1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 4. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" From: @(#)ifconfig.8 8.3 (Berkeley) 1/5/94 29.\" $FreeBSD: src/sbin/ifconfig/ifconfig.8,v 1.124 2006/10/10 09:44:08 ru Exp $ 30.\" 31.Dd July 17, 2010 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 , 159.Dq ipx , 160.\" .Dq iso , 161and 162.Dq link . 163.\" and 164.\" .Dq ns . 165The default is 166.Dq inet . 167.Dq ether 168and 169.Dq lladdr 170are synonyms for 171.Dq link . 172.It Ar dest_address 173Specify the address of the correspondent on the other end 174of a point to point link. 175.It Ar interface 176This 177parameter is a string of the form 178.Dq name unit , 179for example, 180.Dq Li ed0 . 181.El 182.Pp 183The following parameters may be set with 184.Nm : 185.Bl -tag -width indent 186.It Cm add 187Another name for the 188.Cm alias 189parameter. 190Introduced for compatibility 191with 192.Bsx . 193.It Cm alias 194Establish an additional network address for this interface. 195This is sometimes useful when changing network numbers, and 196one wishes to accept packets addressed to the old interface. 197If the address is on the same subnet as the first network address 198for this interface, a non-conflicting netmask must be given. 199Usually 200.Li 0xffffffff 201is most appropriate. 202.It Fl alias 203Remove the network address specified. 204This would be used if you incorrectly specified an alias, or it 205was no longer needed. 206If you have incorrectly set an NS address having the side effect 207of specifying the host portion, removing all NS addresses will 208allow you to respecify the host portion. 209.It Cm anycast 210(Inet6 only.) 211Specify that the address configured is an anycast address. 212Based on the current specification, 213only routers may configure anycast addresses. 214Anycast address will not be used as source address of any of outgoing 215IPv6 packets. 216.It Cm arp 217Enable the use of the Address Resolution Protocol 218.Pq Xr arp 4 219in mapping 220between network level addresses and link level addresses (default). 221This is currently implemented for mapping between 222.Tn DARPA 223Internet 224addresses and 225.Tn IEEE 226802 48-bit MAC addresses (Ethernet, FDDI, and Token Ring addresses). 227.It Fl arp 228Disable the use of the Address Resolution Protocol 229.Pq Xr arp 4 . 230.It Cm staticarp 231If the Address Resolution Protocol is enabled, 232the host will only reply to requests for its addresses, 233and will never send any requests. 234.It Fl staticarp 235If the Address Resolution Protocol is enabled, 236the host will perform normally, 237sending out requests and listening for replies. 238.It Cm broadcast 239(Inet only.) 240Specify the address to use to represent broadcasts to the 241network. 242The default broadcast address is the address with a host part of all 1's. 243.It Cm debug 244Enable driver dependent debugging code; usually, this turns on 245extra console error logging. 246.It Fl debug 247Disable driver dependent debugging code. 248.It Cm promisc 249Put interface into permanently promiscuous mode. 250.It Fl promisc 251Disable permanently promiscuous mode. 252.It Cm delete 253Another name for the 254.Fl alias 255parameter. 256.It Cm down 257Mark an interface 258.Dq down . 259When an interface is marked 260.Dq down , 261the system will not attempt to 262transmit messages through that interface. 263If possible, the interface will be reset to disable reception as well. 264This action does not automatically disable routes using the interface. 265.It Cm eui64 266(Inet6 only.) 267Fill interface index 268(lowermost 64bit of an IPv6 address) 269automatically. 270.It Cm ipdst 271This is used to specify an Internet host who is willing to receive 272IP packets encapsulating IPX packets bound for a remote network. 273An apparent point to point link is constructed, and 274the address specified will be taken as the IPX address and network 275of the destination. 276.It Cm media Ar type 277If the driver supports the media selection system, set the media type 278of the interface to 279.Ar type . 280Some interfaces support the mutually exclusive use of one of several 281different physical media connectors. 282For example, a 10Mbit/s Ethernet 283interface might support the use of either 284.Tn AUI 285or twisted pair connectors. 286Setting the media type to 287.Cm 10base5/AUI 288would change the currently active connector to the AUI port. 289Setting it to 290.Cm 10baseT/UTP 291would activate twisted pair. 292Refer to the interfaces' driver 293specific documentation or man page for a complete list of the 294available types. 295.It Cm mediaopt Ar opts 296If the driver supports the media selection system, set the specified 297media options on the interface. 298The 299.Ar opts 300argument 301is a comma delimited list of options to apply to the interface. 302Refer to the interfaces' driver specific man page for a complete 303list of available options. 304.It Fl mediaopt Ar opts 305If the driver supports the media selection system, disable the 306specified media options on the interface. 307.It Cm mode Ar mode 308If the driver supports the media selection system, set the specified 309operating mode on the interface to 310.Ar mode . 311For IEEE 802.11 wireless interfaces that support multiple operating modes 312this directive is used to select between 802.11a 313.Pq Cm 11a , 314802.11b 315.Pq Cm 11b , 316and 802.11g 317.Pq Cm 11g 318operating modes. 319.It Cm name Ar name 320Set the interface name to 321.Ar name . 322.It Cm rss 323If the driver supports receive side scaling, 324enable receive side scaling on the interface. 325.It Fl rss 326If the driver supports receive side scaling, 327disable receive side scaling on the interface. 328.It Cm rxcsum , txcsum 329If the driver supports user-configurable checksum offloading, 330enable receive (or transmit) checksum offloading on the interface. 331Some drivers may not be able to enable these flags independently 332of each other, so setting one may also set the other. 333The driver will offload as much checksum work as it can reliably 334support, the exact level of offloading varies between drivers. 335.It Fl rxcsum , txcsum 336If the driver supports user-configurable checksum offloading, 337disable receive (or transmit) checksum offloading on the interface. 338These settings may not always be independent of each other. 339.It Cm vlanmtu , vlanhwtag 340If the driver offers user-configurable VLAN support, enable 341reception of extended frames or tag processing in hardware, 342respectively. 343Note that this must be issued on a physical interface associated with 344.Xr vlan 4 , 345not on a 346.Xr vlan 4 347interface itself. 348.It Fl vlanmtu , vlanhwtag 349If the driver offers user-configurable VLAN support, disable 350reception of extended frames or tag processing in hardware, 351respectively. 352.It Cm pollcpu Ar cpu 353Turn on 354.Xr polling 4 355feature and disable interrupts on the interface, 356if the driver supports this mode and 357.Ar cpu 358supports 359.Xr polling 4 . 360Driver will be polled by 361.Ar cpu . 362.It Cm polling 363Turn on 364.Xr polling 4 365feature and disable interrupts on the interface, if the driver supports 366this mode. 367.It Fl polling 368Turn off 369.Xr polling 4 370feature and enable interrupt mode on the interface. 371.It Cm create 372Create the specified network pseudo-device. 373If the interface is given without a unit number, try to create a new 374device with an arbitrary unit number. 375If creation of an arbitrary device is successful, the new device name is 376printed to standard output unless the interface is renamed or destroyed 377in the same 378.Nm 379invocation. 380.It Cm destroy 381Destroy the specified network pseudo-device. 382.It Cm plumb 383Another name for the 384.Cm create 385parameter. 386Included for 387.Tn Solaris 388compatibility. 389.It Cm unplumb 390Another name for the 391.Cm destroy 392parameter. 393Included for 394.Tn Solaris 395compatibility. 396.It Cm metric Ar n 397Set the routing metric of the interface to 398.Ar n , 399default 0. 400The routing metric is used by the routing protocol 401.Pq Xr routed 8 . 402Higher metrics have the effect of making a route 403less favorable; metrics are counted as additional hops 404to the destination network or host. 405.It Cm mtu Ar n 406Set the maximum transmission unit of the interface to 407.Ar n , 408default is interface specific. 409The MTU is used to limit the size of packets that are transmitted on an 410interface. 411Not all interfaces support setting the MTU, and some interfaces have 412range restrictions. 413.It Cm netmask Ar mask 414.\" (Inet and ISO.) 415(Inet only.) 416Specify how much of the address to reserve for subdividing 417networks into sub-networks. 418The mask includes the network part of the local address 419and the subnet part, which is taken from the host field of the address. 420The mask can be specified as a single hexadecimal number 421with a leading 422.Ql 0x , 423with a dot-notation Internet address, 424or with a pseudo-network name listed in the network table 425.Xr networks 5 . 426The mask contains 1's for the bit positions in the 32-bit address 427which are to be used for the network and subnet parts, 428and 0's for the host part. 429The mask should contain at least the standard network portion, 430and the subnet field should be contiguous with the network 431portion. 432.Pp 433The netmask can also be specified in CIDR notation after the address. 434See the 435.Ar address 436option above for more information. 437.It Cm autoconf 438(Inet6 only.) 439Enable autoconfiguration. 440.It Fl autoconf 441Disable autoconfiguration. 442.It Cm pltime Ar n 443(Inet6 only.) 444Set preferred lifetime for the address. 445.It Cm vltime Ar n 446(Inet6 only.) 447Set valid lifetime for the address. 448.It Cm prefixlen Ar len 449(Inet6 only.) 450Specify that 451.Ar len 452bits are reserved for subdividing networks into sub-networks. 453The 454.Ar len 455must be integer, and for syntactical reason it must be between 0 to 128. 456It is almost always 64 under the current IPv6 assignment rule. 457If the parameter is omitted, 64 is used. 458.Pp 459The prefix can also be specified using the slash notation after the address. 460See the 461.Ar address 462option above for more information. 463.It Cm deprecated 464(Inet6 only.) 465Set the IPv6 deprecated address bit. 466.It Fl deprecated 467(Inet6 only.) 468Clear the IPv6 deprecated address bit. 469.It Cm tentative 470(Inet6 only.) 471Set the IPv6 tentative address bit. 472.It Fl tentative 473(Inet6 only.) 474Clear the IPv6 tentative address bit. 475.\" see 476.\" Xr eon 5 . 477.\" .It Cm nsellength Ar n 478.\" .Pf ( Tn ISO 479.\" only) 480.\" This specifies a trailing number of bytes for a received 481.\" .Tn NSAP 482.\" used for local identification, the remaining leading part of which is 483.\" taken to be the 484.\" .Tn NET 485.\" (Network Entity Title). 486.\" The default value is 1, which is conformant to US 487.\" .Tn GOSIP . 488.\" When an ISO address is set in an ifconfig command, 489.\" it is really the 490.\" .Tn NSAP 491.\" which is being specified. 492.\" For example, in 493.\" .Tn US GOSIP , 494.\" 20 hex digits should be 495.\" specified in the 496.\" .Tn ISO NSAP 497.\" to be assigned to the interface. 498.\" There is some evidence that a number different from 1 may be useful 499.\" for 500.\" .Tn AFI 501.\" 37 type addresses. 502.It Cm range Ar netrange 503Under appletalk, set the interface to respond to a 504.Ar netrange 505of the form 506.Ar startnet Ns - Ns Ar endnet . 507Appletalk uses this scheme instead of 508netmasks though 509.Dx 510implements it internally as a set of netmasks. 511.It Cm remove 512Another name for the 513.Fl alias 514parameter. 515Introduced for compatibility 516with 517.Bsx . 518.It Cm phase 519The argument following this specifies the version (phase) of the 520Appletalk network attached to the interface. 521Values of 1 or 2 are permitted. 522.Sm off 523.It Cm link Op Cm 0 No - Cm 2 524.Sm on 525Enable special processing of the link level of the interface. 526These three options are interface specific in actual effect, however, 527they are in general used to select special modes of operation. 528An example 529of this is to enable SLIP compression, or to select the connector type 530for some Ethernet cards. 531Refer to the man page for the specific driver 532for more information. 533.Sm off 534.It Fl link Op Cm 0 No - Cm 2 535.Sm on 536Disable special processing at the link level with the specified interface. 537.It Cm compress 538Another name for the 539.Cm link0 540parameter. 541.It Cm normal 542Another name for the 543.Fl link0 544parameter. 545.It Cm noicmp 546Another name for the 547.Cm link1 548parameter. 549.It Cm monitor 550Put the interface in monitor mode. 551No packets are transmitted, and received packets are discarded after 552.Xr bpf 4 553processing. 554.It Fl monitor 555Take the interface out of monitor mode. 556.It Cm up 557Mark an interface 558.Dq up . 559This may be used to enable an interface after an 560.Dq Nm Cm down . 561It happens automatically when setting the first address on an interface. 562If the interface was reset when previously marked down, 563the hardware will be re-initialized. 564.El 565.Pp 566The following parameters are specific to cloning 567IEEE 802.11 wireless interfaces with the 568.Cm create 569request: 570.Bl -tag -width indent 571.It Cm wlandev Ar device 572Use 573.Ar device 574as the parent for the cloned device. 575.It Cm wlanmode Ar mode 576Specify the operating mode for this cloned device. 577.Ar mode 578is one of 579.Cm sta , 580.Cm ahdemo 581(or 582.Cm adhoc-demo ), 583.Cm ibss , 584(or 585.Cm adhoc ), 586.Cm ap , 587(or 588.Cm hostap ), 589.Cm wds , 590.Cm tdma , 591.Cm mesh , 592and 593.Cm monitor . 594The operating mode of a cloned interface cannot be changed. 595The 596.Cm tdma 597mode is actually implemented as an 598.Cm adhoc-demo 599interface with special properties. 600.It Cm wlanbssid Ar bssid 601The 802.11 mac address to use for the bssid. 602This must be specified at create time for a legacy 603.Cm wds 604device. 605.It Cm wlanaddr Ar address 606The local mac address. 607If this is not specified then a mac address will automatically be assigned 608to the cloned device. 609Typically this address is the same as the address of the parent device 610but if the 611.Cm bssid 612parameter is specified then the driver will craft a unique address for 613the device (if supported). 614.It Cm wdslegacy 615Mark a 616.Cm wds 617device as operating in ``legacy mode''. 618Legacy 619.Cm wds 620devices have a fixed peer relationship and do not, for example, roam 621if their peer stops communicating. 622For completeness a Dynamic WDS (DWDS) interface may marked as 623.Fl wdslegacy . 624.It Cm bssid 625Request a unique local mac address for the cloned device. 626This is only possible if the device supports multiple mac addresses. 627To force use of the parent's mac address use 628.Fl bssid . 629.It Cm beacons 630Mark the cloned interface as depending on hardware support to 631track received beacons. 632To have beacons tracked in software use 633.Fl beacons . 634For 635.Cm hostap 636mode 637.Fl beacons 638can also be used to indicate no beacons should 639be transmitted; this can be useful when creating a WDS configuration but 640.Cm wds 641interfaces can only be created as companions to an access point. 642.El 643.Pp 644The following parameters are specific to IEEE 802.11 wireless interfaces 645cloned with a 646.Cm create 647operation: 648.Bl -tag -width indent 649.It Cm ampdu 650Enable sending and receiving AMPDU frames when using 802.11n (default). 651The 802.11n specification states a compliant station must be capable 652of receiving AMPDU frames but transmision is optional. 653Use 654.Fl ampdu 655to disable all use of AMPDU with 802.11n. 656For testing and/or to work around interoperability problems one can use 657.Cm ampdutx 658and 659.Cm ampdurx 660to control use of AMPDU in one direction. 661.It Cm ampdudensity Ar density 662Set the AMPDU density parameter used when operating with 802.11n. 663This parameter controls the inter-packet gap for AMPDU frames. 664The sending device normally controls this setting but a receiving station 665may request wider gaps. 666Legal values for 667.Ar density 668are 0, .25, .5, 1, 2, 4, 8, and 16 (microseconds). 669A value of 670.Cm - 671is treated the same as 0. 672.It Cm ampdulimit Ar limit 673Set the limit on packet size for receiving AMPDU frames when operating 674with 802.11n. 675Legal values for 676.Ar limit 677are 8192, 16384, 32768, and 65536 but one can also specify 678just the unique prefix: 8, 16, 32, 64. 679Note the sender may limit the size of AMPDU frames to be less 680than the maximum specified by the receiving station. 681.It Cm amsdu 682Enable sending and receiving AMSDU frames when using 802.11n. 683By default AMSDU is received but not transmitted. 684Use 685.Fl amsdu 686to disable all use of AMSDU with 802.11n. 687For testing and/or to work around interoperability problems one can use 688.Cm amsdutx 689and 690.Cm amsdurx 691to control use of AMSDU in one direction. 692.It Cm amsdulimit Ar limit 693Set the limit on packet size for sending and receiving AMSDU frames 694when operating with 802.11n. 695Legal values for 696.Ar limit 697are 7935 and 3839 (bytes). 698Note the sender may limit the size of AMSDU frames to be less 699than the maximum specified by the receiving station. 700Note also that devices are not required to support the 7935 limit, 701only 3839 is required by the specification and the larger value 702may require more memory to be dedicated to support functionality 703that is rarely used. 704.It Cm apbridge 705When operating as an access point, pass packets between 706wireless clients directly (default). 707To instead let them pass up through the 708system and be forwarded using some other mechanism, use 709.Fl apbridge . 710Disabling the internal bridging 711is useful when traffic is to be processed with 712packet filtering. 713.It Cm authmode Ar mode 714Set the desired authentication mode in infrastructure mode. 715Not all adapters support all modes. 716The set of 717valid modes is 718.Cm none , open , shared 719(shared key), 720.Cm 8021x 721(IEEE 802.1x), 722and 723.Cm wpa 724(IEEE WPA/WPA2/802.11i). 725The 726.Cm 8021x 727and 728.Cm wpa 729modes are only useful when using an authentication service 730(a supplicant for client operation or an authenticator when 731operating as an access point). 732Modes are case insensitive. 733.It Cm bgscan 734Enable background scanning when operating as a station. 735Background scanning is a technique whereby a station associated to 736an access point will temporarily leave the channel to scan for 737neighboring stations. 738This allows a station to maintain a cache of nearby access points 739so that roaming between access points can be done without 740a lengthy scan operation. 741Background scanning is done only when a station is not busy and 742any outbound traffic will cancel a scan operation. 743Background scanning should never cause packets to be lost though 744there may be some small latency if outbound traffic interrupts a 745scan operation. 746By default background scanning is enabled if the device is capable. 747To disable background scanning, use 748.Fl bgscan . 749Background scanning is controlled by the 750.Cm bgscanidle 751and 752.Cm bgscanintvl 753parameters. 754Background scanning must be enabled for roaming; this is an artifact 755of the current implementation and may not be required in the future. 756.It Cm bgscanidle Ar idletime 757Set the minimum time a station must be idle (not transmitting or 758receiving frames) before a background scan is initiated. 759The 760.Ar idletime 761parameter is specified in milliseconds. 762By default a station must be idle at least 250 milliseconds before 763a background scan is initiated. 764The idle time may not be set to less than 100 milliseconds. 765.It Cm bgscanintvl Ar interval 766Set the interval at which background scanning is attempted. 767The 768.Ar interval 769parameter is specified in seconds. 770By default a background scan is considered every 300 seconds (5 minutes). 771The 772.Ar interval 773may not be set to less than 15 seconds. 774.It Cm bintval Ar interval 775Set the interval at which beacon frames are sent when operating in 776ad-hoc or ap mode. 777The 778.Ar interval 779parameter is specified in TU's (1024 usecs). 780By default beacon frames are transmitted every 100 TU's. 781.It Cm bmissthreshold Ar count 782Set the number of consecutive missed beacons at which the station 783will attempt to roam (i.e., search for a new access point). 784The 785.Ar count 786parameter must be in the range 1 to 255; though the 787upper bound may be reduced according to device capabilities. 788The default threshold is 7 consecutive missed beacons; but 789this may be overridden by the device driver. 790Another name for the 791.Cm bmissthreshold 792parameter is 793.Cm bmiss . 794.It Cm bssid Ar address 795Specify the MAC address of the access point to use when operating 796as a station in a BSS network. 797This overrides any automatic selection done by the system. 798To disable a previously selected access point, supply 799.Cm any , none , 800or 801.Cm - 802for the address. 803This option is useful when more than one access point uses the same SSID. 804Another name for the 805.Cm bssid 806parameter is 807.Cm ap . 808.It Cm burst 809Enable packet bursting. 810Packet bursting is a transmission technique whereby the wireless 811medium is acquired once to send multiple frames and the interframe 812spacing is reduced. 813This technique can significantly increase throughput by reducing 814transmission overhead. 815Packet bursting is supported by the 802.11e QoS specification 816and some devices that do not support QoS may still be capable. 817By default packet bursting is enabled if a device is capable 818of doing it. 819To disable packet bursting, use 820.Fl burst . 821.It Cm chanlist Ar channels 822Set the desired channels to use when scanning for access 823points, neighbors in an IBSS network, or looking for unoccupied 824channels when operating as an access point. 825The set of channels is specified as a comma-separated list with 826each element in the list representing either a single channel number or a range 827of the form 828.Dq Li a-b . 829Channel numbers must be in the range 1 to 255 and be permissible 830according to the operating characteristics of the device. 831.It Cm channel Ar number 832Set a single desired channel. 833Channels range from 1 to 255, but the exact selection available 834depends on the region your adaptor was manufactured for. 835Setting 836the channel to 837.Li any , 838or 839.Cm - 840will clear any desired channel and, if the device is marked up, 841force a scan for a channel to operate on. 842Alternatively the frequency, in megahertz, may be specified 843instead of the channel number. 844.Pp 845When there are several ways to use a channel the channel 846number/frequency may be appended with attributes to clarify. 847For example, if a device is capable of operating on channel 6 848with 802.11n and 802.11g then one can specify that g-only use 849should be used by specifying ``6:g''. 850Similarly the channel width can be specified by appending it 851with ``/''; e.g. ``6/40'' specifies a 40MHz wide channel, 852These attributes can be combined as in: ``6:ht/40''. 853The full set of flags specified following a `:'' are: 854.Cm a 855(802.11a), 856.Cm b 857(802.11b), 858.Cm d 859(Atheros Dynamic Turbo mode), 860.Cm g 861(802.11g), 862.Cm h 863or 864.Cm n 865(802.11n aka HT), 866.Cm s 867(Atheros Static Turbo mode), 868and 869.Cm t 870(Atheros Dynamic Turbo mode, or appended to ``st'' and ``dt''). 871The full set of channel widths following a '/' are: 872.Cm 5 873(5MHz aka quarter-rate channel), 874.Cm 10 875(10MHz aka half-rate channel), 876.Cm 20 877(20MHz mostly for use in specifying ht20), 878and 879.Cm 40 880(40MHz mostly for use in specifying ht40), 881In addition, 882a 40MHz HT channel specification may include the location 883of the extension channel by appending ``+'' or ``-'' for above and below, 884respectively; e.g. ``2437:ht/40+'' specifies 40MHz wide HT operation 885with the center channel at frequency 2437 and the extension channel above. 886.It Cm country Ar name 887Set the country code to use in calculating the regulatory constraints 888for operation. 889In particular the set of available channels, how the wireless device 890will operation on the channels, and the maximum transmit power that 891can be used on a channel are defined by this setting. 892Country/Region codes are specified as a 2-character abbreviation 893defined by ISO 3166 or using a longer, but possibly ambiguous, spelling; 894e.g. "ES" and "Spain". 895The set of country codes are taken from /etc/regdomain.xml and can also 896be viewed with the ``list countries'' request. 897Note that not all devices support changing the country code from a default 898setting; typically stored in EEPROM. 899See also 900.Cm regdomain , 901.Cm indoor , 902.Cm outdoor , 903and 904.Cm anywhere . 905.It Cm dfs 906Enable Dynamic Frequency Selection (DFS) as specified in 802.11h. 907DFS embodies several facilities including detection of overlapping 908radar signals, dynamic transmit power control, and channel selection 909according to a least-congested criteria. 910DFS support is mandatory for some 5Ghz frequencies in certain 911locales (e.g. ETSI). 912By default DFS is enabled according to the regulatory definitions 913specified in /etc/regdomain.xml and the curent country code, regdomain, 914and channel. 915Note the underlying device (and driver) must support radar detection 916for full DFS support to work. 917To be fully compliant with the local regulatory agency frequencies that 918require DFS should not be used unless it is fully supported. 919Use 920.Fl dfs 921to disable this functionality for testing. 922.It Cm dotd 923Enable support for the 802.11d specification (default). 924When this support is enabled in station mode, beacon frames that advertise 925a country code different than the currently configured country code will 926cause an event to be dispatched to user applications. 927This event can be used by the station to adopt that country code and 928operate according to the associated regulatory constraints. 929When operating as an access point with 802.11d enabled the beacon and 930probe response frames transmitted will advertise the current regulatory 931domain settings. 932To disable 802.11d use 933.Fl dotd . 934.It Cm doth 935Enable 802.11h support including spectrum management. 936When 802.11h is enabled beacon and probe response frames will have 937the SpectrumMgt bit set in the capabilities field and 938country and power constraint information elements will be present. 939802.11h support also includes handling Channel Switch Announcements (CSA) 940which are a mechanism to coordinate channel changes by an access point. 941By default 802.11h is enabled if the device is capable. 942To disable 802.11h use 943.Fl doth . 944.It Cm deftxkey Ar index 945Set the default key to use for transmission. 946Typically this is only set when using WEP encryption. 947Note that you must set a default transmit key 948for the system to know which key to use in encrypting outbound traffic. 949The 950.Cm weptxkey 951is an alias for this request; it is provided for backwards compatibility. 952.It Cm dtimperiod Ar period 953Set the 954DTIM 955period for transmitting buffered multicast data frames when 956operating in ap mode. 957The 958.Ar period 959specifies the number of beacon intervals between DTIM 960and must be in the range 1 to 15. 961By default DTIM is 1 (i.e., DTIM occurs at each beacon). 962.It Cm dturbo 963Enable the use of Atheros Dynamic Turbo mode when communicating with 964another Dynamic Turbo-capable station. 965Dynamic Turbo mode is an Atheros-specific mechanism by which 966stations switch between normal 802.11 operation and a ``boosted'' 967mode in which a 40MHz wide channel is used for communication. 968Stations using Dynamic Turbo mode operate boosted only when the 969channel is free of non-dturbo stations; when a non-dturbo station 970is identified on the channel all stations will automatically drop 971back to normal operation. 972By default, Dynamic Turbo mode is not enabled, even if the device is capable. 973Note that turbo mode (dynamic or static) is only allowed on some 974channels depending on the regulatory constraints; use the 975.Cm list chan 976command to identify the channels where turbo mode may be used. 977To disable Dynamic Turbo mode use 978.Fl dturbo . 979.It Cm dwds 980Enable Dynamic WDS (DWDS) support. 981DWDS is a facility by which 4-address traffic can be carried between 982stations operating in infrastructure mode. 983A station first associates to an access point and authenticates using 984normal procedures (e.g. WPA). 985Then 4-address frames are passed to carry traffic for stations 986operating on either side of the wireless link. 987DWDS extends the normal WDS mechanism by leveraging existing security 988protocols and eliminating static binding. 989.Pp 990When DWDS is enabled on an access point 4-address frames received from 991an authorized station will generate a ``DWDS discovery'' event to user 992applications. 993This event should be used to create a WDS interface that is bound 994to the remote station (and usually plumbed into a bridge). 995Once the WDS interface is up and running 4-address traffic then logically 996flows through that interface. 997.Pp 998When DWDS is enabled on a station, traffic with a destination address 999different from the peer station are encapsulated in a 4-address frame 1000and transmitted to the peer. 1001All 4-address traffic uses the security information of the stations 1002(e.g. cryptographic keys). 1003A station is associated using 802.11n facilities may transport 10044-address traffic using these same mechanisms; this depends on available 1005resources and capabilities of the device. 1006The DWDS implementation guards against layer 2 routing loops of 1007multicast traffic. 1008.It Cm ff 1009Enable the use of Atheros Fast Frames when communicating with 1010another Fast Frames-capable station. 1011Fast Frames are an encapsulation technique by which two 802.3 1012frames are transmitted in a single 802.11 frame. 1013This can noticeably improve throughput but requires that the 1014receiving station understand how to decapsulate the frame. 1015Fast frame use is negotiated using the Atheros 802.11 vendor-specific 1016protocol extension so enabling use is safe when communicating with 1017non-Atheros devices. 1018By default, use of fast frames is enabled if the device is capable. 1019To explicitly disable fast frames, use 1020.Fl ff . 1021.It Cm fragthreshold Ar length 1022Set the threshold for which transmitted frames are broken into fragments. 1023The 1024.Ar length 1025argument is the frame size in bytes and must be in the range 256 to 2346. 1026Setting 1027.Ar length 1028to 1029.Li 2346 , 1030.Cm any , 1031or 1032.Cm - 1033disables transmit fragmentation. 1034Not all adapters honor the fragmentation threshold. 1035.It Cm hidessid 1036When operating as an access point, do not broadcast the SSID 1037in beacon frames or respond to probe request frames unless 1038they are directed to the ap (i.e., they include the ap's SSID). 1039By default, the SSID is included in beacon frames and 1040undirected probe request frames are answered. 1041To re-enable the broadcast of the SSID etc., use 1042.Fl hidessid . 1043.It Cm ht 1044Enable use of High Throughput (HT) when using 802.11n (default). 1045The 802.11n specification includes mechanisms for operation 1046on 20MHz and 40MHz wide channels using different signalling mechanisms 1047than specified in 802.11b, 802.11g, and 802.11a. 1048Stations negotiate use of these facilities, termed HT20 and HT40, 1049when they associate. 1050To disable all use of 802.11n use 1051.Fl ht . 1052To disable use of HT20 (e.g. to force only HT40 use) use 1053.Fl ht20 . 1054To disable use of HT40 use 1055.Fl ht40 . 1056.Pp 1057HT configuration is used to ``auto promote'' operation 1058when several choices are available. 1059For example, if a station associates to an 11n-capable access point 1060it controls whether the station uses legacy operation, HT20, or HT40. 1061When an 11n-capable device is setup as an access point and 1062Auto Channel Selection is used to locate a channel to operate on, 1063HT configuration controls whether legacy, HT20, or HT40 operation is setup 1064on the selected channel. 1065If a fixed channel is specified for a station then HT configuration can 1066be given as part of the channel specification; e.g. 6:ht/20 to setup 1067HT20 operation on channel 6. 1068.It Cm htcompat 1069Enable use of compatibility support for pre-802.11n devices (default). 1070The 802.11n protocol specification went through several incompatible iterations. 1071Some vendors implemented 11n support to older specifications that 1072will not interoperate with a purely 11n-compliant station. 1073In particular the information elements included in management frames 1074for old devices are different. 1075When compatibility support is enabled both standard and compatible data 1076will be provided. 1077Stations that associate using the compatibility mechanisms are flagged 1078in ``list sta''. 1079To disable compatibility support use 1080.Fl htcompat . 1081.It Cm htprotmode Ar technique 1082For interfaces operating in 802.11n, use the specified 1083.Ar technique 1084for protecting HT frames in a mixed legacy/HT network. 1085The set of valid techniques is 1086.Cm off , 1087and 1088.Cm rts 1089(RTS/CTS, default). 1090Technique names are case insensitive. 1091.It Cm inact 1092Enable inactivity processing for stations associated to an 1093access point (default). 1094When operating as an access point the 802.11 layer monitors 1095the activity of each associated station. 1096When a station is inactive for 5 minutes it will send several 1097``probe frames'' to see if the station is still present. 1098If no response is received then the station is deauthenticated. 1099Applications that prefer to handle this work can disable this 1100facility by using 1101.Fl inact . 1102.It Cm indoor 1103Set the location to use in calculating regulatory constraints. 1104The location is also advertised in beacon and probe response frames 1105when 802.11d is enabled with 1106.Cm dotd . 1107See also 1108.Cm outdoor , 1109.Cm anywhere , 1110.Cm country , 1111and 1112.Cm regdomain . 1113.It Cm list active 1114Display the list of channels available for use taking into account 1115any restrictions set with the 1116.Cm chanlist 1117directive. 1118See the description of 1119.Cm list chan 1120for more information. 1121.It Cm list caps 1122Display the adaptor's capabilities, including the operating 1123modes supported. 1124.It Cm list chan 1125Display the list of channels available for use. 1126Channels are shown with their IEEE channel number, equivalent 1127frequency, and usage modes. 1128Channels identified as 1129.Ql 11g 1130are also usable in 1131.Ql 11b 1132mode. 1133Channels identified as 1134.Ql 11a Turbo 1135may be used only for Atheros' Static Turbo mode 1136(specified with 1137.Cm mediaopt turbo ) . 1138Channels marked with a 1139.Ql * 1140have a regulatory constraint that they be passively scanned. 1141This means a station is not permitted to transmit on the channel until 1142it identifies the channel is being used for 802.11 communication; 1143typically by hearing a beacon frame from an access point operating 1144on the channel. 1145.Cm list freq 1146is another way of requesting this information. 1147By default a compacted list of channels is displayed; if the 1148.Fl v 1149option is specified then all channels are shown. 1150.It Cm list countries 1151Display the set of country codes and regulatory domains that can be 1152used in regulatory configuration. 1153.It Cm list mac 1154Display the current MAC Access Control List state. 1155Each address is prefixed with a character that indicates the 1156current policy applied to it: 1157.Ql + 1158indicates the address is allowed access, 1159.Ql - 1160indicates the address is denied access, 1161.Ql * 1162indicates the address is present but the current policy open 1163(so the ACL is not consulted). 1164.It Cm list mesh 1165Displays the mesh routing table, used for forwarding packets on a mesh 1166network. 1167.It Cm list regdomain 1168Display the current regulatory settings including the available channels 1169and transmit power caps. 1170.It Cm list roam 1171Display the parameters that govern roaming operation. 1172.It Cm list txparam 1173Display the parameters that govern transmit operation. 1174.It Cm list txpower 1175Display the transmit power caps for each channel. 1176.It Cm list scan 1177Display the access points and/or ad-hoc neighbors 1178located in the vicinity. 1179This information may be updated automatically by the adapter 1180with a 1181.Cm scan 1182request or through background scanning. 1183Depending on the capabilities of the stations the following 1184flags can be included in the output: 1185.Bl -tag -width 3n 1186.It Li A 1187Authorized. 1188Indicates that the station is permitted to send/receive data frames. 1189.It Li E 1190Extended Rate Phy (ERP). 1191Indicates that the station is operating in an 802.11g network 1192using extended transmit rates. 1193.It Li H 1194High Throughput (HT). 1195Indicates that the station is using HT transmit rates. 1196If a `+' follows immediately after then the station associated 1197using deprecated mechanisms supported only when 1198.Cm htcompat 1199is enabled. 1200.It Li P 1201Power Save. 1202Indicates that the station is operating in power save mode. 1203.It Li Q 1204Quality of Service (QoS). 1205Indicates that the station is using QoS encapsulation for 1206data frame. 1207QoS encapsulation is enabled only when WME mode is enabled. 1208.It Li T 1209Transitional Security Network (TSN). 1210Indicates that the station associated using TSN; see also 1211.Cm tsn 1212below. 1213.It Li W 1214Wi-Fi Protected Setup (WPS). 1215Indicates that the station associated using WPS. 1216.El 1217.Pp 1218By default interesting information elements captured from the neighboring 1219stations are displayed at the end of each row. 1220Possible elements include: 1221.Cm WME 1222(station supports WME), 1223.Cm WPA 1224(station supports WPA), 1225.Cm WPS 1226(station supports WPS), 1227.Cm RSN 1228(station supports 802.11i/RSN), 1229.Cm HTCAP 1230(station supports 802.11n/HT communication), 1231.Cm ATH 1232(station supports Atheros protocol extensions), 1233.Cm VEN 1234(station supports unknown vendor-specific extensions). 1235If the 1236.Fl v 1237flag is used all the information elements and their 1238contents will be shown. 1239Specifying the 1240.Fl v 1241flag also enables display of long SSIDs. 1242The 1243.Cm list ap 1244command is another way of requesting this information. 1245.It Cm list sta 1246When operating as an access point display the stations that are 1247currently associated. 1248When operating in ad-hoc mode display stations identified as 1249neighbors in the IBSS. 1250When operating in mesh mode display stations identified as 1251neighbors in the MBSS. 1252When operating in station mode display the access point. 1253Capabilities advertised by the stations are described under 1254the 1255.Cm scan 1256request. 1257Depending on the capabilities of the stations the following 1258flags can be included in the output: 1259.Bl -tag -width 3n 1260.It Li A 1261Authorized. 1262Indicates that the station is permitted to send/receive data frames. 1263.It Li E 1264Extended Rate Phy (ERP). 1265Indicates that the station is operating in an 802.11g network 1266using extended transmit rates. 1267.It Li H 1268High Throughput (HT). 1269Indicates that the station is using HT transmit rates. 1270If a `+' follows immediately after then the station associated 1271using deprecated mechanisms supported only when 1272.Cm htcompat 1273is enabled. 1274.It Li P 1275Power Save. 1276Indicates that the station is operating in power save mode. 1277.It Li Q 1278Quality of Service (QoS). 1279Indicates that the station is using QoS encapsulation for 1280data frame. 1281QoS encapsulation is enabled only when WME mode is enabled. 1282.It Li T 1283Transitional Security Network (TSN). 1284Indicates that the station associated using TSN; see also 1285.Cm tsn 1286below. 1287.It Li W 1288Wi-Fi Protected Setup (WPS). 1289Indicates that the station associated using WPS. 1290.El 1291.Pp 1292By default information elements received from associated stations 1293are displayed in a short form; the 1294.Fl v 1295flag causes this information to be displayed symbolically. 1296.It Cm list wme 1297Display the current channel parameters to use when operating in WME mode. 1298If the 1299.Fl v 1300option is specified then both channel and BSS parameters are displayed 1301for each AC (first channel, then BSS). 1302When WME mode is enabled for an adaptor this information will be 1303displayed with the regular status; this command is mostly useful 1304for examining parameters when WME mode is disabled. 1305See the description of the 1306.Cm wme 1307directive for information on the various parameters. 1308.It Cm maxretry Ar count 1309Set the maximum number of tries to use in sending unicast frames. 1310The default setting is 6 but drivers may override this with a value 1311they choose. 1312.It Cm mcastrate Ar rate 1313Set the rate for transmitting multicast/broadcast frames. 1314Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s. 1315This rate should be valid for the current operating conditions; 1316if an invalid rate is specified drivers are free to chose an 1317appropriate rate. 1318.It Cm mgtrate Ar rate 1319Set the rate for transmitting management and/or control frames. 1320Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s. 1321.It Cm outdoor 1322Set the location to use in calculating regulatory constraints. 1323The location is also advertised in beacon and probe response frames 1324when 802.11d is enabled with 1325.Cm dotd . 1326See also 1327.Cm anywhere , 1328.Cm country , 1329.Cm indoor , 1330and 1331.Cm regdomain . 1332.It Cm powersave 1333Enable powersave operation. 1334When operating as a client, the station will conserve power by 1335periodically turning off the radio and listening for 1336messages from the access point telling it there are packets waiting. 1337The station must then retrieve the packets. 1338Not all devices support power save operation as a client. 1339The 802.11 specification requires that all access points support 1340power save but some drivers do not. 1341Use 1342.Fl powersave 1343to disable powersave operation when operating as a client. 1344.It Cm powersavemode Ar mode 1345Set powersave mode. 1346The set of valid modes is 1347.Cm off 1348(same as 1349.Fl powersave ) , 1350.Cm on 1351(same as 1352.Cm powersave ) , 1353and 1354.Cm cam 1355(same as 1356.Cm powersave ) . 1357.It Cm powersavesleep Ar sleep 1358Set the desired max powersave sleep time in TU's (1024 usecs). 1359By default the max powersave sleep time is 100 TU's. 1360.It Cm protmode Ar technique 1361For interfaces operating in 802.11g, use the specified 1362.Ar technique 1363for protecting OFDM frames in a mixed 11b/11g network. 1364The set of valid techniques is 1365.Cm off , cts 1366(CTS to self), 1367and 1368.Cm rtscts 1369(RTS/CTS). 1370Technique names are case insensitive. 1371Not all devices support 1372.Cm cts 1373as a protection technique. 1374.It Cm pureg 1375When operating as an access point in 802.11g mode allow only 137611g-capable stations to associate (11b-only stations are not 1377permitted to associate). 1378To allow both 11g and 11b-only stations to associate, use 1379.Fl pureg . 1380.It Cm puren 1381When operating as an access point in 802.11n mode allow only 1382HT-capable stations to associate (legacy stations are not 1383permitted to associate). 1384To allow both HT and legacy stations to associate, use 1385.Fl puren . 1386.It Cm regdomain Ar sku 1387Set the regulatory domain to use in calculating the regulatory constraints 1388for operation. 1389In particular the set of available channels, how the wireless device 1390will operation on the channels, and the maximum transmit power that 1391can be used on a channel are defined by this setting. 1392Regdomain codes (SKU's) are taken from /etc/regdomain.xml and can also 1393be viewed with the ``list countries'' request. 1394Note that not all devices support changing the regdomain from a default 1395setting; typically stored in EEPROM. 1396See also 1397.Cm country , 1398.Cm indoor , 1399.Cm outdoor , 1400and 1401.Cm anywhere . 1402.It Cm rifs 1403Enable use of Reduced InterFrame Spacing (RIFS) when operating in 802.11n 1404on an HT channel. 1405Note that RIFS must be supported by both the station and access point 1406for it to be used. 1407To disable RIFS use 1408.Fl rifs . 1409.It Cm roam:rate Ar rate 1410Set the threshold for controlling roaming when operating in a BSS. 1411The 1412.Ar rate 1413parameter specifies the transmit rate in megabits 1414at which roaming should be considered. 1415If the current transmit rate drops below this setting and background scanning 1416is enabled, then the system will check if a more desirable access point is 1417available and switch over to it. 1418The current scan cache contents are used if they are considered 1419valid according to the 1420.Cm scanvalid 1421parameter; otherwise a background scan operation is triggered before 1422any selection occurs. 1423Each channel type has a separate rate threshold; the default values are: 142412 Mb/s (11a), 2 Mb/s (11b), 2 Mb/s (11g), MCS 1 (11na, 11ng). 1425.It Cm roam:rssi Ar rssi 1426Set the threshold for controlling roaming when operating in a BSS. 1427The 1428.Ar rssi 1429parameter specifies the receive signal strength in dBm units 1430at which roaming should be considered. 1431If the current rssi drops below this setting and background scanning 1432is enabled, then the system will check if a more desirable access point is 1433available and switch over to it. 1434The current scan cache contents are used if they are considered 1435valid according to the 1436.Cm scanvalid 1437parameter; otherwise a background scan operation is triggered before 1438any selection occurs. 1439Each channel type has a separate rssi threshold; the default values are 1440all 7 dBm. 1441.It Cm roaming Ar mode 1442When operating as a station, control how the system will 1443behave when communication with the current access point 1444is broken. 1445The 1446.Ar mode 1447argument may be one of 1448.Cm device 1449(leave it to the hardware device to decide), 1450.Cm auto 1451(handle either in the device or the operating system\[em]as appropriate), 1452.Cm manual 1453(do nothing until explicitly instructed). 1454By default, the device is left to handle this if it is 1455capable; otherwise, the operating system will automatically 1456attempt to reestablish communication. 1457Manual mode is used by applications such as 1458.Xr wpa_supplicant 8 1459that want to control the selection of an access point. 1460.It Cm rtsthreshold Ar length 1461Set the threshold for which 1462transmitted frames are preceded by transmission of an 1463RTS 1464control frame. 1465The 1466.Ar length 1467argument 1468is the frame size in bytes and must be in the range 1 to 2346. 1469Setting 1470.Ar length 1471to 1472.Li 2346 , 1473.Cm any , 1474or 1475.Cm - 1476disables transmission of RTS frames. 1477Not all adapters support setting the RTS threshold. 1478.It Cm scan 1479Initiate a scan of neighboring stations, wait for it to complete, and 1480display all stations found. 1481Only the super-user can initiate a scan. 1482See 1483.Cm list scan 1484for information on the display. 1485By default a background scan is done; otherwise a foreground 1486scan is done and the station may roam to a different access point. 1487The 1488.Cm list scan 1489request can be used to show recent scan results without 1490initiating a new scan. 1491.It Cm scanvalid Ar threshold 1492Set the maximum time the scan cache contents are considered valid; 1493i.e. will be used without first triggering a scan operation to 1494refresh the data. 1495The 1496.Ar threshold 1497parameter is specified in seconds and defaults to 60 seconds. 1498The minimum setting for 1499.Ar threshold 1500is 10 seconds. 1501One should take care setting this threshold; if it is set too low 1502then attempts to roam to another access point may trigger unnecessary 1503background scan operations. 1504.It Cm shortgi 1505Enable use of Short Guard Interval when operating in 802.11n 1506on an HT channel. 1507NB: this currently enables Short GI on both HT40 and HT20 channels. 1508To disable Short GI use 1509.Fl shortgi . 1510.It Cm smps 1511Enable use of Static Spatial Multiplexing Power Save (SMPS) 1512when operating in 802.11n. 1513A station operating with Static SMPS maintains only a single 1514receive chain active (this can significantly reduce power consumption). 1515To disable SMPS use 1516.Fl smps . 1517.It Cm smpsdyn 1518Enable use of Dynamic Spatial Multiplexing Power Save (SMPS) 1519when operating in 802.11n. 1520A station operating with Dynamic SMPS maintains only a single 1521receive chain active but switches to multiple receive chains when it 1522receives an RTS frame (this can significantly reduce power consumption). 1523Note that stations cannot distinguish between RTS/CTS intended to 1524enable multiple receive chains and those used for other purposes. 1525To disable SMPS use 1526.Fl smps . 1527.It Cm ssid Ar ssid 1528Set the desired Service Set Identifier (aka network name). 1529The SSID is a string up to 32 characters 1530in length and may be specified as either a normal string or in 1531hexadecimal when preceded by 1532.Ql 0x . 1533Additionally, the SSID may be cleared by setting it to 1534.Ql - . 1535.It Cm tdmaslot Ar slot 1536When operating with TDMA, use the specified 1537.Ar slot 1538configuration. 1539The 1540.Ar slot 1541is a number between 0 and the maximum number of slots in the BSS. 1542Note that a station configured as slot 0 is a master and 1543will broadcast beacon frames advertising the BSS; 1544stations configured to use other slots will always 1545scan to locate a master before they ever transmit. 1546By default 1547.Cm tdmaslot 1548is set to 1. 1549.It Cm tdmaslotcnt Ar cnt 1550When operating with TDMA, setup a BSS with 1551.Ar cnt 1552slots. 1553The slot count may be at most 8. 1554The current implementation is only tested with two stations 1555(i.e. point to point applications). 1556This setting is only meaningful when a station is configured as slot 0; 1557other stations adopt this setting from the BSS they join. 1558By default 1559.Cm tdmaslotcnt 1560is set to 2. 1561.It Cm tdmaslotlen Ar len 1562When operating with TDMA, setup a BSS such that each station has a slot 1563.Ar len 1564microseconds long. 1565The slot length must be at least 150 microseconds (1/8 TU) 1566and no more than 65 milliseconds. 1567Note that setting too small a slot length may result in poor channel 1568bandwidth utilization due to factors such as timer granularity and 1569guard time. 1570This setting is only meaningful when a station is configured as slot 0; 1571other stations adopt this setting from the BSS they join. 1572By default 1573.Cm tdmaslotlen 1574is set to 10 milliseconds. 1575.It Cm tdmabintval Ar intval 1576When operating with TDMA, setup a BSS such that beacons are transmitted every 1577.Ar intval 1578superframes to synchronize the TDMA slot timing. 1579A superframe is defined as the number of slots times the slot length; e.g. 1580a BSS with two slots of 10 milliseconds has a 20 millisecond superframe. 1581The beacon interval may not be zero. 1582A lower setting of 1583.Cm tdmabintval 1584causes the timers to be resynchronized more often; this can be help if 1585significant timer drift is observed. 1586By default 1587.Cm tdmabintval 1588is set to 5. 1589.It Cm tsn 1590When operating as an access point with WPA/802.11i allow legacy 1591stations to associate using static key WEP and open authentication. 1592To disallow legacy station use of WEP, use 1593.Fl tsn . 1594.It Cm txpower Ar power 1595Set the power used to transmit frames. 1596The 1597.Ar power 1598argument is specified in .5 dBm units. 1599Out of range values are truncated. 1600Typically only a few discreet power settings are available and 1601the driver will use the setting closest to the specified value. 1602Not all adapters support changing the transmit power. 1603.It Cm ucastrate Ar rate 1604Set a fixed rate for transmitting unicast frames. 1605Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s. 1606This rate should be valid for the current operating conditions; 1607if an invalid rate is specified drivers are free to chose an 1608appropriate rate. 1609.It Cm wepmode Ar mode 1610Set the desired WEP mode. 1611Not all adapters support all modes. 1612The set of valid modes is 1613.Cm off , on , 1614and 1615.Cm mixed . 1616The 1617.Cm mixed 1618mode explicitly tells the adaptor to allow association with access 1619points which allow both encrypted and unencrypted traffic. 1620On these adapters, 1621.Cm on 1622means that the access point must only allow encrypted connections. 1623On other adapters, 1624.Cm on 1625is generally another name for 1626.Cm mixed . 1627Modes are case insensitive. 1628.It Cm weptxkey Ar index 1629Set the WEP key to be used for transmission. 1630This is the same as setting the default transmission key with 1631.Cm deftxkey . 1632.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key 1633Set the selected WEP key. 1634If an 1635.Ar index 1636is not given, key 1 is set. 1637A WEP key will be either 5 or 13 1638characters (40 or 104 bits) depending of the local network and the 1639capabilities of the adaptor. 1640It may be specified either as a plain 1641string or as a string of hexadecimal digits preceded by 1642.Ql 0x . 1643For maximum portability, hex keys are recommended; 1644the mapping of text keys to WEP encryption is usually driver-specific. 1645In particular, the 1646.Tn Windows 1647drivers do this mapping differently to 1648.Fx . 1649A key may be cleared by setting it to 1650.Ql - . 1651If WEP is supported then there are at least four keys. 1652Some adapters support more than four keys. 1653If that is the case, then the first four keys 1654(1-4) will be the standard temporary keys and any others will be adaptor 1655specific keys such as permanent keys stored in NVRAM. 1656.Pp 1657Note that you must set a default transmit key with 1658.Cm deftxkey 1659for the system to know which key to use in encrypting outbound traffic. 1660.It Cm wme 1661Enable Wireless Multimedia Extensions (WME) support, if available, 1662for the specified interface. 1663WME is a subset of the IEEE 802.11e standard to support the 1664efficient communication of realtime and multimedia data. 1665To disable WME support, use 1666.Fl wme . 1667Another name for this parameter is 1668.Cm wmm . 1669.Pp 1670The following parameters are meaningful only when WME support is in use. 1671Parameters are specified per-AC (Access Category) and 1672split into those that are used by a station when acting 1673as an access point and those for client stations in the BSS. 1674The latter are received from the access point and may not be changed 1675(at the station). 1676The following Access Categories are recognized: 1677.Pp 1678.Bl -tag -width ".Cm AC_BK" -compact 1679.It Cm AC_BE 1680(or 1681.Cm BE ) 1682best effort delivery, 1683.It Cm AC_BK 1684(or 1685.Cm BK ) 1686background traffic, 1687.It Cm AC_VI 1688(or 1689.Cm VI ) 1690video traffic, 1691.It Cm AC_VO 1692(or 1693.Cm VO ) 1694voice traffic. 1695.El 1696.Pp 1697AC parameters are case-insensitive. 1698Traffic classification is done in the operating system using the 1699vlan priority associated with data frames or the 1700ToS (Type of Service) indication in IP-encapsulated frames. 1701If neither information is present, traffic is assigned to the 1702Best Effort (BE) category. 1703.Bl -tag -width indent 1704.It Cm ack Ar ac 1705Set the ACK policy for QoS transmissions by the local station; 1706this controls whether or not data frames transmitted by a station 1707require an ACK response from the receiving station. 1708To disable waiting for an ACK use 1709.Fl ack . 1710This parameter is applied only to the local station. 1711.It Cm acm Ar ac 1712Enable the Admission Control Mandatory (ACM) mechanism 1713for transmissions by the local station. 1714To disable the ACM use 1715.Fl acm . 1716On stations in a BSS this parameter is read-only and indicates 1717the setting received from the access point. 1718NB: ACM is not supported right now. 1719.It Cm aifs Ar ac Ar count 1720Set the Arbitration Inter Frame Spacing (AIFS) 1721channel 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 cwmin Ar ac Ar count 1726Set the CWmin 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 cwmax Ar ac Ar count 1731Set the CWmax channel access parameter to use for transmissions 1732by the local station. 1733On stations in a BSS this parameter is read-only and indicates 1734the setting received from the access point. 1735.It Cm txoplimit Ar ac Ar limit 1736Set the Transmission Opportunity Limit channel access parameter 1737to use for transmissions by the local station. 1738This parameter defines an interval of time when a WME station 1739has the right to initiate transmissions onto the wireless medium. 1740On stations in a BSS this parameter is read-only and indicates 1741the setting received from the access point. 1742.It Cm bss:aifs Ar ac Ar count 1743Set the AIFS channel access parameter to send to stations in a BSS. 1744This parameter is meaningful only when operating in ap mode. 1745.It Cm bss:cwmin Ar ac Ar count 1746Set the CWmin channel access parameter to send to stations in a BSS. 1747This parameter is meaningful only when operating in ap mode. 1748.It Cm bss:cwmax Ar ac Ar count 1749Set the CWmax channel access parameter to send to stations in a BSS. 1750This parameter is meaningful only when operating in ap mode. 1751.It Cm bss:txoplimit Ar ac Ar limit 1752Set the TxOpLimit channel access parameter to send to stations in a BSS. 1753This parameter is meaningful only when operating in ap mode. 1754.El 1755.It Cm wps 1756Enable Wireless Privacy Subscriber support. 1757Note that WPS support requires a WPS-capable supplicant. 1758To disable this function use 1759.Fl wps . 1760.El 1761.Pp 1762The following parameters support an optional access control list 1763feature available with some adapters when operating in ap mode; see 1764.Xr wlan_acl 4 . 1765This facility allows an access point to accept/deny association 1766requests based on the MAC address of the station. 1767Note that this feature does not significantly enhance security 1768as MAC address spoofing is easy to do. 1769.Bl -tag -width indent 1770.It Cm mac:add Ar address 1771Add the specified MAC address to the database. 1772Depending on the policy setting association requests from the 1773specified station will be allowed or denied. 1774.It Cm mac:allow 1775Set the ACL policy to permit association only by 1776stations registered in the database. 1777.It Cm mac:del Ar address 1778Delete the specified MAC address from the database. 1779.It Cm mac:deny 1780Set the ACL policy to deny association only by 1781stations registered in the database. 1782.It Cm mac:kick Ar address 1783Force the specified station to be deauthenticated. 1784This typically is done to block a station after updating the 1785address database. 1786.It Cm mac:open 1787Set the ACL policy to allow all stations to associate. 1788.It Cm mac:flush 1789Delete all entries in the database. 1790.It Cm mac:radius 1791Set the ACL policy to permit association only by 1792stations approved by a RADIUS server. 1793Note that this feature requires the 1794.Xr hostapd 8 1795program be configured to do the right thing 1796as it handles the RADIUS processing 1797(and marks stations as authorized). 1798.El 1799.Pp 1800The following parameters are related to a wireless interface operating in mesh 1801mode: 1802.Bl -tag -width indent 1803.It Cm meshid Ar meshid 1804Set the desired Mesh Identifier. 1805The Mesh ID is a string up to 32 characters in length. 1806A mesh interface must have a Mesh Identifier specified 1807to reach an operational state. 1808.It Cm meshttl Ar ttl 1809Set the desired ``time to live'' for mesh forwarded packets; 1810this is the number of hops a packet may be forwarded before 1811it is discarded. 1812The default setting for 1813.Cm meshttl 1814is 31. 1815.It Cm meshpeering 1816Enable or disable peering with neighbor mesh stations. 1817Stations must peer before any data packets can be exchanged. 1818By default 1819.Cm meshpeering 1820is enabled. 1821.It Cm meshforward 1822Enable or disable forwarding packets by a mesh interface. 1823By default 1824.Cm meshforward 1825is enabled. 1826.It Cm meshmetric Ar protocol 1827Set the specified 1828.Ar protocol 1829as the link metric protocol used on a mesh network. 1830The default protocol is called 1831.Ar AIRTIME . 1832The mesh interface will restart after changing this setting. 1833.It Cm meshpath Ar protocol 1834Set the specified 1835.Ar protocol 1836as the path selection protocol used on a mesh network. 1837The only available protocol at the moment is called 1838.Ar HWMP 1839(Hybrid Wireless Mesh Protocol). 1840The mesh interface will restart after changing this setting. 1841.It Cm hwmprootmode Ar mode 1842Stations on a mesh network can operate as ``root nodes.'' 1843Root nodes try to find paths to all mesh nodes and advertise themselves 1844regularly. 1845When there is a root mesh node on a network, other mesh nodes can setup 1846paths between themselves faster because they can use the root node 1847to find the destination. 1848This path may not be the best, but on-demand 1849routing will eventually find the best path. 1850The following modes are recognized: 1851.Pp 1852.Bl -tag -width ".Cm PROACTIVE" -compact 1853.It Cm DISABLED 1854Disable root mode. 1855.It Cm NORMAL 1856Send broadcast path requests every two seconds. 1857Nodes on the mesh without a path to this root mesh station with try to 1858discover a path to us. 1859.It Cm PROACTIVE 1860Send broadcast path requests every two seconds and every node must reply with 1861with a path reply even if it already has a path to this root mesh station, 1862.It Cm RANN 1863Send broadcast root annoucement (RANN) frames. 1864Nodes on the mesh without a path to this root mesh station with try to 1865discover a path to us. 1866.El 1867By default 1868.Cm hwmprootmode 1869is set to 1870.Ar DISABLED . 1871.It Cm hwmpmaxhops Ar cnt 1872Set the maximum number of hops allowed in an HMWP path to 1873.Ar cnt . 1874The default setting for 1875.Cm hwmpmaxhops 1876is 31. 1877.El 1878.Pp 1879The following parameters are for compatibility with other systems: 1880.Bl -tag -width indent 1881.It Cm nwid Ar ssid 1882Another name for the 1883.Cm ssid 1884parameter. 1885Included for 1886.Nx 1887compatibility. 1888.It Cm stationname Ar name 1889Set the name of this station. 1890The station name is not part of the IEEE 802.11 1891protocol though some interfaces support it. 1892As such it only 1893seems to be meaningful to identical or virtually identical equipment. 1894Setting the station name is identical in syntax to setting the SSID. 1895One can also use 1896.Cm station 1897for 1898.Bsx 1899compatibility. 1900.It Cm wep 1901Another way of saying 1902.Cm wepmode on . 1903Included for 1904.Bsx 1905compatibility. 1906.It Fl wep 1907Another way of saying 1908.Cm wepmode off . 1909Included for 1910.Bsx 1911compatibility. 1912.It Cm nwkey key 1913Another way of saying: 1914.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" . 1915Included for 1916.Nx 1917compatibility. 1918.It Cm nwkey Xo 1919.Sm off 1920.Ar n : k1 , k2 , k3 , k4 1921.Sm on 1922.Xc 1923Another way of saying 1924.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" . 1925Included for 1926.Nx 1927compatibility. 1928.It Fl nwkey 1929Another way of saying 1930.Cm wepmode off . 1931Included for 1932.Nx 1933compatibility. 1934.El 1935.Pp 1936The following parameters are specific to bridge interfaces: 1937.Bl -tag -width indent 1938.It Cm addm Ar interface 1939Add the interface named by 1940.Ar interface 1941as a member of the bridge. 1942The interface is put into promiscuous mode 1943so that it can receive every packet sent on the network. 1944.It Cm deletem Ar interface 1945Remove the interface named by 1946.Ar interface 1947from the bridge. 1948Promiscuous mode is disabled on the interface when 1949it is removed from the bridge. 1950.It Cm maxaddr Ar size 1951Set the size of the bridge address cache to 1952.Ar size . 1953The default is 100 entries. 1954.It Cm timeout Ar seconds 1955Set the timeout of address cache entries to 1956.Ar seconds 1957seconds. 1958If 1959.Ar seconds 1960is zero, then address cache entries will not be expired. 1961The default is 1200 seconds. 1962.It Cm addr 1963Display the addresses that have been learned by the bridge. 1964.It Cm static Ar interface-name Ar address 1965Add a static entry into the address cache pointing to 1966.Ar interface-name . 1967Static entries are never aged out of the cache or re-placed, even if the 1968address is seen on a different interface. 1969.It Cm deladdr Ar address 1970Delete 1971.Ar address 1972from the address cache. 1973.It Cm flush 1974Delete all dynamically-learned addresses from the address cache. 1975.It Cm flushall 1976Delete all addresses, including static addresses, from the address cache. 1977.It Cm discover Ar interface 1978Mark an interface as a 1979.Dq discovering 1980interface. 1981When the bridge has no address cache entry 1982(either dynamic or static) 1983for the destination address of a packet, 1984the bridge will forward the packet to all 1985member interfaces marked as 1986.Dq discovering . 1987This is the default for all interfaces added to a bridge. 1988.It Fl discover Ar interface 1989Clear the 1990.Dq discovering 1991attribute on a member interface. 1992For packets without the 1993.Dq discovering 1994attribute, the only packets forwarded on the interface are broadcast 1995or multicast packets and packets for which the destination address 1996is known to be on the interface's segment. 1997.It Cm learn Ar interface 1998Mark an interface as a 1999.Dq learning 2000interface. 2001When a packet arrives on such an interface, the source 2002address of the packet is entered into the address cache as being a 2003destination address on the interface's segment. 2004This is the default for all interfaces added to a bridge. 2005.It Fl learn Ar interface 2006Clear the 2007.Dq learning 2008attribute on a member interface. 2009.It Cm span Ar interface 2010Add the interface named by 2011.Ar interface 2012as a span port on the bridge. 2013Span ports transmit a copy of every frame received by the bridge. 2014This is most useful for snooping a bridged network passively on 2015another host connected to one of the span ports of the bridge. 2016.It Fl span Ar interface 2017Delete the interface named by 2018.Ar interface 2019from the list of span ports of the bridge. 2020.It Cm stp Ar interface 2021Enable Spanning Tree protocol on 2022.Ar interface . 2023The 2024.Xr bridge 4 2025driver has support for the IEEE 802.1D Spanning Tree protocol (STP). 2026Spanning Tree is used to detect and remove loops in a network topology. 2027.It Fl stp Ar interface 2028Disable Spanning Tree protocol on 2029.Ar interface . 2030This is the default for all interfaces added to a bridge. 2031.It Cm maxage Ar seconds 2032Set the time that a Spanning Tree protocol configuration is valid. 2033The default is 20 seconds. 2034The minimum is 1 second and the maximum is 255 seconds. 2035.It Cm fwddelay Ar seconds 2036Set the time that must pass before an interface begins forwarding 2037packets when Spanning Tree is enabled. 2038The default is 15 seconds. 2039The minimum is 1 second and the maximum is 255 seconds. 2040.It Cm hellotime Ar seconds 2041Set the time between broadcasting of Spanning Tree protocol 2042configuration messages. 2043The default is 2 seconds. 2044The minimum is 1 second and the maximum is 255 seconds. 2045.It Cm priority Ar value 2046Set the bridge priority for Spanning Tree. 2047The default is 32768. 2048The minimum is 0 and the maximum is 65536. 2049.It Cm ifpriority Ar interface Ar value 2050Set the Spanning Tree priority of 2051.Ar interface 2052to 2053.Ar value . 2054The default is 128. 2055The minimum is 0 and the maximum is 255. 2056.Pp 2057The priority is used to select which interface out of all 2058forwarding and bonded interfaces with the same MAC 2059to output a packet on whe 2060.Cm link2 2061mode is not being used. 2062Note that interfaces in the 'blocking' state do not participate 2063in the priority selection. 2064If the priorities are the same on a non-bonded member, the 2065designated member will be used. 2066.It Cm ifpathcost Ar interface Ar value 2067Set the Spanning Tree path cost of 2068.Ar interface 2069to 2070.Ar value . 2071The default is 55. 2072The minimum is 0 and the maximum is 65535. 2073.Pp 2074The path cost is added to both incoming and outgoing packets on the 2075member, lower values will make the member more valuable. 2076.It Cm ifbondweight Ar interface Ar value 2077Set the number of packets to output on a bonded member before 2078round-robining to the next member. 2079The default is 1. 2080Larger values or different values for each member can be used 2081if bursting would be beneficial or if the outgoing bandwidth 2082on each of the members is asymmetric. 2083For example, one specify a value of 6 on tap0 and 4 on tap1 2084for a 6:4 ratio. 2085Remember that this also controls packet bursting. 2086.It Cm link0 2087The link0 option enables transparent bridging mode. 2088The bridge will make every effort to retain the ethernet header 2089when forwarding packets between interfaces, making the bridging 2090function work more like a hardware bridge device. 2091.It Cm link1 2092The link1 option enables keepalive transmission and automatically 2093places a member into a special blocked mode if no keepalive reception 2094occurs. 2095If either sides of the link uses this option then both sides must use 2096this option. 2097This option is impemented by sending CFG updates on the hello interval 2098to the remote. 2099The link is considered lost after 10 intervals (typically 20 seconds). 2100.It Cm link2 2101The link2 option enables channel bonding (see also ifbondweight). 2102All member interfaces with the same mac address are considered to 2103be in a bonding group. 2104When something like 2105.Xr tap 4 2106is used, you can manually control or copy the mac to create bonding groups. 2107When interface bonding is enabled normally blocked interfaces belonging 2108to the same bonding group as an active forwarding interface will be 2109changed to the bonding state. 2110Both sides of link the member represents must operate in bonding mode 2111for this to work, otherwise the remote end may decide to throw away 2112half your packets. 2113.El 2114.Pp 2115The following parameters are specific to IP tunnel interfaces, 2116.Xr gif 4 : 2117.Bl -tag -width indent 2118.It Cm tunnel Ar src_addr dest_addr 2119Configure the physical source and destination address for IP tunnel 2120interfaces. 2121The arguments 2122.Ar src_addr 2123and 2124.Ar dest_addr 2125are interpreted as the outer source/destination for the encapsulating 2126IPv4/IPv6 header. 2127.It Fl tunnel 2128Unconfigure the physical source and destination address for IP tunnel 2129interfaces previously configured with 2130.Cm tunnel . 2131.It Cm deletetunnel 2132Another name for the 2133.Fl tunnel 2134parameter. 2135.El 2136.Pp 2137The following parameters are specific to 2138.Xr vlan 4 2139interfaces: 2140.Bl -tag -width indent 2141.It Cm vlan Ar vlan_tag 2142Set the VLAN tag value to 2143.Ar vlan_tag . 2144This value is a 16-bit number which is used to create an 802.1Q 2145VLAN header for packets sent from the 2146.Xr vlan 4 2147interface. 2148Note that 2149.Cm vlan 2150and 2151.Cm vlandev 2152must both be set at the same time. 2153.It Cm vlandev Ar iface 2154Associate the physical interface 2155.Ar iface 2156with a 2157.Xr vlan 4 2158interface. 2159Packets transmitted through the 2160.Xr vlan 4 2161interface will be 2162diverted to the specified physical interface 2163.Ar iface 2164with 802.1Q VLAN encapsulation. 2165Packets with 802.1Q encapsulation received 2166by the parent interface with the correct VLAN tag will be diverted to 2167the associated 2168.Xr vlan 4 2169pseudo-interface. 2170The 2171.Xr vlan 4 2172interface is assigned a 2173copy of the parent interface's flags and the parent's ethernet address. 2174The 2175.Cm vlandev 2176and 2177.Cm vlan 2178must both be set at the same time. 2179If the 2180.Xr vlan 4 2181interface already has 2182a physical interface associated with it, this command will fail. 2183To 2184change the association to another physical interface, the existing 2185association must be cleared first. 2186.Pp 2187Note: if the hardware tagging capability 2188is set on the parent interface, the 2189.Xr vlan 4 2190pseudo 2191interface's behavior changes: 2192the 2193.Xr vlan 4 2194interface recognizes that the 2195parent interface supports insertion and extraction of VLAN tags on its 2196own (usually in firmware) and that it should pass packets to and from 2197the parent unaltered. 2198.It Fl vlandev Op Ar iface 2199If the driver is a 2200.Xr vlan 4 2201pseudo device, disassociate the parent interface from it. 2202This breaks the link between the 2203.Xr vlan 4 2204interface and its parent, 2205clears its VLAN tag, flags and its link address and shuts the interface down. 2206The 2207.Ar iface 2208argument is useless and hence deprecated. 2209.El 2210.Pp 2211The following parameters are specific to 2212.Xr carp 4 2213interfaces: 2214.Bl -tag -width indent 2215.It Cm advbase Ar seconds 2216Specifies the base of the advertisement interval in seconds. 2217The acceptable values are 1 to 255. 2218The default value is 1. 2219.\" The default value is 2220.\" .Dv CARP_DFLTINTV . 2221.It Cm advskew Ar interval 2222Specifies the skew to add to the base advertisement interval to 2223make one host advertise slower than another host. 2224It is specified in 1/256 of seconds. 2225The acceptable values are 1 to 254. 2226The default value is 0. 2227.It Cm pass Ar phrase 2228Set the authentication key to 2229.Ar phrase . 2230.It Cm vhid Ar n 2231Set the virtual host ID. 2232This is a required setting. 2233Acceptable values are 1 to 255. 2234.El 2235.Pp 2236The 2237.Nm 2238utility displays the current configuration for a network interface 2239when no optional parameters are supplied. 2240If a protocol family is specified, 2241.Nm 2242will report only the details specific to that protocol family. 2243.Pp 2244If the 2245.Fl m 2246flag is passed before an interface name, 2247.Nm 2248will display the capability list and all 2249of the supported media for the specified interface. 2250If 2251.Fl L 2252flag is supplied, address lifetime is displayed for IPv6 addresses, 2253as time offset string. 2254.Pp 2255Optionally, the 2256.Fl a 2257flag may be used instead of an interface name. 2258This flag instructs 2259.Nm 2260to display information about all interfaces in the system. 2261The 2262.Fl d 2263flag limits this to interfaces that are down, and 2264.Fl u 2265limits this to interfaces that are up. 2266When no arguments are given, 2267.Fl a 2268is implied. 2269.Pp 2270The 2271.Fl l 2272flag may be used to list all available interfaces on the system, with 2273no other additional information. 2274Use of this flag is mutually exclusive 2275with all other flags and commands, except for 2276.Fl d 2277(only list interfaces that are down) 2278and 2279.Fl u 2280(only list interfaces that are up). 2281.Pp 2282The 2283.Fl v 2284flag may be used to get more verbose status for an interface. 2285.Pp 2286The 2287.Fl C 2288flag may be used to list all of the interface cloners available on 2289the system, with no additional information. 2290Use of this flag is mutually exclusive with all other flags and commands. 2291.Pp 2292The 2293.Fl k 2294flag causes keying information for the interface, if available, to be 2295printed. 2296For example, the values of 802.11 WEP keys will be printed, if accessible to 2297the current user. 2298This information is not printed by default, as it may be considered 2299sensitive. 2300.Pp 2301Only the super-user may modify the configuration of a network interface. 2302.Sh DIAGNOSTICS 2303Messages indicating the specified interface does not exist, the 2304requested address is unknown, or the user is not privileged and 2305tried to alter an interface's configuration. 2306.Sh SEE ALSO 2307.Xr netstat 1 , 2308.Xr carp 4 , 2309.Xr ifmedia 4 , 2310.Xr netintro 4 , 2311.Xr polling 4 , 2312.Xr vlan 4 , 2313.\" .Xr eon 5 , 2314.Xr rc 8 , 2315.Xr routed 8 , 2316.Xr sysctl 8 2317.Sh HISTORY 2318The 2319.Nm 2320utility appeared in 2321.Bx 4.2 . 2322.Sh BUGS 2323Basic IPv6 node operation requires a link-local address on each 2324interface configured for IPv6. 2325Normally, such an address is automatically configured by the 2326kernel on each interface added to the system; this behaviour may 2327be disabled by setting the sysctl MIB variable 2328.Va net.inet6.ip6.auto_linklocal 2329to 0. 2330.Pp 2331If you delete such an address using 2332.Nm , 2333the kernel may act very odd. 2334Do this at your own risk. 2335