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 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 , 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 tso 340If the driver supports TCP segmentation offloading, 341enable TCP segmentation offloading on the interface. 342.It Fl tso 343If the driver supports TCP segmentation offloading, 344disable TCP segmentation offloading on the interface. 345.It Cm vlanmtu , vlanhwtag 346If the driver offers user-configurable VLAN support, enable 347reception of extended frames or tag processing in hardware, 348respectively. 349Note that this must be issued on a physical interface associated with 350.Xr vlan 4 , 351not on a 352.Xr vlan 4 353interface itself. 354.It Fl vlanmtu , vlanhwtag 355If the driver offers user-configurable VLAN support, disable 356reception of extended frames or tag processing in hardware, 357respectively. 358.It Cm pollcpu Ar cpu 359Deprecated, use polling or npolling instead. 360.It Cm polling , npolling 361Turn on 362.Xr polling 4 363feature and disable interrupts on the interface, if the driver supports 364this mode. 365.It Fl polling , npolling 366Turn off 367.Xr polling 4 368feature and enable interrupt mode on the interface. 369.It Cm create 370Create the specified network pseudo-device. 371If the interface is given without a unit number, try to create a new 372device with an arbitrary unit number. 373If creation of an arbitrary device is successful, the new device name is 374printed to standard output unless the interface is renamed or destroyed 375in the same 376.Nm 377invocation. 378.It Cm destroy 379Destroy the specified network pseudo-device. 380.It Cm plumb 381Another name for the 382.Cm create 383parameter. 384Included for 385.Tn Solaris 386compatibility. 387.It Cm unplumb 388Another name for the 389.Cm destroy 390parameter. 391Included for 392.Tn Solaris 393compatibility. 394.It Cm metric Ar n 395Set the routing metric of the interface to 396.Ar n , 397default 0. 398The routing metric is used by the routing protocol 399.Pq Xr routed 8 . 400Higher metrics have the effect of making a route 401less favorable; metrics are counted as additional hops 402to the destination network or host. 403.It Cm mtu Ar n 404Set the maximum transmission unit of the interface to 405.Ar n , 406default is interface specific. 407The MTU is used to limit the size of packets that are transmitted on an 408interface. 409Not all interfaces support setting the MTU, and some interfaces have 410range restrictions. 411.It Cm netmask Ar mask 412.\" (Inet and ISO.) 413(Inet only.) 414Specify how much of the address to reserve for subdividing 415networks into sub-networks. 416The mask includes the network part of the local address 417and the subnet part, which is taken from the host field of the address. 418The mask can be specified as a single hexadecimal number 419with a leading 420.Ql 0x , 421with a dot-notation Internet address, 422or with a pseudo-network name listed in the network table 423.Xr networks 5 . 424The mask contains 1's for the bit positions in the 32-bit address 425which are to be used for the network and subnet parts, 426and 0's for the host part. 427The mask should contain at least the standard network portion, 428and the subnet field should be contiguous with the network 429portion. 430.Pp 431The netmask can also be specified in CIDR notation after the address. 432See the 433.Ar address 434option above for more information. 435.It Cm autoconf 436(Inet6 only.) 437Enable autoconfiguration. 438.It Fl autoconf 439Disable autoconfiguration. 440.It Cm pltime Ar n 441(Inet6 only.) 442Set preferred lifetime for the address. 443.It Cm vltime Ar n 444(Inet6 only.) 445Set valid lifetime for the address. 446.It Cm prefixlen Ar len 447(Inet6 only.) 448Specify that 449.Ar len 450bits are reserved for subdividing networks into sub-networks. 451The 452.Ar len 453must be integer, and for syntactical reason it must be between 0 to 128. 454It is almost always 64 under the current IPv6 assignment rule. 455If the parameter is omitted, 64 is used. 456.Pp 457The prefix can also be specified using the slash notation after the address. 458See the 459.Ar address 460option above for more information. 461.It Cm deprecated 462(Inet6 only.) 463Set the IPv6 deprecated address bit. 464.It Fl deprecated 465(Inet6 only.) 466Clear the IPv6 deprecated address bit. 467.It Cm tentative 468(Inet6 only.) 469Set the IPv6 tentative address bit. 470.It Fl tentative 471(Inet6 only.) 472Clear the IPv6 tentative address bit. 473.\" see 474.\" Xr eon 5 . 475.\" .It Cm nsellength Ar n 476.\" .Pf ( Tn ISO 477.\" only) 478.\" This specifies a trailing number of bytes for a received 479.\" .Tn NSAP 480.\" used for local identification, the remaining leading part of which is 481.\" taken to be the 482.\" .Tn NET 483.\" (Network Entity Title). 484.\" The default value is 1, which is conformant to US 485.\" .Tn GOSIP . 486.\" When an ISO address is set in an ifconfig command, 487.\" it is really the 488.\" .Tn NSAP 489.\" which is being specified. 490.\" For example, in 491.\" .Tn US GOSIP , 492.\" 20 hex digits should be 493.\" specified in the 494.\" .Tn ISO NSAP 495.\" to be assigned to the interface. 496.\" There is some evidence that a number different from 1 may be useful 497.\" for 498.\" .Tn AFI 499.\" 37 type addresses. 500.It Cm range Ar netrange 501Under appletalk, set the interface to respond to a 502.Ar netrange 503of the form 504.Ar startnet Ns - Ns Ar endnet . 505Appletalk uses this scheme instead of 506netmasks though 507.Dx 508implements it internally as a set of netmasks. 509.It Cm remove 510Another name for the 511.Fl alias 512parameter. 513Introduced for compatibility 514with 515.Bsx . 516.It Cm phase 517The argument following this specifies the version (phase) of the 518Appletalk network attached to the interface. 519Values of 1 or 2 are permitted. 520.Sm off 521.It Cm link Op Cm 0 No - Cm 2 522.Sm on 523Enable special processing of the link level of the interface. 524These three options are interface specific in actual effect, however, 525they are in general used to select special modes of operation. 526An example 527of this is to enable SLIP compression, or to select the connector type 528for some Ethernet cards. 529Refer to the man page for the specific driver 530for more information. 531.Sm off 532.It Fl link Op Cm 0 No - Cm 2 533.Sm on 534Disable special processing at the link level with the specified interface. 535.It Cm compress 536Another name for the 537.Cm link0 538parameter. 539.It Cm normal 540Another name for the 541.Fl link0 542parameter. 543.It Cm noicmp 544Another name for the 545.Cm link1 546parameter. 547.It Cm monitor 548Put the interface in monitor mode. 549No packets are transmitted, and received packets are discarded after 550.Xr bpf 4 551processing. 552.It Fl monitor 553Take the interface out of monitor mode. 554.It Cm up 555Mark an interface 556.Dq up . 557This may be used to enable an interface after an 558.Dq Nm Cm down . 559It happens automatically when setting the first address on an interface. 560If the interface was reset when previously marked down, 561the hardware will be re-initialized. 562.El 563.Pp 564The following parameters are specific to cloning 565IEEE 802.11 wireless interfaces with the 566.Cm create 567request: 568.Bl -tag -width indent 569.It Cm wlandev Ar device 570Use 571.Ar device 572as the parent for the cloned device. 573.It Cm wlanmode Ar mode 574Specify the operating mode for this cloned device. 575.Ar mode 576is one of 577.Cm sta , 578.Cm ahdemo 579(or 580.Cm adhoc-demo ), 581.Cm ibss , 582(or 583.Cm adhoc ), 584.Cm ap , 585(or 586.Cm hostap ), 587.Cm wds , 588.Cm tdma , 589.Cm mesh , 590and 591.Cm monitor . 592The operating mode of a cloned interface cannot be changed. 593The 594.Cm tdma 595mode is actually implemented as an 596.Cm adhoc-demo 597interface with special properties. 598.It Cm wlanbssid Ar bssid 599The 802.11 mac address to use for the bssid. 600This must be specified at create time for a legacy 601.Cm wds 602device. 603.It Cm wlanaddr Ar address 604The local mac address. 605If this is not specified then a mac address will automatically be assigned 606to the cloned device. 607Typically this address is the same as the address of the parent device 608but if the 609.Cm bssid 610parameter is specified then the driver will craft a unique address for 611the device (if supported). 612.It Cm wdslegacy 613Mark a 614.Cm wds 615device as operating in ``legacy mode''. 616Legacy 617.Cm wds 618devices have a fixed peer relationship and do not, for example, roam 619if their peer stops communicating. 620For completeness a Dynamic WDS (DWDS) interface may marked as 621.Fl wdslegacy . 622.It Cm bssid 623Request a unique local mac address for the cloned device. 624This is only possible if the device supports multiple mac addresses. 625To force use of the parent's mac address use 626.Fl bssid . 627.It Cm beacons 628Mark the cloned interface as depending on hardware support to 629track received beacons. 630To have beacons tracked in software use 631.Fl beacons . 632For 633.Cm hostap 634mode 635.Fl beacons 636can also be used to indicate no beacons should 637be transmitted; this can be useful when creating a WDS configuration but 638.Cm wds 639interfaces can only be created as companions to an access point. 640.El 641.Pp 642The following parameters are specific to IEEE 802.11 wireless interfaces 643cloned with a 644.Cm create 645operation: 646.Bl -tag -width indent 647.It Cm ampdu 648Enable sending and receiving AMPDU frames when using 802.11n (default). 649The 802.11n specification states a compliant station must be capable 650of receiving AMPDU frames but transmission is optional. 651Use 652.Fl ampdu 653to disable all use of AMPDU with 802.11n. 654For testing and/or to work around interoperability problems one can use 655.Cm ampdutx 656and 657.Cm ampdurx 658to control use of AMPDU in one direction. 659.It Cm ampdudensity Ar density 660Set the AMPDU density parameter used when operating with 802.11n. 661This parameter controls the inter-packet gap for AMPDU frames. 662The sending device normally controls this setting but a receiving station 663may request wider gaps. 664Legal values for 665.Ar density 666are 0, .25, .5, 1, 2, 4, 8, and 16 (microseconds). 667A value of 668.Cm - 669is treated the same as 0. 670.It Cm ampdulimit Ar limit 671Set the limit on packet size for receiving AMPDU frames when operating 672with 802.11n. 673Legal values for 674.Ar limit 675are 8192, 16384, 32768, and 65536 but one can also specify 676just the unique prefix: 8, 16, 32, 64. 677Note the sender may limit the size of AMPDU frames to be less 678than the maximum specified by the receiving station. 679.It Cm amsdu 680Enable sending and receiving AMSDU frames when using 802.11n. 681By default AMSDU is received but not transmitted. 682Use 683.Fl amsdu 684to disable all use of AMSDU with 802.11n. 685For testing and/or to work around interoperability problems one can use 686.Cm amsdutx 687and 688.Cm amsdurx 689to control use of AMSDU in one direction. 690.It Cm amsdulimit Ar limit 691Set the limit on packet size for sending and receiving AMSDU frames 692when operating with 802.11n. 693Legal values for 694.Ar limit 695are 7935 and 3839 (bytes). 696Note the sender may limit the size of AMSDU frames to be less 697than the maximum specified by the receiving station. 698Note also that devices are not required to support the 7935 limit, 699only 3839 is required by the specification and the larger value 700may require more memory to be dedicated to support functionality 701that is rarely used. 702.It Cm apbridge 703When operating as an access point, pass packets between 704wireless clients directly (default). 705To instead let them pass up through the 706system and be forwarded using some other mechanism, use 707.Fl apbridge . 708Disabling the internal bridging 709is useful when traffic is to be processed with 710packet filtering. 711.It Cm authmode Ar mode 712Set the desired authentication mode in infrastructure mode. 713Not all adapters support all modes. 714The set of 715valid modes is 716.Cm none , open , shared 717(shared key), 718.Cm 8021x 719(IEEE 802.1x), 720and 721.Cm wpa 722(IEEE WPA/WPA2/802.11i). 723The 724.Cm 8021x 725and 726.Cm wpa 727modes are only useful when using an authentication service 728(a supplicant for client operation or an authenticator when 729operating as an access point). 730Modes are case insensitive. 731.It Cm bgscan 732Enable background scanning when operating as a station. 733Background scanning is a technique whereby a station associated to 734an access point will temporarily leave the channel to scan for 735neighboring stations. 736This allows a station to maintain a cache of nearby access points 737so that roaming between access points can be done without 738a lengthy scan operation. 739Background scanning is done only when a station is not busy and 740any outbound traffic will cancel a scan operation. 741Background scanning should never cause packets to be lost though 742there may be some small latency if outbound traffic interrupts a 743scan operation. 744By default background scanning is enabled if the device is capable. 745To disable background scanning, use 746.Fl bgscan . 747Background scanning is controlled by the 748.Cm bgscanidle 749and 750.Cm bgscanintvl 751parameters. 752Background scanning must be enabled for roaming; this is an artifact 753of the current implementation and may not be required in the future. 754.It Cm bgscanidle Ar idletime 755Set the minimum time a station must be idle (not transmitting or 756receiving frames) before a background scan is initiated. 757The 758.Ar idletime 759parameter is specified in milliseconds. 760By default a station must be idle at least 250 milliseconds before 761a background scan is initiated. 762The idle time may not be set to less than 100 milliseconds. 763.It Cm bgscanintvl Ar interval 764Set the interval at which background scanning is attempted. 765The 766.Ar interval 767parameter is specified in seconds. 768By default a background scan is considered every 300 seconds (5 minutes). 769The 770.Ar interval 771may not be set to less than 15 seconds. 772.It Cm bintval Ar interval 773Set the interval at which beacon frames are sent when operating in 774ad-hoc or ap mode. 775The 776.Ar interval 777parameter is specified in TU's (1024 usecs). 778By default beacon frames are transmitted every 100 TU's. 779.It Cm bmissthreshold Ar count 780Set the number of consecutive missed beacons at which the station 781will attempt to roam (i.e., search for a new access point). 782The 783.Ar count 784parameter must be in the range 1 to 255; though the 785upper bound may be reduced according to device capabilities. 786The default threshold is 7 consecutive missed beacons; but 787this may be overridden by the device driver. 788Another name for the 789.Cm bmissthreshold 790parameter is 791.Cm bmiss . 792.It Cm bssid Ar address 793Specify the MAC address of the access point to use when operating 794as a station in a BSS network. 795This overrides any automatic selection done by the system. 796To disable a previously selected access point, supply 797.Cm any , none , 798or 799.Cm - 800for the address. 801This option is useful when more than one access point uses the same SSID. 802Another name for the 803.Cm bssid 804parameter is 805.Cm ap . 806.It Cm burst 807Enable packet bursting. 808Packet bursting is a transmission technique whereby the wireless 809medium is acquired once to send multiple frames and the interframe 810spacing is reduced. 811This technique can significantly increase throughput by reducing 812transmission overhead. 813Packet bursting is supported by the 802.11e QoS specification 814and some devices that do not support QoS may still be capable. 815By default packet bursting is enabled if a device is capable 816of doing it. 817To disable packet bursting, use 818.Fl burst . 819.It Cm chanlist Ar channels 820Set the desired channels to use when scanning for access 821points, neighbors in an IBSS network, or looking for unoccupied 822channels when operating as an access point. 823The set of channels is specified as a comma-separated list with 824each element in the list representing either a single channel number or a range 825of the form 826.Dq Li a-b . 827Channel numbers must be in the range 1 to 255 and be permissible 828according to the operating characteristics of the device. 829.It Cm channel Ar number 830Set a single desired channel. 831Channels range from 1 to 255, but the exact selection available 832depends on the region your adaptor was manufactured for. 833Setting 834the channel to 835.Li any , 836or 837.Cm - 838will clear any desired channel and, if the device is marked up, 839force a scan for a channel to operate on. 840Alternatively the frequency, in megahertz, may be specified 841instead of the channel number. 842.Pp 843When there are several ways to use a channel the channel 844number/frequency may be appended with attributes to clarify. 845For example, if a device is capable of operating on channel 6 846with 802.11n and 802.11g then one can specify that g-only use 847should be used by specifying ``6:g''. 848Similarly the channel width can be specified by appending it 849with ``/''; e.g. ``6/40'' specifies a 40MHz wide channel, 850These attributes can be combined as in: ``6:ht/40''. 851The full set of flags specified following a `:'' are: 852.Cm a 853(802.11a), 854.Cm b 855(802.11b), 856.Cm d 857(Atheros Dynamic Turbo mode), 858.Cm g 859(802.11g), 860.Cm h 861or 862.Cm n 863(802.11n aka HT), 864.Cm s 865(Atheros Static Turbo mode), 866and 867.Cm t 868(Atheros Dynamic Turbo mode, or appended to ``st'' and ``dt''). 869The full set of channel widths following a '/' are: 870.Cm 5 871(5MHz aka quarter-rate channel), 872.Cm 10 873(10MHz aka half-rate channel), 874.Cm 20 875(20MHz mostly for use in specifying ht20), 876and 877.Cm 40 878(40MHz mostly for use in specifying ht40), 879In addition, 880a 40MHz HT channel specification may include the location 881of the extension channel by appending ``+'' or ``-'' for above and below, 882respectively; e.g. ``2437:ht/40+'' specifies 40MHz wide HT operation 883with the center channel at frequency 2437 and the extension channel above. 884.It Cm country Ar name 885Set the country code to use in calculating the regulatory constraints 886for operation. 887In particular the set of available channels, how the wireless device 888will operation on the channels, and the maximum transmit power that 889can be used on a channel are defined by this setting. 890Country/Region codes are specified as a 2-character abbreviation 891defined by ISO 3166 or using a longer, but possibly ambiguous, spelling; 892e.g. "ES" and "Spain". 893The set of country codes are taken from /etc/regdomain.xml and can also 894be viewed with the ``list countries'' request. 895Note that not all devices support changing the country code from a default 896setting; typically stored in EEPROM. 897See also 898.Cm regdomain , 899.Cm indoor , 900.Cm outdoor , 901and 902.Cm anywhere . 903.It Cm dfs 904Enable Dynamic Frequency Selection (DFS) as specified in 802.11h. 905DFS embodies several facilities including detection of overlapping 906radar signals, dynamic transmit power control, and channel selection 907according to a least-congested criteria. 908DFS support is mandatory for some 5Ghz frequencies in certain 909locales (e.g. ETSI). 910By default DFS is enabled according to the regulatory definitions 911specified in /etc/regdomain.xml and the curent country code, regdomain, 912and channel. 913Note the underlying device (and driver) must support radar detection 914for full DFS support to work. 915To be fully compliant with the local regulatory agency frequencies that 916require DFS should not be used unless it is fully supported. 917Use 918.Fl dfs 919to disable this functionality for testing. 920.It Cm dotd 921Enable support for the 802.11d specification (default). 922When this support is enabled in station mode, beacon frames that advertise 923a country code different than the currently configured country code will 924cause an event to be dispatched to user applications. 925This event can be used by the station to adopt that country code and 926operate according to the associated regulatory constraints. 927When operating as an access point with 802.11d enabled the beacon and 928probe response frames transmitted will advertise the current regulatory 929domain settings. 930To disable 802.11d use 931.Fl dotd . 932.It Cm doth 933Enable 802.11h support including spectrum management. 934When 802.11h is enabled beacon and probe response frames will have 935the SpectrumMgt bit set in the capabilities field and 936country and power constraint information elements will be present. 937802.11h support also includes handling Channel Switch Announcements (CSA) 938which are a mechanism to coordinate channel changes by an access point. 939By default 802.11h is enabled if the device is capable. 940To disable 802.11h use 941.Fl doth . 942.It Cm deftxkey Ar index 943Set the default key to use for transmission. 944Typically this is only set when using WEP encryption. 945Note that you must set a default transmit key 946for the system to know which key to use in encrypting outbound traffic. 947The 948.Cm weptxkey 949is an alias for this request; it is provided for backwards compatibility. 950.It Cm dtimperiod Ar period 951Set the 952DTIM 953period for transmitting buffered multicast data frames when 954operating in ap mode. 955The 956.Ar period 957specifies the number of beacon intervals between DTIM 958and must be in the range 1 to 15. 959By default DTIM is 1 (i.e., DTIM occurs at each beacon). 960.It Cm dturbo 961Enable the use of Atheros Dynamic Turbo mode when communicating with 962another Dynamic Turbo-capable station. 963Dynamic Turbo mode is an Atheros-specific mechanism by which 964stations switch between normal 802.11 operation and a ``boosted'' 965mode in which a 40MHz wide channel is used for communication. 966Stations using Dynamic Turbo mode operate boosted only when the 967channel is free of non-dturbo stations; when a non-dturbo station 968is identified on the channel all stations will automatically drop 969back to normal operation. 970By default, Dynamic Turbo mode is not enabled, even if the device is capable. 971Note that turbo mode (dynamic or static) is only allowed on some 972channels depending on the regulatory constraints; use the 973.Cm list chan 974command to identify the channels where turbo mode may be used. 975To disable Dynamic Turbo mode use 976.Fl dturbo . 977.It Cm dwds 978Enable Dynamic WDS (DWDS) support. 979DWDS is a facility by which 4-address traffic can be carried between 980stations operating in infrastructure mode. 981A station first associates to an access point and authenticates using 982normal procedures (e.g. WPA). 983Then 4-address frames are passed to carry traffic for stations 984operating on either side of the wireless link. 985DWDS extends the normal WDS mechanism by leveraging existing security 986protocols and eliminating static binding. 987.Pp 988When DWDS is enabled on an access point 4-address frames received from 989an authorized station will generate a ``DWDS discovery'' event to user 990applications. 991This event should be used to create a WDS interface that is bound 992to the remote station (and usually plumbed into a bridge). 993Once the WDS interface is up and running 4-address traffic then logically 994flows through that interface. 995.Pp 996When DWDS is enabled on a station, traffic with a destination address 997different from the peer station are encapsulated in a 4-address frame 998and transmitted to the peer. 999All 4-address traffic uses the security information of the stations 1000(e.g. cryptographic keys). 1001A station is associated using 802.11n facilities may transport 10024-address traffic using these same mechanisms; this depends on available 1003resources and capabilities of the device. 1004The DWDS implementation guards against layer 2 routing loops of 1005multicast traffic. 1006.It Cm ff 1007Enable the use of Atheros Fast Frames when communicating with 1008another Fast Frames-capable station. 1009Fast Frames are an encapsulation technique by which two 802.3 1010frames are transmitted in a single 802.11 frame. 1011This can noticeably improve throughput but requires that the 1012receiving station understand how to decapsulate the frame. 1013Fast frame use is negotiated using the Atheros 802.11 vendor-specific 1014protocol extension so enabling use is safe when communicating with 1015non-Atheros devices. 1016By default, use of fast frames is enabled if the device is capable. 1017To explicitly disable fast frames, use 1018.Fl ff . 1019.It Cm fragthreshold Ar length 1020Set the threshold for which transmitted frames are broken into fragments. 1021The 1022.Ar length 1023argument is the frame size in bytes and must be in the range 256 to 2346. 1024Setting 1025.Ar length 1026to 1027.Li 2346 , 1028.Cm any , 1029or 1030.Cm - 1031disables transmit fragmentation. 1032Not all adapters honor the fragmentation threshold. 1033.It Cm hidessid 1034When operating as an access point, do not broadcast the SSID 1035in beacon frames or respond to probe request frames unless 1036they are directed to the ap (i.e., they include the ap's SSID). 1037By default, the SSID is included in beacon frames and 1038undirected probe request frames are answered. 1039To re-enable the broadcast of the SSID etc., use 1040.Fl hidessid . 1041.It Cm ht 1042Enable use of High Throughput (HT) when using 802.11n (default). 1043The 802.11n specification includes mechanisms for operation 1044on 20MHz and 40MHz wide channels using different signalling mechanisms 1045than specified in 802.11b, 802.11g, and 802.11a. 1046Stations negotiate use of these facilities, termed HT20 and HT40, 1047when they associate. 1048To disable all use of 802.11n use 1049.Fl ht . 1050To disable use of HT20 (e.g. to force only HT40 use) use 1051.Fl ht20 . 1052To disable use of HT40 use 1053.Fl ht40 . 1054.Pp 1055HT configuration is used to ``auto promote'' operation 1056when several choices are available. 1057For example, if a station associates to an 11n-capable access point 1058it controls whether the station uses legacy operation, HT20, or HT40. 1059When an 11n-capable device is setup as an access point and 1060Auto Channel Selection is used to locate a channel to operate on, 1061HT configuration controls whether legacy, HT20, or HT40 operation is setup 1062on the selected channel. 1063If a fixed channel is specified for a station then HT configuration can 1064be given as part of the channel specification; e.g. 6:ht/20 to setup 1065HT20 operation on channel 6. 1066.It Cm htcompat 1067Enable use of compatibility support for pre-802.11n devices (default). 1068The 802.11n protocol specification went through several incompatible iterations. 1069Some vendors implemented 11n support to older specifications that 1070will not interoperate with a purely 11n-compliant station. 1071In particular the information elements included in management frames 1072for old devices are different. 1073When compatibility support is enabled both standard and compatible data 1074will be provided. 1075Stations that associate using the compatibility mechanisms are flagged 1076in ``list sta''. 1077To disable compatibility support use 1078.Fl htcompat . 1079.It Cm htprotmode Ar technique 1080For interfaces operating in 802.11n, use the specified 1081.Ar technique 1082for protecting HT frames in a mixed legacy/HT network. 1083The set of valid techniques is 1084.Cm off , 1085and 1086.Cm rts 1087(RTS/CTS, default). 1088Technique names are case insensitive. 1089.It Cm inact 1090Enable inactivity processing for stations associated to an 1091access point (default). 1092When operating as an access point the 802.11 layer monitors 1093the activity of each associated station. 1094When a station is inactive for 5 minutes it will send several 1095``probe frames'' to see if the station is still present. 1096If no response is received then the station is deauthenticated. 1097Applications that prefer to handle this work can disable this 1098facility by using 1099.Fl inact . 1100.It Cm indoor 1101Set the location to use in calculating regulatory constraints. 1102The location is also advertised in beacon and probe response frames 1103when 802.11d is enabled with 1104.Cm dotd . 1105See also 1106.Cm outdoor , 1107.Cm anywhere , 1108.Cm country , 1109and 1110.Cm regdomain . 1111.It Cm list active 1112Display the list of channels available for use taking into account 1113any restrictions set with the 1114.Cm chanlist 1115directive. 1116See the description of 1117.Cm list chan 1118for more information. 1119.It Cm list caps 1120Display the adaptor's capabilities, including the operating 1121modes supported. 1122.It Cm list chan 1123Display the list of channels available for use. 1124Channels are shown with their IEEE channel number, equivalent 1125frequency, and usage modes. 1126Channels identified as 1127.Ql 11g 1128are also usable in 1129.Ql 11b 1130mode. 1131Channels identified as 1132.Ql 11a Turbo 1133may be used only for Atheros' Static Turbo mode 1134(specified with 1135.Cm mediaopt turbo ) . 1136Channels marked with a 1137.Ql * 1138have a regulatory constraint that they be passively scanned. 1139This means a station is not permitted to transmit on the channel until 1140it identifies the channel is being used for 802.11 communication; 1141typically by hearing a beacon frame from an access point operating 1142on the channel. 1143.Cm list freq 1144is another way of requesting this information. 1145By default a compacted list of channels is displayed; if the 1146.Fl v 1147option is specified then all channels are shown. 1148.It Cm list countries 1149Display the set of country codes and regulatory domains that can be 1150used in regulatory configuration. 1151.It Cm list mac 1152Display the current MAC Access Control List state. 1153Each address is prefixed with a character that indicates the 1154current policy applied to it: 1155.Ql + 1156indicates the address is allowed access, 1157.Ql - 1158indicates the address is denied access, 1159.Ql * 1160indicates the address is present but the current policy open 1161(so the ACL is not consulted). 1162.It Cm list mesh 1163Displays the mesh routing table, used for forwarding packets on a mesh 1164network. 1165.It Cm list regdomain 1166Display the current regulatory settings including the available channels 1167and transmit power caps. 1168.It Cm list roam 1169Display the parameters that govern roaming operation. 1170.It Cm list txparam 1171Display the parameters that govern transmit operation. 1172.It Cm list txpower 1173Display the transmit power caps for each channel. 1174.It Cm list scan 1175Display the access points and/or ad-hoc neighbors 1176located in the vicinity. 1177This information may be updated automatically by the adapter 1178with a 1179.Cm scan 1180request or through background scanning. 1181Depending on the capabilities of the stations the following 1182flags can be included in the output: 1183.Bl -tag -width 3n 1184.It Li A 1185Authorized. 1186Indicates that the station is permitted to send/receive data frames. 1187.It Li E 1188Extended Rate Phy (ERP). 1189Indicates that the station is operating in an 802.11g network 1190using extended transmit rates. 1191.It Li H 1192High Throughput (HT). 1193Indicates that the station is using HT transmit rates. 1194If a `+' follows immediately after then the station associated 1195using deprecated mechanisms supported only when 1196.Cm htcompat 1197is enabled. 1198.It Li P 1199Power Save. 1200Indicates that the station is operating in power save mode. 1201.It Li Q 1202Quality of Service (QoS). 1203Indicates that the station is using QoS encapsulation for 1204data frame. 1205QoS encapsulation is enabled only when WME mode is enabled. 1206.It Li T 1207Transitional Security Network (TSN). 1208Indicates that the station associated using TSN; see also 1209.Cm tsn 1210below. 1211.It Li W 1212Wi-Fi Protected Setup (WPS). 1213Indicates that the station associated using WPS. 1214.El 1215.Pp 1216By default interesting information elements captured from the neighboring 1217stations are displayed at the end of each row. 1218Possible elements include: 1219.Cm WME 1220(station supports WME), 1221.Cm WPA 1222(station supports WPA), 1223.Cm WPS 1224(station supports WPS), 1225.Cm RSN 1226(station supports 802.11i/RSN), 1227.Cm HTCAP 1228(station supports 802.11n/HT communication), 1229.Cm ATH 1230(station supports Atheros protocol extensions), 1231.Cm VEN 1232(station supports unknown vendor-specific extensions). 1233If the 1234.Fl v 1235flag is used all the information elements and their 1236contents will be shown. 1237Specifying the 1238.Fl v 1239flag also enables display of long SSIDs. 1240The 1241.Cm list ap 1242command is another way of requesting this information. 1243.It Cm list sta 1244When operating as an access point display the stations that are 1245currently associated. 1246When operating in ad-hoc mode display stations identified as 1247neighbors in the IBSS. 1248When operating in mesh mode display stations identified as 1249neighbors in the MBSS. 1250When operating in station mode display the access point. 1251Capabilities advertised by the stations are described under 1252the 1253.Cm scan 1254request. 1255Depending on the capabilities of the stations the following 1256flags can be included in the output: 1257.Bl -tag -width 3n 1258.It Li A 1259Authorized. 1260Indicates that the station is permitted to send/receive data frames. 1261.It Li E 1262Extended Rate Phy (ERP). 1263Indicates that the station is operating in an 802.11g network 1264using extended transmit rates. 1265.It Li H 1266High Throughput (HT). 1267Indicates that the station is using HT transmit rates. 1268If a `+' follows immediately after then the station associated 1269using deprecated mechanisms supported only when 1270.Cm htcompat 1271is enabled. 1272.It Li P 1273Power Save. 1274Indicates that the station is operating in power save mode. 1275.It Li Q 1276Quality of Service (QoS). 1277Indicates that the station is using QoS encapsulation for 1278data frame. 1279QoS encapsulation is enabled only when WME mode is enabled. 1280.It Li T 1281Transitional Security Network (TSN). 1282Indicates that the station associated using TSN; see also 1283.Cm tsn 1284below. 1285.It Li W 1286Wi-Fi Protected Setup (WPS). 1287Indicates that the station associated using WPS. 1288.El 1289.Pp 1290By default information elements received from associated stations 1291are displayed in a short form; the 1292.Fl v 1293flag causes this information to be displayed symbolically. 1294.It Cm list wme 1295Display the current channel parameters to use when operating in WME mode. 1296If the 1297.Fl v 1298option is specified then both channel and BSS parameters are displayed 1299for each AC (first channel, then BSS). 1300When WME mode is enabled for an adaptor this information will be 1301displayed with the regular status; this command is mostly useful 1302for examining parameters when WME mode is disabled. 1303See the description of the 1304.Cm wme 1305directive for information on the various parameters. 1306.It Cm maxretry Ar count 1307Set the maximum number of tries to use in sending unicast frames. 1308The default setting is 6 but drivers may override this with a value 1309they choose. 1310.It Cm mcastrate Ar rate 1311Set the rate for transmitting multicast/broadcast frames. 1312Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s. 1313This rate should be valid for the current operating conditions; 1314if an invalid rate is specified drivers are free to chose an 1315appropriate rate. 1316.It Cm mgtrate Ar rate 1317Set the rate for transmitting management and/or control frames. 1318Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s. 1319.It Cm outdoor 1320Set the location to use in calculating regulatory constraints. 1321The location is also advertised in beacon and probe response frames 1322when 802.11d is enabled with 1323.Cm dotd . 1324See also 1325.Cm anywhere , 1326.Cm country , 1327.Cm indoor , 1328and 1329.Cm regdomain . 1330.It Cm powersave 1331Enable powersave operation. 1332When operating as a client, the station will conserve power by 1333periodically turning off the radio and listening for 1334messages from the access point telling it there are packets waiting. 1335The station must then retrieve the packets. 1336Not all devices support power save operation as a client. 1337The 802.11 specification requires that all access points support 1338power save but some drivers do not. 1339Use 1340.Fl powersave 1341to disable powersave operation when operating as a client. 1342.It Cm powersavemode Ar mode 1343Set powersave mode. 1344The set of valid modes is 1345.Cm off 1346(same as 1347.Fl powersave ) , 1348.Cm on 1349(same as 1350.Cm powersave ) , 1351and 1352.Cm cam 1353(same as 1354.Cm powersave ) . 1355.It Cm powersavesleep Ar sleep 1356Set the desired max powersave sleep time in TU's (1024 usecs). 1357By default the max powersave sleep time is 100 TU's. 1358.It Cm protmode Ar technique 1359For interfaces operating in 802.11g, use the specified 1360.Ar technique 1361for protecting OFDM frames in a mixed 11b/11g network. 1362The set of valid techniques is 1363.Cm off , cts 1364(CTS to self), 1365and 1366.Cm rtscts 1367(RTS/CTS). 1368Technique names are case insensitive. 1369Not all devices support 1370.Cm cts 1371as a protection technique. 1372.It Cm pureg 1373When operating as an access point in 802.11g mode allow only 137411g-capable stations to associate (11b-only stations are not 1375permitted to associate). 1376To allow both 11g and 11b-only stations to associate, use 1377.Fl pureg . 1378.It Cm puren 1379When operating as an access point in 802.11n mode allow only 1380HT-capable stations to associate (legacy stations are not 1381permitted to associate). 1382To allow both HT and legacy stations to associate, use 1383.Fl puren . 1384.It Cm regdomain Ar sku 1385Set the regulatory domain to use in calculating the regulatory constraints 1386for operation. 1387In particular the set of available channels, how the wireless device 1388will operation on the channels, and the maximum transmit power that 1389can be used on a channel are defined by this setting. 1390Regdomain codes (SKU's) are taken from /etc/regdomain.xml and can also 1391be viewed with the ``list countries'' request. 1392Note that not all devices support changing the regdomain from a default 1393setting; typically stored in EEPROM. 1394See also 1395.Cm country , 1396.Cm indoor , 1397.Cm outdoor , 1398and 1399.Cm anywhere . 1400.It Cm rifs 1401Enable use of Reduced InterFrame Spacing (RIFS) when operating in 802.11n 1402on an HT channel. 1403Note that RIFS must be supported by both the station and access point 1404for it to be used. 1405To disable RIFS use 1406.Fl rifs . 1407.It Cm roam:rate Ar rate 1408Set the threshold for controlling roaming when operating in a BSS. 1409The 1410.Ar rate 1411parameter specifies the transmit rate in megabits 1412at which roaming should be considered. 1413If the current transmit rate drops below this setting and background scanning 1414is enabled, then the system will check if a more desirable access point is 1415available and switch over to it. 1416The current scan cache contents are used if they are considered 1417valid according to the 1418.Cm scanvalid 1419parameter; otherwise a background scan operation is triggered before 1420any selection occurs. 1421Each channel type has a separate rate threshold; the default values are: 142212 Mb/s (11a), 2 Mb/s (11b), 2 Mb/s (11g), MCS 1 (11na, 11ng). 1423.It Cm roam:rssi Ar rssi 1424Set the threshold for controlling roaming when operating in a BSS. 1425The 1426.Ar rssi 1427parameter specifies the receive signal strength in dBm units 1428at which roaming should be considered. 1429If the current rssi drops below this setting and background scanning 1430is enabled, then the system will check if a more desirable access point is 1431available and switch over to it. 1432The current scan cache contents are used if they are considered 1433valid according to the 1434.Cm scanvalid 1435parameter; otherwise a background scan operation is triggered before 1436any selection occurs. 1437Each channel type has a separate rssi threshold; the default values are 1438all 7 dBm. 1439.It Cm roaming Ar mode 1440When operating as a station, control how the system will 1441behave when communication with the current access point 1442is broken. 1443The 1444.Ar mode 1445argument may be one of 1446.Cm device 1447(leave it to the hardware device to decide), 1448.Cm auto 1449(handle either in the device or the operating system\[em]as appropriate), 1450.Cm manual 1451(do nothing until explicitly instructed). 1452By default, the device is left to handle this if it is 1453capable; otherwise, the operating system will automatically 1454attempt to reestablish communication. 1455Manual mode is used by applications such as 1456.Xr wpa_supplicant 8 1457that want to control the selection of an access point. 1458.It Cm rtsthreshold Ar length 1459Set the threshold for which 1460transmitted frames are preceded by transmission of an 1461RTS 1462control frame. 1463The 1464.Ar length 1465argument 1466is the frame size in bytes and must be in the range 1 to 2346. 1467Setting 1468.Ar length 1469to 1470.Li 2346 , 1471.Cm any , 1472or 1473.Cm - 1474disables transmission of RTS frames. 1475Not all adapters support setting the RTS threshold. 1476.It Cm scan 1477Initiate a scan of neighboring stations, wait for it to complete, and 1478display all stations found. 1479Only the super-user can initiate a scan. 1480See 1481.Cm list scan 1482for information on the display. 1483By default a background scan is done; otherwise a foreground 1484scan is done and the station may roam to a different access point. 1485The 1486.Cm list scan 1487request can be used to show recent scan results without 1488initiating a new scan. 1489.It Cm scanvalid Ar threshold 1490Set the maximum time the scan cache contents are considered valid; 1491i.e. will be used without first triggering a scan operation to 1492refresh the data. 1493The 1494.Ar threshold 1495parameter is specified in seconds and defaults to 60 seconds. 1496The minimum setting for 1497.Ar threshold 1498is 10 seconds. 1499One should take care setting this threshold; if it is set too low 1500then attempts to roam to another access point may trigger unnecessary 1501background scan operations. 1502.It Cm shortgi 1503Enable use of Short Guard Interval when operating in 802.11n 1504on an HT channel. 1505NB: this currently enables Short GI on both HT40 and HT20 channels. 1506To disable Short GI use 1507.Fl shortgi . 1508.It Cm smps 1509Enable use of Static Spatial Multiplexing Power Save (SMPS) 1510when operating in 802.11n. 1511A station operating with Static SMPS maintains only a single 1512receive chain active (this can significantly reduce power consumption). 1513To disable SMPS use 1514.Fl smps . 1515.It Cm smpsdyn 1516Enable use of Dynamic Spatial Multiplexing Power Save (SMPS) 1517when operating in 802.11n. 1518A station operating with Dynamic SMPS maintains only a single 1519receive chain active but switches to multiple receive chains when it 1520receives an RTS frame (this can significantly reduce power consumption). 1521Note that stations cannot distinguish between RTS/CTS intended to 1522enable multiple receive chains and those used for other purposes. 1523To disable SMPS use 1524.Fl smps . 1525.It Cm ssid Ar ssid 1526Set the desired Service Set Identifier (aka network name). 1527The SSID is a string up to 32 characters 1528in length and may be specified as either a normal string or in 1529hexadecimal when preceded by 1530.Ql 0x . 1531Additionally, the SSID may be cleared by setting it to 1532.Ql - . 1533.It Cm tdmaslot Ar slot 1534When operating with TDMA, use the specified 1535.Ar slot 1536configuration. 1537The 1538.Ar slot 1539is a number between 0 and the maximum number of slots in the BSS. 1540Note that a station configured as slot 0 is a master and 1541will broadcast beacon frames advertising the BSS; 1542stations configured to use other slots will always 1543scan to locate a master before they ever transmit. 1544By default 1545.Cm tdmaslot 1546is set to 1. 1547.It Cm tdmaslotcnt Ar cnt 1548When operating with TDMA, setup a BSS with 1549.Ar cnt 1550slots. 1551The slot count may be at most 8. 1552The current implementation is only tested with two stations 1553(i.e. point to point applications). 1554This setting is only meaningful when a station is configured as slot 0; 1555other stations adopt this setting from the BSS they join. 1556By default 1557.Cm tdmaslotcnt 1558is set to 2. 1559.It Cm tdmaslotlen Ar len 1560When operating with TDMA, setup a BSS such that each station has a slot 1561.Ar len 1562microseconds long. 1563The slot length must be at least 150 microseconds (1/8 TU) 1564and no more than 65 milliseconds. 1565Note that setting too small a slot length may result in poor channel 1566bandwidth utilization due to factors such as timer granularity and 1567guard time. 1568This setting is only meaningful when a station is configured as slot 0; 1569other stations adopt this setting from the BSS they join. 1570By default 1571.Cm tdmaslotlen 1572is set to 10 milliseconds. 1573.It Cm tdmabintval Ar intval 1574When operating with TDMA, setup a BSS such that beacons are transmitted every 1575.Ar intval 1576superframes to synchronize the TDMA slot timing. 1577A superframe is defined as the number of slots times the slot length; e.g. 1578a BSS with two slots of 10 milliseconds has a 20 millisecond superframe. 1579The beacon interval may not be zero. 1580A lower setting of 1581.Cm tdmabintval 1582causes the timers to be resynchronized more often; this can be help if 1583significant timer drift is observed. 1584By default 1585.Cm tdmabintval 1586is set to 5. 1587.It Cm tsn 1588When operating as an access point with WPA/802.11i allow legacy 1589stations to associate using static key WEP and open authentication. 1590To disallow legacy station use of WEP, use 1591.Fl tsn . 1592.It Cm txpower Ar power 1593Set the power used to transmit frames. 1594The 1595.Ar power 1596argument is specified in .5 dBm units. 1597Out of range values are truncated. 1598Typically only a few discreet power settings are available and 1599the driver will use the setting closest to the specified value. 1600Not all adapters support changing the transmit power. 1601.It Cm ucastrate Ar rate 1602Set a fixed rate for transmitting unicast frames. 1603Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s. 1604This rate should be valid for the current operating conditions; 1605if an invalid rate is specified drivers are free to chose an 1606appropriate rate. 1607.It Cm wepmode Ar mode 1608Set the desired WEP mode. 1609Not all adapters support all modes. 1610The set of valid modes is 1611.Cm off , on , 1612and 1613.Cm mixed . 1614The 1615.Cm mixed 1616mode explicitly tells the adaptor to allow association with access 1617points which allow both encrypted and unencrypted traffic. 1618On these adapters, 1619.Cm on 1620means that the access point must only allow encrypted connections. 1621On other adapters, 1622.Cm on 1623is generally another name for 1624.Cm mixed . 1625Modes are case insensitive. 1626.It Cm weptxkey Ar index 1627Set the WEP key to be used for transmission. 1628This is the same as setting the default transmission key with 1629.Cm deftxkey . 1630.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key 1631Set the selected WEP key. 1632If an 1633.Ar index 1634is not given, key 1 is set. 1635A WEP key will be either 5 or 13 1636characters (40 or 104 bits) depending of the local network and the 1637capabilities of the adaptor. 1638It may be specified either as a plain 1639string or as a string of hexadecimal digits preceded by 1640.Ql 0x . 1641For maximum portability, hex keys are recommended; 1642the mapping of text keys to WEP encryption is usually driver-specific. 1643In particular, the 1644.Tn Windows 1645drivers do this mapping differently to 1646.Fx . 1647A key may be cleared by setting it to 1648.Ql - . 1649If WEP is supported then there are at least four keys. 1650Some adapters support more than four keys. 1651If that is the case, then the first four keys 1652(1-4) will be the standard temporary keys and any others will be adaptor 1653specific keys such as permanent keys stored in NVRAM. 1654.Pp 1655Note that you must set a default transmit key with 1656.Cm deftxkey 1657for the system to know which key to use in encrypting outbound traffic. 1658.It Cm wme 1659Enable Wireless Multimedia Extensions (WME) support, if available, 1660for the specified interface. 1661WME is a subset of the IEEE 802.11e standard to support the 1662efficient communication of realtime and multimedia data. 1663To disable WME support, use 1664.Fl wme . 1665Another name for this parameter is 1666.Cm wmm . 1667.Pp 1668The following parameters are meaningful only when WME support is in use. 1669Parameters are specified per-AC (Access Category) and 1670split into those that are used by a station when acting 1671as an access point and those for client stations in the BSS. 1672The latter are received from the access point and may not be changed 1673(at the station). 1674The following Access Categories are recognized: 1675.Pp 1676.Bl -tag -width ".Cm AC_BK" -compact 1677.It Cm AC_BE 1678(or 1679.Cm BE ) 1680best effort delivery, 1681.It Cm AC_BK 1682(or 1683.Cm BK ) 1684background traffic, 1685.It Cm AC_VI 1686(or 1687.Cm VI ) 1688video traffic, 1689.It Cm AC_VO 1690(or 1691.Cm VO ) 1692voice traffic. 1693.El 1694.Pp 1695AC parameters are case-insensitive. 1696Traffic classification is done in the operating system using the 1697vlan priority associated with data frames or the 1698ToS (Type of Service) indication in IP-encapsulated frames. 1699If neither information is present, traffic is assigned to the 1700Best Effort (BE) category. 1701.Bl -tag -width indent 1702.It Cm ack Ar ac 1703Set the ACK policy for QoS transmissions by the local station; 1704this controls whether or not data frames transmitted by a station 1705require an ACK response from the receiving station. 1706To disable waiting for an ACK use 1707.Fl ack . 1708This parameter is applied only to the local station. 1709.It Cm acm Ar ac 1710Enable the Admission Control Mandatory (ACM) mechanism 1711for transmissions by the local station. 1712To disable the ACM use 1713.Fl acm . 1714On stations in a BSS this parameter is read-only and indicates 1715the setting received from the access point. 1716NB: ACM is not supported right now. 1717.It Cm aifs Ar ac Ar count 1718Set the Arbitration Inter Frame Spacing (AIFS) 1719channel access parameter to use for transmissions 1720by the local station. 1721On stations in a BSS this parameter is read-only and indicates 1722the setting received from the access point. 1723.It Cm cwmin Ar ac Ar count 1724Set the CWmin channel access parameter to use for transmissions 1725by the local station. 1726On stations in a BSS this parameter is read-only and indicates 1727the setting received from the access point. 1728.It Cm cwmax Ar ac Ar count 1729Set the CWmax channel access parameter to use for transmissions 1730by the local station. 1731On stations in a BSS this parameter is read-only and indicates 1732the setting received from the access point. 1733.It Cm txoplimit Ar ac Ar limit 1734Set the Transmission Opportunity Limit channel access parameter 1735to use for transmissions by the local station. 1736This parameter defines an interval of time when a WME station 1737has the right to initiate transmissions onto the wireless medium. 1738On stations in a BSS this parameter is read-only and indicates 1739the setting received from the access point. 1740.It Cm bss:aifs Ar ac Ar count 1741Set the AIFS channel access parameter to send to stations in a BSS. 1742This parameter is meaningful only when operating in ap mode. 1743.It Cm bss:cwmin Ar ac Ar count 1744Set the CWmin channel access parameter to send to stations in a BSS. 1745This parameter is meaningful only when operating in ap mode. 1746.It Cm bss:cwmax Ar ac Ar count 1747Set the CWmax channel access parameter to send to stations in a BSS. 1748This parameter is meaningful only when operating in ap mode. 1749.It Cm bss:txoplimit Ar ac Ar limit 1750Set the TxOpLimit channel access parameter to send to stations in a BSS. 1751This parameter is meaningful only when operating in ap mode. 1752.El 1753.It Cm wps 1754Enable Wireless Privacy Subscriber support. 1755Note that WPS support requires a WPS-capable supplicant. 1756To disable this function use 1757.Fl wps . 1758.El 1759.Pp 1760The following parameters support an optional access control list 1761feature available with some adapters when operating in ap mode; see 1762.Xr wlan_acl 4 . 1763This facility allows an access point to accept/deny association 1764requests based on the MAC address of the station. 1765Note that this feature does not significantly enhance security 1766as MAC address spoofing is easy to do. 1767.Bl -tag -width indent 1768.It Cm mac:add Ar address 1769Add the specified MAC address to the database. 1770Depending on the policy setting association requests from the 1771specified station will be allowed or denied. 1772.It Cm mac:allow 1773Set the ACL policy to permit association only by 1774stations registered in the database. 1775.It Cm mac:del Ar address 1776Delete the specified MAC address from the database. 1777.It Cm mac:deny 1778Set the ACL policy to deny association only by 1779stations registered in the database. 1780.It Cm mac:kick Ar address 1781Force the specified station to be deauthenticated. 1782This typically is done to block a station after updating the 1783address database. 1784.It Cm mac:open 1785Set the ACL policy to allow all stations to associate. 1786.It Cm mac:flush 1787Delete all entries in the database. 1788.It Cm mac:radius 1789Set the ACL policy to permit association only by 1790stations approved by a RADIUS server. 1791Note that this feature requires the 1792.Xr hostapd 8 1793program be configured to do the right thing 1794as it handles the RADIUS processing 1795(and marks stations as authorized). 1796.El 1797.Pp 1798The following parameters are related to a wireless interface operating in mesh 1799mode: 1800.Bl -tag -width indent 1801.It Cm meshid Ar meshid 1802Set the desired Mesh Identifier. 1803The Mesh ID is a string up to 32 characters in length. 1804A mesh interface must have a Mesh Identifier specified 1805to reach an operational state. 1806.It Cm meshttl Ar ttl 1807Set the desired ``time to live'' for mesh forwarded packets; 1808this is the number of hops a packet may be forwarded before 1809it is discarded. 1810The default setting for 1811.Cm meshttl 1812is 31. 1813.It Cm meshpeering 1814Enable or disable peering with neighbor mesh stations. 1815Stations must peer before any data packets can be exchanged. 1816By default 1817.Cm meshpeering 1818is enabled. 1819.It Cm meshforward 1820Enable or disable forwarding packets by a mesh interface. 1821By default 1822.Cm meshforward 1823is enabled. 1824.It Cm meshmetric Ar protocol 1825Set the specified 1826.Ar protocol 1827as the link metric protocol used on a mesh network. 1828The default protocol is called 1829.Ar AIRTIME . 1830The mesh interface will restart after changing this setting. 1831.It Cm meshpath Ar protocol 1832Set the specified 1833.Ar protocol 1834as the path selection protocol used on a mesh network. 1835The only available protocol at the moment is called 1836.Ar HWMP 1837(Hybrid Wireless Mesh Protocol). 1838The mesh interface will restart after changing this setting. 1839.It Cm hwmprootmode Ar mode 1840Stations on a mesh network can operate as ``root nodes.'' 1841Root nodes try to find paths to all mesh nodes and advertise themselves 1842regularly. 1843When there is a root mesh node on a network, other mesh nodes can setup 1844paths between themselves faster because they can use the root node 1845to find the destination. 1846This path may not be the best, but on-demand 1847routing will eventually find the best path. 1848The following modes are recognized: 1849.Pp 1850.Bl -tag -width ".Cm PROACTIVE" -compact 1851.It Cm DISABLED 1852Disable root mode. 1853.It Cm NORMAL 1854Send broadcast path requests every two seconds. 1855Nodes on the mesh without a path to this root mesh station with try to 1856discover a path to us. 1857.It Cm PROACTIVE 1858Send broadcast path requests every two seconds and every node must reply 1859with a path reply even if it already has a path to this root mesh station, 1860.It Cm RANN 1861Send broadcast root announcement (RANN) frames. 1862Nodes on the mesh without a path to this root mesh station with try to 1863discover a path to us. 1864.El 1865By default 1866.Cm hwmprootmode 1867is set to 1868.Ar DISABLED . 1869.It Cm hwmpmaxhops Ar cnt 1870Set the maximum number of hops allowed in an HMWP path to 1871.Ar cnt . 1872The default setting for 1873.Cm hwmpmaxhops 1874is 31. 1875.El 1876.Pp 1877The following parameters are for compatibility with other systems: 1878.Bl -tag -width indent 1879.It Cm nwid Ar ssid 1880Another name for the 1881.Cm ssid 1882parameter. 1883Included for 1884.Nx 1885compatibility. 1886.It Cm stationname Ar name 1887Set the name of this station. 1888The station name is not part of the IEEE 802.11 1889protocol though some interfaces support it. 1890As such it only 1891seems to be meaningful to identical or virtually identical equipment. 1892Setting the station name is identical in syntax to setting the SSID. 1893One can also use 1894.Cm station 1895for 1896.Bsx 1897compatibility. 1898.It Cm wep 1899Another way of saying 1900.Cm wepmode on . 1901Included for 1902.Bsx 1903compatibility. 1904.It Fl wep 1905Another way of saying 1906.Cm wepmode off . 1907Included for 1908.Bsx 1909compatibility. 1910.It Cm nwkey key 1911Another way of saying: 1912.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" . 1913Included for 1914.Nx 1915compatibility. 1916.It Cm nwkey Xo 1917.Sm off 1918.Ar n : k1 , k2 , k3 , k4 1919.Sm on 1920.Xc 1921Another way of saying 1922.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" . 1923Included for 1924.Nx 1925compatibility. 1926.It Fl nwkey 1927Another way of saying 1928.Cm wepmode off . 1929Included for 1930.Nx 1931compatibility. 1932.El 1933.Pp 1934The following parameters are specific to bridge interfaces: 1935.Bl -tag -width indent 1936.It Cm addm Ar interface 1937Add the interface named by 1938.Ar interface 1939as a member of the bridge. 1940The interface is put into promiscuous mode 1941so that it can receive every packet sent on the network. 1942.It Cm deletem Ar interface 1943Remove the interface named by 1944.Ar interface 1945from the bridge. 1946Promiscuous mode is disabled on the interface when 1947it is removed from the bridge. 1948.It Cm maxaddr Ar size 1949Set the size of the bridge address cache to 1950.Ar size . 1951The default is 100 entries. 1952.It Cm timeout Ar seconds 1953Set the timeout of address cache entries to 1954.Ar seconds 1955seconds. 1956If 1957.Ar seconds 1958is zero, then address cache entries will not be expired. 1959The default is 1200 seconds. 1960.It Cm addr 1961Display the addresses that have been learned by the bridge. 1962.It Cm static Ar interface-name Ar address 1963Add a static entry into the address cache pointing to 1964.Ar interface-name . 1965Static entries are never aged out of the cache or re-placed, even if the 1966address is seen on a different interface. 1967.It Cm deladdr Ar address 1968Delete 1969.Ar address 1970from the address cache. 1971.It Cm flush 1972Delete all dynamically-learned addresses from the address cache. 1973.It Cm flushall 1974Delete all addresses, including static addresses, from the address cache. 1975.It Cm discover Ar interface 1976Mark an interface as a 1977.Dq discovering 1978interface. 1979When the bridge has no address cache entry 1980(either dynamic or static) 1981for the destination address of a packet, 1982the bridge will forward the packet to all 1983member interfaces marked as 1984.Dq discovering . 1985This is the default for all interfaces added to a bridge. 1986.It Fl discover Ar interface 1987Clear the 1988.Dq discovering 1989attribute on a member interface. 1990For packets without the 1991.Dq discovering 1992attribute, the only packets forwarded on the interface are broadcast 1993or multicast packets and packets for which the destination address 1994is known to be on the interface's segment. 1995.It Cm learn Ar interface 1996Mark an interface as a 1997.Dq learning 1998interface. 1999When a packet arrives on such an interface, the source 2000address of the packet is entered into the address cache as being a 2001destination address on the interface's segment. 2002This is the default for all interfaces added to a bridge. 2003.It Fl learn Ar interface 2004Clear the 2005.Dq learning 2006attribute on a member interface. 2007.It Cm span Ar interface 2008Add the interface named by 2009.Ar interface 2010as a span port on the bridge. 2011Span ports transmit a copy of every frame received by the bridge. 2012This is most useful for snooping a bridged network passively on 2013another host connected to one of the span ports of the bridge. 2014.It Fl span Ar interface 2015Delete the interface named by 2016.Ar interface 2017from the list of span ports of the bridge. 2018.It Cm stp Ar interface 2019Enable Spanning Tree protocol on 2020.Ar interface . 2021The 2022.Xr bridge 4 2023driver has support for the IEEE 802.1D Spanning Tree protocol (STP). 2024Spanning Tree is used to detect and remove loops in a network topology. 2025.It Fl stp Ar interface 2026Disable Spanning Tree protocol on 2027.Ar interface . 2028This is the default for all interfaces added to a bridge. 2029.It Cm maxage Ar seconds 2030Set the time that a Spanning Tree protocol configuration is valid. 2031The default is 20 seconds. 2032The minimum is 1 second and the maximum is 255 seconds. 2033.It Cm fwddelay Ar seconds 2034Set the time that must pass before an interface begins forwarding 2035packets when Spanning Tree is enabled. 2036The default is 15 seconds. 2037The minimum is 1 second and the maximum is 255 seconds. 2038.It Cm hellotime Ar seconds 2039Set the time between broadcasting of Spanning Tree protocol 2040configuration messages. 2041The default is 2 seconds. 2042The minimum is 1 second and the maximum is 255 seconds. 2043.It Cm priority Ar value 2044Set the bridge priority for Spanning Tree. 2045The default is 32768. 2046The minimum is 0 and the maximum is 65536. 2047.It Cm ifpriority Ar interface Ar value 2048Set the Spanning Tree priority of 2049.Ar interface 2050to 2051.Ar value . 2052The default is 128. 2053The minimum is 0 and the maximum is 255. 2054.Pp 2055The priority is used to select which interface out of all 2056forwarding and bonded interfaces with the same MAC 2057to output a packet on whe 2058.Cm link2 2059mode is not being used. 2060Note that interfaces in the 'blocking' state do not participate 2061in the priority selection. 2062If the priorities are the same on a non-bonded member, the 2063designated member will be used. 2064.It Cm ifpathcost Ar interface Ar value 2065Set the Spanning Tree path cost of 2066.Ar interface 2067to 2068.Ar value . 2069The default is 55. 2070The minimum is 0 and the maximum is 65535. 2071.Pp 2072The path cost is added to both incoming and outgoing packets on the 2073member, lower values will make the member more valuable. 2074.It Cm ifbondweight Ar interface Ar value 2075Set the number of packets to output on a bonded member before 2076round-robining to the next member. 2077The default is 1. 2078Larger values or different values for each member can be used 2079if bursting would be beneficial or if the outgoing bandwidth 2080on each of the members is asymmetric. 2081For example, one specify a value of 6 on tap0 and 4 on tap1 2082for a 6:4 ratio. 2083Remember that this also controls packet bursting. 2084.It Cm link0 2085The link0 option enables transparent bridging mode. 2086The bridge will make every effort to retain the ethernet header 2087when forwarding packets between interfaces, making the bridging 2088function work more like a hardware bridge device. 2089.It Cm link1 2090The link1 option enables keepalive transmission and automatically 2091places a member into a special blocked mode if no keepalive reception 2092occurs. 2093If either sides of the link uses this option then both sides must use 2094this option. 2095This option is impemented by sending CFG updates on the hello interval 2096to the remote. 2097The link is considered lost after 10 intervals (typically 20 seconds). 2098.It Cm link2 2099The link2 option enables channel bonding (see also ifbondweight). 2100All member interfaces with the same mac address are considered to 2101be in a bonding group. 2102When something like 2103.Xr tap 4 2104is used, you can manually control or copy the mac to create bonding groups. 2105When interface bonding is enabled normally blocked interfaces belonging 2106to the same bonding group as an active forwarding interface will be 2107changed to the bonding state. 2108Both sides of link the member represents must operate in bonding mode 2109for this to work, otherwise the remote end may decide to throw away 2110half your packets. 2111.El 2112.Pp 2113The following parameters are specific to IP tunnel interfaces, 2114.Xr gif 4 : 2115.Bl -tag -width indent 2116.It Cm tunnel Ar src_addr dest_addr 2117Configure the physical source and destination address for IP tunnel 2118interfaces. 2119The arguments 2120.Ar src_addr 2121and 2122.Ar dest_addr 2123are interpreted as the outer source/destination for the encapsulating 2124IPv4/IPv6 header. 2125.It Fl tunnel 2126Unconfigure the physical source and destination address for IP tunnel 2127interfaces previously configured with 2128.Cm tunnel . 2129.It Cm deletetunnel 2130Another name for the 2131.Fl tunnel 2132parameter. 2133.El 2134.Pp 2135The following parameters are specific to 2136.Xr vlan 4 2137interfaces: 2138.Bl -tag -width indent 2139.It Cm vlan Ar vlan_tag 2140Set the VLAN tag value to 2141.Ar vlan_tag . 2142This value is a 16-bit number which is used to create an 802.1Q 2143VLAN header for packets sent from the 2144.Xr vlan 4 2145interface. 2146Note that 2147.Cm vlan 2148and 2149.Cm vlandev 2150must both be set at the same time. 2151.It Cm vlandev Ar iface 2152Associate the physical interface 2153.Ar iface 2154with a 2155.Xr vlan 4 2156interface. 2157Packets transmitted through the 2158.Xr vlan 4 2159interface will be 2160diverted to the specified physical interface 2161.Ar iface 2162with 802.1Q VLAN encapsulation. 2163Packets with 802.1Q encapsulation received 2164by the parent interface with the correct VLAN tag will be diverted to 2165the associated 2166.Xr vlan 4 2167pseudo-interface. 2168The 2169.Xr vlan 4 2170interface is assigned a 2171copy of the parent interface's flags and the parent's ethernet address. 2172The 2173.Cm vlandev 2174and 2175.Cm vlan 2176must both be set at the same time. 2177If the 2178.Xr vlan 4 2179interface already has 2180a physical interface associated with it, this command will fail. 2181To 2182change the association to another physical interface, the existing 2183association must be cleared first. 2184.Pp 2185Note: if the hardware tagging capability 2186is set on the parent interface, the 2187.Xr vlan 4 2188pseudo 2189interface's behavior changes: 2190the 2191.Xr vlan 4 2192interface recognizes that the 2193parent interface supports insertion and extraction of VLAN tags on its 2194own (usually in firmware) and that it should pass packets to and from 2195the parent unaltered. 2196.It Fl vlandev Op Ar iface 2197If the driver is a 2198.Xr vlan 4 2199pseudo device, disassociate the parent interface from it. 2200This breaks the link between the 2201.Xr vlan 4 2202interface and its parent, 2203clears its VLAN tag, flags and its link address and shuts the interface down. 2204The 2205.Ar iface 2206argument is useless and hence deprecated. 2207.El 2208.Pp 2209The following parameters are specific to 2210.Xr carp 4 2211interfaces: 2212.Bl -tag -width indent 2213.It Cm advbase Ar seconds 2214Specifies the base of the advertisement interval in seconds. 2215The acceptable values are 1 to 255. 2216The default value is 1. 2217.\" The default value is 2218.\" .Dv CARP_DFLTINTV . 2219.It Cm advskew Ar interval 2220Specifies the skew to add to the base advertisement interval to 2221make one host advertise slower than another host. 2222It is specified in 1/256 of seconds. 2223The acceptable values are 1 to 254. 2224The default value is 0. 2225.It Cm pass Ar phrase 2226Set the authentication key to 2227.Ar phrase . 2228.It Cm vhid Ar n 2229Set the virtual host ID. 2230This is a required setting. 2231Acceptable values are 1 to 255. 2232.El 2233.Pp 2234The 2235.Nm 2236utility displays the current configuration for a network interface 2237when no optional parameters are supplied. 2238If a protocol family is specified, 2239.Nm 2240will report only the details specific to that protocol family. 2241.Pp 2242If the 2243.Fl m 2244flag is passed before an interface name, 2245.Nm 2246will display the capability list and all 2247of the supported media for the specified interface. 2248If 2249.Fl L 2250flag is supplied, address lifetime is displayed for IPv6 addresses, 2251as time offset string. 2252.Pp 2253Optionally, the 2254.Fl a 2255flag may be used instead of an interface name. 2256This flag instructs 2257.Nm 2258to display information about all interfaces in the system. 2259The 2260.Fl d 2261flag limits this to interfaces that are down, and 2262.Fl u 2263limits this to interfaces that are up. 2264When no arguments are given, 2265.Fl a 2266is implied. 2267.Pp 2268The 2269.Fl l 2270flag may be used to list all available interfaces on the system, with 2271no other additional information. 2272Use of this flag is mutually exclusive 2273with all other flags and commands, except for 2274.Fl d 2275(only list interfaces that are down) 2276and 2277.Fl u 2278(only list interfaces that are up). 2279.Pp 2280The 2281.Fl v 2282flag may be used to get more verbose status for an interface. 2283.Pp 2284The 2285.Fl C 2286flag may be used to list all of the interface cloners available on 2287the system, with no additional information. 2288Use of this flag is mutually exclusive with all other flags and commands. 2289.Pp 2290The 2291.Fl k 2292flag causes keying information for the interface, if available, to be 2293printed. 2294For example, the values of 802.11 WEP keys will be printed, if accessible to 2295the current user. 2296This information is not printed by default, as it may be considered 2297sensitive. 2298.Pp 2299Only the super-user may modify the configuration of a network interface. 2300.Sh DIAGNOSTICS 2301Messages indicating the specified interface does not exist, the 2302requested address is unknown, or the user is not privileged and 2303tried to alter an interface's configuration. 2304.Sh SEE ALSO 2305.Xr netstat 1 , 2306.Xr carp 4 , 2307.Xr ifmedia 4 , 2308.Xr netintro 4 , 2309.Xr polling 4 , 2310.Xr vlan 4 , 2311.\" .Xr eon 5 , 2312.Xr rc 8 , 2313.Xr routed 8 , 2314.Xr sysctl 8 2315.Sh HISTORY 2316The 2317.Nm 2318utility appeared in 2319.Bx 4.2 . 2320.Sh BUGS 2321Basic IPv6 node operation requires a link-local address on each 2322interface configured for IPv6. 2323Normally, such an address is automatically configured by the 2324kernel on each interface added to the system; this behaviour may 2325be disabled by setting the sysctl MIB variable 2326.Va net.inet6.ip6.auto_linklocal 2327to 0. 2328.Pp 2329If you delete such an address using 2330.Nm , 2331the kernel may act very odd. 2332Do this at your own risk. 2333