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 November 27, 2006 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.Nm 75.Op Fl g Ar groupname 76.Sh DESCRIPTION 77The 78.Nm 79utility is used to assign an address 80to a network interface and/or configure 81network interface parameters. 82The 83.Nm 84utility must be used at boot time to define the network address 85of each interface present on a machine; it may also be used at 86a later time to redefine an interface's address 87or other operating parameters. 88.Pp 89The following options are available: 90.Bl -tag -width indent 91.It Ar address 92For the 93.Tn DARPA Ns -Internet 94family, 95the address is either a host name present in the host name data 96base, 97.Xr hosts 5 , 98or a 99.Tn DARPA 100Internet address expressed in the Internet standard 101.Dq dot notation . 102.Pp 103It is also possible to use the CIDR notation (also known as the 104slash notation) to include the netmask. 105That is, one can specify an address like 106.Li 192.168.0.1/16 . 107.Pp 108For 109.Dq inet6 110family, it is also possible to specify the prefix length using the slash 111notation, like 112.Li ::1/128 . 113See the 114.Cm prefixlen 115parameter below for more information. 116.\" For the Xerox Network Systems(tm) family, 117.\" addresses are 118.\" .Ar net:a.b.c.d.e.f , 119.\" where 120.\" .Ar net 121.\" is the assigned network number (in decimal), 122.\" and each of the six bytes of the host number, 123.\" .Ar a 124.\" through 125.\" .Ar f , 126.\" are specified in hexadecimal. 127.\" The host number may be omitted on IEEE 802 protocol 128.\" (Ethernet, FDDI, and Token Ring) interfaces, 129.\" which use the hardware physical address, 130.\" and on interfaces other than the first. 131.\" For the 132.\" .Tn ISO 133.\" family, addresses are specified as a long hexadecimal string, 134.\" as in the Xerox family. 135.\" However, two consecutive dots imply a zero 136.\" byte, and the dots are optional, if the user wishes to (carefully) 137.\" count out long strings of digits in network byte order. 138.Pp 139The link-level 140.Pq Dq link 141address 142is specified as a series of colon-separated hex digits. 143This can be used to 144e.g.\& set a new MAC address on an ethernet interface, though the 145mechanism used is not ethernet-specific. 146If the interface is already 147up when this option is used, it will be briefly brought down and 148then brought back up again in order to ensure that the receive 149filter in the underlying ethernet hardware is properly reprogrammed. 150.It Ar address_family 151Specify the 152address family 153which affects interpretation of the remaining parameters. 154Since an interface can receive transmissions in differing protocols 155with different naming schemes, specifying the address family is recommended. 156The address or protocol families currently 157supported are 158.Dq inet , 159.Dq inet6 , 160.Dq atalk , 161.Dq ipx , 162.\" .Dq iso , 163and 164.Dq link . 165.\" and 166.\" .Dq ns . 167The default is 168.Dq inet . 169.Dq ether 170and 171.Dq lladdr 172are synonyms for 173.Dq link . 174.It Ar dest_address 175Specify the address of the correspondent on the other end 176of a point to point link. 177.It Ar interface 178This 179parameter is a string of the form 180.Dq name unit , 181for example, 182.Dq Li ed0 . 183.It Ar groupname 184List the interfaces in the given group. 185.El 186.Pp 187The following parameters may be set with 188.Nm : 189.Bl -tag -width indent 190.It Cm add 191Another name for the 192.Cm alias 193parameter. 194Introduced for compatibility 195with 196.Bsx . 197.It Cm alias 198Establish an additional network address for this interface. 199This is sometimes useful when changing network numbers, and 200one wishes to accept packets addressed to the old interface. 201If the address is on the same subnet as the first network address 202for this interface, a non-conflicting netmask must be given. 203Usually 204.Li 0xffffffff 205is most appropriate. 206.It Fl alias 207Remove the network address specified. 208This would be used if you incorrectly specified an alias, or it 209was no longer needed. 210If you have incorrectly set an NS address having the side effect 211of specifying the host portion, removing all NS addresses will 212allow you to respecify the host portion. 213.It Cm anycast 214(Inet6 only.) 215Specify that the address configured is an anycast address. 216Based on the current specification, 217only routers may configure anycast addresses. 218Anycast address will not be used as source address of any of outgoing 219IPv6 packets. 220.It Cm arp 221Enable the use of the Address Resolution Protocol 222.Pq Xr arp 4 223in mapping 224between network level addresses and link level addresses (default). 225This is currently implemented for mapping between 226.Tn DARPA 227Internet 228addresses and 229.Tn IEEE 230802 48-bit MAC addresses (Ethernet, FDDI, and Token Ring addresses). 231.It Fl arp 232Disable the use of the Address Resolution Protocol 233.Pq Xr arp 4 . 234.It Cm staticarp 235If the Address Resolution Protocol is enabled, 236the host will only reply to requests for its addresses, 237and will never send any requests. 238.It Fl staticarp 239If the Address Resolution Protocol is enabled, 240the host will perform normally, 241sending out requests and listening for replies. 242.It Cm broadcast 243(Inet only.) 244Specify the address to use to represent broadcasts to the 245network. 246The default broadcast address is the address with a host part of all 1's. 247.It Cm debug 248Enable driver dependent debugging code; usually, this turns on 249extra console error logging. 250.It Fl debug 251Disable driver dependent debugging code. 252.It Cm promisc 253Put interface into permanently promiscuous mode. 254.It Fl promisc 255Disable permanently promiscuous mode. 256.It Cm delete 257Another name for the 258.Fl alias 259parameter. 260.It Cm down 261Mark an interface 262.Dq down . 263When an interface is marked 264.Dq down , 265the system will not attempt to 266transmit messages through that interface. 267If possible, the interface will be reset to disable reception as well. 268This action does not automatically disable routes using the interface. 269.It Cm group Ar group-name 270Assign the interface to a 271.Dq group . 272Any interface can be in multiple groups. 273.Pp 274Cloned interfaces are members of their interface family group by default. 275For example, a PPP interface such as 276.Em ppp0 277is a member of the PPP interface family group, 278.Em ppp . 279.\" The interface(s) the default route(s) point to are members of the 280.\" .Em egress 281.\" interface group. 282.It Cm -group Ar group-name 283Remove the interface from the given 284.Dq group . 285.It Cm eui64 286(Inet6 only.) 287Fill interface index 288(lowermost 64bit of an IPv6 address) 289automatically. 290.It Cm ipdst 291This is used to specify an Internet host who is willing to receive 292IP packets encapsulating IPX packets bound for a remote network. 293An apparent point to point link is constructed, and 294the address specified will be taken as the IPX address and network 295of the destination. 296.It Cm maclabel Ar label 297If Mandatory Access Control support is enabled in the kernel, 298set the MAC label to 299.Ar label . 300.\" (see 301.\" .Xr maclabel 7 ) . 302.It Cm media Ar type 303If the driver supports the media selection system, set the media type 304of the interface to 305.Ar type . 306Some interfaces support the mutually exclusive use of one of several 307different physical media connectors. 308For example, a 10Mbit/s Ethernet 309interface might support the use of either 310.Tn AUI 311or twisted pair connectors. 312Setting the media type to 313.Cm 10base5/AUI 314would change the currently active connector to the AUI port. 315Setting it to 316.Cm 10baseT/UTP 317would activate twisted pair. 318Refer to the interfaces' driver 319specific documentation or man page for a complete list of the 320available types. 321.It Cm mediaopt Ar opts 322If the driver supports the media selection system, set the specified 323media options on the interface. 324The 325.Ar opts 326argument 327is a comma delimited list of options to apply to the interface. 328Refer to the interfaces' driver specific man page for a complete 329list of available options. 330.It Fl mediaopt Ar opts 331If the driver supports the media selection system, disable the 332specified media options on the interface. 333.It Cm mode Ar mode 334If the driver supports the media selection system, set the specified 335operating mode on the interface to 336.Ar mode . 337For IEEE 802.11 wireless interfaces that support multiple operating modes 338this directive is used to select between 802.11a 339.Pq Cm 11a , 340802.11b 341.Pq Cm 11b , 342and 802.11g 343.Pq Cm 11g 344operating modes. 345.It Cm name Ar name 346Set the interface name to 347.Ar name . 348.It Cm rxcsum , txcsum 349If the driver supports user-configurable checksum offloading, 350enable receive (or transmit) checksum offloading on the interface. 351Some drivers may not be able to enable these flags independently 352of each other, so setting one may also set the other. 353The driver will offload as much checksum work as it can reliably 354support, the exact level of offloading varies between drivers. 355.It Fl rxcsum , txcsum 356If the driver supports user-configurable checksum offloading, 357disable receive (or transmit) checksum offloading on the interface. 358These settings may not always be independent of each other. 359.It Cm tso 360If the driver supports 361.Xr tcp 4 362segmentation offloading, enable TSO on the interface. 363Some drivers may not be able to support TSO for 364.Xr ip 4 365and 366.Xr ip6 4 367packets, so they may enable only one of them. 368.It Fl tso 369If the driver supports 370.Xr tcp 4 371segmentation offloading, disable TSO on the interface. 372It will always disable TSO for 373.Xr ip 4 374and 375.Xr ip6 4 . 376.It Cm vlanmtu , vlanhwtag 377If the driver offers user-configurable VLAN support, enable 378reception of extended frames or tag processing in hardware, 379respectively. 380Note that this must be issued on a physical interface associated with 381.Xr vlan 4 , 382not on a 383.Xr vlan 4 384interface itself. 385.It Fl vlanmtu , vlanhwtag 386If the driver offers user-configurable VLAN support, disable 387reception of extended frames or tag processing in hardware, 388respectively. 389.It Cm polling 390Turn on 391.Xr polling 4 392feature and disable interrupts on the interface, if driver supports 393this mode. 394.It Fl polling 395Turn off 396.Xr polling 4 397feature and enable interrupt mode on the interface. 398.It Cm create 399Create the specified network pseudo-device. 400If the interface is given without a unit number, try to create a new 401device with an arbitrary unit number. 402If creation of an arbitrary device is successful, the new device name is 403printed to standard output unless the interface is renamed or destroyed 404in the same 405.Nm 406invocation. 407.It Cm destroy 408Destroy the specified network pseudo-device. 409.It Cm plumb 410Another name for the 411.Cm create 412parameter. 413Included for 414.Tn Solaris 415compatibility. 416.It Cm unplumb 417Another name for the 418.Cm destroy 419parameter. 420Included for 421.Tn Solaris 422compatibility. 423.It Cm metric Ar n 424Set the routing metric of the interface to 425.Ar n , 426default 0. 427The routing metric is used by the routing protocol 428.Pq Xr routed 8 . 429Higher metrics have the effect of making a route 430less favorable; metrics are counted as additional hops 431to the destination network or host. 432.It Cm mtu Ar n 433Set the maximum transmission unit of the interface to 434.Ar n , 435default is interface specific. 436The MTU is used to limit the size of packets that are transmitted on an 437interface. 438Not all interfaces support setting the MTU, and some interfaces have 439range restrictions. 440.It Cm netmask Ar mask 441.\" (Inet and ISO.) 442(Inet only.) 443Specify how much of the address to reserve for subdividing 444networks into sub-networks. 445The mask includes the network part of the local address 446and the subnet part, which is taken from the host field of the address. 447The mask can be specified as a single hexadecimal number 448with a leading 449.Ql 0x , 450with a dot-notation Internet address, 451or with a pseudo-network name listed in the network table 452.Xr networks 5 . 453The mask contains 1's for the bit positions in the 32-bit address 454which are to be used for the network and subnet parts, 455and 0's for the host part. 456The mask should contain at least the standard network portion, 457and the subnet field should be contiguous with the network 458portion. 459.Pp 460The netmask can also be specified in CIDR notation after the address. 461See the 462.Ar address 463option above for more information. 464.It Cm prefixlen Ar len 465(Inet6 only.) 466Specify that 467.Ar len 468bits are reserved for subdividing networks into sub-networks. 469The 470.Ar len 471must be integer, and for syntactical reason it must be between 0 to 128. 472It is almost always 64 under the current IPv6 assignment rule. 473If the parameter is omitted, 64 is used. 474.Pp 475The prefix can also be specified using the slash notation after the address. 476See the 477.Ar address 478option above for more information. 479.\" see 480.\" Xr eon 5 . 481.\" .It Cm nsellength Ar n 482.\" .Pf ( Tn ISO 483.\" only) 484.\" This specifies a trailing number of bytes for a received 485.\" .Tn NSAP 486.\" used for local identification, the remaining leading part of which is 487.\" taken to be the 488.\" .Tn NET 489.\" (Network Entity Title). 490.\" The default value is 1, which is conformant to US 491.\" .Tn GOSIP . 492.\" When an ISO address is set in an ifconfig command, 493.\" it is really the 494.\" .Tn NSAP 495.\" which is being specified. 496.\" For example, in 497.\" .Tn US GOSIP , 498.\" 20 hex digits should be 499.\" specified in the 500.\" .Tn ISO NSAP 501.\" to be assigned to the interface. 502.\" There is some evidence that a number different from 1 may be useful 503.\" for 504.\" .Tn AFI 505.\" 37 type addresses. 506.It Cm range Ar netrange 507Under appletalk, set the interface to respond to a 508.Ar netrange 509of the form 510.Ar startnet Ns - Ns Ar endnet . 511Appletalk uses this scheme instead of 512netmasks though 513.Fx 514implements it internally as a set of netmasks. 515.It Cm remove 516Another name for the 517.Fl alias 518parameter. 519Introduced for compatibility 520with 521.Bsx . 522.It Cm phase 523The argument following this specifies the version (phase) of the 524Appletalk network attached to the interface. 525Values of 1 or 2 are permitted. 526.Sm off 527.It Cm link Op Cm 0 No - Cm 2 528.Sm on 529Enable special processing of the link level of the interface. 530These three options are interface specific in actual effect, however, 531they are in general used to select special modes of operation. 532An example 533of this is to enable SLIP compression, or to select the connector type 534for some Ethernet cards. 535Refer to the man page for the specific driver 536for more information. 537.Sm off 538.It Fl link Op Cm 0 No - Cm 2 539.Sm on 540Disable special processing at the link level with the specified interface. 541.It Cm monitor 542Put the interface in monitor mode. 543No packets are transmitted, and received packets are discarded after 544.Xr bpf 4 545processing. 546.It Fl monitor 547Take the interface out of monitor mode. 548.It Cm up 549Mark an interface 550.Dq up . 551This may be used to enable an interface after an 552.Dq Nm Cm down . 553It happens automatically when setting the first address on an interface. 554If the interface was reset when previously marked down, 555the hardware will be re-initialized. 556.El 557.Pp 558The following parameters are specific to IEEE 802.11 wireless interfaces: 559.Bl -tag -width indent 560.It Cm apbridge 561When operating as an access point, pass packets between 562wireless clients directly (default). 563To instead let them pass up through the 564system and be forwarded using some other mechanism, use 565.Fl apbridge . 566Disabling the internal bridging 567is useful when traffic is to be processed with 568packet filtering. 569.It Cm authmode Ar mode 570Set the desired authentication mode in infrastructure mode. 571Not all adaptors support all modes. 572The set of 573valid modes is 574.Cm none , open , shared 575(shared key), 576.Cm 8021x 577(IEEE 802.1x), 578and 579.Cm wpa 580(IEEE WPA/WPA2/802.11i). 581The 582.Cm 8021x 583and 584.Cm wpa 585modes are only useful when using an authentication service 586(a supplicant for client operation or an authenticator when 587operating as an access point). 588Modes are case insensitive. 589.It Cm bintval Ar interval 590Set the interval at which beacon frames are sent when operating in 591ad-hoc or ap mode. 592The 593.Ar interval 594parameter is specified in TU's (1/1024 msecs). 595By default beacon frames are transmitted every 100 TU's. 596.It Cm bmissthreshold Ar count 597Set the number of consecutive missed beacons at which the station 598will attempt to roam (i.e., search for a new access point). 599The 600.Ar count 601parameter must be in the range 1 to 255; though the 602upper bound may be reduced according to device capabilities. 603The default threshold is 7 consecutive missed beacons; but 604this may be overridden by the device driver. 605Another name for the 606.Cm bmissthreshold 607parameter is 608.Cm bmiss . 609.It Cm bssid Ar address 610Specify the MAC address of the access point to use when operating 611as a station in a BSS network. 612This overrides any automatic selection done by the system. 613To disable a previously selected access point, supply 614.Cm any , none , 615or 616.Cm - 617for the address. 618This option is useful when more than one access point uses the same SSID. 619Another name for the 620.Cm bssid 621parameter is 622.Cm ap . 623.It Cm burst 624Enable packet bursting. 625Packet bursting is a transmission technique whereby the wireless 626medium is acquired once to send multiple frames and the interframe 627spacing is reduced. 628This technique can significantly increase throughput by reducing 629transmission overhead. 630Packet bursting is supported by the 802.11e QoS specification 631and some devices that do not support QoS may still be capable. 632By default packet bursting is enabled if a device is capable 633of doing it. 634To disable packet bursting, use 635.Fl burst . 636.It Cm chanlist Ar channels 637Set the desired channels to use when scanning for access 638points, neighbors in an IBSS network, or looking for unoccupied 639channels when operating as an access point. 640The set of channels is specified as a comma-separated list with 641each element in the list representing either a single channel number or a range 642of the form 643.Dq Li a-b . 644Channel numbers must be in the range 1 to 255 and be permissible 645according to the operating characteristics of the device. 646.It Cm channel Ar number 647Set a single desired channel. 648Channels range from 1 to 255, but the exact selection available 649depends on the region your adaptor was manufactured for. 650Setting 651the channel to 652.Li 0 , 653.Cm any , 654or 655.Cm - 656will give you the default for your adaptor. 657Some 658adaptors ignore this setting unless you are in ad-hoc mode. 659Alternatively the frequency, in megahertz, may be specified 660instead of the channel number. 661.It Cm deftxkey Ar index 662Set the default key to use for transmission. 663Typically this is only set when using WEP encryption. 664The 665.Cm weptxkey 666is an alias for this request; it is provided for backwards compatibility. 667.It Cm dtimperiod Ar period 668Set the 669DTIM 670period for transmitting buffered multicast data frames when 671operating in ap mode. 672The 673.Ar period 674specifies the number of beacon intervals between DTIM 675and must be in the range 1 to 15. 676By default DTIM is 1 (i.e., DTIM occurs at each beacon). 677.It Cm fragthreshold Ar length 678Set the threshold for which transmitted frames are broken into fragments. 679The 680.Ar length 681argument is the frame size in bytes and must be in the range 256 to 2346. 682Setting 683.Ar length 684to 685.Li 2346 , 686.Cm any , 687or 688.Cm - 689disables transmit fragmentation. 690Not all adaptors honor the fragmentation threshold. 691.It Cm hidessid 692When operating as an access point, do not broadcast the SSID 693in beacon frames or respond to probe request frames unless 694they are directed to the ap (i.e., they include the ap's SSID). 695By default, the SSID is included in beacon frames and 696undirected probe request frames are answered. 697To re-enable the broadcast of the SSID etc., use 698.Fl hidessid . 699.It Cm list active 700Display the list of channels available for use taking into account 701any restrictions set with the 702.Cm chanlist 703directive. 704See the description of 705.Cm list chan 706for more information. 707.It Cm list caps 708Display the adaptor's capabilities, including the operating 709modes supported. 710.It Cm list chan 711Display the list of channels available for use. 712Channels are shown with their IEEE channel number, equivalent 713frequency, and usage modes. 714Channels identified as 715.Ql 11g 716are also usable in 717.Ql 11b 718mode. 719Channels identified as 720.Ql 11a Turbo 721may be used only for Atheros' Static Turbo mode 722(specified with 723. Cm mediaopt turbo ) . 724Channels marked with a 725.Ql * 726have a regulatory constraint that they be passively scanned. 727This means a station is not permitted to transmit on the channel until 728it identifies the channel is being used for 802.11 communication; 729typically by hearing a beacon frame from an access point operating 730on the channel. 731.Cm list freq 732is another way of requesting this information. 733.It Cm list mac 734Display the current MAC Access Control List state. 735Each address is prefixed with a character that indicates the 736current policy applied to it: 737.Ql + 738indicates the address is allowed access, 739.Ql - 740indicates the address is denied access, 741.Ql * 742indicates the address is present but the current policy open 743(so the ACL is not consulted). 744.It Cm list scan 745Display the access points and/or ad-hoc neighbors 746located in the vicinity. 747The 748.Fl v 749flag may be used to display long SSIDs. 750This information may be updated automatically by the adaptor 751and/or with a 752.Cm scan 753request. 754.Cm list ap 755is another way of requesting this information. 756.It Cm list sta 757When operating as an access point display the stations that are 758currently associated. 759When operating in ad-hoc mode display stations identified as 760neighbors in the IBSS. 761Capabilities advertised by the stations are described under 762the 763.Cm scan 764request. 765Depending on the capabilities of the stations the following 766flags can be included in the output: 767.Bl -tag -width 3n 768.It Li A 769Authorized. 770Indicates that the station is permitted to send/receive data frames. 771.It Li E 772Extended Rate Phy (ERP). 773Indicates that the station is operating in an 802.11g network 774using extended transmit rates. 775.It Li P 776Power Save. 777Indicates that the station is operating in power save mode. 778.It Li Q 779Quality of Service (QoS). 780Indicates that the station is using QoS encapsulation for 781data frame. 782QoS encapsulation is enabled only when WME mode is enabled. 783.El 784.It Cm list wme 785Display the current parameters to use when operating in WME mode. 786When WME mode is enabled for an adaptor this information will be 787displayed with the regular status; this command is mostly useful 788for examining parameters when WME mode is disabled. 789See the description of the 790.Cm wme 791directive for information on the various parameters. 792.It Cm mcastrate Ar rate 793Set the rate for transmitting multicast/broadcast frames. 794Rates are specified as megabits/second in decimal; e.g.\& 5.5 for 5.5 Mb/s. 795This rate should be valid for the current operating conditions; 796if an invalid rate is specified drivers are free to chose an 797appropriate rate. 798.It Cm powersave 799Enable powersave operation. 800When operating as a client, the station will conserve power by 801periodically turning off the radio and listening for 802messages from the access point telling it there are packets waiting. 803The station must then retrieve the packets. 804When operating as an access point, the station must honor power 805save operation of associated clients. 806Not all devices support power save operation, either as a client 807or as an access point. 808Use 809.Fl powersave 810to disable powersave operation. 811.It Cm powersavesleep Ar sleep 812Set the desired max powersave sleep time in milliseconds. 813.It Cm protmode Ar technique 814For interfaces operating in 802.11g, use the specified 815.Ar technique 816for protecting OFDM frames in a mixed 11b/11g network. 817The set of valid techniques is 818.Cm off , cts 819(CTS to self), 820and 821.Cm rtscts 822(RTS/CTS). 823Technique names are case insensitive. 824.It Cm pureg 825When operating as an access point in 802.11g mode allow only 82611g-capable stations to associate (11b-only stations are not 827permitted to associate). 828To allow both 11g and 11b-only stations to associate, use 829.Fl pureg . 830.It Cm roaming Ar mode 831When operating as a station, control how the system will 832behave when communication with the current access point 833is broken. 834The 835.Ar mode 836argument may be one of 837.Cm device 838(leave it to the hardware device to decide), 839.Cm auto 840(handle either in the device or the operating system\[em]as appropriate), 841.Cm manual 842(do nothing until explicitly instructed). 843By default, the device is left to handle this if it is 844capable; otherwise, the operating system will automatically 845attempt to reestablish communication. 846Manual mode is mostly useful when an application wants to 847control the selection of an access point. 848.It Cm rtsthreshold Ar length 849Set the threshold for which 850transmitted frames are preceded by transmission of an 851RTS 852control frame. 853The 854.Ar length 855argument 856is the frame size in bytes and must be in the range 1 to 2346. 857Setting 858.Ar length 859to 860.Li 2346 , 861.Cm any , 862or 863.Cm - 864disables transmission of RTS frames. 865Not all adaptors support setting the RTS threshold. 866.It Cm ssid Ar ssid 867Set the desired Service Set Identifier (aka network name). 868The SSID is a string up to 32 characters 869in length and may be specified as either a normal string or in 870hexadecimal when preceded by 871.Ql 0x . 872Additionally, the SSID may be cleared by setting it to 873.Ql - . 874.It Cm scan 875Initiate a scan of neighboring stations, wait for it to complete, and 876display all stations found. 877Only the super-user can initiate a scan. 878Depending on the capabilities of the APs, the following 879flags can be included in the output: 880.Bl -tag -width 3n 881.It Li A 882Channel Agility. 883Indicates that the station support channel hopping as described by the 884IEEE 802.11b specification. 885.It Li B 886Packet Binary Convolution Code (PBCC). 887A modulation alternative to the standard OFDM method. 888.It Dv C 889Pollreq 890.It Dv c 891Pollable 892.It Dv D 893Direct Sequence Spread Spectrum (DSSSOFDM). 894Indicates the the station supports DSSS modulation. 895.It Li E 896Extended Service Set (ESS). 897Indicates that the station is part of an infrastructure network 898(in contrast to an IBSS/ad-hoc network). 899.It Li I 900IBSS/ad-hoc network. 901Indicates that the station is part of an ad-hoc network 902(in contrast to an ESS network). 903.It Li P 904Privacy. 905Data confidentiality is required for all data frames 906exchanged within the BSS. 907This means that this BSS requires the station to 908use cryptographic means such as WEP, TKIP or AES-CCMP to 909encrypt/decrypt data frames being exchanged with others. 910.It Dv R 911Robust Security Network (RSN). 912Indicates that the station supports the IEEE 802.11i authentication 913and key management protocol. 914.It Li S 915Short Preamble. 916Indicates that the network is using short preambles (defined 917in 802.11b High Rate/DSSS PHY, short preamble utilizes a 91856 bit sync field in contrast to a 128 bit field used in long 919preamble mode). 920.It Li s 921Short slot time. 922Indicates that the network is using a short slot time. 923.El 924.Pp 925The 926.Cm list scan 927request can be used to show recent scan results without 928initiating a new scan. 929.Pp 930The 931.Fl v 932flag may be used to prevent the shortening of long SSIDs. 933.It Cm stationname Ar name 934Set the name of this station. 935It appears that the station name is not really part of the IEEE 802.11 936protocol though all interfaces seem to support it. 937As such it only 938seems to be meaningful to identical or virtually identical equipment. 939Setting the station name is identical in syntax to setting the SSID. 940.It Cm txpower Ar power 941Set the power used to transmit frames. 942The 943.Ar power 944argument 945is a unitless value in the range 0 to 100 that is interpreted 946by drivers to derive a device-specific value. 947Out of range values are truncated. 948Typically only a few discreet power settings are available and 949the driver will use the setting closest to the specified value. 950Not all adaptors support changing the transmit power. 951.It Cm wepmode Ar mode 952Set the desired WEP mode. 953Not all adaptors support all modes. 954The set of valid modes is 955.Cm off , on , 956and 957.Cm mixed . 958The 959.Cm mixed 960mode explicitly tells the adaptor to allow association with access 961points which allow both encrypted and unencrypted traffic. 962On these adaptors, 963.Cm on 964means that the access point must only allow encrypted connections. 965On other adaptors, 966.Cm on 967is generally another name for 968.Cm mixed . 969Modes are case insensitive. 970.It Cm weptxkey Ar index 971Set the WEP key to be used for transmission. 972This is the same as setting the default transmission key with 973.Cm deftxkey . 974.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key 975Set the selected WEP key. 976If an 977.Ar index 978is not given, key 1 is set. 979A WEP key will be either 5 or 13 980characters (40 or 104 bits) depending of the local network and the 981capabilities of the adaptor. 982It may be specified either as a plain 983string or as a string of hexadecimal digits preceded by 984.Ql 0x . 985For maximum portability, hex keys are recommended; 986the mapping of text keys to WEP encryption is usually driver-specific. 987In particular, the 988.Tn Windows 989drivers do this mapping differently to 990.Fx . 991A key may be cleared by setting it to 992.Ql - . 993If WEP is supported then there are at least four keys. 994Some adaptors support more than four keys. 995If that is the case, then the first four keys 996(1-4) will be the standard temporary keys and any others will be adaptor 997specific keys such as permanent keys stored in NVRAM. 998.It Cm wme 999Enable Wireless Multimedia Extensions (WME) support, if available, 1000for the specified interface. 1001WME is a subset of the IEEE 802.11e standard to support the 1002efficient communication of realtime and multimedia data. 1003To disable WME support, use 1004.Fl wme . 1005.Pp 1006The following parameters are meaningful only when WME support is in use. 1007Parameters are specified per-AC (Access Category) and 1008split into those that are used by a station when acting 1009as an access point and those for client stations in the BSS. 1010The latter are received from the access point and may not be changed 1011(at the station). 1012The following Access Categories are recognized: 1013.Pp 1014.Bl -tag -width ".Cm AC_BK" -compact 1015.It Cm AC_BE 1016(or 1017.Cm BE ) 1018best effort delivery, 1019.It Cm AC_BK 1020(or 1021.Cm BK ) 1022background traffic, 1023.It Cm AC_VI 1024(or 1025.Cm VI ) 1026video traffic, 1027.It Cm AC_VO 1028(or 1029.Cm VO ) 1030voice traffic. 1031.El 1032.Pp 1033AC parameters are case-insensitive. 1034Traffic classification is done in the operating system using the 1035vlan priority associated with data frames or the 1036ToS (Type of Service) indication in IP-encapsulated frames. 1037If neither information is present, traffic is assigned to the 1038Best Effort (BE) category. 1039.Bl -tag -width indent 1040.It Cm ack Ar ac 1041Set the ACK policy for QoS transmissions by the local station; 1042this controls whether or not data frames transmitted by a station 1043require an ACK response from the receiving station. 1044To disable waiting for an ACK use 1045.Fl ack . 1046This parameter is applied only to the local station. 1047.It Cm acm Ar ac 1048Enable the Admission Control Mandatory (ACM) mechanism 1049for transmissions by the local station. 1050To disable the ACM use 1051.Fl acm . 1052On stations in a BSS this parameter is read-only and indicates 1053the setting received from the access point. 1054NB: ACM is not supported right now. 1055.It Cm aifs Ar ac Ar count 1056Set the Arbitration Inter Frame Spacing (AIFS) 1057channel access parameter to use for transmissions 1058by the local station. 1059On stations in a BSS this parameter is read-only and indicates 1060the setting received from the access point. 1061.It Cm cwmin Ar ac Ar count 1062Set the CWmin channel access parameter to use for transmissions 1063by the local station. 1064On stations in a BSS this parameter is read-only and indicates 1065the setting received from the access point. 1066.It Cm cwmax Ar ac Ar count 1067Set the CWmax channel access parameter to use for transmissions 1068by the local station. 1069On stations in a BSS this parameter is read-only and indicates 1070the setting received from the access point. 1071.It Cm txoplimit Ar ac Ar limit 1072Set the Transmission Opportunity Limit channel access parameter 1073to use for transmissions by the local station. 1074This parameter defines an interval of time when a WME station 1075has the right to initiate transmissions onto the wireless medium. 1076On stations in a BSS this parameter is read-only and indicates 1077the setting received from the access point. 1078.It Cm bss:aifs Ar ac Ar count 1079Set the AIFS channel access parameter to send to stations in a BSS. 1080This parameter is meaningful only when operating in ap mode. 1081.It Cm bss:cwmin Ar ac Ar count 1082Set the CWmin channel access parameter to send to stations in a BSS. 1083This parameter is meaningful only when operating in ap mode. 1084.It Cm bss:cwmax Ar ac Ar count 1085Set the CWmax channel access parameter to send to stations in a BSS. 1086This parameter is meaningful only when operating in ap mode. 1087.It Cm bss:txoplimit Ar ac Ar limit 1088Set the TxOpLimit channel access parameter to send to stations in a BSS. 1089This parameter is meaningful only when operating in ap mode. 1090.El 1091.El 1092.Pp 1093The following parameters support an optional access control list 1094feature available with some adaptors when operating in ap mode; see 1095.Xr wlan_acl 4 . 1096This facility allows an access point to accept/deny association 1097requests based on the MAC address of the station. 1098Note that this feature does not significantly enhance security 1099as MAC address spoofing is easy to do. 1100.Bl -tag -width indent 1101.It Cm mac:add Ar address 1102Add the specified MAC address to the database. 1103Depending on the policy setting association requests from the 1104specified station will be allowed or denied. 1105.It Cm mac:allow 1106Set the ACL policy to permit association only by 1107stations registered in the database. 1108.It Cm mac:del Ar address 1109Delete the specified MAC address from the database. 1110.It Cm mac:deny 1111Set the ACL policy to deny association only by 1112stations registered in the database. 1113.It Cm mac:kick Ar address 1114Force the specified station to be deauthenticated. 1115This typically is done to block a station after updating the 1116address database. 1117.It Cm mac:open 1118Set the ACL policy to allow all stations to associate. 1119.It Cm mac:flush 1120Delete all entries in the database. 1121.El 1122.Pp 1123The following parameters are for compatibility with other systems: 1124.Bl -tag -width indent 1125.It Cm nwid Ar ssid 1126Another name for the 1127.Cm ssid 1128parameter. 1129Included for 1130.Nx 1131compatibility. 1132.It Cm station Ar name 1133Another name for the 1134.Cm stationname 1135parameter. 1136Included for 1137.Bsx 1138compatibility. 1139.It Cm wep 1140Another way of saying 1141.Cm wepmode on . 1142Included for 1143.Bsx 1144compatibility. 1145.It Fl wep 1146Another way of saying 1147.Cm wepmode off . 1148Included for 1149.Bsx 1150compatibility. 1151.It Cm nwkey key 1152Another way of saying: 1153.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" . 1154Included for 1155.Nx 1156compatibility. 1157.It Cm nwkey Xo 1158.Sm off 1159.Ar n : k1 , k2 , k3 , k4 1160.Sm on 1161.Xc 1162Another way of saying 1163.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" . 1164Included for 1165.Nx 1166compatibility. 1167.It Fl nwkey 1168Another way of saying 1169.Cm wepmode off . 1170Included for 1171.Nx 1172compatibility. 1173.El 1174.Pp 1175The following parameters are specific to bridge interfaces: 1176.Bl -tag -width indent 1177.It Cm addm Ar interface 1178Add the interface named by 1179.Ar interface 1180as a member of the bridge. 1181The interface is put into promiscuous mode 1182so that it can receive every packet sent on the network. 1183.It Cm deletem Ar interface 1184Remove the interface named by 1185.Ar interface 1186from the bridge. 1187Promiscuous mode is disabled on the interface when 1188it is removed from the bridge. 1189.It Cm maxaddr Ar size 1190Set the size of the bridge address cache to 1191.Ar size . 1192The default is 100 entries. 1193.It Cm timeout Ar seconds 1194Set the timeout of address cache entries to 1195.Ar seconds 1196seconds. 1197If 1198.Ar seconds 1199is zero, then address cache entries will not be expired. 1200The default is 240 seconds. 1201.It Cm addr 1202Display the addresses that have been learned by the bridge. 1203.It Cm static Ar interface-name Ar address 1204Add a static entry into the address cache pointing to 1205.Ar interface-name . 1206Static entries are never aged out of the cache or re-placed, even if the 1207address is seen on a different interface. 1208.It Cm deladdr Ar address 1209Delete 1210.Ar address 1211from the address cache. 1212.It Cm flush 1213Delete all dynamically-learned addresses from the address cache. 1214.It Cm flushall 1215Delete all addresses, including static addresses, from the address cache. 1216.It Cm discover Ar interface 1217Mark an interface as a 1218.Dq discovering 1219interface. 1220When the bridge has no address cache entry 1221(either dynamic or static) 1222for the destination address of a packet, 1223the bridge will forward the packet to all 1224member interfaces marked as 1225.Dq discovering . 1226This is the default for all interfaces added to a bridge. 1227.It Cm -discover Ar interface 1228Clear the 1229.Dq discovering 1230attribute on a member interface. 1231For packets without the 1232.Dq discovering 1233attribute, the only packets forwarded on the interface are broadcast 1234or multicast packets and packets for which the destination address 1235is known to be on the interface's segment. 1236.It Cm learn Ar interface 1237Mark an interface as a 1238.Dq learning 1239interface. 1240When a packet arrives on such an interface, the source 1241address of the packet is entered into the address cache as being a 1242destination address on the interface's segment. 1243This is the default for all interfaces added to a bridge. 1244.It Cm -learn Ar interface 1245Clear the 1246.Dq learning 1247attribute on a member interface. 1248.It Cm sticky Ar interface 1249Mark an interface as a 1250.Dq sticky 1251interface. 1252Dynamically learned address entries are treated at static once entered into 1253the cache. 1254Sticky entries are never aged out of the cache or replaced, even if the 1255address is seen on a different interface. 1256.It Cm -sticky Ar interface 1257Clear the 1258.Dq sticky 1259attribute on a member interface. 1260.It Cm span Ar interface 1261Add the interface named by 1262.Ar interface 1263as a span port on the bridge. 1264Span ports transmit a copy of every frame received by the bridge. 1265This is most useful for snooping a bridged network passively on 1266another host connected to one of the span ports of the bridge. 1267.It Cm -span Ar interface 1268Delete the interface named by 1269.Ar interface 1270from the list of span ports of the bridge. 1271.It Cm stp Ar interface 1272Enable Spanning Tree protocol on 1273.Ar interface . 1274The 1275.Xr if_bridge 4 1276driver has support for the IEEE 802.1D Spanning Tree protocol (STP). 1277Spanning Tree is used to detect and remove loops in a network topology. 1278.It Cm -stp Ar interface 1279Disable Spanning Tree protocol on 1280.Ar interface . 1281This is the default for all interfaces added to a bridge. 1282.It Cm edge Ar interface 1283Set 1284.Ar interface 1285as an edge port. 1286An edge port connects directly to end stations cannot create bridging 1287loops in the network, this allows it to transition straight to forwarding. 1288.It Cm -edge Ar interface 1289Disable edge status on 1290.Ar interface . 1291.It Cm autoedge Ar interface 1292Allow 1293.Ar interface 1294to automatically detect edge status. 1295This is the default for all interfaces added to a bridge. 1296.It Cm -autoedge Ar interface 1297Disable automatic edge status on 1298.Ar interface . 1299.It Cm ptp Ar interface 1300Set the 1301.Ar interface 1302as a point to point link. 1303This is required for straight transitions to forwarding and 1304should be enabled on a direct link to another RSTP capable switch. 1305.It Cm -ptp Ar interface 1306Disable point to point link status on 1307.Ar interface . 1308This should be disabled for a half duplex link and for an interface 1309connected to a shared network segment, 1310like a hub or a wireless network. 1311.It Cm autoptp Ar interface 1312Automatically detect the point to point status on 1313.Ar interface 1314by checking the full duplex link status. 1315This is the default for interfaces added to the bridge. 1316.It Cm -autoptp Ar interface 1317Disable automatic point to point link detection on 1318.Ar interface . 1319.It Cm maxage Ar seconds 1320Set the time that a Spanning Tree protocol configuration is valid. 1321The default is 20 seconds. 1322The minimum is 6 seconds and the maximum is 40 seconds. 1323.It Cm fwddelay Ar seconds 1324Set the time that must pass before an interface begins forwarding 1325packets when Spanning Tree is enabled. 1326The default is 15 seconds. 1327The minimum is 4 seconds and the maximum is 30 seconds. 1328.It Cm hellotime Ar seconds 1329Set the time between broadcasting of Spanning Tree protocol 1330configuration messages. 1331The hello time may only be changed when operating in legacy stp mode. 1332The default is 2 seconds. 1333The minimum is 1 second and the maximum is 2 seconds. 1334.It Cm priority Ar value 1335Set the bridge priority for Spanning Tree. 1336The default is 32768. 1337The minimum is 0 and the maximum is 61440. 1338.It Cm protocol Ar value 1339Set the Spanning Tree protocol. 1340The default is rstp. 1341The available options are stp and rstp. 1342.It Cm holdcnt Ar value 1343Set the transmit hold count for Spanning Tree. 1344This is the number of packets transmitted before being rate limited. 1345The default is 6. 1346The minimum is 1 and the maximum is 10. 1347.It Cm ifpriority Ar interface Ar value 1348Set the Spanning Tree priority of 1349.Ar interface 1350to 1351.Ar value . 1352The default is 128. 1353The minimum is 0 and the maximum is 240. 1354.It Cm ifpathcost Ar interface Ar value 1355Set the Spanning Tree path cost of 1356.Ar interface 1357to 1358.Ar value . 1359The default is calculated from the link speed. 1360To change a previously selected path cost back to automatic, set the 1361cost to 0. 1362The minimum is 1 and the maximum is 200000000. 1363.El 1364.Pp 1365The following parameters are specific to IP tunnel interfaces, 1366.Xr gif 4 : 1367.Bl -tag -width indent 1368.It Cm tunnel Ar src_addr dest_addr 1369Configure the physical source and destination address for IP tunnel 1370interfaces. 1371The arguments 1372.Ar src_addr 1373and 1374.Ar dest_addr 1375are interpreted as the outer source/destination for the encapsulating 1376IPv4/IPv6 header. 1377.It Fl tunnel 1378Unconfigure the physical source and destination address for IP tunnel 1379interfaces previously configured with 1380.Cm tunnel . 1381.It Cm deletetunnel 1382Another name for the 1383.Fl tunnel 1384parameter. 1385.El 1386.Pp 1387The following parameters are specific to 1388.Xr pfsync 4 1389interfaces: 1390.Bl -tag -width indent 1391.It Cm maxupd Ar n 1392Set the maximum number of updates for a single state which 1393can be collapsed into one. 1394This is an 8-bit number; the default value is 128. 1395.El 1396.Pp 1397The following parameters are specific to 1398.Xr vlan 4 1399interfaces: 1400.Bl -tag -width indent 1401.It Cm vlan Ar vlan_tag 1402Set the VLAN tag value to 1403.Ar vlan_tag . 1404This value is a 16-bit number which is used to create an 802.1Q 1405VLAN header for packets sent from the 1406.Xr vlan 4 1407interface. 1408Note that 1409.Cm vlan 1410and 1411.Cm vlandev 1412must both be set at the same time. 1413.It Cm vlandev Ar iface 1414Associate the physical interface 1415.Ar iface 1416with a 1417.Xr vlan 4 1418interface. 1419Packets transmitted through the 1420.Xr vlan 4 1421interface will be 1422diverted to the specified physical interface 1423.Ar iface 1424with 802.1Q VLAN encapsulation. 1425Packets with 802.1Q encapsulation received 1426by the parent interface with the correct VLAN tag will be diverted to 1427the associated 1428.Xr vlan 4 1429pseudo-interface. 1430The 1431.Xr vlan 4 1432interface is assigned a 1433copy of the parent interface's flags and the parent's ethernet address. 1434The 1435.Cm vlandev 1436and 1437.Cm vlan 1438must both be set at the same time. 1439If the 1440.Xr vlan 4 1441interface already has 1442a physical interface associated with it, this command will fail. 1443To 1444change the association to another physical interface, the existing 1445association must be cleared first. 1446.Pp 1447Note: if the hardware tagging capability 1448is set on the parent interface, the 1449.Xr vlan 4 1450pseudo 1451interface's behavior changes: 1452the 1453.Xr vlan 4 1454interface recognizes that the 1455parent interface supports insertion and extraction of VLAN tags on its 1456own (usually in firmware) and that it should pass packets to and from 1457the parent unaltered. 1458.It Fl vlandev Op Ar iface 1459If the driver is a 1460.Xr vlan 4 1461pseudo device, disassociate the parent interface from it. 1462This breaks the link between the 1463.Xr vlan 4 1464interface and its parent, 1465clears its VLAN tag, flags and its link address and shuts the interface down. 1466The 1467.Ar iface 1468argument is useless and hence deprecated. 1469.El 1470.Pp 1471The following parameters are specific to 1472.Xr carp 4 1473interfaces: 1474.Bl -tag -width indent 1475.It Cm advbase Ar seconds 1476Specifies the base of the advertisement interval in seconds. 1477The acceptable values are 1 to 255. 1478The default value is 1. 1479.\" The default value is 1480.\" .Dv CARP_DFLTINTV . 1481.It Cm advskew Ar interval 1482Specifies the skew to add to the base advertisement interval to 1483make one host advertise slower than another host. 1484It is specified in 1/256 of seconds. 1485The acceptable values are 1 to 254. 1486The default value is 0. 1487.It Cm pass Ar phrase 1488Set the authentication key to 1489.Ar phrase . 1490.It Cm vhid Ar n 1491Set the virtual host ID. 1492This is a required setting. 1493Acceptable values are 1 to 255. 1494.El 1495.Pp 1496The 1497.Nm 1498utility displays the current configuration for a network interface 1499when no optional parameters are supplied. 1500If a protocol family is specified, 1501.Nm 1502will report only the details specific to that protocol family. 1503.Pp 1504If the 1505.Fl m 1506flag is passed before an interface name, 1507.Nm 1508will display the capability list and all 1509of the supported media for the specified interface. 1510If 1511.Fl L 1512flag is supplied, address lifetime is displayed for IPv6 addresses, 1513as time offset string. 1514.Pp 1515Optionally, the 1516.Fl a 1517flag may be used instead of an interface name. 1518This flag instructs 1519.Nm 1520to display information about all interfaces in the system. 1521The 1522.Fl d 1523flag limits this to interfaces that are down, and 1524.Fl u 1525limits this to interfaces that are up. 1526When no arguments are given, 1527.Fl a 1528is implied. 1529.Pp 1530The 1531.Fl l 1532flag may be used to list all available interfaces on the system, with 1533no other additional information. 1534Use of this flag is mutually exclusive 1535with all other flags and commands, except for 1536.Fl d 1537(only list interfaces that are down) 1538and 1539.Fl u 1540(only list interfaces that are up). 1541.Pp 1542The 1543.Fl v 1544flag may be used to get more verbose status for an interface. 1545.Pp 1546The 1547.Fl C 1548flag may be used to list all of the interface cloners available on 1549the system, with no additional information. 1550Use of this flag is mutually exclusive with all other flags and commands. 1551.Pp 1552The 1553.Fl k 1554flag causes keying information for the interface, if available, to be 1555printed. 1556For example, the values of 802.11 WEP keys will be printed, if accessible to 1557the current user. 1558This information is not printed by default, as it may be considered 1559sensitive. 1560.Pp 1561Only the super-user may modify the configuration of a network interface. 1562.Sh NOTES 1563The media selection system is relatively new and only some drivers support 1564it (or have need for it). 1565.Sh DIAGNOSTICS 1566Messages indicating the specified interface does not exist, the 1567requested address is unknown, or the user is not privileged and 1568tried to alter an interface's configuration. 1569.Sh SEE ALSO 1570.Xr netstat 1 , 1571.Xr carp 4 , 1572.Xr netintro 4 , 1573.Xr pfsync 4 , 1574.Xr polling 4 , 1575.Xr vlan 4 , 1576.\" .Xr eon 5 , 1577.Xr rc 8 , 1578.Xr routed 8 , 1579.Xr sysctl 8 1580.Sh HISTORY 1581The 1582.Nm 1583utility appeared in 1584.Bx 4.2 . 1585.Sh BUGS 1586Basic IPv6 node operation requires a link-local address on each 1587interface configured for IPv6. 1588Normally, such an address is automatically configured by the 1589kernel on each interface added to the system; this behaviour may 1590be disabled by setting the sysctl MIB variable 1591.Va net.inet6.ip6.auto_linklocal 1592to 0. 1593.Pp 1594If you delete such an address using 1595.Nm , 1596the kernel may act very odd. 1597Do this at your own risk. 1598