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 non-conflicting netmask must be given. 197Usually 198.Li 0xffffffff 199is most appropriate. 200.It Fl alias 201Remove the network address specified. 202This would be used if you incorrectly specified an alias, or it 203was no longer needed. 204If you have incorrectly set an NS address having the side effect 205of specifying the host portion, removing all NS addresses will 206allow you to respecify the host portion. 207.It Cm anycast 208(Inet6 only.) 209Specify that the address configured is an anycast address. 210Based on the current specification, 211only routers may configure anycast addresses. 212Anycast address will not be used as source address of any of outgoing 213IPv6 packets. 214.It Cm arp 215Enable the use of the Address Resolution Protocol 216.Pq Xr arp 4 217in mapping 218between network level addresses and link level addresses (default). 219This is currently implemented for mapping between 220.Tn DARPA 221Internet 222addresses and 223.Tn IEEE 224802 48-bit MAC addresses (Ethernet, FDDI, and Token Ring addresses). 225.It Fl arp 226Disable the use of the Address Resolution Protocol 227.Pq Xr arp 4 . 228.It Cm broadcast 229(Inet only.) 230Specify the address to use to represent broadcasts to the 231network. 232The default broadcast address is the address with a host part of all 1's. 233.It Cm debug 234Enable driver dependent debugging code; usually, this turns on 235extra console error logging. 236.It Fl debug 237Disable driver dependent debugging code. 238.It Cm delete 239Another name for the 240.Fl alias 241parameter. 242.It Cm down 243Mark an interface 244.Dq down . 245When an interface is marked 246.Dq down , 247the system will not attempt to 248transmit messages through that interface. 249If possible, the interface will be reset to disable reception as well. 250This action does not automatically disable routes using the interface. 251.\" .It Cm ipdst 252.\" This is used to specify an Internet host who is willing to receive 253.\" ip packets encapsulating NS packets bound for a remote network. 254.\" An apparent point to point link is constructed, and 255.\" the address specified will be taken as the NS address and network 256.\" of the destination. 257.\" IP encapsulation of 258.\" .Tn CLNP 259.\" packets is done differently. 260.It Cm media Ar type 261If the driver supports the media selection system, set the media type 262of the interface to 263.Ar type . 264Some interfaces support the mutually exclusive use of one of several 265different physical media connectors. 266For example, a 10Mb/s Ethernet 267interface might support the use of either 268.Tn AUI 269or twisted pair connectors. 270Setting the media type to 271.Dq 10base5/AUI 272would change the currently active connector to the AUI port. 273Setting it to 274.Dq 10baseT/UTP 275would activate twisted pair. 276Refer to the interfaces' driver 277specific documentation or man page for a complete list of the 278available types. 279.It Cm mediaopt Ar opts 280If the driver supports the media selection system, set the specified 281media options on the interface. 282The 283.Ar opts 284argument 285is a comma delimited list of options to apply to the interface. 286Refer to the interfaces' driver specific man page for a complete 287list of available options. 288.It Fl mediaopt Ar opts 289If the driver supports the media selection system, disable the 290specified media options on the interface. 291.It Cm tunnel Ar src_addr dest_addr 292(IP tunnel devices only.) 293Configure the physical source and destination address for IP tunnel 294interfaces 295.Pq Xr gif 4 . 296The arguments 297.Ar src_addr 298and 299.Ar dest_addr 300are interpreted as the outer source/destination for the encapsulating 301IPv4/IPv6 header. 302.It Cm deletetunnel 303Unconfigure the physical source and destination address for IP tunnel 304interfaces previously configured with 305.Cm tunnel . 306.It Cm create 307Create the specified network pseudo-device. 308If the interface is given without a unit number, try to create a new 309device with an arbitrary unit number. 310If creation of an arbitrary device is successful, the new device name is 311printed to standard output. 312.It Cm destroy 313Destroy the specified network pseudo-device. 314.It Cm plumb 315Another name for the 316.Cm create 317parameter. 318Included for 319.Tn Solaris 320compatibility. 321.It Cm unplumb 322Another name for the 323.Cm destroy 324parameter. 325Included for 326.Tn Solaris 327compatibility. 328.It Cm vlan Ar vlan_tag 329If the interface is a vlan pseudo interface, set the vlan tag value 330to 331.Ar vlan_tag . 332This value is a 16-bit number which is used to create an 802.1Q 333vlan header for packets sent from the vlan interface. 334Note that 335.Cm vlan 336and 337.Cm vlandev 338must both be set at the same time. 339.It Cm vlandev Ar iface 340If the interface is a vlan pseudo device, associate physical interface 341.Ar iface 342with it. 343Packets transmitted through the vlan interface will be 344diverted to the specified physical interface 345.Ar iface 346with 802.1Q vlan encapsulation. 347Packets with 802.1Q encapsulation received 348by the parent interface with the correct vlan tag will be diverted to 349the associated vlan pseudo-interface. 350The vlan interface is assigned a 351copy of the parent interface's flags and the parent's ethernet address. 352The 353.Cm vlandev 354and 355.Cm vlan 356must both be set at the same time. 357If the vlan interface already has 358a physical interface associated with it, this command will fail. 359To 360change the association to another physical interface, the existing 361association must be cleared first. 362.Pp 363Note: if the 364.Cm link0 365flag is set on the vlan interface, the vlan pseudo 366interface's behavior changes: the 367.Cm link0 368tells the vlan interface that the 369parent interface supports insertion and extraction of vlan tags on its 370own (usually in firmware) and that it should pass packets to and from 371the parent unaltered. 372.It Fl vlandev Ar iface 373If the driver is a vlan pseudo device, disassociate the physical interface 374.Ar iface 375from it. 376This breaks the link between the vlan interface and its parent, 377clears its vlan tag, flags and its link address and shuts the interface down. 378.It Cm metric Ar n 379Set the routing metric of the interface to 380.Ar n , 381default 0. 382The routing metric is used by the routing protocol 383.Pq Xr routed 8 . 384Higher metrics have the effect of making a route 385less favorable; metrics are counted as addition hops 386to the destination network or host. 387.It Cm mtu Ar n 388Set the maximum transmission unit of the interface to 389.Ar n , 390default is interface specific. 391The MTU is used to limit the size of packets that are transmitted on an 392interface. 393Not all interfaces support setting the MTU, and some interfaces have 394range restrictions. 395.It Cm netmask Ar mask 396.\" (Inet and ISO.) 397(Inet only.) 398Specify how much of the address to reserve for subdividing 399networks into sub-networks. 400The mask includes the network part of the local address 401and the subnet part, which is taken from the host field of the address. 402The mask can be specified as a single hexadecimal number 403with a leading 404.Ql 0x , 405with a dot-notation Internet address, 406or with a pseudo-network name listed in the network table 407.Xr networks 5 . 408The mask contains 1's for the bit positions in the 32-bit address 409which are to be used for the network and subnet parts, 410and 0's for the host part. 411The mask should contain at least the standard network portion, 412and the subnet field should be contiguous with the network 413portion. 414.Pp 415The netmask can also be specified in CIDR notation after the address. 416See the 417.Ar address 418option above for more information. 419.It Cm prefixlen Ar len 420(Inet6 only.) 421Specify that 422.Ar len 423bits are reserved for subdividing networks into sub-networks. 424The 425.Ar len 426must be integer, and for syntactical reason it must be between 0 to 128. 427It is almost always 64 under the current IPv6 assignment rule. 428If the parameter is omitted, 64 is used. 429.Pp 430The prefix can also be specified using the slash notation after the address. 431See the 432.Ar address 433option above for more information. 434.\" see 435.\" Xr eon 5 . 436.\" .It Cm nsellength Ar n 437.\" .Pf ( Tn ISO 438.\" only) 439.\" This specifies a trailing number of bytes for a received 440.\" .Tn NSAP 441.\" used for local identification, the remaining leading part of which is 442.\" taken to be the 443.\" .Tn NET 444.\" (Network Entity Title). 445.\" The default value is 1, which is conformant to US 446.\" .Tn GOSIP . 447.\" When an ISO address is set in an ifconfig command, 448.\" it is really the 449.\" .Tn NSAP 450.\" which is being specified. 451.\" For example, in 452.\" .Tn US GOSIP , 453.\" 20 hex digits should be 454.\" specified in the 455.\" .Tn ISO NSAP 456.\" to be assigned to the interface. 457.\" There is some evidence that a number different from 1 may be useful 458.\" for 459.\" .Tn AFI 460.\" 37 type addresses. 461.It Cm range Ar netrange 462Under appletalk, set the interface to respond to a 463.Ar netrange 464of the form 465.Ar startnet Ns - Ns Ar endnet . 466Appletalk uses this scheme instead of 467netmasks though 468.Fx 469implements it internally as a set of netmasks. 470.It Cm remove 471Another name for the 472.Fl alias 473parameter. 474Introduced for compatibility 475with 476.Bsx . 477.It Cm phase 478The argument following this specifies the version (phase) of the 479Appletalk network attached to the interface. 480Values of 1 or 2 are permitted. 481.Sm off 482.It Cm link Op Cm 0 No - Cm 2 483.Sm on 484Enable special processing of the link level of the interface. 485These three options are interface specific in actual effect, however, 486they are in general used to select special modes of operation. 487An example 488of this is to enable SLIP compression, or to select the connector type 489for some Ethernet cards. 490Refer to the man page for the specific driver 491for more information. 492.Sm off 493.It Fl link Op Cm 0 No - Cm 2 494.Sm on 495Disable special processing at the link level with the specified interface. 496.It Cm up 497Mark an interface 498.Dq up . 499This may be used to enable an interface after an 500.Dq Nm Cm down . 501It happens automatically when setting the first address on an interface. 502If the interface was reset when previously marked down, 503the hardware will be re-initialized. 504.It Cm ssid Ar ssid 505For IEEE 802.11 wireless interfaces, set the desired Service Set 506Identifier (aka network name). 507The SSID is a string up to 32 characters 508in length and may be specified as either a normal string or in 509hexadecimal when proceeded by 510.Ql 0x . 511Additionally, the SSID may be cleared by setting it to 512.Ql - . 513.It Cm nwid Ar ssid 514Another name for the 515.Cm ssid 516parameter. 517Included for 518.Nx 519compatibility. 520.It Cm stationname Ar name 521For IEEE 802.11 wireless interfaces, set the name of this station. 522It appears that the station name is not really part of the IEEE 802.11 523protocol though all interfaces seem to support it. 524As such it only 525seems to be meaningful to identical or virtually identical equipment. 526Setting the station name is identical in syntax to setting the SSID. 527.It Cm station Ar name 528Another name for the 529.Cm stationname 530parameter. 531Included for 532.Bsx 533compatibility. 534.It Cm channel Ar number 535For IEEE 802.11 wireless interfaces, set the desired channel. 536Channels range from 1 to 14, but the exact selection available 537depends on the region your adaptor was manufactured for. 538Setting 539the channel to 0 will give you the default for your adaptor. 540Many 541adaptors ignore this setting unless you are in ad-hoc mode. 542.It Cm authmode Ar mode 543For IEEE 802.11 wireless interfaces, set the desired authentication mode 544in infrastructure mode. 545Not all adaptors support all modes. 546The set of 547valid modes is 548.Dq none , 549.Dq open , 550and 551.Dq shared . 552Modes are case insensitive. 553.It Cm powersave 554For IEEE 802.11 wireless interfaces, enable powersave mode. 555.It Fl powersave 556For IEEE 802.11 wireless interfaces, disable powersave mode. 557.It Cm powersavesleep Ar sleep 558For IEEE 802.11 wireless interfaces, set the desired max powersave sleep 559time in milliseconds. 560.It Cm wepmode Ar mode 561For IEEE 802.11 wireless interfaces, set the desired WEP mode. 562Not all adaptors support all modes. 563The set of valid modes is 564.Dq off , 565.Dq on , 566and 567.Dq mixed . 568.Dq Mixed 569mode explicitly tells the adaptor to allow association with access 570points which allow both encrypted and unencrypted traffic. 571On these adaptors, 572.Dq on 573means that the access point must only allow encrypted connections. 574On other adaptors, 575.Dq on 576is generally another name for 577.Dq mixed . 578Modes are case insensitive. 579.It Cm weptxkey Ar index 580For IEEE 802.11 wireless interfaces, set the WEP key to be used for 581transmission. 582.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key 583For IEEE 802.11 wireless interfaces, set the selected WEP key. 584If an 585.Ar index 586is not given, key 1 is set. 587A WEP key will be either 5 or 13 588characters (40 or 104 bits) depending of the local network and the 589capabilities of the adaptor. 590It may be specified either as a plain 591string or as a string of hexadecimal digits proceeded by 592.Ql 0x . 593A key may be cleared by setting it to 594.Ql - . 595If WEP is supported then there are at least four keys. 596Some adaptors support more than four keys. 597If that is the case, then the first four keys 598(1-4) will be the standard temporary keys and any others will be adaptor 599specific keys such as permanent keys stored in NVRAM. 600.It Cm wep 601Another way of saying 602.Cm wepmode on . 603Included for 604.Bsx 605compatibility. 606.It Fl wep 607Another way of saying 608.Cm wepmode off . 609Included for 610.Bsx 611compatibility. 612.It Cm nwkey key 613Another way of saying: 614.Pp 615.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" . 616.Pp 617Included for 618.Nx 619compatibility. 620.It Cm nwkey Xo 621.Sm off 622.Ar n : k1 , k2 , k3 , k4 623.Sm on 624.Xc 625Another way of saying 626.Pp 627.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" . 628.Pp 629Included for 630.Nx 631compatibility. 632.It Fl nwkey 633Another way of saying 634.Cm wepmode off . 635.Pp 636Included for 637.Nx 638compatibility. 639.El 640.Pp 641.Nm Ifconfig 642displays the current configuration for a network interface 643when no optional parameters are supplied. 644If a protocol family is specified, 645.Nm 646will report only the details specific to that protocol family. 647.Pp 648If the driver does supports the media selection system, the supported 649media list will be included in the output. 650.Pp 651If the 652.Fl m 653flag is passed before an interface name, 654.Nm 655will display all 656of the supported media for the specified interface. 657If 658.Fl L 659flag is supplied, address lifetime is displayed for IPv6 addresses, 660as time offset string. 661.Pp 662Optionally, the 663.Fl a 664flag may be used instead of an interface name. 665This flag instructs 666.Nm 667to display information about all interfaces in the system. 668The 669.Fl d 670flag limits this to interfaces that are down, and 671.Fl u 672limits this to interfaces that are up. 673When no arguments are given, 674.Fl a 675is implied. 676.Pp 677The 678.Fl l 679flag may be used to list all available interfaces on the system, with 680no other additional information. 681Use of this flag is mutually exclusive 682with all other flags and commands, except for 683.Fl d 684(only list interfaces that are down) 685and 686.Fl u 687(only list interfaces that are up). 688.Pp 689The 690.Fl C 691flag may be used to list all of the interface cloners available on 692the system, with no additional information. 693Use of this flag is mutually exclusive with all other flags and commands. 694.Pp 695Only the super-user may modify the configuration of a network interface. 696.Sh NOTES 697The media selection system is relatively new and only some drivers support 698it (or have need for it). 699.Sh DIAGNOSTICS 700Messages indicating the specified interface does not exist, the 701requested address is unknown, or the user is not privileged and 702tried to alter an interface's configuration. 703.Sh BUGS 704IPv6 link-local addresses are required for several basic communication 705between IPv6 node. 706If they are deleted by 707.Nm 708manually, the kernel might show very strange behavior. 709So, such manual deletions are strongly discouraged. 710.Sh SEE ALSO 711.Xr netstat 1 , 712.Xr netintro 4 , 713.\" .Xr eon 5 , 714.Xr rc 8 , 715.Xr routed 8 716.Sh HISTORY 717The 718.Nm 719command appeared in 720.Bx 4.2 . 721