1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 4. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" From: @(#)ifconfig.8 8.3 (Berkeley) 1/5/94 29.\" $FreeBSD$ 30.\" 31.Dd July 30, 2008 32.Dt IFCONFIG 8 33.Os 34.Sh NAME 35.Nm ifconfig 36.Nd configure network interface parameters 37.Sh SYNOPSIS 38.Nm 39.Op Fl L 40.Op Fl k 41.Op Fl m 42.Op Fl n 43.Ar interface 44.Op Cm create 45.Op Ar address_family 46.Oo 47.Ar address 48.Op Ar dest_address 49.Oc 50.Op Ar parameters 51.Nm 52.Ar interface 53.Cm destroy 54.Nm 55.Fl a 56.Op Fl L 57.Op Fl d 58.Op Fl m 59.Op Fl u 60.Op Fl v 61.Op Ar address_family 62.Nm 63.Fl l 64.Op Fl d 65.Op Fl u 66.Op Ar address_family 67.Nm 68.Op Fl L 69.Op Fl d 70.Op Fl k 71.Op Fl m 72.Op Fl u 73.Op Fl v 74.Op Fl C 75.Nm 76.Op Fl g Ar groupname 77.Sh DESCRIPTION 78The 79.Nm 80utility is used to assign an address 81to a network interface and/or configure 82network interface parameters. 83The 84.Nm 85utility must be used at boot time to define the network address 86of each interface present on a machine; it may also be used at 87a later time to redefine an interface's address 88or other operating parameters. 89.Pp 90The following options are available: 91.Bl -tag -width indent 92.It Ar address 93For the 94.Tn DARPA Ns -Internet 95family, 96the address is either a host name present in the host name data 97base, 98.Xr hosts 5 , 99or a 100.Tn DARPA 101Internet address expressed in the Internet standard 102.Dq dot notation . 103.Pp 104It is also possible to use the CIDR notation (also known as the 105slash notation) to include the netmask. 106That is, one can specify an address like 107.Li 192.168.0.1/16 . 108.Pp 109For 110.Dq inet6 111family, it is also possible to specify the prefix length using the slash 112notation, like 113.Li ::1/128 . 114See the 115.Cm prefixlen 116parameter below for more information. 117.\" For the Xerox Network Systems(tm) family, 118.\" addresses are 119.\" .Ar net:a.b.c.d.e.f , 120.\" where 121.\" .Ar net 122.\" is the assigned network number (in decimal), 123.\" and each of the six bytes of the host number, 124.\" .Ar a 125.\" through 126.\" .Ar f , 127.\" are specified in hexadecimal. 128.\" The host number may be omitted on IEEE 802 protocol 129.\" (Ethernet, FDDI, and Token Ring) interfaces, 130.\" which use the hardware physical address, 131.\" and on interfaces other than the first. 132.\" For the 133.\" .Tn ISO 134.\" family, addresses are specified as a long hexadecimal string, 135.\" as in the Xerox family. 136.\" However, two consecutive dots imply a zero 137.\" byte, and the dots are optional, if the user wishes to (carefully) 138.\" count out long strings of digits in network byte order. 139.Pp 140The link-level 141.Pq Dq link 142address 143is specified as a series of colon-separated hex digits. 144This can be used to 145e.g.\& set a new MAC address on an ethernet interface, though the 146mechanism used is not ethernet-specific. 147If the interface is already 148up when this option is used, it will be briefly brought down and 149then brought back up again in order to ensure that the receive 150filter in the underlying ethernet hardware is properly reprogrammed. 151.It Ar address_family 152Specify the 153address family 154which affects interpretation of the remaining parameters. 155Since an interface can receive transmissions in differing protocols 156with different naming schemes, specifying the address family is recommended. 157The address or protocol families currently 158supported are 159.Dq inet , 160.Dq inet6 , 161.Dq atalk , 162.Dq ipx , 163.\" .Dq iso , 164and 165.Dq link . 166.\" and 167.\" .Dq ns . 168The default is 169.Dq inet . 170.Dq ether 171and 172.Dq lladdr 173are synonyms for 174.Dq link . 175.It Ar dest_address 176Specify the address of the correspondent on the other end 177of a point to point link. 178.It Ar interface 179This 180parameter is a string of the form 181.Dq name unit , 182for example, 183.Dq Li ed0 . 184.It Ar groupname 185List the interfaces in the given group. 186.El 187.Pp 188The following parameters may be set with 189.Nm : 190.Bl -tag -width indent 191.It Cm add 192Another name for the 193.Cm alias 194parameter. 195Introduced for compatibility 196with 197.Bsx . 198.It Cm alias 199Establish an additional network address for this interface. 200This is sometimes useful when changing network numbers, and 201one wishes to accept packets addressed to the old interface. 202If the address is on the same subnet as the first network address 203for this interface, a non-conflicting netmask must be given. 204Usually 205.Li 0xffffffff 206is most appropriate. 207.It Fl alias 208Remove the network address specified. 209This would be used if you incorrectly specified an alias, or it 210was no longer needed. 211If you have incorrectly set an NS address having the side effect 212of specifying the host portion, removing all NS addresses will 213allow you to respecify the host portion. 214.It Cm anycast 215(Inet6 only.) 216Specify that the address configured is an anycast address. 217Based on the current specification, 218only routers may configure anycast addresses. 219Anycast address will not be used as source address of any of outgoing 220IPv6 packets. 221.It Cm arp 222Enable the use of the Address Resolution Protocol 223.Pq Xr arp 4 224in mapping 225between network level addresses and link level addresses (default). 226This is currently implemented for mapping between 227.Tn DARPA 228Internet 229addresses and 230.Tn IEEE 231802 48-bit MAC addresses (Ethernet, FDDI, and Token Ring addresses). 232.It Fl arp 233Disable the use of the Address Resolution Protocol 234.Pq Xr arp 4 . 235.It Cm staticarp 236If the Address Resolution Protocol is enabled, 237the host will only reply to requests for its addresses, 238and will never send any requests. 239.It Fl staticarp 240If the Address Resolution Protocol is enabled, 241the host will perform normally, 242sending out requests and listening for replies. 243.It Cm broadcast 244(Inet only.) 245Specify the address to use to represent broadcasts to the 246network. 247The default broadcast address is the address with a host part of all 1's. 248.It Cm debug 249Enable driver dependent debugging code; usually, this turns on 250extra console error logging. 251.It Fl debug 252Disable driver dependent debugging code. 253.It Cm promisc 254Put interface into permanently promiscuous mode. 255.It Fl promisc 256Disable permanently promiscuous mode. 257.It Cm delete 258Another name for the 259.Fl alias 260parameter. 261.It Cm down 262Mark an interface 263.Dq down . 264When an interface is marked 265.Dq down , 266the system will not attempt to 267transmit messages through that interface. 268If possible, the interface will be reset to disable reception as well. 269This action does not automatically disable routes using the interface. 270.It Cm group Ar group-name 271Assign the interface to a 272.Dq group . 273Any interface can be in multiple groups. 274.Pp 275Cloned interfaces are members of their interface family group by default. 276For example, a PPP interface such as 277.Em ppp0 278is a member of the PPP interface family group, 279.Em ppp . 280.\" The interface(s) the default route(s) point to are members of the 281.\" .Em egress 282.\" interface group. 283.It Cm -group Ar group-name 284Remove the interface from the given 285.Dq group . 286.It Cm eui64 287(Inet6 only.) 288Fill interface index 289(lowermost 64bit of an IPv6 address) 290automatically. 291.It Cm ipdst 292This is used to specify an Internet host who is willing to receive 293IP packets encapsulating IPX packets bound for a remote network. 294An apparent point to point link is constructed, and 295the address specified will be taken as the IPX address and network 296of the destination. 297.It Cm maclabel Ar label 298If Mandatory Access Control support is enabled in the kernel, 299set the MAC label to 300.Ar label . 301.\" (see 302.\" .Xr maclabel 7 ) . 303.It Cm media Ar type 304If the driver supports the media selection system, set the media type 305of the interface to 306.Ar type . 307Some interfaces support the mutually exclusive use of one of several 308different physical media connectors. 309For example, a 10Mbit/s Ethernet 310interface might support the use of either 311.Tn AUI 312or twisted pair connectors. 313Setting the media type to 314.Cm 10base5/AUI 315would change the currently active connector to the AUI port. 316Setting it to 317.Cm 10baseT/UTP 318would activate twisted pair. 319Refer to the interfaces' driver 320specific documentation or man page for a complete list of the 321available types. 322.It Cm mediaopt Ar opts 323If the driver supports the media selection system, set the specified 324media options on the interface. 325The 326.Ar opts 327argument 328is a comma delimited list of options to apply to the interface. 329Refer to the interfaces' driver specific man page for a complete 330list of available options. 331.It Fl mediaopt Ar opts 332If the driver supports the media selection system, disable the 333specified media options on the interface. 334.It Cm mode Ar mode 335If the driver supports the media selection system, set the specified 336operating mode on the interface to 337.Ar mode . 338For IEEE 802.11 wireless interfaces that support multiple operating modes 339this directive is used to select between 802.11a 340.Pq Cm 11a , 341802.11b 342.Pq Cm 11b , 343and 802.11g 344.Pq Cm 11g 345operating modes. 346.It Cm inst Ar minst , Cm instance Ar minst 347Set the media instance to 348.Ar minst . 349This is useful for devices which have multiple physical layer interfaces 350.Pq PHYs . 351.It Cm name Ar name 352Set the interface name to 353.Ar name . 354.It Cm rxcsum , txcsum 355If the driver supports user-configurable checksum offloading, 356enable receive (or transmit) checksum offloading on the interface. 357Some drivers may not be able to enable these flags independently 358of each other, so setting one may also set the other. 359The driver will offload as much checksum work as it can reliably 360support, the exact level of offloading varies between drivers. 361.It Fl rxcsum , txcsum 362If the driver supports user-configurable checksum offloading, 363disable receive (or transmit) checksum offloading on the interface. 364These settings may not always be independent of each other. 365.It Cm tso 366If the driver supports 367.Xr tcp 4 368segmentation offloading, enable TSO on the interface. 369Some drivers may not be able to support TSO for 370.Xr ip 4 371and 372.Xr ip6 4 373packets, so they may enable only one of them. 374.It Fl tso 375If the driver supports 376.Xr tcp 4 377segmentation offloading, disable TSO on the interface. 378It will always disable TSO for 379.Xr ip 4 380and 381.Xr ip6 4 . 382.It Cm lro 383If the driver supports 384.Xr tcp 4 385large receive offloading, enable LRO on the interface. 386.It Fl lro 387If the driver supports 388.Xr tcp 4 389large receive offloading, disable LRO on the interface. 390.It Cm wol , wol_ucast , wol_mcast , wol_magic 391Enable Wake On Lan (WOL) support, if available. 392WOL is a facility whereby a machine in a low power state may be woken 393in response to a received packet. 394There are three types of packets that may wake a system: 395ucast (directed solely to the machine's mac address), 396mcast (directed to a broadcast or multicast address), 397or 398magic (unicast or multicast frames with a ``magic contents''). 399Not all devices support WOL, those that do indicate the mechanisms 400they support in their capabilities. 401.Cm wol 402is a synonym for enabling all available WOL mechanisms. 403To disable WOL use 404.Fl wol . 405.It Cm vlanmtu , vlanhwtag 406If the driver offers user-configurable VLAN support, enable 407reception of extended frames or tag processing in hardware, 408respectively. 409Note that this must be issued on a physical interface associated with 410.Xr vlan 4 , 411not on a 412.Xr vlan 4 413interface itself. 414.It Fl vlanmtu , vlanhwtag 415If the driver offers user-configurable VLAN support, disable 416reception of extended frames or tag processing in hardware, 417respectively. 418.It Cm polling 419Turn on 420.Xr polling 4 421feature and disable interrupts on the interface, if driver supports 422this mode. 423.It Fl polling 424Turn off 425.Xr polling 4 426feature and enable interrupt mode on the interface. 427.It Cm create 428Create the specified network pseudo-device. 429If the interface is given without a unit number, try to create a new 430device with an arbitrary unit number. 431If creation of an arbitrary device is successful, the new device name is 432printed to standard output unless the interface is renamed or destroyed 433in the same 434.Nm 435invocation. 436.It Cm destroy 437Destroy the specified network pseudo-device. 438.It Cm plumb 439Another name for the 440.Cm create 441parameter. 442Included for 443.Tn Solaris 444compatibility. 445.It Cm unplumb 446Another name for the 447.Cm destroy 448parameter. 449Included for 450.Tn Solaris 451compatibility. 452.It Cm metric Ar n 453Set the routing metric of the interface to 454.Ar n , 455default 0. 456The routing metric is used by the routing protocol 457.Pq Xr routed 8 . 458Higher metrics have the effect of making a route 459less favorable; metrics are counted as additional hops 460to the destination network or host. 461.It Cm mtu Ar n 462Set the maximum transmission unit of the interface to 463.Ar n , 464default is interface specific. 465The MTU is used to limit the size of packets that are transmitted on an 466interface. 467Not all interfaces support setting the MTU, and some interfaces have 468range restrictions. 469.It Cm netmask Ar mask 470.\" (Inet and ISO.) 471(Inet only.) 472Specify how much of the address to reserve for subdividing 473networks into sub-networks. 474The mask includes the network part of the local address 475and the subnet part, which is taken from the host field of the address. 476The mask can be specified as a single hexadecimal number 477with a leading 478.Ql 0x , 479with a dot-notation Internet address, 480or with a pseudo-network name listed in the network table 481.Xr networks 5 . 482The mask contains 1's for the bit positions in the 32-bit address 483which are to be used for the network and subnet parts, 484and 0's for the host part. 485The mask should contain at least the standard network portion, 486and the subnet field should be contiguous with the network 487portion. 488.Pp 489The netmask can also be specified in CIDR notation after the address. 490See the 491.Ar address 492option above for more information. 493.It Cm prefixlen Ar len 494(Inet6 only.) 495Specify that 496.Ar len 497bits are reserved for subdividing networks into sub-networks. 498The 499.Ar len 500must be integer, and for syntactical reason it must be between 0 to 128. 501It is almost always 64 under the current IPv6 assignment rule. 502If the parameter is omitted, 64 is used. 503.Pp 504The prefix can also be specified using the slash notation after the address. 505See the 506.Ar address 507option above for more information. 508.\" see 509.\" Xr eon 5 . 510.\" .It Cm nsellength Ar n 511.\" .Pf ( Tn ISO 512.\" only) 513.\" This specifies a trailing number of bytes for a received 514.\" .Tn NSAP 515.\" used for local identification, the remaining leading part of which is 516.\" taken to be the 517.\" .Tn NET 518.\" (Network Entity Title). 519.\" The default value is 1, which is conformant to US 520.\" .Tn GOSIP . 521.\" When an ISO address is set in an ifconfig command, 522.\" it is really the 523.\" .Tn NSAP 524.\" which is being specified. 525.\" For example, in 526.\" .Tn US GOSIP , 527.\" 20 hex digits should be 528.\" specified in the 529.\" .Tn ISO NSAP 530.\" to be assigned to the interface. 531.\" There is some evidence that a number different from 1 may be useful 532.\" for 533.\" .Tn AFI 534.\" 37 type addresses. 535.It Cm range Ar netrange 536Under appletalk, set the interface to respond to a 537.Ar netrange 538of the form 539.Ar startnet Ns - Ns Ar endnet . 540Appletalk uses this scheme instead of 541netmasks though 542.Fx 543implements it internally as a set of netmasks. 544.It Cm remove 545Another name for the 546.Fl alias 547parameter. 548Introduced for compatibility 549with 550.Bsx . 551.It Cm phase 552The argument following this specifies the version (phase) of the 553Appletalk network attached to the interface. 554Values of 1 or 2 are permitted. 555.Sm off 556.It Cm link Op Cm 0 No - Cm 2 557.Sm on 558Enable special processing of the link level of the interface. 559These three options are interface specific in actual effect, however, 560they are in general used to select special modes of operation. 561An example 562of this is to enable SLIP compression, or to select the connector type 563for some Ethernet cards. 564Refer to the man page for the specific driver 565for more information. 566.Sm off 567.It Fl link Op Cm 0 No - Cm 2 568.Sm on 569Disable special processing at the link level with the specified interface. 570.It Cm monitor 571Put the interface in monitor mode. 572No packets are transmitted, and received packets are discarded after 573.Xr bpf 4 574processing. 575.It Fl monitor 576Take the interface out of monitor mode. 577.It Cm up 578Mark an interface 579.Dq up . 580This may be used to enable an interface after an 581.Dq Nm Cm down . 582It happens automatically when setting the first address on an interface. 583If the interface was reset when previously marked down, 584the hardware will be re-initialized. 585.El 586.Pp 587The following parameters are specific to cloning 588IEEE 802.11 wireless interfaces with the 589.Cm create 590request: 591.Bl -tag -width indent 592.It Cm wlandev Ar device 593Use 594.Ar device 595as the parent for the cloned device. 596.It Cm wlanmode Ar mode 597Specify the operating mode for this cloned device. 598.Ar mode 599is one of 600.Cm sta , 601.Cm ahdemo 602(or 603.Cm adhoc-demo ), 604.Cm ibss , 605(or 606.Cm adhoc ), 607.Cm ap , 608(or 609.Cm hostap ), 610.Cm wds , 611and 612.Cm monitor . 613The operating mode of a cloned interface cannot be changed. 614.It Cm wlanbssid Ar bssid 615The 802.11 mac address to use for the bssid. 616This must be specified at create time for a legacy 617.Cm wds 618device. 619.It Cm wlanaddr Ar address 620The local mac address. 621If this is not specified then a mac address will automatically be assigned 622to the cloned device. 623Typically this address is the same as the address of the parent device 624but if the 625.Cm bssid 626parameter is specified then the driver will craft a unique address for 627the device (if supported). 628.It Cm wdslegacy 629Mark a 630.Cm wds 631device as operating in ``legacy mode''. 632Legacy 633.Cm wds 634devices have a fixed peer relationship and do not, for example, roam 635if their peer stops communicating. 636For completeness a Dynamic WDS (DWDS) interface may marked as 637.Fl wdslegacy . 638.It Cm bssid 639Request a unique local mac address for the cloned device. 640This is only possible if the device supports multiple mac addresses. 641To force use of the parent's mac address use 642.Fl bssid . 643.It Cm beacons 644Mark the cloned interface as depending on hardware support to 645track received beacons. 646To have beacons tracked in software use 647.Fl beacons . 648For 649.Cm hostap 650mode 651.Fl beacons 652can also be used to indicate no beacons should 653be transmitted; this can be useful when creating a WDS configuration but 654.Cm wds 655interfaces can only be created as companions to an access point. 656.El 657.Pp 658The following parameters are specific to IEEE 802.11 wireless interfaces 659cloned with a 660.Cm create 661operation: 662.Bl -tag -width indent 663.It Cm ampdu 664Enable sending and receiving AMPDU frames when using 802.11n (default). 665The 802.11n specification states a compliant station must be capable 666of receiving AMPDU frames but transmision is optional. 667Use 668.Fl ampdu 669to disable all use of AMPDU with 802.11n. 670For testing and/or to work around interoperability problems one can use 671.Cm ampdutx 672and 673.Cm ampdurx 674to control use of AMPDU in one direction. 675.It Cm ampdudensity Ar density 676Set the AMPDU density parameter used when operating with 802.11n. 677This parameter controls the inter-packet gap for AMPDU frames. 678The sending device normally controls this setting but a receiving station 679may request wider gaps. 680Legal values for 681.Ar density 682are 0, .25, .5, 1, 2, 4, 8, and 16 (microseconds). 683A value of 684.Cm - 685is treated the same as 0. 686.It Cm ampdulimit Ar limit 687Set the limit on packet size for receiving AMPDU frames when operating 688with 802.11n. 689Legal values for 690.Ar limit 691are 8192, 16384, 32768, and 65536 but one can also specify 692just the unique prefix: 8, 16, 32, 64. 693Note the sender may limit the size of AMPDU frames to be less 694than the maximum specified by the receiving station. 695.It Cm amsdu 696Enable sending and receiving AMSDU frames when using 802.11n. 697By default AMSDU is received but not transmitted. 698Use 699.Fl amsdu 700to disable all use of AMSDU with 802.11n. 701For testing and/or to work around interoperability problems one can use 702.Cm amsdutx 703and 704.Cm amsdurx 705to control use of AMSDU in one direction. 706.It Cm amsdulimit Ar limit 707Set the limit on packet size for sending and receiving AMSDU frames 708when operating with 802.11n. 709Legal values for 710.Ar limit 711are 7935 and 3839 (bytes). 712Note the sender may limit the size of AMSDU frames to be less 713than the maximum specified by the receiving station. 714Note also that devices are not required to support the 7935 limit, 715only 3839 is required by the specification and the larger value 716may require more memory to be dedicated to support functionality 717that is rarely used. 718.It Cm apbridge 719When operating as an access point, pass packets between 720wireless clients directly (default). 721To instead let them pass up through the 722system and be forwarded using some other mechanism, use 723.Fl apbridge . 724Disabling the internal bridging 725is useful when traffic is to be processed with 726packet filtering. 727.It Cm authmode Ar mode 728Set the desired authentication mode in infrastructure mode. 729Not all adapters support all modes. 730The set of 731valid modes is 732.Cm none , open , shared 733(shared key), 734.Cm 8021x 735(IEEE 802.1x), 736and 737.Cm wpa 738(IEEE WPA/WPA2/802.11i). 739The 740.Cm 8021x 741and 742.Cm wpa 743modes are only useful when using an authentication service 744(a supplicant for client operation or an authenticator when 745operating as an access point). 746Modes are case insensitive. 747.It Cm bgscan 748Enable background scanning when operating as a station. 749Background scanning is a technique whereby a station associated to 750an access point will temporarily leave the channel to scan for 751neighboring stations. 752This allows a station to maintain a cache of nearby access points 753so that roaming between access points can be done without 754a lengthy scan operation. 755Background scanning is done only when a station is not busy and 756any outbound traffic will cancel a scan operation. 757Background scanning should never cause packets to be lost though 758there may be some small latency if outbound traffic interrupts a 759scan operation. 760By default background scanning is enabled if the device is capable. 761To disable background scanning, use 762.Fl bgscan . 763Background scanning is controlled by the 764.Cm bgscanidle 765and 766.Cm bgscanintvl 767parameters. 768Background scanning must be enabled for roaming; this is an artifact 769of the current implementation and may not be required in the future. 770.It Cm bgscanidle Ar idletime 771Set the minimum time a station must be idle (not transmitting or 772receiving frames) before a background scan is initiated. 773The 774.Ar idletime 775parameter is specified in milliseconds. 776By default a station must be idle at least 250 milliseconds before 777a background scan is initiated. 778The idle time may not be set to less than 100 milliseconds. 779.It Cm bgscanintvl Ar interval 780Set the interval at which background scanning is attempted. 781The 782.Ar interval 783parameter is specified in seconds. 784By default a background scan is considered every 300 seconds (5 minutes). 785The 786.Ar interval 787may not be set to less than 15 seconds. 788.It Cm bintval Ar interval 789Set the interval at which beacon frames are sent when operating in 790ad-hoc or ap mode. 791The 792.Ar interval 793parameter is specified in TU's (1024 usecs). 794By default beacon frames are transmitted every 100 TU's. 795.It Cm bmissthreshold Ar count 796Set the number of consecutive missed beacons at which the station 797will attempt to roam (i.e., search for a new access point). 798The 799.Ar count 800parameter must be in the range 1 to 255; though the 801upper bound may be reduced according to device capabilities. 802The default threshold is 7 consecutive missed beacons; but 803this may be overridden by the device driver. 804Another name for the 805.Cm bmissthreshold 806parameter is 807.Cm bmiss . 808.It Cm bssid Ar address 809Specify the MAC address of the access point to use when operating 810as a station in a BSS network. 811This overrides any automatic selection done by the system. 812To disable a previously selected access point, supply 813.Cm any , none , 814or 815.Cm - 816for the address. 817This option is useful when more than one access point uses the same SSID. 818Another name for the 819.Cm bssid 820parameter is 821.Cm ap . 822.It Cm burst 823Enable packet bursting. 824Packet bursting is a transmission technique whereby the wireless 825medium is acquired once to send multiple frames and the interframe 826spacing is reduced. 827This technique can significantly increase throughput by reducing 828transmission overhead. 829Packet bursting is supported by the 802.11e QoS specification 830and some devices that do not support QoS may still be capable. 831By default packet bursting is enabled if a device is capable 832of doing it. 833To disable packet bursting, use 834.Fl burst . 835.It Cm chanlist Ar channels 836Set the desired channels to use when scanning for access 837points, neighbors in an IBSS network, or looking for unoccupied 838channels when operating as an access point. 839The set of channels is specified as a comma-separated list with 840each element in the list representing either a single channel number or a range 841of the form 842.Dq Li a-b . 843Channel numbers must be in the range 1 to 255 and be permissible 844according to the operating characteristics of the device. 845.It Cm channel Ar number 846Set a single desired channel. 847Channels range from 1 to 255, but the exact selection available 848depends on the region your adaptor was manufactured for. 849Setting 850the channel to 851.Li any , 852or 853.Cm - 854will clear any desired channel and, if the device is marked up, 855force a scan for a channel to operate on. 856Alternatively the frequency, in megahertz, may be specified 857instead of the channel number. 858.Pp 859When there are several ways to use a channel the channel 860number/frequency may be appended with attributes to clarify. 861For example, if a device is capable of operating on channel 6 862with 802.11n and 802.11g then one can specify that g-only use 863should be used by specifying ``6:g''. 864Similarly the channel width can be specified by appending it 865with ``/''; e.g. ``6/40'' specifies a 40MHz wide channel, 866These attributes can be combined as in: ``6:ht/40''. 867The full set of flags specified following a `:'' are: 868.Cm a 869(802.11a), 870.Cm b 871(802.11b), 872.Cm d 873(Atheros Dynamic Turbo mode), 874.Cm g 875(802.11g), 876.Cm h 877or 878.Cm n 879(802.11n aka HT), 880.Cm s 881(Atheros Static Turbo mode), 882and 883.Cm t 884(Atheros Dynamic Turbo mode, or appended to ``st'' and ``dt''). 885The full set of channel widths following a '/' are: 886.Cm 5 887(5MHz aka quarter-rate channel), 888.Cm 10 889(10MHz aka half-rate channel), 890.Cm 20 891(20MHz mostly for use in specifying ht20), 892and 893.Cm 40 894(40MHz mostly for use in specifying ht40), 895In addition, 896a 40MHz HT channel specification may include the location 897of the extension channel by appending ``+'' or ``-'' for above and below, 898respectively; e.g. ``2437:ht/40+'' specifies 40MHz wide HT operation 899with the center channel at frequency 2437 and the extension channel above. 900.It Cm country Ar name 901Set the country code to use in calculating the regulatory constraints 902for operation. 903In particular the set of available channels, how the wireless device 904will operation on the channels, and the maximum transmit power that 905can be used on a channel are defined by this setting. 906Country/Region codes are specified as a 2-character abbreviation 907defined by ISO 3166 or using a longer, but possibly ambiguous, spelling; 908e.g. "ES" and "Spain". 909The set of country codes are taken from /etc/regdomain.xml and can also 910be viewed with the ``list countries'' request. 911Note that not all devices support changing the country code from a default 912setting; typically stored in EEPROM. 913See also 914.Cm regdomain , 915.Cm indoor , 916.Cm outdoor , 917and 918.Cm anywhere . 919.It Cm dfs 920Enable Dynamic Frequency Selection (DFS) as specified in 802.11h. 921DFS embodies several facilities including detection of overlapping 922radar signals, dynamic transmit power control, and channel selection 923according to a least-congested criteria. 924DFS support is mandatory for some 5Ghz frequencies in certain 925locales (e.g. ETSI). 926By default DFS is enabled according to the regulatory definitions 927specified in /etc/regdomain.xml and the curent country code, regdomain, 928and channel. 929Note the underlying device (and driver) must support radar detection 930for full DFS support to work. 931To be fully compliant with the local regulatory agency frequencies that 932require DFS should not be used unless it is fully supported. 933Use 934.Fl dfs 935to disable this functionality for testing. 936.It Cm dotd 937Enable support for the 802.11d specification (default). 938When this support is enabled in station mode, beacon frames that advertise 939a country code different than the currently configured country code will 940cause an event to be dispatched to user applications. 941This event can be used by the station to adopt that country code and 942operate according to the associated regulatory constraints. 943When operating as an access point with 802.11d enabled the beacon and 944probe response frames transmitted will advertise the current regulatory 945domain settings. 946To disable 802.11d use 947.Fl dotd . 948.It Cm doth 949Enable 802.11h support including spectrum management. 950When 802.11h is enabled beacon and probe response frames will have 951the SpectrumMgt bit set in the capabilities field and 952country and power constraint information elements will be present. 953802.11h support also includes handling Channel Switch Announcements (CSA) 954which are a mechanism to coordinate channel changes by an access point. 955By default 802.11h is enabled if the device is capable. 956To disable 802.11h use 957.Fl doth . 958.It Cm deftxkey Ar index 959Set the default key to use for transmission. 960Typically this is only set when using WEP encryption. 961Note that you must set a default transmit key 962for the system to know which key to use in encrypting outbound traffic. 963The 964.Cm weptxkey 965is an alias for this request; it is provided for backwards compatibility. 966.It Cm dtimperiod Ar period 967Set the 968DTIM 969period for transmitting buffered multicast data frames when 970operating in ap mode. 971The 972.Ar period 973specifies the number of beacon intervals between DTIM 974and must be in the range 1 to 15. 975By default DTIM is 1 (i.e., DTIM occurs at each beacon). 976.It Cm dturbo 977Enable the use of Atheros Dynamic Turbo mode when communicating with 978another Dynamic Turbo-capable station. 979Dynamic Turbo mode is an Atheros-specific mechanism by which 980stations switch between normal 802.11 operation and a ``boosted'' 981mode in which a 40MHz wide channel is used for communication. 982Stations using Dynamic Turbo mode operate boosted only when the 983channel is free of non-dturbo stations; when a non-dturbo station 984is identified on the channel all stations will automatically drop 985back to normal operation. 986By default, Dynamic Turbo mode is not enabled, even if the device is capable. 987Note that turbo mode (dynamic or static) is only allowed on some 988channels depending on the regulatory constraints; use the 989.Cm list chan 990command to identify the channels where turbo mode may be used. 991To disable Dynamic Turbo mode use 992.Fl dturbo . 993.It Cm dwds 994Enable Dynamic WDS (DWDS) support. 995DWDS is a facility by which 4-address traffic can be carried between 996stations operating in infrastructure mode. 997A station first associates to an access point and authenticates using 998normal procedures (e.g. WPA). 999Then 4-address frames are passed to carry traffic for stations 1000operating on either side of the wireless link. 1001DWDS extends the normal WDS mechanism by leveraging existing security 1002protocols and eliminating static binding. 1003.Pp 1004When DWDS is enabled on an access point 4-address frames received from 1005an authorized station will generate a ``DWDS discovery'' event to user 1006applications. 1007This event should be used to create a WDS interface that is bound 1008to the remote station (and usually plumbed into a bridge). 1009Once the WDS interface is up and running 4-address traffic then logically 1010flows through that interface. 1011.Pp 1012When DWDS is enabled on a station, traffic with a destination address 1013different from the peer station are encapsulated in a 4-address frame 1014and transmitted to the peer. 1015All 4-address traffic uses the security information of the stations 1016(e.g. cryptographic keys). 1017A station is associated using 802.11n facilities may transport 10184-address traffic using these same mechanisms; this depends on available 1019resources and capabilities of the device. 1020The DWDS implementation guards against layer 2 routing loops of 1021multicast traffic. 1022.It Cm ff 1023Enable the use of Atheros Fast Frames when communicating with 1024another Fast Frames-capable station. 1025Fast Frames are an encapsulation technique by which two 802.3 1026frames are transmitted in a single 802.11 frame. 1027This can noticeably improve throughput but requires that the 1028receiving station understand how to decapsulate the frame. 1029Fast frame use is negotiated using the Atheros 802.11 vendor-specific 1030protocol extension so enabling use is safe when communicating with 1031non-Atheros devices. 1032By default, use of fast frames is enabled if the device is capable. 1033To explicitly disable fast frames, use 1034.Fl ff . 1035.It Cm fragthreshold Ar length 1036Set the threshold for which transmitted frames are broken into fragments. 1037The 1038.Ar length 1039argument is the frame size in bytes and must be in the range 256 to 2346. 1040Setting 1041.Ar length 1042to 1043.Li 2346 , 1044.Cm any , 1045or 1046.Cm - 1047disables transmit fragmentation. 1048Not all adapters honor the fragmentation threshold. 1049.It Cm hidessid 1050When operating as an access point, do not broadcast the SSID 1051in beacon frames or respond to probe request frames unless 1052they are directed to the ap (i.e., they include the ap's SSID). 1053By default, the SSID is included in beacon frames and 1054undirected probe request frames are answered. 1055To re-enable the broadcast of the SSID etc., use 1056.Fl hidessid . 1057.It Cm ht 1058Enable use of High Throughput (HT) when using 802.11n (default). 1059The 802.11n specification includes mechanisms for operation 1060on 20MHz and 40MHz wide channels using different signalling mechanisms 1061than specified in 802.11b, 802.11g, and 802.11a. 1062Stations negotiate use of these facilities, termed HT20 and HT40, 1063when they associate. 1064To disable all use of 802.11n use 1065.Fl ht . 1066To disable use of HT20 (e.g. to force only HT40 use) use 1067.Fl ht20 . 1068To disable use of HT40 use 1069.Fl ht40 . 1070.Pp 1071HT configuration is used to ``auto promote'' operation 1072when several choices are available. 1073For example, if a station associates to an 11n-capable access point 1074it controls whether the station uses legacy operation, HT20, or HT40. 1075When an 11n-capable device is setup as an access point and 1076Auto Channel Selection is used to locate a channel to operate on, 1077HT configuration controls whether legacy, HT20, or HT40 operation is setup 1078on the selected channel. 1079If a fixed channel is specified for a station then HT configuration can 1080be given as part of the channel specification; e.g. 6:ht/20 to setup 1081HT20 operation on channel 6. 1082.It Cm htcompat 1083Enable use of compatibility support for pre-802.11n devices (default). 1084The 802.11n protocol specification went through several incompatible iterations. 1085Some vendors implemented 11n support to older specifications that 1086will not interoperate with a purely 11n-compliant station. 1087In particular the information elements included in management frames 1088for old devices are different. 1089When compatibility support is enabled both standard and compatible data 1090will be provided. 1091Stations that associate using the compatiblity mechanisms are flagged 1092in ``list sta''. 1093To disable compatiblity support use 1094.Fl htcompat . 1095.It Cm htprotmode Ar technique 1096For interfaces operating in 802.11n, use the specified 1097.Ar technique 1098for protecting HT frames in a mixed legacy/HT network. 1099The set of valid techniques is 1100.Cm off , 1101and 1102.Cm rts 1103(RTS/CTS, default). 1104Technique names are case insensitive. 1105.It Cm inact 1106Enable inactivity processing for stations associated to an 1107access point (default). 1108When operating as an access point the 802.11 layer monitors 1109the activity of each associated station. 1110When a station is inactive for 5 minutes it will send several 1111``probe frames'' to see if the station is still present. 1112If no response is received then the station is deauthenticated. 1113Applications that prefer to handle this work can disable this 1114facility by using 1115.Fl inact . 1116.It Cm indoor 1117Set the location to use in calculating regulatory constraints. 1118The location is also advertised in beacon and probe response frames 1119when 802.11d is enabled with 1120.Cm dotd . 1121See also 1122.Cm outdoor , 1123.Cm anywhere , 1124.Cm country , 1125and 1126.Cm regdomain . 1127.It Cm list active 1128Display the list of channels available for use taking into account 1129any restrictions set with the 1130.Cm chanlist 1131directive. 1132See the description of 1133.Cm list chan 1134for more information. 1135.It Cm list caps 1136Display the adaptor's capabilities, including the operating 1137modes supported. 1138.It Cm list chan 1139Display the list of channels available for use. 1140Channels are shown with their IEEE channel number, equivalent 1141frequency, and usage modes. 1142Channels identified as 1143.Ql 11g 1144are also usable in 1145.Ql 11b 1146mode. 1147Channels identified as 1148.Ql 11a Turbo 1149may be used only for Atheros' Static Turbo mode 1150(specified with 1151. Cm mediaopt turbo ) . 1152Channels marked with a 1153.Ql * 1154have a regulatory constraint that they be passively scanned. 1155This means a station is not permitted to transmit on the channel until 1156it identifies the channel is being used for 802.11 communication; 1157typically by hearing a beacon frame from an access point operating 1158on the channel. 1159.Cm list freq 1160is another way of requesting this information. 1161By default a compacted list of channels is displayed; if the 1162.Fl v 1163option is specified then all channels are shown. 1164.It Cm list countries 1165Display the set of country codes and regulatory domains that can be 1166used in regulatory configuration. 1167.It Cm list mac 1168Display the current MAC Access Control List state. 1169Each address is prefixed with a character that indicates the 1170current policy applied to it: 1171.Ql + 1172indicates the address is allowed access, 1173.Ql - 1174indicates the address is denied access, 1175.Ql * 1176indicates the address is present but the current policy open 1177(so the ACL is not consulted). 1178.It Cm list regdomain 1179Display the current regulatory settings including the available channels 1180and transmit power caps. 1181.It Cm list roam 1182Display the parameters that govern roaming operation. 1183.It Cm list txparam 1184Display the parameters that govern transmit operation. 1185.It Cm list txpower 1186Display the transmit power caps for each channel. 1187.It Cm list scan 1188Display the access points and/or ad-hoc neighbors 1189located in the vicinity. 1190This information may be updated automatically by the adapter 1191with a 1192.Cm scan 1193request or through background scanning. 1194Depending on the capabilities of the stations the following 1195flags can be included in the output: 1196.Bl -tag -width 3n 1197.It Li A 1198Authorized. 1199Indicates that the station is permitted to send/receive data frames. 1200.It Li E 1201Extended Rate Phy (ERP). 1202Indicates that the station is operating in an 802.11g network 1203using extended transmit rates. 1204.It Li H 1205High Throughput (HT). 1206Indicates that the station is using HT transmit rates. 1207If a `+' follows immediately after then the station associated 1208using deprecated mechanisms supported only when 1209.Cm htcompat 1210is enabled. 1211.It Li P 1212Power Save. 1213Indicates that the station is operating in power save mode. 1214.It Li Q 1215Quality of Service (QoS). 1216Indicates that the station is using QoS encapsulation for 1217data frame. 1218QoS encapsulation is enabled only when WME mode is enabled. 1219.It Li T 1220Transitional Security Network (TSN). 1221Indicates that the station associated using TSN; see also 1222.Cm tsn 1223below. 1224.It Li W 1225Wi-Fi Protected Setup (WPS). 1226Indicates that the station associated using WPS. 1227.El 1228.Pp 1229By default interesting information elements captured from the neighboring 1230stations are displayed at the end of each row. 1231Possible elements include: 1232.Cm WME 1233(station supports WME), 1234.Cm WPA 1235(station supports WPA), 1236.Cm RSN 1237(station supports 802.11i/RSN), 1238.Cm HTCAP 1239(station supports 802.11n/HT communication), 1240.Cm ATH 1241(station supoprts Atheros protocol extensions), 1242.Cm VEN 1243(station supports unknown vendor-specific extensions). 1244If the 1245.Fl v 1246flag is used all the information elements and their 1247contents will be shown. 1248Specifying The 1249.Fl v 1250flag also enables display of long SSIDs. 1251.Cm list ap 1252is another way of requesting this information. 1253.It Cm list sta 1254When operating as an access point display the stations that are 1255currently associated. 1256When operating in ad-hoc mode display stations identified as 1257neighbors in the IBSS. 1258When operating in station mode display the access point. 1259Capabilities advertised by the stations are described under 1260the 1261.Cm scan 1262request. 1263Depending on the capabilities of the stations the following 1264flags can be included in the output: 1265.Bl -tag -width 3n 1266.It Li A 1267Authorized. 1268Indicates that the station is permitted to send/receive data frames. 1269.It Li E 1270Extended Rate Phy (ERP). 1271Indicates that the station is operating in an 802.11g network 1272using extended transmit rates. 1273.It Li H 1274High Throughput (HT). 1275Indicates that the station is using HT transmit rates. 1276If a `+' follows immediately after then the station associated 1277using deprecated mechanisms supported only when 1278.Cm htcompat 1279is enabled. 1280.It Li P 1281Power Save. 1282Indicates that the station is operating in power save mode. 1283.It Li Q 1284Quality of Service (QoS). 1285Indicates that the station is using QoS encapsulation for 1286data frame. 1287QoS encapsulation is enabled only when WME mode is enabled. 1288.It Li T 1289Transitional Security Network (TSN). 1290Indicates that the station associated using TSN; see also 1291.Cm tsn 1292below. 1293.It Li W 1294Wi-Fi Protected Setup (WPS). 1295Indicates that the station associated using WPS. 1296.El 1297.Pp 1298By default information elements received from associated stations 1299are displayed in a short form; the 1300.Fl v 1301flag causes this information to be displayed symbolicaly. 1302.It Cm list wme 1303Display the current parameters to use when operating in WME mode. 1304When WME mode is enabled for an adaptor this information will be 1305displayed with the regular status; this command is mostly useful 1306for examining parameters when WME mode is disabled. 1307See the description of the 1308.Cm wme 1309directive for information on the various parameters. 1310.It Cm maxretry Ar count 1311Set the maximum number of tries to use in sending unicast frames. 1312The default setting is 6 but drivers may override this with a value 1313they choose. 1314.It Cm mcastrate Ar rate 1315Set the rate for transmitting multicast/broadcast frames. 1316Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s. 1317This rate should be valid for the current operating conditions; 1318if an invalid rate is specified drivers are free to chose an 1319appropriate rate. 1320.It Cm mgtrate Ar rate 1321Set the rate for transmitting management and/or control frames. 1322Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s. 1323.It Cm outdoor 1324Set the location to use in calculating regulatory constraints. 1325The location is also advertised in beacon and probe response frames 1326when 802.11d is enabled with 1327.Cm dotd . 1328See also 1329.Cm anywhere , 1330.Cm country , 1331.Cm indoor , 1332and 1333.Cm regdomain . 1334.It Cm powersave 1335Enable powersave operation. 1336When operating as a client, the station will conserve power by 1337periodically turning off the radio and listening for 1338messages from the access point telling it there are packets waiting. 1339The station must then retrieve the packets. 1340Not all devices support power save operation as a client. 1341The 802.11 specification requires that all access points support 1342power save but some drivers do not. 1343Use 1344.Fl powersave 1345to disable powersave operation when operating as a client. 1346.It Cm powersavesleep Ar sleep 1347Set the desired max powersave sleep time in TU's (1024 usecs). 1348By default the max powersave sleep time is 100 TU's. 1349.It Cm protmode Ar technique 1350For interfaces operating in 802.11g, use the specified 1351.Ar technique 1352for protecting OFDM frames in a mixed 11b/11g network. 1353The set of valid techniques is 1354.Cm off , cts 1355(CTS to self), 1356and 1357.Cm rtscts 1358(RTS/CTS). 1359Technique names are case insensitive. 1360Not all devices support 1361.Cm cts 1362as a protection technique. 1363.It Cm pureg 1364When operating as an access point in 802.11g mode allow only 136511g-capable stations to associate (11b-only stations are not 1366permitted to associate). 1367To allow both 11g and 11b-only stations to associate, use 1368.Fl pureg . 1369.It Cm puren 1370When operating as an access point in 802.11n mode allow only 1371HT-capable stations to associate (legacy stations are not 1372permitted to associate). 1373To allow both HT and legacy stations to associate, use 1374.Fl puren . 1375.It Cm regdomain Ar sku 1376Set the regulatory domain to use in calculating the regulatory constraints 1377for operation. 1378In particular the set of available channels, how the wireless device 1379will operation on the channels, and the maximum transmit power that 1380can be used on a channel are defined by this setting. 1381Regdomain codes (SKU's) are taken from /etc/regdomain.xml and can also 1382be viewed with the ``list countries'' request. 1383Note that not all devices support changing the regdomain from a default 1384setting; typically stored in EEPROM. 1385See also 1386.Cm country , 1387.Cm indoor , 1388.Cm outdoor , 1389and 1390.Cm anywhere . 1391.It Cm roam:rate Ar rate 1392Set the threshold for controlling roaming when operating in a BSS. 1393The 1394.Ar rate 1395parameter specifies the transmit rate in megabits 1396at which roaming should be considered. 1397If the current transmit rate drops below this setting and background scanning 1398is enabled, then the system will check if a more desirable access point is 1399available and switch over to it. 1400The current scan cache contents are used if they are considered 1401valid according to the 1402.Cm scanvalid 1403parameter; otherwise a background scan operation is triggered before 1404any selection occurs. 1405Each channel type has a separate rate threshold; the default values are: 140612 Mb/s (11a), 2 Mb/s (11b), 2 Mb/s (11g), MCS 1 (11na, 11ng). 1407.It Cm roam:rssi Ar rssi 1408Set the threshold for controlling roaming when operating in a BSS. 1409The 1410.Ar rssi 1411parameter specifies the receive signal strength in dBm units 1412at which roaming should be considered. 1413If the current rssi 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. 1421Rach channel type has a separate rssi threshold; the default values are 1422all 7 dBm. 1423.It Cm roaming Ar mode 1424When operating as a station, control how the system will 1425behave when communication with the current access point 1426is broken. 1427The 1428.Ar mode 1429argument may be one of 1430.Cm device 1431(leave it to the hardware device to decide), 1432.Cm auto 1433(handle either in the device or the operating system\[em]as appropriate), 1434.Cm manual 1435(do nothing until explicitly instructed). 1436By default, the device is left to handle this if it is 1437capable; otherwise, the operating system will automatically 1438attempt to reestablish communication. 1439Manual mode is used by applications such as 1440.Xr wpa_supplicant 8 1441that want to control the selection of an access point. 1442.It Cm rtsthreshold Ar length 1443Set the threshold for which 1444transmitted frames are preceded by transmission of an 1445RTS 1446control frame. 1447The 1448.Ar length 1449argument 1450is the frame size in bytes and must be in the range 1 to 2346. 1451Setting 1452.Ar length 1453to 1454.Li 2346 , 1455.Cm any , 1456or 1457.Cm - 1458disables transmission of RTS frames. 1459Not all adapters support setting the RTS threshold. 1460.It Cm scan 1461Initiate a scan of neighboring stations, wait for it to complete, and 1462display all stations found. 1463Only the super-user can initiate a scan. 1464See 1465.Cm list scan 1466for information on the display. 1467By default a background scan is done; otherwise a foreground 1468scan is done and the station may roam to a different access point. 1469The 1470.Cm list scan 1471request can be used to show recent scan results without 1472initiating a new scan. 1473.It Cm scanvalid Ar threshold 1474Set the maximum time the scan cache contents are considered valid; 1475i.e. will be used without first triggering a scan operation to 1476refresh the data. 1477The 1478.Ar threshold 1479parameter is specified in seconds and defaults to 60 seconds. 1480The minimum setting for 1481.Ar threshold 1482is 10 seconds. 1483One should take care setting this threshold; if it is set too low 1484then attempts to roam to another access point may trigger unnecessary 1485background scan operations. 1486.It Cm shortgi 1487Enable use of Short Guard Interval when operating in 802.11n 1488on an HT channel. 1489NB: this currently enables Short GI on both HT40 and HT20 channels. 1490To disable Short GI use 1491.Fl shortgi . 1492.It Cm ssid Ar ssid 1493Set the desired Service Set Identifier (aka network name). 1494The SSID is a string up to 32 characters 1495in length and may be specified as either a normal string or in 1496hexadecimal when preceded by 1497.Ql 0x . 1498Additionally, the SSID may be cleared by setting it to 1499.Ql - . 1500.It Cm tsn 1501When operating as an access point with WPA/802.11i allow legacy 1502stations to associate using static key WEP and open authentication. 1503To disallow legacy station use of WEP, use 1504.Fl tsn . 1505.It Cm txpower Ar power 1506Set the power used to transmit frames. 1507The 1508.Ar power 1509argument is specified in .5 dBm units. 1510Out of range values are truncated. 1511Typically only a few discreet power settings are available and 1512the driver will use the setting closest to the specified value. 1513Not all adapters support changing the transmit power. 1514.It Cm ucastrate Ar rate 1515Set a fixed rate for transmitting unicast frames. 1516Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s. 1517This rate should be valid for the current operating conditions; 1518if an invalid rate is specified drivers are free to chose an 1519appropriate rate. 1520.It Cm wepmode Ar mode 1521Set the desired WEP mode. 1522Not all adapters support all modes. 1523The set of valid modes is 1524.Cm off , on , 1525and 1526.Cm mixed . 1527The 1528.Cm mixed 1529mode explicitly tells the adaptor to allow association with access 1530points which allow both encrypted and unencrypted traffic. 1531On these adapters, 1532.Cm on 1533means that the access point must only allow encrypted connections. 1534On other adapters, 1535.Cm on 1536is generally another name for 1537.Cm mixed . 1538Modes are case insensitive. 1539.It Cm weptxkey Ar index 1540Set the WEP key to be used for transmission. 1541This is the same as setting the default transmission key with 1542.Cm deftxkey . 1543.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key 1544Set the selected WEP key. 1545If an 1546.Ar index 1547is not given, key 1 is set. 1548A WEP key will be either 5 or 13 1549characters (40 or 104 bits) depending of the local network and the 1550capabilities of the adaptor. 1551It may be specified either as a plain 1552string or as a string of hexadecimal digits preceded by 1553.Ql 0x . 1554For maximum portability, hex keys are recommended; 1555the mapping of text keys to WEP encryption is usually driver-specific. 1556In particular, the 1557.Tn Windows 1558drivers do this mapping differently to 1559.Fx . 1560A key may be cleared by setting it to 1561.Ql - . 1562If WEP is supported then there are at least four keys. 1563Some adapters support more than four keys. 1564If that is the case, then the first four keys 1565(1-4) will be the standard temporary keys and any others will be adaptor 1566specific keys such as permanent keys stored in NVRAM. 1567.Pp 1568Note that you must set a default transmit key with 1569.Cm deftxkey 1570for the system to know which key to use in encrypting outbound traffic. 1571.It Cm wme 1572Enable Wireless Multimedia Extensions (WME) support, if available, 1573for the specified interface. 1574WME is a subset of the IEEE 802.11e standard to support the 1575efficient communication of realtime and multimedia data. 1576To disable WME support, use 1577.Fl wme . 1578Another name for this parameter is 1579.Cm wmm . 1580.Pp 1581The following parameters are meaningful only when WME support is in use. 1582Parameters are specified per-AC (Access Category) and 1583split into those that are used by a station when acting 1584as an access point and those for client stations in the BSS. 1585The latter are received from the access point and may not be changed 1586(at the station). 1587The following Access Categories are recognized: 1588.Pp 1589.Bl -tag -width ".Cm AC_BK" -compact 1590.It Cm AC_BE 1591(or 1592.Cm BE ) 1593best effort delivery, 1594.It Cm AC_BK 1595(or 1596.Cm BK ) 1597background traffic, 1598.It Cm AC_VI 1599(or 1600.Cm VI ) 1601video traffic, 1602.It Cm AC_VO 1603(or 1604.Cm VO ) 1605voice traffic. 1606.El 1607.Pp 1608AC parameters are case-insensitive. 1609Traffic classification is done in the operating system using the 1610vlan priority associated with data frames or the 1611ToS (Type of Service) indication in IP-encapsulated frames. 1612If neither information is present, traffic is assigned to the 1613Best Effort (BE) category. 1614.Bl -tag -width indent 1615.It Cm ack Ar ac 1616Set the ACK policy for QoS transmissions by the local station; 1617this controls whether or not data frames transmitted by a station 1618require an ACK response from the receiving station. 1619To disable waiting for an ACK use 1620.Fl ack . 1621This parameter is applied only to the local station. 1622.It Cm acm Ar ac 1623Enable the Admission Control Mandatory (ACM) mechanism 1624for transmissions by the local station. 1625To disable the ACM use 1626.Fl acm . 1627On stations in a BSS this parameter is read-only and indicates 1628the setting received from the access point. 1629NB: ACM is not supported right now. 1630.It Cm aifs Ar ac Ar count 1631Set the Arbitration Inter Frame Spacing (AIFS) 1632channel access parameter to use for transmissions 1633by the local station. 1634On stations in a BSS this parameter is read-only and indicates 1635the setting received from the access point. 1636.It Cm cwmin Ar ac Ar count 1637Set the CWmin channel access parameter to use for transmissions 1638by the local station. 1639On stations in a BSS this parameter is read-only and indicates 1640the setting received from the access point. 1641.It Cm cwmax Ar ac Ar count 1642Set the CWmax channel access parameter to use for transmissions 1643by the local station. 1644On stations in a BSS this parameter is read-only and indicates 1645the setting received from the access point. 1646.It Cm txoplimit Ar ac Ar limit 1647Set the Transmission Opportunity Limit channel access parameter 1648to use for transmissions by the local station. 1649This parameter defines an interval of time when a WME station 1650has the right to initiate transmissions onto the wireless medium. 1651On stations in a BSS this parameter is read-only and indicates 1652the setting received from the access point. 1653.It Cm bss:aifs Ar ac Ar count 1654Set the AIFS channel access parameter to send to stations in a BSS. 1655This parameter is meaningful only when operating in ap mode. 1656.It Cm bss:cwmin Ar ac Ar count 1657Set the CWmin channel access parameter to send to stations in a BSS. 1658This parameter is meaningful only when operating in ap mode. 1659.It Cm bss:cwmax Ar ac Ar count 1660Set the CWmax channel access parameter to send to stations in a BSS. 1661This parameter is meaningful only when operating in ap mode. 1662.It Cm bss:txoplimit Ar ac Ar limit 1663Set the TxOpLimit channel access parameter to send to stations in a BSS. 1664This parameter is meaningful only when operating in ap mode. 1665.El 1666.It Cm wps 1667Enable Wireless Privacy Subscriber support. 1668Note that WPS support requires a WPS-capable supplicant. 1669To disable this function use 1670.Fl wps . 1671.El 1672.Pp 1673The following parameters support an optional access control list 1674feature available with some adapters when operating in ap mode; see 1675.Xr wlan_acl 4 . 1676This facility allows an access point to accept/deny association 1677requests based on the MAC address of the station. 1678Note that this feature does not significantly enhance security 1679as MAC address spoofing is easy to do. 1680.Bl -tag -width indent 1681.It Cm mac:add Ar address 1682Add the specified MAC address to the database. 1683Depending on the policy setting association requests from the 1684specified station will be allowed or denied. 1685.It Cm mac:allow 1686Set the ACL policy to permit association only by 1687stations registered in the database. 1688.It Cm mac:del Ar address 1689Delete the specified MAC address from the database. 1690.It Cm mac:deny 1691Set the ACL policy to deny association only by 1692stations registered in the database. 1693.It Cm mac:kick Ar address 1694Force the specified station to be deauthenticated. 1695This typically is done to block a station after updating the 1696address database. 1697.It Cm mac:open 1698Set the ACL policy to allow all stations to associate. 1699.It Cm mac:flush 1700Delete all entries in the database. 1701.It Cm mac:radius 1702Set the ACL policy to permit association only by 1703stations approved by a RADIUS server. 1704Note that this feature requires the 1705.Xr hostapd 8 1706program be configured to do the right thing 1707as it handles the RADIUS processing 1708(and marks stations as authorized). 1709.El 1710.Pp 1711The following parameters are for compatibility with other systems: 1712.Bl -tag -width indent 1713.It Cm nwid Ar ssid 1714Another name for the 1715.Cm ssid 1716parameter. 1717Included for 1718.Nx 1719compatibility. 1720.It Cm stationname Ar name 1721Set the name of this station. 1722The station name is not part of the IEEE 802.11 1723protocol though some interfaces support it. 1724As such it only 1725seems to be meaningful to identical or virtually identical equipment. 1726Setting the station name is identical in syntax to setting the SSID. 1727One can also use 1728.Cm station 1729for 1730.Bsx 1731compatibility. 1732.It Cm wep 1733Another way of saying 1734.Cm wepmode on . 1735Included for 1736.Bsx 1737compatibility. 1738.It Fl wep 1739Another way of saying 1740.Cm wepmode off . 1741Included for 1742.Bsx 1743compatibility. 1744.It Cm nwkey key 1745Another way of saying: 1746.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" . 1747Included for 1748.Nx 1749compatibility. 1750.It Cm nwkey Xo 1751.Sm off 1752.Ar n : k1 , k2 , k3 , k4 1753.Sm on 1754.Xc 1755Another way of saying 1756.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" . 1757Included for 1758.Nx 1759compatibility. 1760.It Fl nwkey 1761Another way of saying 1762.Cm wepmode off . 1763Included for 1764.Nx 1765compatibility. 1766.El 1767.Pp 1768The following parameters are specific to bridge interfaces: 1769.Bl -tag -width indent 1770.It Cm addm Ar interface 1771Add the interface named by 1772.Ar interface 1773as a member of the bridge. 1774The interface is put into promiscuous mode 1775so that it can receive every packet sent on the network. 1776.It Cm deletem Ar interface 1777Remove the interface named by 1778.Ar interface 1779from the bridge. 1780Promiscuous mode is disabled on the interface when 1781it is removed from the bridge. 1782.It Cm maxaddr Ar size 1783Set the size of the bridge address cache to 1784.Ar size . 1785The default is 100 entries. 1786.It Cm timeout Ar seconds 1787Set the timeout of address cache entries to 1788.Ar seconds 1789seconds. 1790If 1791.Ar seconds 1792is zero, then address cache entries will not be expired. 1793The default is 240 seconds. 1794.It Cm addr 1795Display the addresses that have been learned by the bridge. 1796.It Cm static Ar interface-name Ar address 1797Add a static entry into the address cache pointing to 1798.Ar interface-name . 1799Static entries are never aged out of the cache or re-placed, even if the 1800address is seen on a different interface. 1801.It Cm deladdr Ar address 1802Delete 1803.Ar address 1804from the address cache. 1805.It Cm flush 1806Delete all dynamically-learned addresses from the address cache. 1807.It Cm flushall 1808Delete all addresses, including static addresses, from the address cache. 1809.It Cm discover Ar interface 1810Mark an interface as a 1811.Dq discovering 1812interface. 1813When the bridge has no address cache entry 1814(either dynamic or static) 1815for the destination address of a packet, 1816the bridge will forward the packet to all 1817member interfaces marked as 1818.Dq discovering . 1819This is the default for all interfaces added to a bridge. 1820.It Cm -discover Ar interface 1821Clear the 1822.Dq discovering 1823attribute on a member interface. 1824For packets without the 1825.Dq discovering 1826attribute, the only packets forwarded on the interface are broadcast 1827or multicast packets and packets for which the destination address 1828is known to be on the interface's segment. 1829.It Cm learn Ar interface 1830Mark an interface as a 1831.Dq learning 1832interface. 1833When a packet arrives on such an interface, the source 1834address of the packet is entered into the address cache as being a 1835destination address on the interface's segment. 1836This is the default for all interfaces added to a bridge. 1837.It Cm -learn Ar interface 1838Clear the 1839.Dq learning 1840attribute on a member interface. 1841.It Cm sticky Ar interface 1842Mark an interface as a 1843.Dq sticky 1844interface. 1845Dynamically learned address entries are treated at static once entered into 1846the cache. 1847Sticky entries are never aged out of the cache or replaced, even if the 1848address is seen on a different interface. 1849.It Cm -sticky Ar interface 1850Clear the 1851.Dq sticky 1852attribute on a member interface. 1853.It Cm private Ar interface 1854Mark an interface as a 1855.Dq private 1856interface. 1857A private interface does not forward any traffic to any other port that is also 1858a private interface. 1859.It Cm -private Ar interface 1860Clear the 1861.Dq private 1862attribute on a member interface. 1863.It Cm span Ar interface 1864Add the interface named by 1865.Ar interface 1866as a span port on the bridge. 1867Span ports transmit a copy of every frame received by the bridge. 1868This is most useful for snooping a bridged network passively on 1869another host connected to one of the span ports of the bridge. 1870.It Cm -span Ar interface 1871Delete the interface named by 1872.Ar interface 1873from the list of span ports of the bridge. 1874.It Cm stp Ar interface 1875Enable Spanning Tree protocol on 1876.Ar interface . 1877The 1878.Xr if_bridge 4 1879driver has support for the IEEE 802.1D Spanning Tree protocol (STP). 1880Spanning Tree is used to detect and remove loops in a network topology. 1881.It Cm -stp Ar interface 1882Disable Spanning Tree protocol on 1883.Ar interface . 1884This is the default for all interfaces added to a bridge. 1885.It Cm edge Ar interface 1886Set 1887.Ar interface 1888as an edge port. 1889An edge port connects directly to end stations cannot create bridging 1890loops in the network, this allows it to transition straight to forwarding. 1891.It Cm -edge Ar interface 1892Disable edge status on 1893.Ar interface . 1894.It Cm autoedge Ar interface 1895Allow 1896.Ar interface 1897to automatically detect edge status. 1898This is the default for all interfaces added to a bridge. 1899.It Cm -autoedge Ar interface 1900Disable automatic edge status on 1901.Ar interface . 1902.It Cm ptp Ar interface 1903Set the 1904.Ar interface 1905as a point to point link. 1906This is required for straight transitions to forwarding and 1907should be enabled on a direct link to another RSTP capable switch. 1908.It Cm -ptp Ar interface 1909Disable point to point link status on 1910.Ar interface . 1911This should be disabled for a half duplex link and for an interface 1912connected to a shared network segment, 1913like a hub or a wireless network. 1914.It Cm autoptp Ar interface 1915Automatically detect the point to point status on 1916.Ar interface 1917by checking the full duplex link status. 1918This is the default for interfaces added to the bridge. 1919.It Cm -autoptp Ar interface 1920Disable automatic point to point link detection on 1921.Ar interface . 1922.It Cm maxage Ar seconds 1923Set the time that a Spanning Tree protocol configuration is valid. 1924The default is 20 seconds. 1925The minimum is 6 seconds and the maximum is 40 seconds. 1926.It Cm fwddelay Ar seconds 1927Set the time that must pass before an interface begins forwarding 1928packets when Spanning Tree is enabled. 1929The default is 15 seconds. 1930The minimum is 4 seconds and the maximum is 30 seconds. 1931.It Cm hellotime Ar seconds 1932Set the time between broadcasting of Spanning Tree protocol 1933configuration messages. 1934The hello time may only be changed when operating in legacy stp mode. 1935The default is 2 seconds. 1936The minimum is 1 second and the maximum is 2 seconds. 1937.It Cm priority Ar value 1938Set the bridge priority for Spanning Tree. 1939The default is 32768. 1940The minimum is 0 and the maximum is 61440. 1941.It Cm proto Ar value 1942Set the Spanning Tree protocol. 1943The default is rstp. 1944The available options are stp and rstp. 1945.It Cm holdcnt Ar value 1946Set the transmit hold count for Spanning Tree. 1947This is the number of packets transmitted before being rate limited. 1948The default is 6. 1949The minimum is 1 and the maximum is 10. 1950.It Cm ifpriority Ar interface Ar value 1951Set the Spanning Tree priority of 1952.Ar interface 1953to 1954.Ar value . 1955The default is 128. 1956The minimum is 0 and the maximum is 240. 1957.It Cm ifpathcost Ar interface Ar value 1958Set the Spanning Tree path cost of 1959.Ar interface 1960to 1961.Ar value . 1962The default is calculated from the link speed. 1963To change a previously selected path cost back to automatic, set the 1964cost to 0. 1965The minimum is 1 and the maximum is 200000000. 1966.It Cm ifmaxaddr Ar interface Ar size 1967Set the maximum number of hosts allowed from an interface, packets with unknown 1968source addresses are dropped until an existing host cache entry expires or is 1969removed. 1970Set to 0 to disable. 1971.El 1972.Pp 1973The following parameters are specific to lagg interfaces: 1974.Bl -tag -width indent 1975.It Cm laggport Ar interface 1976Add the interface named by 1977.Ar interface 1978as a port of the aggregation interface. 1979.It Cm -laggport Ar interface 1980Remove the interface named by 1981.Ar interface 1982from the aggregation interface. 1983.It Cm laggproto Ar proto 1984Set the aggregation protocol. 1985The default is failover. 1986The available options are failover, fec, lacp, loadbalance, roundrobin and 1987none. 1988.El 1989.Pp 1990The following parameters are specific to IP tunnel interfaces, 1991.Xr gif 4 : 1992.Bl -tag -width indent 1993.It Cm tunnel Ar src_addr dest_addr 1994Configure the physical source and destination address for IP tunnel 1995interfaces. 1996The arguments 1997.Ar src_addr 1998and 1999.Ar dest_addr 2000are interpreted as the outer source/destination for the encapsulating 2001IPv4/IPv6 header. 2002.It Fl tunnel 2003Unconfigure the physical source and destination address for IP tunnel 2004interfaces previously configured with 2005.Cm tunnel . 2006.It Cm deletetunnel 2007Another name for the 2008.Fl tunnel 2009parameter. 2010.El 2011.Pp 2012The following parameters are specific to GRE tunnel interfaces, 2013.Xr gre 4 : 2014.Bl -tag -width indent 2015.It Cm grekey Ar key 2016Configure the GRE key to be used for outgoing packets. 2017Note that 2018.Xr gre 4 will always accept GRE packets with invalid or absent keys. 2019This command will result in a four byte MTU reduction on the interface. 2020.El 2021.Pp 2022The following parameters are specific to 2023.Xr pfsync 4 2024interfaces: 2025.Bl -tag -width indent 2026.It Cm maxupd Ar n 2027Set the maximum number of updates for a single state which 2028can be collapsed into one. 2029This is an 8-bit number; the default value is 128. 2030.El 2031.Pp 2032The following parameters are specific to 2033.Xr vlan 4 2034interfaces: 2035.Bl -tag -width indent 2036.It Cm vlan Ar vlan_tag 2037Set the VLAN tag value to 2038.Ar vlan_tag . 2039This value is a 16-bit number which is used to create an 802.1Q 2040VLAN header for packets sent from the 2041.Xr vlan 4 2042interface. 2043Note that 2044.Cm vlan 2045and 2046.Cm vlandev 2047must both be set at the same time. 2048.It Cm vlandev Ar iface 2049Associate the physical interface 2050.Ar iface 2051with a 2052.Xr vlan 4 2053interface. 2054Packets transmitted through the 2055.Xr vlan 4 2056interface will be 2057diverted to the specified physical interface 2058.Ar iface 2059with 802.1Q VLAN encapsulation. 2060Packets with 802.1Q encapsulation received 2061by the parent interface with the correct VLAN tag will be diverted to 2062the associated 2063.Xr vlan 4 2064pseudo-interface. 2065The 2066.Xr vlan 4 2067interface is assigned a 2068copy of the parent interface's flags and the parent's ethernet address. 2069The 2070.Cm vlandev 2071and 2072.Cm vlan 2073must both be set at the same time. 2074If the 2075.Xr vlan 4 2076interface already has 2077a physical interface associated with it, this command will fail. 2078To 2079change the association to another physical interface, the existing 2080association must be cleared first. 2081.Pp 2082Note: if the hardware tagging capability 2083is set on the parent interface, the 2084.Xr vlan 4 2085pseudo 2086interface's behavior changes: 2087the 2088.Xr vlan 4 2089interface recognizes that the 2090parent interface supports insertion and extraction of VLAN tags on its 2091own (usually in firmware) and that it should pass packets to and from 2092the parent unaltered. 2093.It Fl vlandev Op Ar iface 2094If the driver is a 2095.Xr vlan 4 2096pseudo device, disassociate the parent interface from it. 2097This breaks the link between the 2098.Xr vlan 4 2099interface and its parent, 2100clears its VLAN tag, flags and its link address and shuts the interface down. 2101The 2102.Ar iface 2103argument is useless and hence deprecated. 2104.El 2105.Pp 2106The following parameters are specific to 2107.Xr carp 4 2108interfaces: 2109.Bl -tag -width indent 2110.It Cm advbase Ar seconds 2111Specifies the base of the advertisement interval in seconds. 2112The acceptable values are 1 to 255. 2113The default value is 1. 2114.\" The default value is 2115.\" .Dv CARP_DFLTINTV . 2116.It Cm advskew Ar interval 2117Specifies the skew to add to the base advertisement interval to 2118make one host advertise slower than another host. 2119It is specified in 1/256 of seconds. 2120The acceptable values are 1 to 254. 2121The default value is 0. 2122.It Cm pass Ar phrase 2123Set the authentication key to 2124.Ar phrase . 2125.It Cm vhid Ar n 2126Set the virtual host ID. 2127This is a required setting. 2128Acceptable values are 1 to 255. 2129.El 2130.Pp 2131The 2132.Nm 2133utility displays the current configuration for a network interface 2134when no optional parameters are supplied. 2135If a protocol family is specified, 2136.Nm 2137will report only the details specific to that protocol family. 2138.Pp 2139If the 2140.Fl m 2141flag is passed before an interface name, 2142.Nm 2143will display the capability list and all 2144of the supported media for the specified interface. 2145If 2146.Fl L 2147flag is supplied, address lifetime is displayed for IPv6 addresses, 2148as time offset string. 2149.Pp 2150Optionally, the 2151.Fl a 2152flag may be used instead of an interface name. 2153This flag instructs 2154.Nm 2155to display information about all interfaces in the system. 2156The 2157.Fl d 2158flag limits this to interfaces that are down, and 2159.Fl u 2160limits this to interfaces that are up. 2161When no arguments are given, 2162.Fl a 2163is implied. 2164.Pp 2165The 2166.Fl l 2167flag may be used to list all available interfaces on the system, with 2168no other additional information. 2169Use of this flag is mutually exclusive 2170with all other flags and commands, except for 2171.Fl d 2172(only list interfaces that are down) 2173and 2174.Fl u 2175(only list interfaces that are up). 2176.Pp 2177The 2178.Fl v 2179flag may be used to get more verbose status for an interface. 2180.Pp 2181The 2182.Fl C 2183flag may be used to list all of the interface cloners available on 2184the system, with no additional information. 2185Use of this flag is mutually exclusive with all other flags and commands. 2186.Pp 2187The 2188.Fl k 2189flag causes keying information for the interface, if available, to be 2190printed. 2191For example, the values of 802.11 WEP keys will be printed, if accessible to 2192the current user. 2193This information is not printed by default, as it may be considered 2194sensitive. 2195.Pp 2196If the network interface driver is not present in the kernel then 2197.Nm 2198will attempt to load it. 2199The 2200.Fl n 2201flag disables this behavior. 2202.Pp 2203Only the super-user may modify the configuration of a network interface. 2204.Sh NOTES 2205The media selection system is relatively new and only some drivers support 2206it (or have need for it). 2207.Sh EXAMPLES 2208Assign the IPv4 address 2209.Li 192.0.2.10 , 2210with a network mask of 2211.Li 255.255.255.0 , 2212to the interface 2213.Li fxp0 : 2214.Dl # ifconfig fxp0 inet 192.0.2.10 netmask 255.255.255.0 2215.Pp 2216Add the IPv4 address 2217.Li 192.0.2.45 , 2218with the CIDR network prefix 2219.Li /28 , 2220to the interface 2221.Li ed0 , 2222using 2223.Cm add 2224as a synonym for the canonical form of the option 2225.Cm alias : 2226.Dl # ifconfig ed0 inet 192.0.2.45/28 add 2227.Pp 2228Remove the IPv4 address 2229.Li 192.0.2.45 2230from the interface 2231.Li ed0 : 2232.Dl # ifconfig ed0 inet 192.0.2.45 -alias 2233.Pp 2234Add the IPv6 address 2235.Li 2001:DB8:DBDB::123/48 2236to the interface 2237.Li em0 : 2238.Dl # ifconfig em0 inet6 2001:db8:bdbd::123 prefixlen 48 alias 2239Note that lower case hexadecimal IPv6 addresses are acceptable. 2240.Pp 2241Remove the IPv6 address added in the above example, 2242using the 2243.Li / 2244character as shorthand for the network prefix, 2245and using 2246.Cm delete 2247as a synonym for the canonical form of the option 2248.Fl alias : 2249.Dl # ifconfig em0 inet6 2001:db8:bdbd::123/48 delete 2250.Pp 2251Configure the interface 2252.Li xl0 , 2253to use 100baseTX, full duplex Ethernet media options: 2254.Dl # ifconfig xl0 media 100baseTX mediaopt full-duplex 2255.Pp 2256Create the software network interface 2257.Li gif1 : 2258.Dl # ifconfig gif1 create 2259.Pp 2260Destroy the software network interface 2261.Li gif1 : 2262.Dl # ifconfig gif1 destroy 2263.Sh DIAGNOSTICS 2264Messages indicating the specified interface does not exist, the 2265requested address is unknown, or the user is not privileged and 2266tried to alter an interface's configuration. 2267.Sh SEE ALSO 2268.Xr netstat 1 , 2269.Xr carp 4 , 2270.Xr netintro 4 , 2271.Xr pfsync 4 , 2272.Xr polling 4 , 2273.Xr vlan 4 , 2274.\" .Xr eon 5 , 2275.Xr rc 8 , 2276.Xr routed 8 , 2277.Xr sysctl 8 2278.Sh HISTORY 2279The 2280.Nm 2281utility appeared in 2282.Bx 4.2 . 2283.Sh BUGS 2284Basic IPv6 node operation requires a link-local address on each 2285interface configured for IPv6. 2286Normally, such an address is automatically configured by the 2287kernel on each interface added to the system; this behaviour may 2288be disabled by setting the sysctl MIB variable 2289.Va net.inet6.ip6.auto_linklocal 2290to 0. 2291.Pp 2292If you delete such an address using 2293.Nm , 2294the kernel may act very odd. 2295Do this at your own risk. 2296