1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgment: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" From: @(#)ifconfig.8 8.3 (Berkeley) 1/5/94 33.\" $FreeBSD$ 34.\" 35.Dd July 2, 2001 36.Dt IFCONFIG 8 37.Os 38.Sh NAME 39.Nm ifconfig 40.Nd configure network interface parameters 41.Sh SYNOPSIS 42.Nm 43.Op Fl L 44.Op Fl m 45.Ar interface 46.Op Cm create 47.Op Ar address_family 48.Oo 49.Ar address 50.Op Ar dest_address 51.Oc 52.Op Ar parameters 53.Nm 54.Ar interface 55.Cm destroy 56.Nm 57.Fl a 58.Op Fl L 59.Op Fl d 60.Op Fl m 61.Op Fl u 62.Op Ar address_family 63.Nm 64.Fl l 65.Op Fl d 66.Op Fl u 67.Op Ar address_family 68.Nm 69.Op Fl L 70.Op Fl d 71.Op Fl m 72.Op Fl u 73.Op Fl C 74.Sh DESCRIPTION 75.Nm Ifconfig 76is used to assign an address 77to a network interface and/or configure 78network interface parameters. 79.Nm Ifconfig 80must be used at boot time to define the network address 81of each interface present on a machine; it may also be used at 82a later time to redefine an interface's address 83or other operating parameters. 84.Pp 85The following options are available: 86.Bl -tag -width indent 87.It Ar address 88For the 89.Tn DARPA Ns -Internet 90family, 91the address is either a host name present in the host name data 92base, 93.Xr hosts 5 , 94or a 95.Tn DARPA 96Internet address expressed in the Internet standard 97.Dq dot notation . 98.Pp 99It is also possible to use the CIDR notation (also known as the 100slash notation) to include the netmask. 101That is, one can specify an address like 102.Li 192.168.0.1/16 . 103.Pp 104For 105.Dq inet6 106family, it is also possible to specify the prefix length using the slash 107notation, like 108.Li ::1/128 . 109See the 110.Cm prefixlen 111parameter below for more information. 112.\" For the Xerox Network Systems(tm) family, 113.\" addresses are 114.\" .Ar net:a.b.c.d.e.f , 115.\" where 116.\" .Ar net 117.\" is the assigned network number (in decimal), 118.\" and each of the six bytes of the host number, 119.\" .Ar a 120.\" through 121.\" .Ar f , 122.\" are specified in hexadecimal. 123.\" The host number may be omitted on IEEE 802 protocol 124.\" (Ethernet, FDDI, and Token Ring) interfaces, 125.\" which use the hardware physical address, 126.\" and on interfaces other than the first. 127.\" For the 128.\" .Tn ISO 129.\" family, addresses are specified as a long hexadecimal string, 130.\" as in the Xerox family. 131.\" However, two consecutive dots imply a zero 132.\" byte, and the dots are optional, if the user wishes to (carefully) 133.\" count out long strings of digits in network byte order. 134.Pp 135The link-level 136.Pq Dq link 137address 138is specified as a series of colon-separated hex digits. 139This can be used to 140e.g. set a new MAC address on an ethernet interface, though the 141mechanism used is not ethernet-specific. 142If the interface is already 143up when this option is used, it will be briefly brought down and 144then brought back up again in order to ensure that the receive 145filter in the underlying ethernet hardware is properly reprogrammed. 146.It Ar address_family 147Specify the 148address family 149which affects interpretation of the remaining parameters. 150Since an interface can receive transmissions in differing protocols 151with different naming schemes, specifying the address family is recommended. 152The address or protocol families currently 153supported are 154.Dq inet , 155.Dq inet6 , 156.Dq atalk , 157.Dq ipx , 158.\" .Dq iso , 159and 160.Dq link . 161.\" and 162.\" .Dq ns . 163The default is 164.Dq inet . 165.Dq ether 166and 167.Dq lladdr 168are synonyms for 169.Dq link . 170.It Ar dest_address 171Specify the address of the correspondent on the other end 172of a point to point link. 173.It Ar interface 174This 175parameter is a string of the form 176.Dq name unit , 177for example, 178.Dq Li ed0 . 179.El 180.Pp 181The following parameters may be set with 182.Nm : 183.Bl -tag -width indent 184.It Cm add 185Another name for the 186.Cm alias 187parameter. 188Introduced for compatibility 189with 190.Bsx . 191.It Cm alias 192Establish an additional network address for this interface. 193This is sometimes useful when changing network numbers, and 194one wishes to accept packets addressed to the old interface. 195If the address is on the same subnet as the first network address 196for this interface, a netmask of 197.Li 0xffffffff 198has to be specified. 199.It Fl alias 200Remove the network address specified. 201This would be used if you incorrectly specified an alias, or it 202was no longer needed. 203If you have incorrectly set an NS address having the side effect 204of specifying the host portion, removing all NS addresses will 205allow you to respecify the host portion. 206.It Cm anycast 207(Inet6 only.) 208Specify that the address configured is an anycast address. 209Based on the current specification, 210only routers may configure anycast addresses. 211Anycast address will not be used as source address of any of outgoing 212IPv6 packets. 213.It Cm arp 214Enable the use of the Address Resolution Protocol 215.Pq Xr arp 4 216in mapping 217between network level addresses and link level addresses (default). 218This is currently implemented for mapping between 219.Tn DARPA 220Internet 221addresses and 222.Tn IEEE 223802 48-bit MAC addresses (Ethernet, FDDI, and Token Ring addresses). 224.It Fl arp 225Disable the use of the Address Resolution Protocol 226.Pq Xr arp 4 . 227.It Cm broadcast 228(Inet only.) 229Specify the address to use to represent broadcasts to the 230network. 231The default broadcast address is the address with a host part of all 1's. 232.It Cm debug 233Enable driver dependent debugging code; usually, this turns on 234extra console error logging. 235.It Fl debug 236Disable driver dependent debugging code. 237.It Cm delete 238Another name for the 239.Fl alias 240parameter. 241.It Cm down 242Mark an interface 243.Dq down . 244When an interface is marked 245.Dq down , 246the system will not attempt to 247transmit messages through that interface. 248If possible, the interface will be reset to disable reception as well. 249This action does not automatically disable routes using the interface. 250.\" .It Cm ipdst 251.\" This is used to specify an Internet host who is willing to receive 252.\" ip packets encapsulating NS packets bound for a remote network. 253.\" An apparent point to point link is constructed, and 254.\" the address specified will be taken as the NS address and network 255.\" of the destination. 256.\" IP encapsulation of 257.\" .Tn CLNP 258.\" packets is done differently. 259.It Cm media Ar type 260If the driver supports the media selection system, set the media type 261of the interface to 262.Ar type . 263Some interfaces support the mutually exclusive use of one of several 264different physical media connectors. 265For example, a 10Mb/s Ethernet 266interface might support the use of either 267.Tn AUI 268or twisted pair connectors. 269Setting the media type to 270.Dq 10base5/AUI 271would change the currently active connector to the AUI port. 272Setting it to 273.Dq 10baseT/UTP 274would activate twisted pair. 275Refer to the interfaces' driver 276specific documentation or man page for a complete list of the 277available types. 278.It Cm mediaopt Ar opts 279If the driver supports the media selection system, set the specified 280media options on the interface. 281The 282.Ar opts 283argument 284is a comma delimited list of options to apply to the interface. 285Refer to the interfaces' driver specific man page for a complete 286list of available options. 287.It Fl mediaopt Ar opts 288If the driver supports the media selection system, disable the 289specified media options on the interface. 290.It Cm tunnel Ar src_addr dest_addr 291(IP tunnel devices only.) 292Configure the physical source and destination address for IP tunnel 293interfaces 294.Pq Xr gif 4 . 295The arguments 296.Ar src_addr 297and 298.Ar dest_addr 299are interpreted as the outer source/destination for the encapsulating 300IPv4/IPv6 header. 301.It Cm deletetunnel 302Unconfigure the physical source and destination address for IP tunnel 303interfaces previously configured with 304.Cm tunnel . 305.It Cm create 306Create the specified network pseudo-device. 307If the interface is given without a unit number, try to create a new 308device with an arbitrary unit number. 309If creation of an arbitrary device is successful, the new device name is 310printed to standard output. 311.It Cm destroy 312Destroy the specified network pseudo-device. 313.It Cm plumb 314Another name for the 315.Cm create 316parameter. 317Included for 318.Tn Solaris 319compatibility. 320.It Cm unplumb 321Another name for the 322.Cm destroy 323parameter. 324Included for 325.Tn Solaris 326compatibility. 327.It Cm vlan Ar vlan_tag 328If the interface is a vlan pseudo interface, set the vlan tag value 329to 330.Ar vlan_tag . 331This value is a 16-bit number which is used to create an 802.1Q 332vlan header for packets sent from the vlan interface. 333Note that 334.Cm vlan 335and 336.Cm vlandev 337must both be set at the same time. 338.It Cm vlandev Ar iface 339If the interface is a vlan pseudo device, associate physical interface 340.Ar iface 341with it. 342Packets transmitted through the vlan interface will be 343diverted to the specified physical interface 344.Ar iface 345with 802.1Q vlan encapsulation. 346Packets with 802.1Q encapsulation received 347by the parent interface with the correct vlan tag will be diverted to 348the associated vlan pseudo-interface. 349The vlan interface is assigned a 350copy of the parent interface's flags and the parent's ethernet address. 351The 352.Cm vlandev 353and 354.Cm vlan 355must both be set at the same time. 356If the vlan interface already has 357a physical interface associated with it, this command will fail. 358To 359change the association to another physical interface, the existing 360association must be cleared first. 361.Pp 362Note: if the 363.Cm link0 364flag is set on the vlan interface, the vlan pseudo 365interface's behavior changes: the 366.Cm link0 367tells the vlan interface that the 368parent interface supports insertion and extraction of vlan tags on its 369own (usually in firmware) and that it should pass packets to and from 370the parent unaltered. 371.It Fl vlandev Ar iface 372If the driver is a vlan pseudo device, disassociate the physical interface 373.Ar iface 374from it. 375This breaks the link between the vlan interface and its parent, 376clears its vlan tag, flags and its link address and shuts the interface down. 377.It Cm metric Ar n 378Set the routing metric of the interface to 379.Ar n , 380default 0. 381The routing metric is used by the routing protocol 382.Pq Xr routed 8 . 383Higher metrics have the effect of making a route 384less favorable; metrics are counted as addition hops 385to the destination network or host. 386.It Cm mtu Ar n 387Set the maximum transmission unit of the interface to 388.Ar n , 389default is interface specific. 390The MTU is used to limit the size of packets that are transmitted on an 391interface. 392Not all interfaces support setting the MTU, and some interfaces have 393range restrictions. 394.It Cm netmask Ar mask 395.\" (Inet and ISO.) 396(Inet only.) 397Specify how much of the address to reserve for subdividing 398networks into sub-networks. 399The mask includes the network part of the local address 400and the subnet part, which is taken from the host field of the address. 401The mask can be specified as a single hexadecimal number 402with a leading 403.Ql 0x , 404with a dot-notation Internet address, 405or with a pseudo-network name listed in the network table 406.Xr networks 5 . 407The mask contains 1's for the bit positions in the 32-bit address 408which are to be used for the network and subnet parts, 409and 0's for the host part. 410The mask should contain at least the standard network portion, 411and the subnet field should be contiguous with the network 412portion. 413.Pp 414The netmask can also be specified in CIDR notation after the address. 415See the 416.Ar address 417option above for more information. 418.It Cm prefixlen Ar len 419(Inet6 only.) 420Specify that 421.Ar len 422bits are reserved for subdividing networks into sub-networks. 423The 424.Ar len 425must be integer, and for syntactical reason it must be between 0 to 128. 426It is almost always 64 under the current IPv6 assignment rule. 427If the parameter is omitted, 64 is used. 428.Pp 429The prefix can also be specified using the slash notation after the address. 430See the 431.Ar address 432option above for more information. 433.\" see 434.\" Xr eon 5 . 435.\" .It Cm nsellength Ar n 436.\" .Pf ( Tn ISO 437.\" only) 438.\" This specifies a trailing number of bytes for a received 439.\" .Tn NSAP 440.\" used for local identification, the remaining leading part of which is 441.\" taken to be the 442.\" .Tn NET 443.\" (Network Entity Title). 444.\" The default value is 1, which is conformant to US 445.\" .Tn GOSIP . 446.\" When an ISO address is set in an ifconfig command, 447.\" it is really the 448.\" .Tn NSAP 449.\" which is being specified. 450.\" For example, in 451.\" .Tn US GOSIP , 452.\" 20 hex digits should be 453.\" specified in the 454.\" .Tn ISO NSAP 455.\" to be assigned to the interface. 456.\" There is some evidence that a number different from 1 may be useful 457.\" for 458.\" .Tn AFI 459.\" 37 type addresses. 460.It Cm range Ar netrange 461Under appletalk, set the interface to respond to a 462.Ar netrange 463of the form 464.Ar startnet Ns - Ns Ar endnet . 465Appletalk uses this scheme instead of 466netmasks though 467.Fx 468implements it internally as a set of netmasks. 469.It Cm remove 470Another name for the 471.Fl alias 472parameter. 473Introduced for compatibility 474with 475.Bsx . 476.It Cm phase 477The argument following this specifies the version (phase) of the 478Appletalk network attached to the interface. 479Values of 1 or 2 are permitted. 480.Sm off 481.It Cm link Op Cm 0 No - Cm 2 482.Sm on 483Enable special processing of the link level of the interface. 484These three options are interface specific in actual effect, however, 485they are in general used to select special modes of operation. 486An example 487of this is to enable SLIP compression, or to select the connector type 488for some Ethernet cards. 489Refer to the man page for the specific driver 490for more information. 491.Sm off 492.It Fl link Op Cm 0 No - Cm 2 493.Sm on 494Disable special processing at the link level with the specified interface. 495.It Cm up 496Mark an interface 497.Dq up . 498This may be used to enable an interface after an 499.Dq Nm Cm down . 500It happens automatically when setting the first address on an interface. 501If the interface was reset when previously marked down, 502the hardware will be re-initialized. 503.It Cm ssid Ar ssid 504For IEEE 802.11 wireless interfaces, set the desired Service Set 505Identifier (aka network name). 506The SSID is a string up to 32 characters 507in length and may be specified as either a normal string or in 508hexadecimal when proceeded by 509.Ql 0x . 510Additionally, the SSID may be cleared by setting it to 511.Ql - . 512.It Cm nwid Ar ssid 513Another name for the 514.Cm ssid 515parameter. 516Included for 517.Nx 518compatibility. 519.It Cm stationname Ar name 520For IEEE 802.11 wireless interfaces, set the name of this station. 521It appears that the station name is not really part of the IEEE 802.11 522protocol though all interfaces seem to support it. 523As such it only 524seems to be meaningful to identical or virtually identical equipment. 525Setting the station name is identical in syntax to setting the SSID. 526.It Cm station Ar name 527Another name for the 528.Cm stationname 529parameter. 530Included for 531.Bsx 532compatibility. 533.It Cm channel Ar number 534For IEEE 802.11 wireless interfaces, set the desired channel. 535Channels range from 1 to 14, but the exact selection available 536depends on the region your adaptor was manufactured for. 537Setting 538the channel to 0 will give you the default for your adaptor. 539Many 540adaptors ignore this setting unless you are in ad-hoc mode. 541.It Cm authmode Ar mode 542For IEEE 802.11 wireless interfaces, set the desired authentication mode 543in infrastructure mode. 544Not all adaptors support all modes. 545The set of 546valid modes is 547.Dq none , 548.Dq open , 549and 550.Dq shared . 551Modes are case insensitive. 552.It Cm powersave 553For IEEE 802.11 wireless interfaces, enable powersave mode. 554.It Fl powersave 555For IEEE 802.11 wireless interfaces, disable powersave mode. 556.It Cm powersavesleep Ar sleep 557For IEEE 802.11 wireless interfaces, set the desired max powersave sleep 558time in milliseconds. 559.It Cm wepmode Ar mode 560For IEEE 802.11 wireless interfaces, set the desired WEP mode. 561Not all adaptors support all modes. 562The set of valid modes is 563.Dq off , 564.Dq on , 565and 566.Dq mixed . 567.Dq Mixed 568mode explicitly tells the adaptor to allow association with access 569points which allow both encrypted and unencrypted traffic. 570On these adaptors, 571.Dq on 572means that the access point must only allow encrypted connections. 573On other adaptors, 574.Dq on 575is generally another name for 576.Dq mixed . 577Modes are case insensitive. 578.It Cm weptxkey Ar index 579For IEEE 802.11 wireless interfaces, set the WEP key to be used for 580transmission. 581.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key 582For IEEE 802.11 wireless interfaces, set the selected WEP key. 583If an 584.Ar index 585is not given, key 1 is set. 586A WEP key will be either 5 or 13 587characters (40 or 104 bits) depending of the local network and the 588capabilities of the adaptor. 589It may be specified either as a plain 590string or as a string of hexadecimal digits proceeded by 591.Ql 0x . 592A key may be cleared by setting it to 593.Ql - . 594If WEP is supported then there are at least four keys. 595Some adaptors support more than four keys. 596If that is the case, then the first four keys 597(1-4) will be the standard temporary keys and any others will be adaptor 598specific keys such as permanent keys stored in NVRAM. 599.It Cm wep 600Another way of saying 601.Cm wepmode on . 602Included for 603.Bsx 604compatibility. 605.It Fl wep 606Another way of saying 607.Cm wepmode off . 608Included for 609.Bsx 610compatibility. 611.It Cm nwkey key 612Another way of saying: 613.Pp 614.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" . 615.Pp 616Included for 617.Nx 618compatibility. 619.It Cm nwkey Xo 620.Sm off 621.Ar n : k1 , k2 , k3 , k4 622.Sm on 623.Xc 624Another way of saying 625.Pp 626.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" . 627.Pp 628Included for 629.Nx 630compatibility. 631.It Fl nwkey 632Another way of saying 633.Cm wepmode off . 634.Pp 635Included for 636.Nx 637compatibility. 638.El 639.Pp 640.Nm Ifconfig 641displays the current configuration for a network interface 642when no optional parameters are supplied. 643If a protocol family is specified, 644.Nm 645will report only the details specific to that protocol family. 646.Pp 647If the driver does supports the media selection system, the supported 648media list will be included in the output. 649.Pp 650If the 651.Fl m 652flag is passed before an interface name, 653.Nm 654will display all 655of the supported media for the specified interface. 656If 657.Fl L 658flag is supplied, address lifetime is displayed for IPv6 addresses, 659as time offset string. 660.Pp 661Optionally, the 662.Fl a 663flag may be used instead of an interface name. 664This flag instructs 665.Nm 666to display information about all interfaces in the system. 667The 668.Fl d 669flag limits this to interfaces that are down, and 670.Fl u 671limits this to interfaces that are up. 672When no arguments are given, 673.Fl a 674is implied. 675.Pp 676The 677.Fl l 678flag may be used to list all available interfaces on the system, with 679no other additional information. 680Use of this flag is mutually exclusive 681with all other flags and commands, except for 682.Fl d 683(only list interfaces that are down) 684and 685.Fl u 686(only list interfaces that are up). 687.Pp 688The 689.Fl C 690flag may be used to list all of the interface cloners available on 691the system, with no additional information. 692Use of this flag is mutually exclusive with all other flags and commands. 693.Pp 694Only the super-user may modify the configuration of a network interface. 695.Sh NOTES 696The media selection system is relatively new and only some drivers support 697it (or have need for it). 698.Sh DIAGNOSTICS 699Messages indicating the specified interface does not exist, the 700requested address is unknown, or the user is not privileged and 701tried to alter an interface's configuration. 702.Sh BUGS 703IPv6 link-local addresses are required for several basic communication 704between IPv6 node. 705If they are deleted by 706.Nm 707manually, the kernel might show very strange behavior. 708So, such manual deletions are strongly discouraged. 709.Sh SEE ALSO 710.Xr netstat 1 , 711.Xr netintro 4 , 712.\" .Xr eon 5 , 713.Xr rc 8 , 714.Xr routed 8 715.Sh HISTORY 716The 717.Nm 718command appeared in 719.Bx 4.2 . 720