter is meaningful only when operating in ap mode.
1665.It Cm bss:cwmax Ar ac Ar count
1666Set the CWmax channel access parameter to send to stations in a BSS.
1667This parameter is meaningful only when operating in ap mode.
1668.It Cm bss:txoplimit Ar ac Ar limit
1669Set the TxOpLimit channel access parameter to send to stations in a BSS.
1670This parameter is meaningful only when operating in ap mode.
1671.El
1672.It Cm wps
1673Enable Wireless Privacy Subscriber support.
1674Note that WPS support requires a WPS-capable supplicant.
1675To disable this function use
1676.Fl wps .
1677.El
1678.Pp
1679The following parameters support an optional access control list
1680feature available with some adapters when operating in ap mode; see
1681.Xr wlan_acl 4 .
1682This facility allows an access point to accept/deny association
1683requests based on the MAC address of the station.
1684Note that this feature does not significantly enhance security
1685as MAC address spoofing is easy to do.
1686.Bl -tag -width indent
1687.It Cm mac:add Ar address
1688Add the specified MAC address to the database.
1689Depending on the policy setting association requests from the
1690specified station will be allowed or denied.
1691.It Cm mac:allow
1692Set the ACL policy to permit association only by
1693stations registered in the database.
1694.It Cm mac:del Ar address
1695Delete the specified MAC address from the database.
1696.It Cm mac:deny
1697Set the ACL policy to deny association only by
1698stations registered in the database.
1699.It Cm mac:kick Ar address
1700Force the specified station to be deauthenticated.
1701This typically is done to block a station after updating the
1702address database.
1703.It Cm mac:open
1704Set the ACL policy to allow all stations to associate.
1705.It Cm mac:flush
1706Delete all entries in the database.
1707.It Cm mac:radius
1708Set the ACL policy to permit association only by
1709stations approved by a RADIUS server.
1710Note that this feature requires the
1711.Xr hostapd 8
1712program be configured to do the right thing
1713as it handles the RADIUS processing
1714(and marks stations as authorized).
1715.El
1716.Pp
1717The following parameters are for compatibility with other systems:
1718.Bl -tag -width indent
1719.It Cm nwid Ar ssid
1720Another name for the
1721.Cm ssid
1722parameter.
1723Included for
1724.Nx
1725compatibility.
1726.It Cm stationname Ar name
1727Set the name of this station.
1728The station name is not part of the IEEE 802.11
1729protocol though some interfaces support it.
1730As such it only
1731seems to be meaningful to identical or virtually identical equipment.
1732Setting the station name is identical in syntax to setting the SSID.
1733One can also use
1734.Cm station
1735for
1736.Bsx
1737compatibility.
1738.It Cm wep
1739Another way of saying
1740.Cm wepmode on .
1741Included for
1742.Bsx
1743compatibility.
1744.It Fl wep
1745Another way of saying
1746.Cm wepmode off .
1747Included for
1748.Bsx
1749compatibility.
1750.It Cm nwkey key
1751Another way of saying:
1752.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" .
1753Included for
1754.Nx
1755compatibility.
1756.It Cm nwkey Xo
1757.Sm off
1758.Ar n : k1 , k2 , k3 , k4
1759.Sm on
1760.Xc
1761Another way of saying
1762.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" .
1763Included for
1764.Nx
1765compatibility.
1766.It Fl nwkey
1767Another way of saying
1768.Cm wepmode off .
1769Included for
1770.Nx
1771compatibility.
1772.El
1773.Pp
1774The following parameters are specific to bridge interfaces:
1775.Bl -tag -width indent
1776.It Cm addm Ar interface
1777Add the interface named by
1778.Ar interface
1779as a member of the bridge.
1780The interface is put into promiscuous mode
1781so that it can receive every packet sent on the network.
1782.It Cm deletem Ar interface
1783Remove the interface named by
1784.Ar interface
1785from the bridge.
1786Promiscuous mode is disabled on the interface when
1787it is removed from the bridge.
1788.It Cm maxaddr Ar size
1789Set the size of the bridge address cache to
1790.Ar size .
1791The default is 100 entries.
1792.It Cm timeout Ar seconds
1793Set the timeout of address cache entries to
1794.Ar seconds
1795seconds.
1796If
1797.Ar seconds
1798is zero, then address cache entries will not be expired.
1799The default is 240 seconds.
1800.It Cm addr
1801Display the addresses that have been learned by the bridge.
1802.It Cm static Ar interface-name Ar address
1803Add a static entry into the address cache pointing to
1804.Ar interface-name .
1805Static entries are never aged out of the cache or re-placed, even if the
1806address is seen on a different interface.
1807.It Cm deladdr Ar address
1808Delete
1809.Ar address
1810from the address cache.
1811.It Cm flush
1812Delete all dynamically-learned addresses from the address cache.
1813.It Cm flushall
1814Delete all addresses, including static addresses, from the address cache.
1815.It Cm discover Ar interface
1816Mark an interface as a
1817.Dq discovering
1818interface.
1819When the bridge has no address cache entry
1820(either dynamic or static)
1821for the destination address of a packet,
1822the bridge will forward the packet to all
1823member interfaces marked as
1824.Dq discovering .
1825This is the default for all interfaces added to a bridge.
1826.It Cm -discover Ar interface
1827Clear the
1828.Dq discovering
1829attribute on a member interface.
1830For packets without the
1831.Dq discovering
1832attribute, the only packets forwarded on the interface are broadcast
1833or multicast packets and packets for which the destination address
1834is known to be on the interface's segment.
1835.It Cm learn Ar interface
1836Mark an interface as a
1837.Dq learning
1838interface.
1839When a packet arrives on such an interface, the source
1840address of the packet is entered into the address cache as being a
1841destination address on the interface's segment.
1842This is the default for all interfaces added to a bridge.
1843.It Cm -learn Ar interface
1844Clear the
1845.Dq learning
1846attribute on a member interface.
1847.It Cm sticky Ar interface
1848Mark an interface as a
1849.Dq sticky
1850interface.
1851Dynamically learned address entries are treated at static once entered into
1852the cache.
1853Sticky entries are never aged out of the cache or replaced, even if the
1854address is seen on a different interface.
1855.It Cm -sticky Ar interface
1856Clear the
1857.Dq sticky
1858attribute on a member interface.
1859.It Cm private Ar interface
1860Mark an interface as a
1861.Dq private
1862interface.
1863A private interface does not forward any traffic to any other port that is also
1864a private interface.
1865.It Cm -private Ar interface
1866Clear the
1867.Dq private
1868attribute on a member interface.
1869.It Cm span Ar interface
1870Add the interface named by
1871.Ar interface
1872as a span port on the bridge.
1873Span ports transmit a copy of every frame received by the bridge.
1874This is most useful for snooping a bridged network passively on
1875another host connected to one of the span ports of the bridge.
1876.It Cm -span Ar interface
1877Delete the interface named by
1878.Ar interface
1879from the list of span ports of the bridge.
1880.It Cm stp Ar interface
1881Enable Spanning Tree protocol on
1882.Ar interface .
1883The
1884.Xr if_bridge 4
1885driver has support for the IEEE 802.1D Spanning Tree protocol (STP).
1886Spanning Tree is used to detect and remove loops in a network topology.
1887.It Cm -stp Ar interface
1888Disable Spanning Tree protocol on
1889.Ar interface .
1890This is the default for all interfaces added to a bridge.
1891.It Cm edge Ar interface
1892Set
1893.Ar interface
1894as an edge port.
1895An edge port connects directly to end stations cannot create bridging
1896loops in the network, this allows it to transition straight to forwarding.
1897.It Cm -edge Ar interface
1898Disable edge status on
1899.Ar interface .
1900.It Cm autoedge Ar interface
1901Allow
1902.Ar interface
1903to automatically detect edge status.
1904This is the default for all interfaces added to a bridge.
1905.It Cm -autoedge Ar interface
1906Disable automatic edge status on
1907.Ar interface .
1908.It Cm ptp Ar interface
1909Set the
1910.Ar interface
1911as a point to point link.
1912This is required for straight transitions to forwarding and
1913should be enabled on a direct link to another RSTP capable switch.
1914.It Cm -ptp Ar interface
1915Disable point to point link status on
1916.Ar interface .
1917This should be disabled for a half duplex link and for an interface
1918connected to a shared network segment,
1919like a hub or a wireless network.
1920.It Cm autoptp Ar interface
1921Automatically detect the point to point status on
1922.Ar interface
1923by checking the full duplex link status.
1924This is the default for interfaces added to the bridge.
1925.It Cm -autoptp Ar interface
1926Disable automatic point to point link detection on
1927.Ar interface .
1928.It Cm maxage Ar seconds
1929Set the time that a Spanning Tree protocol configuration is valid.
1930The default is 20 seconds.
1931The minimum is 6 seconds and the maximum is 40 seconds.
1932.It Cm fwddelay Ar seconds
1933Set the time that must pass before an interface begins forwarding
1934packets when Spanning Tree is enabled.
1935The default is 15 seconds.
1936The minimum is 4 seconds and the maximum is 30 seconds.
1937.It Cm hellotime Ar seconds
1938Set the time between broadcasting of Spanning Tree protocol
1939configuration messages.
1940The hello time may only be changed when operating in legacy stp mode.
1941The default is 2 seconds.
1942The minimum is 1 second and the maximum is 2 seconds.
1943.It Cm priority Ar value
1944Set the bridge priority for Spanning Tree.
1945The default is 32768.
1946The minimum is 0 and the maximum is 61440.
1947.It Cm proto Ar value
1948Set the Spanning Tree protocol.
1949The default is rstp.
1950The available options are stp and rstp.
1951.It Cm holdcnt Ar value
1952Set the transmit hold count for Spanning Tree.
1953This is the number of packets transmitted before being rate limited.
1954The default is 6.
1955The minimum is 1 and the maximum is 10.
1956.It Cm ifpriority Ar interface Ar value
1957Set the Spanning Tree priority of
1958.Ar interface
1959to
1960.Ar value .
1961The default is 128.
1962The minimum is 0 and the maximum is 240.
1963.It Cm ifpathcost Ar interface Ar value
1964Set the Spanning Tree path cost of
1965.Ar interface
1966to
1967.Ar value .
1968The default is calculated from the link speed.
1969To change a previously selected path cost back to automatic, set the
1970cost to 0.
1971The minimum is 1 and the maximum is 200000000.
1972.It Cm ifmaxaddr Ar interface Ar size
1973Set the maximum number of hosts allowed from an interface, packets with unknown
1974source addresses are dropped until an existing host cache entry expires or is
1975removed.
1976Set to 0 to disable.
1977.El
1978.Pp
1979The following parameters are specific to lagg interfaces:
1980.Bl -tag -width indent
1981.It Cm laggport Ar interface
1982Add the interface named by
1983.Ar interface
1984as a port of the aggregation interface.
1985.It Cm -laggport Ar interface
1986Remove the interface named by
1987.Ar interface
1988from the aggregation interface.
1989.It Cm laggproto Ar proto
1990Set the aggregation protocol.
1991The default is failover.
1992The available options are failover, fec, lacp, loadbalance, roundrobin and
1993none.
1994.El
1995.Pp
1996The following parameters are specific to IP tunnel interfaces,
1997.Xr gif 4 :
1998.Bl -tag -width indent
1999.It Cm tunnel Ar src_addr dest_addr
2000Configure the physical source and destination address for IP tunnel
2001interfaces.
2002The arguments
2003.Ar src_addr
2004and
2005.Ar dest_addr
2006are interpreted as the outer source/destination for the encapsulating
2007IPv4/IPv6 header.
2008.It Fl tunnel
2009Unconfigure the physical source and destination address for IP tunnel
2010interfaces previously configured with
2011.Cm tunnel .
2012.It Cm deletetunnel
2013Another name for the
2014.Fl tunnel
2015parameter.
2016.El
2017.Pp
2018The following parameters are specific to GRE tunnel interfaces,
2019.Xr gre 4 :
2020.Bl -tag -width indent
2021.It Cm grekey Ar key
2022Configure the GRE key to be used for outgoing packets.
2023Note that
2024.Xr gre 4 will always accept GRE packets with invalid or absent keys.
2025This command will result in a four byte MTU reduction on the interface.
2026.El
2027.Pp
2028The following parameters are specific to
2029.Xr pfsync 4
2030interfaces:
2031.Bl -tag -width indent
2032.It Cm maxupd Ar n
2033Set the maximum number of updates for a single state which
2034can be collapsed into one.
2035This is an 8-bit number; the default value is 128.
2036.El
2037.Pp
2038The following parameters are specific to
2039.Xr vlan 4
2040interfaces:
2041.Bl -tag -width indent
2042.It Cm vlan Ar vlan_tag
2043Set the VLAN tag value to
2044.Ar vlan_tag .
2045This value is a 16-bit number which is used to create an 802.1Q
2046VLAN header for packets sent from the
2047.Xr vlan 4
2048interface.
2049Note that
2050.Cm vlan
2051and
2052.Cm vlandev
2053must both be set at the same time.
2054.It Cm vlandev Ar iface
2055Associate the physical interface
2056.Ar iface
2057with a
2058.Xr vlan 4
2059interface.
2060Packets transmitted through the
2061.Xr vlan 4
2062interface will be
2063diverted to the specified physical interface
2064.Ar iface
2065with 802.1Q VLAN encapsulation.
2066Packets with 802.1Q encapsulation received
2067by the parent interface with the correct VLAN tag will be diverted to
2068the associated
2069.Xr vlan 4
2070pseudo-interface.
2071The
2072.Xr vlan 4
2073interface is assigned a
2074copy of the parent interface's flags and the parent's ethernet address.
2075The
2076.Cm vlandev
2077and
2078.Cm vlan
2079must both be set at the same time.
2080If the
2081.Xr vlan 4
2082interface already has
2083a physical interface associated with it, this command will fail.
2084To
2085change the association to another physical interface, the existing
2086association must be cleared first.
2087.Pp
2088Note: if the hardware tagging capability
2089is set on the parent interface, the
2090.Xr vlan 4
2091pseudo
2092interface's behavior changes:
2093the
2094.Xr vlan 4
2095interface recognizes that the
2096parent interface supports insertion and extraction of VLAN tags on its
2097own (usually in firmware) and that it should pass packets to and from
2098the parent unaltered.
2099.It Fl vlandev Op Ar iface
2100If the driver is a
2101.Xr vlan 4
2102pseudo device, disassociate the parent interface from it.
2103This breaks the link between the
2104.Xr vlan 4
2105interface and its parent,
2106clears its VLAN tag, flags and its link address and shuts the interface down.
2107The
2108.Ar iface
2109argument is useless and hence deprecated.
2110.El
2111.Pp
2112The following parameters are specific to
2113.Xr carp 4
2114interfaces:
2115.Bl -tag -width indent
2116.It Cm advbase Ar seconds
2117Specifies the base of the advertisement interval in seconds.
2118The acceptable values are 1 to 255.
2119The default value is 1.
2120.\" The default value is
2121.\" .Dv CARP_DFLTINTV .
2122.It Cm advskew Ar interval
2123Specifies the skew to add to the base advertisement interval to
2124make one host advertise slower than another host.
2125It is specified in 1/256 of seconds.
2126The acceptable values are 1 to 254.
2127The default value is 0.
2128.It Cm pass Ar phrase
2129Set the authentication key to
2130.Ar phrase .
2131.It Cm vhid Ar n
2132Set the virtual host ID.
2133This is a required setting.
2134Acceptable values are 1 to 255.
2135.El
2136.Pp
2137The
2138.Nm
2139utility displays the current configuration for a network interface
2140when no optional parameters are supplied.
2141If a protocol family is specified,
2142.Nm
2143will report only the details specific to that protocol family.
2144.Pp
2145If the
2146.Fl m
2147flag is passed before an interface name,
2148.Nm
2149will display the capability list and all
2150of the supported media for the specified interface.
2151If
2152.Fl L
2153flag is supplied, address lifetime is displayed for IPv6 addresses,
2154as time offset string.
2155.Pp
2156Optionally, the
2157.Fl a
2158flag may be used instead of an interface name.
2159This flag instructs
2160.Nm
2161to display information about all interfaces in the system.
2162The
2163.Fl d
2164flag limits this to interfaces that are down, and
2165.Fl u
2166limits this to interfaces that are up.
2167When no arguments are given,
2168.Fl a
2169is implied.
2170.Pp
2171The
2172.Fl l
2173flag may be used to list all available interfaces on the system, with
2174no other additional information.
2175Use of this flag is mutually exclusive
2176with all other flags and commands, except for
2177.Fl d
2178(only list interfaces that are down)
2179and
2180.Fl u
2181(only list interfaces that are up).
2182.Pp
2183The
2184.Fl v
2185flag may be used to get more verbose status for an interface.
2186.Pp
2187The
2188.Fl C
2189flag may be used to list all of the interface cloners available on
2190the system, with no additional information.
2191Use of this flag is mutually exclusive with all other flags and commands.
2192.Pp
2193The
2194.Fl k
2195flag causes keying information for the interface, if available, to be
2196printed.
2197For example, the values of 802.11 WEP keys will be printed, if accessible to
2198the current user.
2199This information is not printed by default, as it may be considered
2200sensitive.
2201.Pp
2202If the network interface driver is not present in the kernel then
2203.Nm
2204will attempt to load it.
2205The
2206.Fl n
2207flag disables this behavior.
2208.Pp
2209Only the super-user may modify the configuration of a network interface.
2210.Sh NOTES
2211The media selection system is relatively new and only some drivers support
2212it (or have need for it).
2213.Sh EXAMPLES
2214Assign the IPv4 address
2215.Li 192.0.2.10 ,
2216with a network mask of
2217.Li 255.255.255.0 ,
2218to the interface
2219.Li fxp0 :
2220.Dl # ifconfig fxp0 inet 192.0.2.10 netmask 255.255.255.0
2221.Pp
2222Add the IPv4 address
2223.Li 192.0.2.45 ,
2224with the CIDR network prefix
2225.Li /28 ,
2226to the interface
2227.Li ed0 ,
2228using
2229.Cm add
2230as a synonym for the canonical form of the option
2231.Cm alias :
2232.Dl # ifconfig ed0 inet 192.0.2.45/28 add
2233.Pp
2234Remove the IPv4 address
2235.Li 192.0.2.45
2236from the interface
2237.Li ed0 :
2238.Dl # ifconfig ed0 inet 192.0.2.45 -alias
2239.Pp
2240Add the IPv6 address
2241.Li 2001:DB8:DBDB::123/48
2242to the interface
2243.Li em0 :
2244.Dl # ifconfig em0 inet6 2001:db8:bdbd::123 prefixlen 48 alias
2245Note that lower case hexadecimal IPv6 addresses are acceptable.
2246.Pp
2247Remove the IPv6 address added in the above example,
2248using the
2249.Li /
2250character as shorthand for the network prefix,
2251and using
2252.Cm delete
2253as a synonym for the canonical form of the option
2254.Fl alias :
2255.Dl # ifconfig em0 inet6 2001:db8:bdbd::123/48 delete
2256.Pp
2257Configure the interface
2258.Li xl0 ,
2259to use 100baseTX, full duplex Ethernet media options:
2260.Dl # ifconfig xl0 media 100baseTX mediaopt full-duplex
2261.Pp
2262Create the software network interface
2263.Li gif1 :
2264.Dl # ifconfig gif1 create
2265.Pp
2266Destroy the software network interface
2267.Li gif1 :
2268.Dl # ifconfig gif1 destroy
2269.Sh DIAGNOSTICS
2270Messages indicating the specified interface does not exist, the
2271requested address is unknown, or the user is not privileged and
2272tried to alter an interface's configuration.
2273.Sh SEE ALSO
2274.Xr netstat 1 ,
2275.Xr carp 4 ,
2276.Xr netintro 4 ,
2277.Xr pfsync 4 ,
2278.Xr polling 4 ,
2279.Xr vlan 4 ,
2280.\" .Xr eon 5 ,
2281.Xr rc 8 ,
2282.Xr routed 8 ,
2283.Xr sysctl 8
2284.Sh HISTORY
2285The
2286.Nm
2287utility appeared in
2288.Bx 4.2 .
2289.Sh BUGS
2290Basic IPv6 node operation requires a link-local address on each
2291interface configured for IPv6.
2292Normally, such an address is automatically configured by the
2293kernel on each interface added to the system; this behaviour may
2294be disabled by setting the sysctl MIB variable
2295.Va net.inet6.ip6.auto_linklocal
2296to 0.
2297.Pp
2298If you delete such an address using
2299.Nm ,
2300the kernel may act very odd.
2301Do this at your own risk.
2302