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.\" 3. 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: src/sbin/ifconfig/ifconfig.8,v 1.124 2006/10/10 09:44:08 ru Exp $ 30.\" 31.Dd November 12, 2012 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.Ar interface 43.Op Cm create 44.Op Ar address_family 45.Oo 46.Ar address 47.Op Ar dest_address 48.Oc 49.Op Ar parameters 50.Nm 51.Ar interface 52.Cm destroy 53.Nm 54.Fl a 55.Op Fl L 56.Op Fl d 57.Op Fl m 58.Op Fl u 59.Op Fl v 60.Op Ar address_family 61.Nm 62.Fl l 63.Op Fl d 64.Op Fl u 65.Op Ar address_family 66.Nm 67.Op Fl L 68.Op Fl d 69.Op Fl k 70.Op Fl m 71.Op Fl u 72.Op Fl v 73.Op Fl C 74.Sh DESCRIPTION 75The 76.Nm 77utility is used to assign an address 78to a network interface and/or configure 79network interface parameters. 80The 81.Nm 82utility must be used at boot time to define the network address 83of each interface present on a machine; it may also be used at 84a later time to redefine an interface's address 85or other operating parameters. 86.Pp 87The following options are available: 88.Bl -tag -width indent 89.It Ar address 90For the 91.Tn DARPA Ns -Internet 92family, 93the address is either a host name present in the host name data 94base, 95.Xr hosts 5 , 96or a 97.Tn DARPA 98Internet address expressed in the Internet standard 99.Dq dot notation . 100.Pp 101It is also possible to use the CIDR notation (also known as the 102slash notation) to include the netmask. 103That is, one can specify an address like 104.Li 192.168.0.1/16 . 105.Pp 106For 107.Dq inet6 108family, it is also possible to specify the prefix length using the slash 109notation, like 110.Li ::1/128 . 111See the 112.Cm prefixlen 113parameter below for more information. 114.\" For the Xerox Network Systems(tm) family, 115.\" addresses are 116.\" .Ar net:a.b.c.d.e.f , 117.\" where 118.\" .Ar net 119.\" is the assigned network number (in decimal), 120.\" and each of the six bytes of the host number, 121.\" .Ar a 122.\" through 123.\" .Ar f , 124.\" are specified in hexadecimal. 125.\" The host number may be omitted on IEEE 802 protocol 126.\" (Ethernet, FDDI, and Token Ring) interfaces, 127.\" which use the hardware physical address, 128.\" and on interfaces other than the first. 129.\" For the 130.\" .Tn ISO 131.\" family, addresses are specified as a long hexadecimal string, 132.\" as in the Xerox family. 133.\" However, two consecutive dots imply a zero 134.\" byte, and the dots are optional, if the user wishes to (carefully) 135.\" count out long strings of digits in network byte order. 136.Pp 137The link-level 138.Pq Dq link 139address 140is specified as a series of colon-separated hex digits. 141This can be used to 142e.g.\& set a new MAC address on an ethernet interface, though the 143mechanism used is not ethernet-specific. 144If the interface is already 145up when this option is used, it will be briefly brought down and 146then brought back up again in order to ensure that the receive 147filter in the underlying ethernet hardware is properly reprogrammed. 148.It Ar address_family 149Specify the 150address family 151which affects interpretation of the remaining parameters. 152Since an interface can receive transmissions in differing protocols 153with different naming schemes, specifying the address family is recommended. 154The address or protocol families currently 155supported are 156.Dq inet , 157.Dq inet6 , 158.Dq atalk , 159and 160.Dq link . 161The default is 162.Dq inet . 163.Dq ether 164and 165.Dq lladdr 166are synonyms for 167.Dq link . 168.It Ar dest_address 169Specify the address of the correspondent on the other end 170of a point to point link. 171.It Ar interface 172This 173parameter is a string of the form 174.Dq name unit , 175for example, 176.Dq Li ed0 . 177.El 178.Pp 179The following parameters may be set with 180.Nm : 181.Bl -tag -width indent 182.It Cm add 183Another name for the 184.Cm alias 185parameter. 186Introduced for compatibility 187with 188.Bsx . 189.It Cm alias 190Establish an additional network address for this interface. 191This is sometimes useful when changing network numbers, and 192one wishes to accept packets addressed to the old interface. 193If the address is on the same subnet as the first network address 194for this interface, a non-conflicting netmask must be given. 195Usually 196.Li 0xffffffff 197is most appropriate. 198.It Fl alias 199Remove the network address specified. 200This would be used if you incorrectly specified an alias, or it 201was no longer needed. 202If you have incorrectly set an NS address having the side effect 203of specifying the host portion, removing all NS addresses will 204allow you to respecify the host portion. 205.It Cm anycast 206(Inet6 only.) 207Specify that the address configured is an anycast address. 208Based on the current specification, 209only routers may configure anycast addresses. 210Anycast address will not be used as source address of any of outgoing 211IPv6 packets. 212.It Cm arp 213Enable the use of the Address Resolution Protocol 214.Pq Xr arp 4 215in mapping 216between network level addresses and link level addresses (default). 217This is currently implemented for mapping between 218.Tn DARPA 219Internet 220addresses and 221.Tn IEEE 222802 48-bit MAC addresses (Ethernet, FDDI, and Token Ring addresses). 223.It Fl arp 224Disable the use of the Address Resolution Protocol 225.Pq Xr arp 4 . 226.It Cm staticarp 227If the Address Resolution Protocol is enabled, 228the host will only reply to requests for its addresses, 229and will never send any requests. 230.It Fl staticarp 231If the Address Resolution Protocol is enabled, 232the host will perform normally, 233sending out requests and listening for replies. 234.It Cm broadcast 235(Inet only.) 236Specify the address to use to represent broadcasts to the 237network. 238The default broadcast address is the address with a host part of all 1's. 239.It Cm debug 240Enable driver dependent debugging code; usually, this turns on 241extra console error logging. 242.It Fl debug 243Disable driver dependent debugging code. 244.It Cm promisc 245Put interface into permanently promiscuous mode. 246.It Fl promisc 247Disable permanently promiscuous mode. 248.It Cm delete 249Another name for the 250.Fl alias 251parameter. 252.It Cm down 253Mark an interface 254.Dq down . 255When an interface is marked 256.Dq down , 257the system will not attempt to 258transmit messages through that interface. 259If possible, the interface will be reset to disable reception as well. 260This action does not automatically disable routes using the interface. 261.It Cm eui64 262(Inet6 only.) 263Fill interface index 264(lowermost 64bit of an IPv6 address) 265automatically. 266.It Cm media Ar type 267If the driver supports the media selection system, set the media type 268of the interface to 269.Ar type . 270Some interfaces support the mutually exclusive use of one of several 271different physical media connectors. 272For example, a 10Mbit/s Ethernet 273interface might support the use of either 274.Tn AUI 275or twisted pair connectors. 276Setting the media type to 277.Cm 10base5/AUI 278would change the currently active connector to the AUI port. 279Setting it to 280.Cm 10baseT/UTP 281would activate twisted pair. 282Refer to the interfaces' driver 283specific documentation or man page for a complete list of the 284available types. 285.It Cm mediaopt Ar opts 286If the driver supports the media selection system, set the specified 287media options on the interface. 288The 289.Ar opts 290argument 291is a comma delimited list of options to apply to the interface. 292Refer to the interfaces' driver specific man page for a complete 293list of available options. 294.It Fl mediaopt Ar opts 295If the driver supports the media selection system, disable the 296specified media options on the interface. 297.It Cm mode Ar mode 298If the driver supports the media selection system, set the specified 299operating mode on the interface to 300.Ar mode . 301For IEEE 802.11 wireless interfaces that support multiple operating modes 302this directive is used to select between 802.11a 303.Pq Cm 11a , 304802.11b 305.Pq Cm 11b , 306and 802.11g 307.Pq Cm 11g 308operating modes. 309.It Cm name Ar name 310Set the interface name to 311.Ar name . 312.It Cm rss 313If the driver supports receive side scaling, 314enable receive side scaling on the interface. 315.It Fl rss 316If the driver supports receive side scaling, 317disable receive side scaling on the interface. 318.It Cm rxcsum , txcsum 319If the driver supports user-configurable checksum offloading, 320enable receive (or transmit) checksum offloading on the interface. 321Some drivers may not be able to enable these flags independently 322of each other, so setting one may also set the other. 323The driver will offload as much checksum work as it can reliably 324support, the exact level of offloading varies between drivers. 325.It Fl rxcsum , txcsum 326If the driver supports user-configurable checksum offloading, 327disable receive (or transmit) checksum offloading on the interface. 328These settings may not always be independent of each other. 329.It Cm tso 330If the driver supports TCP segmentation offloading, 331enable TCP segmentation offloading on the interface. 332.It Fl tso 333If the driver supports TCP segmentation offloading, 334disable TCP segmentation offloading on the interface. 335.It Cm vlanmtu , vlanhwtag 336If the driver offers user-configurable VLAN support, enable 337reception of extended frames or tag processing in hardware, 338respectively. 339Note that this must be issued on a physical interface associated with 340.Xr vlan 4 , 341not on a 342.Xr vlan 4 343interface itself. 344.It Fl vlanmtu , vlanhwtag 345If the driver offers user-configurable VLAN support, disable 346reception of extended frames or tag processing in hardware, 347respectively. 348.It Cm pollcpu Ar cpu 349Deprecated, use polling or npolling instead. 350.It Cm polling , npolling 351Turn on 352.Xr polling 4 353feature and disable interrupts on the interface, if the driver supports 354this mode. 355.It Fl polling , npolling 356Turn off 357.Xr polling 4 358feature and enable interrupt mode on the interface. 359.It Cm create 360Create the specified network pseudo-device. 361If the interface is given without a unit number, try to create a new 362device with an arbitrary unit number. 363If creation of an arbitrary device is successful, the new device name is 364printed to standard output unless the interface is renamed or destroyed 365in the same 366.Nm 367invocation. 368.It Cm destroy 369Destroy the specified network pseudo-device. 370.It Cm plumb 371Another name for the 372.Cm create 373parameter. 374Included for 375.Tn Solaris 376compatibility. 377.It Cm unplumb 378Another name for the 379.Cm destroy 380parameter. 381Included for 382.Tn Solaris 383compatibility. 384.It Cm metric Ar n 385Set the routing metric of the interface to 386.Ar n , 387default 0. 388The routing metric is used by the routing protocol 389.Pq Xr routed 8 . 390Higher metrics have the effect of making a route 391less favorable; metrics are counted as additional hops 392to the destination network or host. 393.It Cm mtu Ar n 394Set the maximum transmission unit of the interface to 395.Ar n , 396default is interface specific. 397The MTU is used to limit the size of packets that are transmitted on an 398interface. 399Not all interfaces support setting the MTU, and some interfaces have 400range restrictions. 401.It Cm tsolen Ar n 402Set the maximum amount of data 403that TCP segmentation offloading is allowed to aggregate to 404.Ar n , 405the default value is interface specific. 406This setting only takes effect on interfaces 407that support TCP segmentation offloading. 408.It Cm netmask Ar mask 409.\" (Inet and ISO.) 410(Inet only.) 411Specify how much of the address to reserve for subdividing 412networks into sub-networks. 413The mask includes the network part of the local address 414and the subnet part, which is taken from the host field of the address. 415The mask can be specified as a single hexadecimal number 416with a leading 417.Ql 0x , 418with a dot-notation Internet address, 419or with a pseudo-network name listed in the network table 420.Xr networks 5 . 421The mask contains 1's for the bit positions in the 32-bit address 422which are to be used for the network and subnet parts, 423and 0's for the host part. 424The mask should contain at least the standard network portion, 425and the subnet field should be contiguous with the network 426portion. 427.Pp 428The netmask can also be specified in CIDR notation after the address. 429See the 430.Ar address 431option above for more information. 432.It Cm autoconf 433(Inet6 only.) 434Enable autoconfiguration. 435.It Fl autoconf 436Disable autoconfiguration. 437.It Cm pltime Ar n 438(Inet6 only.) 439Set preferred lifetime for the address. 440.It Cm vltime Ar n 441(Inet6 only.) 442Set valid lifetime for the address. 443.It Cm prefixlen Ar len 444(Inet6 only.) 445Specify that 446.Ar len 447bits are reserved for subdividing networks into sub-networks. 448The 449.Ar len 450must be integer, and for syntactical reason it must be between 0 to 128. 451It is almost always 64 under the current IPv6 assignment rule. 452If the parameter is omitted, 64 is used. 453.Pp 454The prefix can also be specified using the slash notation after the address. 455See the 456.Ar address 457option above for more information. 458.It Cm deprecated 459(Inet6 only.) 460Set the IPv6 deprecated address bit. 461.It Fl deprecated 462(Inet6 only.) 463Clear the IPv6 deprecated address bit. 464.It Cm tentative 465(Inet6 only.) 466Set the IPv6 tentative address bit. 467.It Fl tentative 468(Inet6 only.) 469Clear the IPv6 tentative address bit. 470.\" see 471.\" Xr eon 5 . 472.\" .It Cm nsellength Ar n 473.\" .Pf ( Tn ISO 474.\" only) 475.\" This specifies a trailing number of bytes for a received 476.\" .Tn NSAP 477.\" used for local identification, the remaining leading part of which is 478.\" taken to be the 479.\" .Tn NET 480.\" (Network Entity Title). 481.\" The default value is 1, which is conformant to US 482.\" .Tn GOSIP . 483.\" When an ISO address is set in an ifconfig command, 484.\" it is really the 485.\" .Tn NSAP 486.\" which is being specified. 487.\" For example, in 488.\" .Tn US GOSIP , 489.\" 20 hex digits should be 490.\" specified in the 491.\" .Tn ISO NSAP 492.\" to be assigned to the interface. 493.\" There is some evidence that a number different from 1 may be useful 494.\" for 495.\" .Tn AFI 496.\" 37 type addresses. 497.It Cm range Ar netrange 498Under appletalk, set the interface to respond to a 499.Ar netrange 500of the form 501.Ar startnet Ns - Ns Ar endnet . 502Appletalk uses this scheme instead of 503netmasks though 504.Dx 505implements it internally as a set of netmasks. 506.It Cm remove 507Another name for the 508.Fl alias 509parameter. 510Introduced for compatibility 511with 512.Bsx . 513.It Cm phase 514The argument following this specifies the version (phase) of the 515Appletalk network attached to the interface. 516Values of 1 or 2 are permitted. 517.Sm off 518.It Cm link Op Cm 0 No - Cm 2 519.Sm on 520Enable special processing of the link level of the interface. 521These three options are interface specific in actual effect, however, 522they are in general used to select special modes of operation. 523An example 524of this is to enable SLIP compression, or to select the connector type 525for some Ethernet cards. 526Refer to the man page for the specific driver 527for more information. 528.Sm off 529.It Fl link Op Cm 0 No - Cm 2 530.Sm on 531Disable special processing at the link level with the specified interface. 532.It Cm compress 533Another name for the 534.Cm link0 535parameter. 536.It Cm normal 537Another name for the 538.Fl link0 539parameter. 540.It Cm noicmp 541Another name for the 542.Cm link1 543parameter. 544.It Cm monitor 545Put the interface in monitor mode. 546No packets are transmitted, and received packets are discarded after 547.Xr bpf 4 548processing. 549.It Fl monitor 550Take the interface out of monitor mode. 551.It Cm up 552Mark an interface 553.Dq up . 554This may be used to enable an interface after an 555.Dq Nm Cm down . 556It happens automatically when setting the first address on an interface. 557If the interface was reset when previously marked down, 558the hardware will be re-initialized. 559.El 560.Pp 561The following parameters are specific to cloning 562IEEE 802.11 wireless interfaces with the 563.Cm create 564request: 565.Bl -tag -width indent 566.It Cm wlandev Ar device 567Use 568.Ar device 569as the parent for the cloned device. 570.It Cm wlanmode Ar mode 571Specify the operating mode for this cloned device. 572.Ar mode 573is one of 574.Cm sta , 575.Cm ahdemo 576(or 577.Cm adhoc-demo ), 578.Cm ibss , 579(or 580.Cm adhoc ), 581.Cm ap , 582(or 583.Cm hostap ), 584.Cm wds , 585.Cm tdma , 586.Cm mesh , 587and 588.Cm monitor . 589The operating mode of a cloned interface cannot be changed. 590The 591.Cm tdma 592mode is actually implemented as an 593.Cm adhoc-demo 594interface with special properties. 595.It Cm wlanbssid Ar bssid 596The 802.11 mac address to use for the bssid. 597This must be specified at create time for a legacy 598.Cm wds 599device. 600.It Cm wlanaddr Ar address 601The local mac address. 602If this is not specified then a mac address will automatically be assigned 603to the cloned device. 604Typically this address is the same as the address of the parent device 605but if the 606.Cm bssid 607parameter is specified then the driver will craft a unique address for 608the device (if supported). 609.It Cm wdslegacy 610Mark a 611.Cm wds 612device as operating in ``legacy mode''. 613Legacy 614.Cm wds 615devices have a fixed peer relationship and do not, for example, roam 616if their peer stops communicating. 617For completeness a Dynamic WDS (DWDS) interface may marked as 618.Fl wdslegacy . 619.It Cm bssid 620Request a unique local mac address for the cloned device. 621This is only possible if the device supports multiple mac addresses. 622To force use of the parent's mac address use 623.Fl bssid . 624.It Cm beacons 625Mark the cloned interface as depending on hardware support to 626track received beacons. 627To have beacons tracked in software use 628.Fl beacons . 629For 630.Cm hostap 631mode 632.Fl beacons 633can also be used to indicate no beacons should 634be transmitted; this can be useful when creating a WDS configuration but 635.Cm wds 636interfaces can only be created as companions to an access point. 637.El 638.Pp 639The following parameters are specific to IEEE 802.11 wireless interfaces 640cloned with a 641.Cm create 642operation: 643.Bl -tag -width indent 644.It Cm ampdu 645Enable sending and receiving AMPDU frames when using 802.11n (default). 646The 802.11n specification states a compliant station must be capable 647of receiving AMPDU frames but transmission is optional. 648Use 649.Fl ampdu 650to disable all use of AMPDU with 802.11n. 651For testing and/or to work around interoperability problems one can use 652.Cm ampdutx 653and 654.Cm ampdurx 655to control use of AMPDU in one direction. 656.It Cm ampdudensity Ar density 657Set the AMPDU density parameter used when operating with 802.11n. 658This parameter controls the inter-packet gap for AMPDU frames. 659The sending device normally controls this setting but a receiving station 660may request wider gaps. 661Legal values for 662.Ar density 663are 0, .25, .5, 1, 2, 4, 8, and 16 (microseconds). 664A value of 665.Cm - 666is treated the same as 0. 667.It Cm ampdulimit Ar limit 668Set the limit on packet size for receiving AMPDU frames when operating 669with 802.11n. 670Legal values for 671.Ar limit 672are 8192, 16384, 32768, and 65536 but one can also specify 673just the unique prefix: 8, 16, 32, 64. 674Note the sender may limit the size of AMPDU frames to be less 675than the maximum specified by the receiving station. 676.It Cm amsdu 677Enable sending and receiving AMSDU frames when using 802.11n. 678By default AMSDU is received but not transmitted. 679Use 680.Fl amsdu 681to disable all use of AMSDU with 802.11n. 682For testing and/or to work around interoperability problems one can use 683.Cm amsdutx 684and 685.Cm amsdurx 686to control use of AMSDU in one direction. 687.It Cm amsdulimit Ar limit 688Set the limit on packet size for sending and receiving AMSDU frames 689when operating with 802.11n. 690Legal values for 691.Ar limit 692are 7935 and 3839 (bytes). 693Note the sender may limit the size of AMSDU frames to be less 694than the maximum specified by the receiving station. 695Note also that devices are not required to support the 7935 limit, 696only 3839 is required by the specification and the larger value 697may require more memory to be dedicated to support functionality 698that is rarely used. 699.It Cm apbridge 700When operating as an access point, pass packets between 701wireless clients directly (default). 702To instead let them pass up through the 703system and be forwarded using some other mechanism, use 704.Fl apbridge . 705Disabling the internal bridging 706is useful when traffic is to be processed with 707packet filtering. 708.It Cm authmode Ar mode 709Set the desired authentication mode in infrastructure mode. 710Not all adapters support all modes. 711The set of 712valid modes is 713.Cm none , open , shared 714(shared key), 715.Cm 8021x 716(IEEE 802.1x), 717and 718.Cm wpa 719(IEEE WPA/WPA2/802.11i). 720The 721.Cm 8021x 722and 723.Cm wpa 724modes are only useful when using an authentication service 725(a supplicant for client operation or an authenticator when 726operating as an access point). 727Modes are case insensitive. 728.It Cm bgscan 729Enable background scanning when operating as a station. 730Background scanning is a technique whereby a station associated to 731an access point will temporarily leave the channel to scan for 732neighboring stations. 733This allows a station to maintain a cache of nearby access points 734so that roaming between access points can be done without 735a lengthy scan operation. 736Background scanning is done only when a station is not busy and 737any outbound traffic will cancel a scan operation. 738Background scanning should never cause packets to be lost though 739there may be some small latency if outbound traffic interrupts a 740scan operation. 741By default background scanning is enabled if the device is capable. 742To disable background scanning, use 743.Fl bgscan . 744Background scanning is controlled by the 745.Cm bgscanidle 746and 747.Cm bgscanintvl 748parameters. 749Background scanning must be enabled for roaming; this is an artifact 750of the current implementation and may not be required in the future. 751.It Cm bgscanidle Ar idletime 752Set the minimum time a station must be idle (not transmitting or 753receiving frames) before a background scan is initiated. 754The 755.Ar idletime 756parameter is specified in milliseconds. 757By default a station must be idle at least 250 milliseconds before 758a background scan is initiated. 759The idle time may not be set to less than 100 milliseconds. 760.It Cm bgscanintvl Ar interval 761Set the interval at which background scanning is attempted. 762The 763.Ar interval 764parameter is specified in seconds. 765By default a background scan is considered every 300 seconds (5 minutes). 766The 767.Ar interval 768may not be set to less than 15 seconds. 769.It Cm bintval Ar interval 770Set the interval at which beacon frames are sent when operating in 771ad-hoc or ap mode. 772The 773.Ar interval 774parameter is specified in TU's (1024 usecs). 775By default beacon frames are transmitted every 100 TU's. 776.It Cm bmissthreshold Ar count 777Set the number of consecutive missed beacons at which the station 778will attempt to roam (i.e., search for a new access point). 779The 780.Ar count 781parameter must be in the range 1 to 255; though the 782upper bound may be reduced according to device capabilities. 783The default threshold is 7 consecutive missed beacons; but 784this may be overridden by the device driver. 785Another name for the 786.Cm bmissthreshold 787parameter is 788.Cm bmiss . 789.It Cm bssid Ar address 790Specify the MAC address of the access point to use when operating 791as a station in a BSS network. 792This overrides any automatic selection done by the system. 793To disable a previously selected access point, supply 794.Cm any , none , 795or 796.Cm - 797for the address. 798This option is useful when more than one access point uses the same SSID. 799Another name for the 800.Cm bssid 801parameter is 802.Cm ap . 803.It Cm burst 804Enable packet bursting. 805Packet bursting is a transmission technique whereby the wireless 806medium is acquired once to send multiple frames and the interframe 807spacing is reduced. 808This technique can significantly increase throughput by reducing 809transmission overhead. 810Packet bursting is supported by the 802.11e QoS specification 811and some devices that do not support QoS may still be capable. 812By default packet bursting is enabled if a device is capable 813of doing it. 814To disable packet bursting, use 815.Fl burst . 816.It Cm chanlist Ar channels 817Set the desired channels to use when scanning for access 818points, neighbors in an IBSS network, or looking for unoccupied 819channels when operating as an access point. 820The set of channels is specified as a comma-separated list with 821each element in the list representing either a single channel number or a range 822of the form 823.Dq Li a-b . 824Channel numbers must be in the range 1 to 255 and be permissible 825according to the operating characteristics of the device. 826.It Cm channel Ar number 827Set a single desired channel. 828Channels range from 1 to 255, but the exact selection available 829depends on the region your adaptor was manufactured for. 830Setting 831the channel to 832.Li any , 833or 834.Cm - 835will clear any desired channel and, if the device is marked up, 836force a scan for a channel to operate on. 837Alternatively the frequency, in megahertz, may be specified 838instead of the channel number. 839.Pp 840When there are several ways to use a channel the channel 841number/frequency may be appended with attributes to clarify. 842For example, if a device is capable of operating on channel 6 843with 802.11n and 802.11g then one can specify that g-only use 844should be used by specifying ``6:g''. 845Similarly the channel width can be specified by appending it 846with ``/''; e.g. ``6/40'' specifies a 40MHz wide channel, 847These attributes can be combined as in: ``6:ht/40''. 848The full set of flags specified following a `:'' are: 849.Cm a 850(802.11a), 851.Cm b 852(802.11b), 853.Cm d 854(Atheros Dynamic Turbo mode), 855.Cm g 856(802.11g), 857.Cm h 858or 859.Cm n 860(802.11n aka HT), 861.Cm s 862(Atheros Static Turbo mode), 863and 864.Cm t 865(Atheros Dynamic Turbo mode, or appended to ``st'' and ``dt''). 866The full set of channel widths following a '/' are: 867.Cm 5 868(5MHz aka quarter-rate channel), 869.Cm 10 870(10MHz aka half-rate channel), 871.Cm 20 872(20MHz mostly for use in specifying ht20), 873and 874.Cm 40 875(40MHz mostly for use in specifying ht40), 876In addition, 877a 40MHz HT channel specification may include the location 878of the extension channel by appending ``+'' or ``-'' for above and below, 879respectively; e.g. ``2437:ht/40+'' specifies 40MHz wide HT operation 880with the center channel at frequency 2437 and the extension channel above. 881.It Cm country Ar name 882Set the country code to use in calculating the regulatory constraints 883for operation. 884In particular the set of available channels, how the wireless device 885will operation on the channels, and the maximum transmit power that 886can be used on a channel are defined by this setting. 887Country/Region codes are specified as a 2-character abbreviation 888defined by ISO 3166 or using a longer, but possibly ambiguous, spelling; 889e.g. "ES" and "Spain". 890The set of country codes are taken from /etc/regdomain.xml and can also 891be viewed with the ``list countries'' request. 892Note that not all devices support changing the country code from a default 893setting; typically stored in EEPROM. 894See also 895.Cm regdomain , 896.Cm indoor , 897.Cm outdoor , 898and 899.Cm anywhere . 900.It Cm dfs 901Enable Dynamic Frequency Selection (DFS) as specified in 802.11h. 902DFS embodies several facilities including detection of overlapping 903radar signals, dynamic transmit power control, and channel selection 904according to a least-congested criteria. 905DFS support is mandatory for some 5Ghz frequencies in certain 906locales (e.g. ETSI). 907By default DFS is enabled according to the regulatory definitions 908specified in /etc/regdomain.xml and the curent country code, regdomain, 909and channel. 910Note the underlying device (and driver) must support radar detection 911for full DFS support to work. 912To be fully compliant with the local regulatory agency frequencies that 913require DFS should not be used unless it is fully supported. 914Use 915.Fl dfs 916to disable this functionality for testing. 917.It Cm dotd 918Enable support for the 802.11d specification (default). 919When this support is enabled in station mode, beacon frames that advertise 920a country code different than the currently configured country code will 921cause an event to be dispatched to user applications. 922This event can be used by the station to adopt that country code and 923operate according to the associated regulatory constraints. 924When operating as an access point with 802.11d enabled the beacon and 925probe response frames transmitted will advertise the current regulatory 926domain settings. 927To disable 802.11d use 928.Fl dotd . 929.It Cm doth 930Enable 802.11h support including spectrum management. 931When 802.11h is enabled beacon and probe response frames will have 932the SpectrumMgt bit set in the capabilities field and 933country and power constraint information elements will be present. 934802.11h support also includes handling Channel Switch Announcements (CSA) 935which are a mechanism to coordinate channel changes by an access point. 936By default 802.11h is enabled if the device is capable. 937To disable 802.11h use 938.Fl doth . 939.It Cm deftxkey Ar index 940Set the default key to use for transmission. 941Typically this is only set when using WEP encryption. 942Note that you must set a default transmit key 943for the system to know which key to use in encrypting outbound traffic. 944The 945.Cm weptxkey 946is an alias for this request; it is provided for backwards compatibility. 947.It Cm dtimperiod Ar period 948Set the 949DTIM 950period for transmitting buffered multicast data frames when 951operating in ap mode. 952The 953.Ar period 954specifies the number of beacon intervals between DTIM 955and must be in the range 1 to 15. 956By default DTIM is 1 (i.e., DTIM occurs at each beacon). 957.It Cm dturbo 958Enable the use of Atheros Dynamic Turbo mode when communicating with 959another Dynamic Turbo-capable station. 960Dynamic Turbo mode is an Atheros-specific mechanism by which 961stations switch between normal 802.11 operation and a ``boosted'' 962mode in which a 40MHz wide channel is used for communication. 963Stations using Dynamic Turbo mode operate boosted only when the 964channel is free of non-dturbo stations; when a non-dturbo station 965is identified on the channel all stations will automatically drop 966back to normal operation. 967By default, Dynamic Turbo mode is not enabled, even if the device is capable. 968Note that turbo mode (dynamic or static) is only allowed on some 969channels depending on the regulatory constraints; use the 970.Cm list chan 971command to identify the channels where turbo mode may be used. 972To disable Dynamic Turbo mode use 973.Fl dturbo . 974.It Cm dwds 975Enable Dynamic WDS (DWDS) support. 976DWDS is a facility by which 4-address traffic can be carried between 977stations operating in infrastructure mode. 978A station first associates to an access point and authenticates using 979normal procedures (e.g. WPA). 980Then 4-address frames are passed to carry traffic for stations 981operating on either side of the wireless link. 982DWDS extends the normal WDS mechanism by leveraging existing security 983protocols and eliminating static binding. 984.Pp 985When DWDS is enabled on an access point 4-address frames received from 986an authorized station will generate a ``DWDS discovery'' event to user 987applications. 988This event should be used to create a WDS interface that is bound 989to the remote station (and usually plumbed into a bridge). 990Once the WDS interface is up and running 4-address traffic then logically 991flows through that interface. 992.Pp 993When DWDS is enabled on a station, traffic with a destination address 994different from the peer station are encapsulated in a 4-address frame 995and transmitted to the peer. 996All 4-address traffic uses the security information of the stations 997(e.g. cryptographic keys). 998A station is associated using 802.11n facilities may transport 9994-address traffic using these same mechanisms; this depends on available 1000resources and capabilities of the device. 1001The DWDS implementation guards against layer 2 routing loops of 1002multicast traffic. 1003.It Cm ff 1004Enable the use of Atheros Fast Frames when communicating with 1005another Fast Frames-capable station. 1006Fast Frames are an encapsulation technique by which two 802.3 1007frames are transmitted in a single 802.11 frame. 1008This can noticeably improve throughput but requires that the 1009receiving station understand how to decapsulate the frame. 1010Fast frame use is negotiated using the Atheros 802.11 vendor-specific 1011protocol extension so enabling use is safe when communicating with 1012non-Atheros devices. 1013By default, use of fast frames is enabled if the device is capable. 1014To explicitly disable fast frames, use 1015.Fl ff . 1016.It Cm fragthreshold Ar length 1017Set the threshold for which transmitted frames are broken into fragments. 1018The 1019.Ar length 1020argument is the frame size in bytes and must be in the range 256 to 2346. 1021Setting 1022.Ar length 1023to 1024.Li 2346 , 1025.Cm any , 1026or 1027.Cm - 1028disables transmit fragmentation. 1029Not all adapters honor the fragmentation threshold. 1030.It Cm hidessid 1031When operating as an access point, do not broadcast the SSID 1032in beacon frames or respond to probe request frames unless 1033they are directed to the ap (i.e., they include the ap's SSID). 1034By default, the SSID is included in beacon frames and 1035undirected probe request frames are answered. 1036To re-enable the broadcast of the SSID etc., use 1037.Fl hidessid . 1038.It Cm ht 1039Enable use of High Throughput (HT) when using 802.11n (default). 1040The 802.11n specification includes mechanisms for operation 1041on 20MHz and 40MHz wide channels using different signalling mechanisms 1042than specified in 802.11b, 802.11g, and 802.11a. 1043Stations negotiate use of these facilities, termed HT20 and HT40, 1044when they associate. 1045To disable all use of 802.11n use 1046.Fl ht . 1047To disable use of HT20 (e.g. to force only HT40 use) use 1048.Fl ht20 . 1049To disable use of HT40 use 1050.Fl ht40 . 1051.Pp 1052HT configuration is used to ``auto promote'' operation 1053when several choices are available. 1054For example, if a station associates to an 11n-capable access point 1055it controls whether the station uses legacy operation, HT20, or HT40. 1056When an 11n-capable device is setup as an access point and 1057Auto Channel Selection is used to locate a channel to operate on, 1058HT configuration controls whether legacy, HT20, or HT40 operation is setup 1059on the selected channel. 1060If a fixed channel is specified for a station then HT configuration can 1061be given as part of the channel specification; e.g. 6:ht/20 to setup 1062HT20 operation on channel 6. 1063.It Cm htcompat 1064Enable use of compatibility support for pre-802.11n devices (default). 1065The 802.11n protocol specification went through several incompatible iterations. 1066Some vendors implemented 11n support to older specifications that 1067will not interoperate with a purely 11n-compliant station. 1068In particular the information elements included in management frames 1069for old devices are different. 1070When compatibility support is enabled both standard and compatible data 1071will be provided. 1072Stations that associate using the compatibility mechanisms are flagged 1073in ``list sta''. 1074To disable compatibility support use 1075.Fl htcompat . 1076.It Cm htprotmode Ar technique 1077For interfaces operating in 802.11n, use the specified 1078.Ar technique 1079for protecting HT frames in a mixed legacy/HT network. 1080The set of valid techniques is 1081.Cm off , 1082and 1083.Cm rts 1084(RTS/CTS, default). 1085Technique names are case insensitive. 1086.It Cm inact 1087Enable inactivity processing for stations associated to an 1088access point (default). 1089When operating as an access point the 802.11 layer monitors 1090the activity of each associated station. 1091When a station is inactive for 5 minutes it will send several 1092``probe frames'' to see if the station is still present. 1093If no response is received then the station is deauthenticated. 1094Applications that prefer to handle this work can disable this 1095facility by using 1096.Fl inact . 1097.It Cm indoor 1098Set the location to use in calculating regulatory constraints. 1099The location is also advertised in beacon and probe response frames 1100when 802.11d is enabled with 1101.Cm dotd . 1102See also 1103.Cm outdoor , 1104.Cm anywhere , 1105.Cm country , 1106and 1107.Cm regdomain . 1108.It Cm list active 1109Display the list of channels available for use taking into account 1110any restrictions set with the 1111.Cm chanlist 1112directive. 1113See the description of 1114.Cm list chan 1115for more information. 1116.It Cm list caps 1117Display the adaptor's capabilities, including the operating 1118modes supported. 1119.It Cm list chan 1120Display the list of channels available for use. 1121Channels are shown with their IEEE channel number, equivalent 1122frequency, and usage modes. 1123Channels identified as 1124.Ql 11g 1125are also usable in 1126.Ql 11b 1127mode. 1128Channels identified as 1129.Ql 11a Turbo 1130may be used only for Atheros' Static Turbo mode 1131(specified with 1132.Cm mediaopt turbo ) . 1133Channels marked with a 1134.Ql * 1135have a regulatory constraint that they be passively scanned. 1136This means a station is not permitted to transmit on the channel until 1137it identifies the channel is being used for 802.11 communication; 1138typically by hearing a beacon frame from an access point operating 1139on the channel. 1140.Cm list freq 1141is another way of requesting this information. 1142By default a compacted list of channels is displayed; if the 1143.Fl v 1144option is specified then all channels are shown. 1145.It Cm list countries 1146Display the set of country codes and regulatory domains that can be 1147used in regulatory configuration. 1148.It Cm list mac 1149Display the current MAC Access Control List state. 1150Each address is prefixed with a character that indicates the 1151current policy applied to it: 1152.Ql + 1153indicates the address is allowed access, 1154.Ql - 1155indicates the address is denied access, 1156.Ql * 1157indicates the address is present but the current policy open 1158(so the ACL is not consulted). 1159.It Cm list mesh 1160Displays the mesh routing table, used for forwarding packets on a mesh 1161network. 1162.It Cm list regdomain 1163Display the current regulatory settings including the available channels 1164and transmit power caps. 1165.It Cm list roam 1166Display the parameters that govern roaming operation. 1167.It Cm list txparam 1168Display the parameters that govern transmit operation. 1169.It Cm list txpower 1170Display the transmit power caps for each channel. 1171.It Cm list scan 1172Display the access points and/or ad-hoc neighbors 1173located in the vicinity. 1174This information may be updated automatically by the adapter 1175with a 1176.Cm scan 1177request or through background scanning. 1178Depending on the capabilities of the stations the following 1179flags can be included in the output: 1180.Bl -tag -width 3n 1181.It Li A 1182Authorized. 1183Indicates that the station is permitted to send/receive data frames. 1184.It Li E 1185Extended Rate Phy (ERP). 1186Indicates that the station is operating in an 802.11g network 1187using extended transmit rates. 1188.It Li H 1189High Throughput (HT). 1190Indicates that the station is using HT transmit rates. 1191If a `+' follows immediately after then the station associated 1192using deprecated mechanisms supported only when 1193.Cm htcompat 1194is enabled. 1195.It Li P 1196Power Save. 1197Indicates that the station is operating in power save mode. 1198.It Li Q 1199Quality of Service (QoS). 1200Indicates that the station is using QoS encapsulation for 1201data frame. 1202QoS encapsulation is enabled only when WME mode is enabled. 1203.It Li T 1204Transitional Security Network (TSN). 1205Indicates that the station associated using TSN; see also 1206.Cm tsn 1207below. 1208.It Li W 1209Wi-Fi Protected Setup (WPS). 1210Indicates that the station associated using WPS. 1211.El 1212.Pp 1213By default interesting information elements captured from the neighboring 1214stations are displayed at the end of each row. 1215Possible elements include: 1216.Cm WME 1217(station supports WME), 1218.Cm WPA 1219(station supports WPA), 1220.Cm WPS 1221(station supports WPS), 1222.Cm RSN 1223(station supports 802.11i/RSN), 1224.Cm HTCAP 1225(station supports 802.11n/HT communication), 1226.Cm ATH 1227(station supports Atheros protocol extensions), 1228.Cm VEN 1229(station supports unknown vendor-specific extensions). 1230If the 1231.Fl v 1232flag is used all the information elements and their 1233contents will be shown. 1234Specifying the 1235.Fl v 1236flag also enables display of long SSIDs. 1237The 1238.Cm list ap 1239command is another way of requesting this information. 1240.It Cm list sta 1241When operating as an access point display the stations that are 1242currently associated. 1243When operating in ad-hoc mode display stations identified as 1244neighbors in the IBSS. 1245When operating in mesh mode display stations identified as 1246neighbors in the MBSS. 1247When operating in station mode display the access point. 1248Capabilities advertised by the stations are described under 1249the 1250.Cm scan 1251request. 1252Depending on the capabilities of the stations the following 1253flags can be included in the output: 1254.Bl -tag -width 3n 1255.It Li A 1256Authorized. 1257Indicates that the station is permitted to send/receive data frames. 1258.It Li E 1259Extended Rate Phy (ERP). 1260Indicates that the station is operating in an 802.11g network 1261using extended transmit rates. 1262.It Li H 1263High Throughput (HT). 1264Indicates that the station is using HT transmit rates. 1265If a `+' follows immediately after then the station associated 1266using deprecated mechanisms supported only when 1267.Cm htcompat 1268is enabled. 1269.It Li P 1270Power Save. 1271Indicates that the station is operating in power save mode. 1272.It Li Q 1273Quality of Service (QoS). 1274Indicates that the station is using QoS encapsulation for 1275data frame. 1276QoS encapsulation is enabled only when WME mode is enabled. 1277.It Li T 1278Transitional Security Network (TSN). 1279Indicates that the station associated using TSN; see also 1280.Cm tsn 1281below. 1282.It Li W 1283Wi-Fi Protected Setup (WPS). 1284Indicates that the station associated using WPS. 1285.El 1286.Pp 1287By default information elements received from associated stations 1288are displayed in a short form; the 1289.Fl v 1290flag causes this information to be displayed symbolically. 1291.It Cm list wme 1292Display the current channel parameters to use when operating in WME mode. 1293If the 1294.Fl v 1295option is specified then both channel and BSS parameters are displayed 1296for each AC (first channel, then BSS). 1297When WME mode is enabled for an adaptor this information will be 1298displayed with the regular status; this command is mostly useful 1299for examining parameters when WME mode is disabled. 1300See the description of the 1301.Cm wme 1302directive for information on the various parameters. 1303.It Cm maxretry Ar count 1304Set the maximum number of tries to use in sending unicast frames. 1305The default setting is 6 but drivers may override this with a value 1306they choose. 1307.It Cm mcastrate Ar rate 1308Set the rate for transmitting multicast/broadcast frames. 1309Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s. 1310This rate should be valid for the current operating conditions; 1311if an invalid rate is specified drivers are free to chose an 1312appropriate rate. 1313.It Cm mgtrate Ar rate 1314Set the rate for transmitting management and/or control frames. 1315Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s. 1316.It Cm outdoor 1317Set the location to use in calculating regulatory constraints. 1318The location is also advertised in beacon and probe response frames 1319when 802.11d is enabled with 1320.Cm dotd . 1321See also 1322.Cm anywhere , 1323.Cm country , 1324.Cm indoor , 1325and 1326.Cm regdomain . 1327.It Cm powersave 1328Enable powersave operation. 1329When operating as a client, the station will conserve power by 1330periodically turning off the radio and listening for 1331messages from the access point telling it there are packets waiting. 1332The station must then retrieve the packets. 1333Not all devices support power save operation as a client. 1334The 802.11 specification requires that all access points support 1335power save but some drivers do not. 1336Use 1337.Fl powersave 1338to disable powersave operation when operating as a client. 1339.It Cm powersavemode Ar mode 1340Set powersave mode. 1341The set of valid modes is 1342.Cm off 1343(same as 1344.Fl powersave ) , 1345.Cm on 1346(same as 1347.Cm powersave ) , 1348and 1349.Cm cam 1350(same as 1351.Cm powersave ) . 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 rifs 1398Enable use of Reduced InterFrame Spacing (RIFS) when operating in 802.11n 1399on an HT channel. 1400Note that RIFS must be supported by both the station and access point 1401for it to be used. 1402To disable RIFS use 1403.Fl rifs . 1404.It Cm roam:rate Ar rate 1405Set the threshold for controlling roaming when operating in a BSS. 1406The 1407.Ar rate 1408parameter specifies the transmit rate in megabits 1409at which roaming should be considered. 1410If the current transmit rate drops below this setting and background scanning 1411is enabled, then the system will check if a more desirable access point is 1412available and switch over to it. 1413The current scan cache contents are used if they are considered 1414valid according to the 1415.Cm scanvalid 1416parameter; otherwise a background scan operation is triggered before 1417any selection occurs. 1418Each channel type has a separate rate threshold; the default values are: 141912 Mb/s (11a), 2 Mb/s (11b), 2 Mb/s (11g), MCS 1 (11na, 11ng). 1420.It Cm roam:rssi Ar rssi 1421Set the threshold for controlling roaming when operating in a BSS. 1422The 1423.Ar rssi 1424parameter specifies the receive signal strength in dBm units 1425at which roaming should be considered. 1426If the current rssi drops below this setting and background scanning 1427is enabled, then the system will check if a more desirable access point is 1428available and switch over to it. 1429The current scan cache contents are used if they are considered 1430valid according to the 1431.Cm scanvalid 1432parameter; otherwise a background scan operation is triggered before 1433any selection occurs. 1434Each channel type has a separate rssi threshold; the default values are 1435all 7 dBm. 1436.It Cm roaming Ar mode 1437When operating as a station, control how the system will 1438behave when communication with the current access point 1439is broken. 1440The 1441.Ar mode 1442argument may be one of 1443.Cm device 1444(leave it to the hardware device to decide), 1445.Cm auto 1446(handle either in the device or the operating system\[em]as appropriate), 1447.Cm manual 1448(do nothing until explicitly instructed). 1449By default, the device is left to handle this if it is 1450capable; otherwise, the operating system will automatically 1451attempt to reestablish communication. 1452Manual mode is used by applications such as 1453.Xr wpa_supplicant 8 1454that want to control the selection of an access point. 1455.It Cm rtsthreshold Ar length 1456Set the threshold for which 1457transmitted frames are preceded by transmission of an 1458RTS 1459control frame. 1460The 1461.Ar length 1462argument 1463is the frame size in bytes and must be in the range 1 to 2346. 1464Setting 1465.Ar length 1466to 1467.Li 2346 , 1468.Cm any , 1469or 1470.Cm - 1471disables transmission of RTS frames. 1472Not all adapters support setting the RTS threshold. 1473.It Cm scan 1474Initiate a scan of neighboring stations, wait for it to complete, and 1475display all stations found. 1476Only the super-user can initiate a scan. 1477See 1478.Cm list scan 1479for information on the display. 1480By default a background scan is done; otherwise a foreground 1481scan is done and the station may roam to a different access point. 1482The 1483.Cm list scan 1484request can be used to show recent scan results without 1485initiating a new scan. 1486.It Cm scanvalid Ar threshold 1487Set the maximum time the scan cache contents are considered valid; 1488i.e. will be used without first triggering a scan operation to 1489refresh the data. 1490The 1491.Ar threshold 1492parameter is specified in seconds and defaults to 60 seconds. 1493The minimum setting for 1494.Ar threshold 1495is 10 seconds. 1496One should take care setting this threshold; if it is set too low 1497then attempts to roam to another access point may trigger unnecessary 1498background scan operations. 1499.It Cm shortgi 1500Enable use of Short Guard Interval when operating in 802.11n 1501on an HT channel. 1502NB: this currently enables Short GI on both HT40 and HT20 channels. 1503To disable Short GI use 1504.Fl shortgi . 1505.It Cm smps 1506Enable use of Static Spatial Multiplexing Power Save (SMPS) 1507when operating in 802.11n. 1508A station operating with Static SMPS maintains only a single 1509receive chain active (this can significantly reduce power consumption). 1510To disable SMPS use 1511.Fl smps . 1512.It Cm smpsdyn 1513Enable use of Dynamic Spatial Multiplexing Power Save (SMPS) 1514when operating in 802.11n. 1515A station operating with Dynamic SMPS maintains only a single 1516receive chain active but switches to multiple receive chains when it 1517receives an RTS frame (this can significantly reduce power consumption). 1518Note that stations cannot distinguish between RTS/CTS intended to 1519enable multiple receive chains and those used for other purposes. 1520To disable SMPS use 1521.Fl smps . 1522.It Cm ssid Ar ssid 1523Set the desired Service Set Identifier (aka network name). 1524The SSID is a string up to 32 characters 1525in length and may be specified as either a normal string or in 1526hexadecimal when preceded by 1527.Ql 0x . 1528Additionally, the SSID may be cleared by setting it to 1529.Ql - . 1530.It Cm tdmaslot Ar slot 1531When operating with TDMA, use the specified 1532.Ar slot 1533configuration. 1534The 1535.Ar slot 1536is a number between 0 and the maximum number of slots in the BSS. 1537Note that a station configured as slot 0 is a master and 1538will broadcast beacon frames advertising the BSS; 1539stations configured to use other slots will always 1540scan to locate a master before they ever transmit. 1541By default 1542.Cm tdmaslot 1543is set to 1. 1544.It Cm tdmaslotcnt Ar cnt 1545When operating with TDMA, setup a BSS with 1546.Ar cnt 1547slots. 1548The slot count may be at most 8. 1549The current implementation is only tested with two stations 1550(i.e. point to point applications). 1551This setting is only meaningful when a station is configured as slot 0; 1552other stations adopt this setting from the BSS they join. 1553By default 1554.Cm tdmaslotcnt 1555is set to 2. 1556.It Cm tdmaslotlen Ar len 1557When operating with TDMA, setup a BSS such that each station has a slot 1558.Ar len 1559microseconds long. 1560The slot length must be at least 150 microseconds (1/8 TU) 1561and no more than 65 milliseconds. 1562Note that setting too small a slot length may result in poor channel 1563bandwidth utilization due to factors such as timer granularity and 1564guard time. 1565This setting is only meaningful when a station is configured as slot 0; 1566other stations adopt this setting from the BSS they join. 1567By default 1568.Cm tdmaslotlen 1569is set to 10 milliseconds. 1570.It Cm tdmabintval Ar intval 1571When operating with TDMA, setup a BSS such that beacons are transmitted every 1572.Ar intval 1573superframes to synchronize the TDMA slot timing. 1574A superframe is defined as the number of slots times the slot length; e.g. 1575a BSS with two slots of 10 milliseconds has a 20 millisecond superframe. 1576The beacon interval may not be zero. 1577A lower setting of 1578.Cm tdmabintval 1579causes the timers to be resynchronized more often; this can be help if 1580significant timer drift is observed. 1581By default 1582.Cm tdmabintval 1583is set to 5. 1584.It Cm tsn 1585When operating as an access point with WPA/802.11i allow legacy 1586stations to associate using static key WEP and open authentication. 1587To disallow legacy station use of WEP, use 1588.Fl tsn . 1589.It Cm txpower Ar power 1590Set the power used to transmit frames. 1591The 1592.Ar power 1593argument is specified in .5 dBm units. 1594Out of range values are truncated. 1595Typically only a few discreet power settings are available and 1596the driver will use the setting closest to the specified value. 1597Not all adapters support changing the transmit power. 1598.It Cm ucastrate Ar rate 1599Set a fixed rate for transmitting unicast frames. 1600Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s. 1601This rate should be valid for the current operating conditions; 1602if an invalid rate is specified drivers are free to chose an 1603appropriate rate. 1604.It Cm wepmode Ar mode 1605Set the desired WEP mode. 1606Not all adapters support all modes. 1607The set of valid modes is 1608.Cm off , on , 1609and 1610.Cm mixed . 1611The 1612.Cm mixed 1613mode explicitly tells the adaptor to allow association with access 1614points which allow both encrypted and unencrypted traffic. 1615On these adapters, 1616.Cm on 1617means that the access point must only allow encrypted connections. 1618On other adapters, 1619.Cm on 1620is generally another name for 1621.Cm mixed . 1622Modes are case insensitive. 1623.It Cm weptxkey Ar index 1624Set the WEP key to be used for transmission. 1625This is the same as setting the default transmission key with 1626.Cm deftxkey . 1627.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key 1628Set the selected WEP key. 1629If an 1630.Ar index 1631is not given, key 1 is set. 1632A WEP key will be either 5 or 13 1633characters (40 or 104 bits) depending of the local network and the 1634capabilities of the adaptor. 1635It may be specified either as a plain 1636string or as a string of hexadecimal digits preceded by 1637.Ql 0x . 1638For maximum portability, hex keys are recommended; 1639the mapping of text keys to WEP encryption is usually driver-specific. 1640In particular, the 1641.Tn Windows 1642drivers do this mapping differently to 1643.Fx . 1644A key may be cleared by setting it to 1645.Ql - . 1646If WEP is supported then there are at least four keys. 1647Some adapters support more than four keys. 1648If that is the case, then the first four keys 1649(1-4) will be the standard temporary keys and any others will be adaptor 1650specific keys such as permanent keys stored in NVRAM. 1651.Pp 1652Note that you must set a default transmit key with 1653.Cm deftxkey 1654for the system to know which key to use in encrypting outbound traffic. 1655.It Cm wme 1656Enable Wireless Multimedia Extensions (WME) support, if available, 1657for the specified interface. 1658WME is a subset of the IEEE 802.11e standard to support the 1659efficient communication of realtime and multimedia data. 1660To disable WME support, use 1661.Fl wme . 1662Another name for this parameter is 1663.Cm wmm . 1664.Pp 1665The following parameters are meaningful only when WME support is in use. 1666Parameters are specified per-AC (Access Category) and 1667split into those that are used by a station when acting 1668as an access point and those for client stations in the BSS. 1669The latter are received from the access point and may not be changed 1670(at the station). 1671The following Access Categories are recognized: 1672.Pp 1673.Bl -tag -width ".Cm AC_BK" -compact 1674.It Cm AC_BE 1675(or 1676.Cm BE ) 1677best effort delivery, 1678.It Cm AC_BK 1679(or 1680.Cm BK ) 1681background traffic, 1682.It Cm AC_VI 1683(or 1684.Cm VI ) 1685video traffic, 1686.It Cm AC_VO 1687(or 1688.Cm VO ) 1689voice traffic. 1690.El 1691.Pp 1692AC parameters are case-insensitive. 1693Traffic classification is done in the operating system using the 1694vlan priority associated with data frames or the 1695ToS (Type of Service) indication in IP-encapsulated frames. 1696If neither information is present, traffic is assigned to the 1697Best Effort (BE) category. 1698.Bl -tag -width indent 1699.It Cm ack Ar ac 1700Set the ACK policy for QoS transmissions by the local station; 1701this controls whether or not data frames transmitted by a station 1702require an ACK response from the receiving station. 1703To disable waiting for an ACK use 1704.Fl ack . 1705This parameter is applied only to the local station. 1706.It Cm acm Ar ac 1707Enable the Admission Control Mandatory (ACM) mechanism 1708for transmissions by the local station. 1709To disable the ACM use 1710.Fl acm . 1711On stations in a BSS this parameter is read-only and indicates 1712the setting received from the access point. 1713NB: ACM is not supported right now. 1714.It Cm aifs Ar ac Ar count 1715Set the Arbitration Inter Frame Spacing (AIFS) 1716channel access parameter to use for transmissions 1717by the local station. 1718On stations in a BSS this parameter is read-only and indicates 1719the setting received from the access point. 1720.It Cm cwmin Ar ac Ar count 1721Set the CWmin channel access parameter to use for transmissions 1722by the local station. 1723On stations in a BSS this parameter is read-only and indicates 1724the setting received from the access point. 1725.It Cm cwmax Ar ac Ar count 1726Set the CWmax channel access parameter to use for transmissions 1727by the local station. 1728On stations in a BSS this parameter is read-only and indicates 1729the setting received from the access point. 1730.It Cm txoplimit Ar ac Ar limit 1731Set the Transmission Opportunity Limit channel access parameter 1732to use for transmissions by the local station. 1733This parameter defines an interval of time when a WME station 1734has the right to initiate transmissions onto the wireless medium. 1735On stations in a BSS this parameter is read-only and indicates 1736the setting received from the access point. 1737.It Cm bss:aifs Ar ac Ar count 1738Set the AIFS channel access parameter to send to stations in a BSS. 1739This parameter is meaningful only when operating in ap mode. 1740.It Cm bss:cwmin Ar ac Ar count 1741Set the CWmin channel access parameter to send to stations in a BSS. 1742This parameter is meaningful only when operating in ap mode. 1743.It Cm bss:cwmax Ar ac Ar count 1744Set the CWmax channel access parameter to send to stations in a BSS. 1745This parameter is meaningful only when operating in ap mode. 1746.It Cm bss:txoplimit Ar ac Ar limit 1747Set the TxOpLimit channel access parameter to send to stations in a BSS. 1748This parameter is meaningful only when operating in ap mode. 1749.El 1750.It Cm wps 1751Enable Wireless Privacy Subscriber support. 1752Note that WPS support requires a WPS-capable supplicant. 1753To disable this function use 1754.Fl wps . 1755.El 1756.Pp 1757The following parameters support an optional access control list 1758feature available with some adapters when operating in ap mode; see 1759.Xr wlan_acl 4 . 1760This facility allows an access point to accept/deny association 1761requests based on the MAC address of the station. 1762Note that this feature does not significantly enhance security 1763as MAC address spoofing is easy to do. 1764.Bl -tag -width indent 1765.It Cm mac:add Ar address 1766Add the specified MAC address to the database. 1767Depending on the policy setting association requests from the 1768specified station will be allowed or denied. 1769.It Cm mac:allow 1770Set the ACL policy to permit association only by 1771stations registered in the database. 1772.It Cm mac:del Ar address 1773Delete the specified MAC address from the database. 1774.It Cm mac:deny 1775Set the ACL policy to deny association only by 1776stations registered in the database. 1777.It Cm mac:kick Ar address 1778Force the specified station to be deauthenticated. 1779This typically is done to block a station after updating the 1780address database. 1781.It Cm mac:open 1782Set the ACL policy to allow all stations to associate. 1783.It Cm mac:flush 1784Delete all entries in the database. 1785.It Cm mac:radius 1786Set the ACL policy to permit association only by 1787stations approved by a RADIUS server. 1788Note that this feature requires the 1789.Xr hostapd 8 1790program be configured to do the right thing 1791as it handles the RADIUS processing 1792(and marks stations as authorized). 1793.El 1794.Pp 1795The following parameters are related to a wireless interface operating in mesh 1796mode: 1797.Bl -tag -width indent 1798.It Cm meshid Ar meshid 1799Set the desired Mesh Identifier. 1800The Mesh ID is a string up to 32 characters in length. 1801A mesh interface must have a Mesh Identifier specified 1802to reach an operational state. 1803.It Cm meshttl Ar ttl 1804Set the desired ``time to live'' for mesh forwarded packets; 1805this is the number of hops a packet may be forwarded before 1806it is discarded. 1807The default setting for 1808.Cm meshttl 1809is 31. 1810.It Cm meshpeering 1811Enable or disable peering with neighbor mesh stations. 1812Stations must peer before any data packets can be exchanged. 1813By default 1814.Cm meshpeering 1815is enabled. 1816.It Cm meshforward 1817Enable or disable forwarding packets by a mesh interface. 1818By default 1819.Cm meshforward 1820is enabled. 1821.It Cm meshmetric Ar protocol 1822Set the specified 1823.Ar protocol 1824as the link metric protocol used on a mesh network. 1825The default protocol is called 1826.Ar AIRTIME . 1827The mesh interface will restart after changing this setting. 1828.It Cm meshpath Ar protocol 1829Set the specified 1830.Ar protocol 1831as the path selection protocol used on a mesh network. 1832The only available protocol at the moment is called 1833.Ar HWMP 1834(Hybrid Wireless Mesh Protocol). 1835The mesh interface will restart after changing this setting. 1836.It Cm hwmprootmode Ar mode 1837Stations on a mesh network can operate as ``root nodes.'' 1838Root nodes try to find paths to all mesh nodes and advertise themselves 1839regularly. 1840When there is a root mesh node on a network, other mesh nodes can setup 1841paths between themselves faster because they can use the root node 1842to find the destination. 1843This path may not be the best, but on-demand 1844routing will eventually find the best path. 1845The following modes are recognized: 1846.Pp 1847.Bl -tag -width ".Cm PROACTIVE" -compact 1848.It Cm DISABLED 1849Disable root mode. 1850.It Cm NORMAL 1851Send broadcast path requests every two seconds. 1852Nodes on the mesh without a path to this root mesh station with try to 1853discover a path to us. 1854.It Cm PROACTIVE 1855Send broadcast path requests every two seconds and every node must reply 1856with a path reply even if it already has a path to this root mesh station, 1857.It Cm RANN 1858Send broadcast root announcement (RANN) frames. 1859Nodes on the mesh without a path to this root mesh station with try to 1860discover a path to us. 1861.El 1862By default 1863.Cm hwmprootmode 1864is set to 1865.Ar DISABLED . 1866.It Cm hwmpmaxhops Ar cnt 1867Set the maximum number of hops allowed in an HMWP path to 1868.Ar cnt . 1869The default setting for 1870.Cm hwmpmaxhops 1871is 31. 1872.El 1873.Pp 1874The following parameters are for compatibility with other systems: 1875.Bl -tag -width indent 1876.It Cm nwid Ar ssid 1877Another name for the 1878.Cm ssid 1879parameter. 1880Included for 1881.Nx 1882compatibility. 1883.It Cm stationname Ar name 1884Set the name of this station. 1885The station name is not part of the IEEE 802.11 1886protocol though some interfaces support it. 1887As such it only 1888seems to be meaningful to identical or virtually identical equipment. 1889Setting the station name is identical in syntax to setting the SSID. 1890One can also use 1891.Cm station 1892for 1893.Bsx 1894compatibility. 1895.It Cm wep 1896Another way of saying 1897.Cm wepmode on . 1898Included for 1899.Bsx 1900compatibility. 1901.It Fl wep 1902Another way of saying 1903.Cm wepmode off . 1904Included for 1905.Bsx 1906compatibility. 1907.It Cm nwkey key 1908Another way of saying: 1909.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" . 1910Included for 1911.Nx 1912compatibility. 1913.It Cm nwkey Xo 1914.Sm off 1915.Ar n : k1 , k2 , k3 , k4 1916.Sm on 1917.Xc 1918Another way of saying 1919.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" . 1920Included for 1921.Nx 1922compatibility. 1923.It Fl nwkey 1924Another way of saying 1925.Cm wepmode off . 1926Included for 1927.Nx 1928compatibility. 1929.El 1930.Pp 1931The following parameters are specific to bridge interfaces: 1932.Bl -tag -width indent 1933.It Cm addm Ar interface 1934Add the interface named by 1935.Ar interface 1936as a member of the bridge. 1937The interface is put into promiscuous mode 1938so that it can receive every packet sent on the network. 1939.It Cm deletem Ar interface 1940Remove the interface named by 1941.Ar interface 1942from the bridge. 1943Promiscuous mode is disabled on the interface when 1944it is removed from the bridge. 1945.It Cm maxaddr Ar size 1946Set the size of the bridge address cache to 1947.Ar size . 1948The default is 100 entries. 1949.It Cm timeout Ar seconds 1950Set the timeout of address cache entries to 1951.Ar seconds 1952seconds. 1953If 1954.Ar seconds 1955is zero, then address cache entries will not be expired. 1956The default is 1200 seconds. 1957.It Cm addr 1958Display the addresses that have been learned by the bridge. 1959.It Cm static Ar interface-name Ar address 1960Add a static entry into the address cache pointing to 1961.Ar interface-name . 1962Static entries are never aged out of the cache or re-placed, even if the 1963address is seen on a different interface. 1964.It Cm deladdr Ar address 1965Delete 1966.Ar address 1967from the address cache. 1968.It Cm flush 1969Delete all dynamically-learned addresses from the address cache. 1970.It Cm flushall 1971Delete all addresses, including static addresses, from the address cache. 1972.It Cm discover Ar interface 1973Mark an interface as a 1974.Dq discovering 1975interface. 1976When the bridge has no address cache entry 1977(either dynamic or static) 1978for the destination address of a packet, 1979the bridge will forward the packet to all 1980member interfaces marked as 1981.Dq discovering . 1982This is the default for all interfaces added to a bridge. 1983.It Fl discover Ar interface 1984Clear the 1985.Dq discovering 1986attribute on a member interface. 1987For packets without the 1988.Dq discovering 1989attribute, the only packets forwarded on the interface are broadcast 1990or multicast packets and packets for which the destination address 1991is known to be on the interface's segment. 1992.It Cm learn Ar interface 1993Mark an interface as a 1994.Dq learning 1995interface. 1996When a packet arrives on such an interface, the source 1997address of the packet is entered into the address cache as being a 1998destination address on the interface's segment. 1999This is the default for all interfaces added to a bridge. 2000.It Fl learn Ar interface 2001Clear the 2002.Dq learning 2003attribute on a member interface. 2004.It Cm span Ar interface 2005Add the interface named by 2006.Ar interface 2007as a span port on the bridge. 2008Span ports transmit a copy of every frame received by the bridge. 2009This is most useful for snooping a bridged network passively on 2010another host connected to one of the span ports of the bridge. 2011.It Fl span Ar interface 2012Delete the interface named by 2013.Ar interface 2014from the list of span ports of the bridge. 2015.It Cm stp Ar interface 2016Enable Spanning Tree protocol on 2017.Ar interface . 2018The 2019.Xr bridge 4 2020driver has support for the IEEE 802.1D Spanning Tree protocol (STP). 2021Spanning Tree is used to detect and remove loops in a network topology. 2022.It Fl stp Ar interface 2023Disable Spanning Tree protocol on 2024.Ar interface . 2025This is the default for all interfaces added to a bridge. 2026.It Cm maxage Ar seconds 2027Set the time that a Spanning Tree protocol configuration is valid. 2028The default is 20 seconds. 2029The minimum is 1 second and the maximum is 255 seconds. 2030.It Cm fwddelay Ar seconds 2031Set the time that must pass before an interface begins forwarding 2032packets when Spanning Tree is enabled. 2033The default is 15 seconds. 2034The minimum is 1 second and the maximum is 255 seconds. 2035.It Cm hellotime Ar seconds 2036Set the time between broadcasting of Spanning Tree protocol 2037configuration messages. 2038The default is 2 seconds. 2039The minimum is 1 second and the maximum is 255 seconds. 2040.It Cm priority Ar value 2041Set the bridge priority for Spanning Tree. 2042The default is 32768. 2043The minimum is 0 and the maximum is 65536. 2044.It Cm ifpriority Ar interface Ar value 2045Set the Spanning Tree priority of 2046.Ar interface 2047to 2048.Ar value . 2049The default is 128. 2050The minimum is 0 and the maximum is 255. 2051.Pp 2052The priority is used to select which interface out of all 2053forwarding and bonded interfaces with the same MAC 2054to output a packet on whe 2055.Cm link2 2056mode is not being used. 2057Note that interfaces in the 'blocking' state do not participate 2058in the priority selection. 2059If the priorities are the same on a non-bonded member, the 2060designated member will be used. 2061.It Cm ifpathcost Ar interface Ar value 2062Set the Spanning Tree path cost of 2063.Ar interface 2064to 2065.Ar value . 2066The default is 55. 2067The minimum is 0 and the maximum is 65535. 2068.Pp 2069The path cost is added to both incoming and outgoing packets on the 2070member, lower values will make the member more valuable. 2071.It Cm ifbondweight Ar interface Ar value 2072Set the number of packets to output on a bonded member before 2073round-robining to the next member. 2074The default is 1. 2075Larger values or different values for each member can be used 2076if bursting would be beneficial or if the outgoing bandwidth 2077on each of the members is asymmetric. 2078For example, one specify a value of 6 on tap0 and 4 on tap1 2079for a 6:4 ratio. 2080Remember that this also controls packet bursting. 2081.It Cm link0 2082The link0 option enables transparent bridging mode. 2083The bridge will make every effort to retain the ethernet header 2084when forwarding packets between interfaces, making the bridging 2085function work more like a hardware bridge device. 2086.It Cm link1 2087The link1 option enables keepalive transmission and automatically 2088places a member into a special blocked mode if no keepalive reception 2089occurs. 2090If either sides of the link uses this option then both sides must use 2091this option. 2092This option is impemented by sending CFG updates on the hello interval 2093to the remote. 2094The link is considered lost after 10 intervals (typically 20 seconds). 2095.It Cm link2 2096The link2 option enables channel bonding (see also ifbondweight). 2097All member interfaces with the same mac address are considered to 2098be in a bonding group. 2099When something like 2100.Xr tap 4 2101is used, you can manually control or copy the mac to create bonding groups. 2102When interface bonding is enabled normally blocked interfaces belonging 2103to the same bonding group as an active forwarding interface will be 2104changed to the bonding state. 2105Both sides of link the member represents must operate in bonding mode 2106for this to work, otherwise the remote end may decide to throw away 2107half your packets. 2108.El 2109.Pp 2110The following parameters are specific to IP tunnel interfaces, 2111.Xr gif 4 : 2112.Bl -tag -width indent 2113.It Cm tunnel Ar src_addr dest_addr 2114Configure the physical source and destination address for IP tunnel 2115interfaces. 2116The arguments 2117.Ar src_addr 2118and 2119.Ar dest_addr 2120are interpreted as the outer source/destination for the encapsulating 2121IPv4/IPv6 header. 2122.It Fl tunnel 2123Unconfigure the physical source and destination address for IP tunnel 2124interfaces previously configured with 2125.Cm tunnel . 2126.It Cm deletetunnel 2127Another name for the 2128.Fl tunnel 2129parameter. 2130.El 2131.Pp 2132The following parameters are specific to 2133.Xr vlan 4 2134interfaces: 2135.Bl -tag -width indent 2136.It Cm vlan Ar vlan_tag 2137Set the VLAN tag value to 2138.Ar vlan_tag . 2139This value is a 16-bit number which is used to create an 802.1Q 2140VLAN header for packets sent from the 2141.Xr vlan 4 2142interface. 2143Note that 2144.Cm vlan 2145and 2146.Cm vlandev 2147must both be set at the same time. 2148.It Cm vlandev Ar iface 2149Associate the physical interface 2150.Ar iface 2151with a 2152.Xr vlan 4 2153interface. 2154Packets transmitted through the 2155.Xr vlan 4 2156interface will be 2157diverted to the specified physical interface 2158.Ar iface 2159with 802.1Q VLAN encapsulation. 2160Packets with 802.1Q encapsulation received 2161by the parent interface with the correct VLAN tag will be diverted to 2162the associated 2163.Xr vlan 4 2164pseudo-interface. 2165The 2166.Xr vlan 4 2167interface is assigned a 2168copy of the parent interface's flags and the parent's ethernet address. 2169The 2170.Cm vlandev 2171and 2172.Cm vlan 2173must both be set at the same time. 2174If the 2175.Xr vlan 4 2176interface already has 2177a physical interface associated with it, this command will fail. 2178To 2179change the association to another physical interface, the existing 2180association must be cleared first. 2181.Pp 2182Note: if the hardware tagging capability 2183is set on the parent interface, the 2184.Xr vlan 4 2185pseudo 2186interface's behavior changes: 2187the 2188.Xr vlan 4 2189interface recognizes that the 2190parent interface supports insertion and extraction of VLAN tags on its 2191own (usually in firmware) and that it should pass packets to and from 2192the parent unaltered. 2193.It Fl vlandev Op Ar iface 2194If the driver is a 2195.Xr vlan 4 2196pseudo device, disassociate the parent interface from it. 2197This breaks the link between the 2198.Xr vlan 4 2199interface and its parent, 2200clears its VLAN tag, flags and its link address and shuts the interface down. 2201The 2202.Ar iface 2203argument is useless and hence deprecated. 2204.El 2205.Pp 2206The following parameters are specific to 2207.Xr carp 4 2208interfaces: 2209.Bl -tag -width indent 2210.It Cm advbase Ar seconds 2211Specifies the base of the advertisement interval in seconds. 2212The acceptable values are 1 to 255. 2213The default value is 1. 2214.\" The default value is 2215.\" .Dv CARP_DFLTINTV . 2216.It Cm advskew Ar interval 2217Specifies the skew to add to the base advertisement interval to 2218make one host advertise slower than another host. 2219It is specified in 1/256 of seconds. 2220The acceptable values are 1 to 254. 2221The default value is 0. 2222.It Cm pass Ar phrase 2223Set the authentication key to 2224.Ar phrase . 2225.It Cm vhid Ar n 2226Set the virtual host ID. 2227This is a required setting. 2228Acceptable values are 1 to 255. 2229.El 2230.Pp 2231The 2232.Nm 2233utility displays the current configuration for a network interface 2234when no optional parameters are supplied. 2235If a protocol family is specified, 2236.Nm 2237will report only the details specific to that protocol family. 2238.Pp 2239If the 2240.Fl m 2241flag is passed before an interface name, 2242.Nm 2243will display the capability list, 2244the maximum amount of data 2245that TCP segmentation offloading is allowed to aggregate and 2246all of the supported media for the specified interface. 2247If 2248.Fl L 2249flag is supplied, address lifetime is displayed for IPv6 addresses, 2250as time offset string. 2251.Pp 2252Optionally, the 2253.Fl a 2254flag may be used instead of an interface name. 2255This flag instructs 2256.Nm 2257to display information about all interfaces in the system. 2258The 2259.Fl d 2260flag limits this to interfaces that are down, and 2261.Fl u 2262limits this to interfaces that are up. 2263When no arguments are given, 2264.Fl a 2265is implied. 2266.Pp 2267The 2268.Fl l 2269flag may be used to list all available interfaces on the system, with 2270no other additional information. 2271Use of this flag is mutually exclusive 2272with all other flags and commands, except for 2273.Fl d 2274(only list interfaces that are down) 2275and 2276.Fl u 2277(only list interfaces that are up). 2278.Pp 2279The 2280.Fl v 2281flag may be used to get more verbose status for an interface. 2282.Pp 2283The 2284.Fl C 2285flag may be used to list all of the interface cloners available on 2286the system, with no additional information. 2287Use of this flag is mutually exclusive with all other flags and commands. 2288.Pp 2289The 2290.Fl k 2291flag causes keying information for the interface, if available, to be 2292printed. 2293For example, the values of 802.11 WEP keys will be printed, if accessible to 2294the current user. 2295This information is not printed by default, as it may be considered 2296sensitive. 2297.Pp 2298Only the super-user may modify the configuration of a network interface. 2299.Sh DIAGNOSTICS 2300Messages indicating the specified interface does not exist, the 2301requested address is unknown, or the user is not privileged and 2302tried to alter an interface's configuration. 2303.Sh SEE ALSO 2304.Xr netstat 1 , 2305.Xr carp 4 , 2306.Xr ifmedia 4 , 2307.Xr netintro 4 , 2308.Xr polling 4 , 2309.Xr vlan 4 , 2310.\" .Xr eon 5 , 2311.Xr rc 8 , 2312.Xr routed 8 , 2313.Xr sysctl 8 2314.Sh HISTORY 2315The 2316.Nm 2317utility appeared in 2318.Bx 4.2 . 2319.Sh BUGS 2320Basic IPv6 node operation requires a link-local address on each 2321interface configured for IPv6. 2322Normally, such an address is automatically configured by the 2323kernel on each interface added to the system; this behaviour may 2324be disabled by setting the sysctl MIB variable 2325.Va net.inet6.ip6.auto_linklocal 2326to 0. 2327.Pp 2328If you delete such an address using 2329.Nm , 2330the kernel may act very odd. 2331Do this at your own risk. 2332