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 eui64 252(Inet6 only.) 253Fill interface index 254.Pq lowermost 64bit of an IPv6 address 255automatically. 256.\" .It Cm ipdst 257.\" This is used to specify an Internet host who is willing to receive 258.\" ip packets encapsulating NS packets bound for a remote network. 259.\" An apparent point to point link is constructed, and 260.\" the address specified will be taken as the NS address and network 261.\" of the destination. 262.\" IP encapsulation of 263.\" .Tn CLNP 264.\" packets is done differently. 265.It Cm media Ar type 266If the driver supports the media selection system, set the media type 267of the interface to 268.Ar type . 269Some interfaces support the mutually exclusive use of one of several 270different physical media connectors. 271For example, a 10Mb/s Ethernet 272interface might support the use of either 273.Tn AUI 274or twisted pair connectors. 275Setting the media type to 276.Dq 10base5/AUI 277would change the currently active connector to the AUI port. 278Setting it to 279.Dq 10baseT/UTP 280would activate twisted pair. 281Refer to the interfaces' driver 282specific documentation or man page for a complete list of the 283available types. 284.It Cm mediaopt Ar opts 285If the driver supports the media selection system, set the specified 286media options on the interface. 287The 288.Ar opts 289argument 290is a comma delimited list of options to apply to the interface. 291Refer to the interfaces' driver specific man page for a complete 292list of available options. 293.It Fl mediaopt Ar opts 294If the driver supports the media selection system, disable the 295specified media options on the interface. 296.It Cm tunnel Ar src_addr dest_addr 297(IP tunnel devices only.) 298Configure the physical source and destination address for IP tunnel 299interfaces 300.Pq Xr gif 4 . 301The arguments 302.Ar src_addr 303and 304.Ar dest_addr 305are interpreted as the outer source/destination for the encapsulating 306IPv4/IPv6 header. 307.It Cm deletetunnel 308Unconfigure the physical source and destination address for IP tunnel 309interfaces previously configured with 310.Cm tunnel . 311.It Cm create 312Create the specified network pseudo-device. 313If the interface is given without a unit number, try to create a new 314device with an arbitrary unit number. 315If creation of an arbitrary device is successful, the new device name is 316printed to standard output. 317.It Cm destroy 318Destroy the specified network pseudo-device. 319.It Cm plumb 320Another name for the 321.Cm create 322parameter. 323Included for 324.Tn Solaris 325compatibility. 326.It Cm unplumb 327Another name for the 328.Cm destroy 329parameter. 330Included for 331.Tn Solaris 332compatibility. 333.It Cm vlan Ar vlan_tag 334If the interface is a vlan pseudo interface, set the vlan tag value 335to 336.Ar vlan_tag . 337This value is a 16-bit number which is used to create an 802.1Q 338vlan header for packets sent from the vlan interface. 339Note that 340.Cm vlan 341and 342.Cm vlandev 343must both be set at the same time. 344.It Cm vlandev Ar iface 345If the interface is a vlan pseudo device, associate physical interface 346.Ar iface 347with it. 348Packets transmitted through the vlan interface will be 349diverted to the specified physical interface 350.Ar iface 351with 802.1Q vlan encapsulation. 352Packets with 802.1Q encapsulation received 353by the parent interface with the correct vlan tag will be diverted to 354the associated vlan pseudo-interface. 355The vlan interface is assigned a 356copy of the parent interface's flags and the parent's ethernet address. 357The 358.Cm vlandev 359and 360.Cm vlan 361must both be set at the same time. 362If the vlan interface already has 363a physical interface associated with it, this command will fail. 364To 365change the association to another physical interface, the existing 366association must be cleared first. 367.Pp 368Note: if the 369.Cm link0 370flag is set on the vlan interface, the vlan pseudo 371interface's behavior changes: the 372.Cm link0 373tells the vlan interface that the 374parent interface supports insertion and extraction of vlan tags on its 375own (usually in firmware) and that it should pass packets to and from 376the parent unaltered. 377.It Fl vlandev Ar iface 378If the driver is a vlan pseudo device, disassociate the physical interface 379.Ar iface 380from it. 381This breaks the link between the vlan interface and its parent, 382clears its vlan tag, flags and its link address and shuts the interface down. 383.It Cm metric Ar n 384Set the routing metric of the interface to 385.Ar n , 386default 0. 387The routing metric is used by the routing protocol 388.Pq Xr routed 8 . 389Higher metrics have the effect of making a route 390less favorable; metrics are counted as addition hops 391to the destination network or host. 392.It Cm mtu Ar n 393Set the maximum transmission unit of the interface to 394.Ar n , 395default is interface specific. 396The MTU is used to limit the size of packets that are transmitted on an 397interface. 398Not all interfaces support setting the MTU, and some interfaces have 399range restrictions. 400.It Cm netmask Ar mask 401.\" (Inet and ISO.) 402(Inet only.) 403Specify how much of the address to reserve for subdividing 404networks into sub-networks. 405The mask includes the network part of the local address 406and the subnet part, which is taken from the host field of the address. 407The mask can be specified as a single hexadecimal number 408with a leading 409.Ql 0x , 410with a dot-notation Internet address, 411or with a pseudo-network name listed in the network table 412.Xr networks 5 . 413The mask contains 1's for the bit positions in the 32-bit address 414which are to be used for the network and subnet parts, 415and 0's for the host part. 416The mask should contain at least the standard network portion, 417and the subnet field should be contiguous with the network 418portion. 419.Pp 420The netmask can also be specified in CIDR notation after the address. 421See the 422.Ar address 423option above for more information. 424.It Cm prefixlen Ar len 425(Inet6 only.) 426Specify that 427.Ar len 428bits are reserved for subdividing networks into sub-networks. 429The 430.Ar len 431must be integer, and for syntactical reason it must be between 0 to 128. 432It is almost always 64 under the current IPv6 assignment rule. 433If the parameter is omitted, 64 is used. 434.Pp 435The prefix can also be specified using the slash notation after the address. 436See the 437.Ar address 438option above for more information. 439.\" see 440.\" Xr eon 5 . 441.\" .It Cm nsellength Ar n 442.\" .Pf ( Tn ISO 443.\" only) 444.\" This specifies a trailing number of bytes for a received 445.\" .Tn NSAP 446.\" used for local identification, the remaining leading part of which is 447.\" taken to be the 448.\" .Tn NET 449.\" (Network Entity Title). 450.\" The default value is 1, which is conformant to US 451.\" .Tn GOSIP . 452.\" When an ISO address is set in an ifconfig command, 453.\" it is really the 454.\" .Tn NSAP 455.\" which is being specified. 456.\" For example, in 457.\" .Tn US GOSIP , 458.\" 20 hex digits should be 459.\" specified in the 460.\" .Tn ISO NSAP 461.\" to be assigned to the interface. 462.\" There is some evidence that a number different from 1 may be useful 463.\" for 464.\" .Tn AFI 465.\" 37 type addresses. 466.It Cm range Ar netrange 467Under appletalk, set the interface to respond to a 468.Ar netrange 469of the form 470.Ar startnet Ns - Ns Ar endnet . 471Appletalk uses this scheme instead of 472netmasks though 473.Fx 474implements it internally as a set of netmasks. 475.It Cm remove 476Another name for the 477.Fl alias 478parameter. 479Introduced for compatibility 480with 481.Bsx . 482.It Cm phase 483The argument following this specifies the version (phase) of the 484Appletalk network attached to the interface. 485Values of 1 or 2 are permitted. 486.Sm off 487.It Cm link Op Cm 0 No - Cm 2 488.Sm on 489Enable special processing of the link level of the interface. 490These three options are interface specific in actual effect, however, 491they are in general used to select special modes of operation. 492An example 493of this is to enable SLIP compression, or to select the connector type 494for some Ethernet cards. 495Refer to the man page for the specific driver 496for more information. 497.Sm off 498.It Fl link Op Cm 0 No - Cm 2 499.Sm on 500Disable special processing at the link level with the specified interface. 501.It Cm up 502Mark an interface 503.Dq up . 504This may be used to enable an interface after an 505.Dq Nm Cm down . 506It happens automatically when setting the first address on an interface. 507If the interface was reset when previously marked down, 508the hardware will be re-initialized. 509.It Cm ssid Ar ssid 510For IEEE 802.11 wireless interfaces, set the desired Service Set 511Identifier (aka network name). 512The SSID is a string up to 32 characters 513in length and may be specified as either a normal string or in 514hexadecimal when proceeded by 515.Ql 0x . 516Additionally, the SSID may be cleared by setting it to 517.Ql - . 518.It Cm nwid Ar ssid 519Another name for the 520.Cm ssid 521parameter. 522Included for 523.Nx 524compatibility. 525.It Cm stationname Ar name 526For IEEE 802.11 wireless interfaces, set the name of this station. 527It appears that the station name is not really part of the IEEE 802.11 528protocol though all interfaces seem to support it. 529As such it only 530seems to be meaningful to identical or virtually identical equipment. 531Setting the station name is identical in syntax to setting the SSID. 532.It Cm station Ar name 533Another name for the 534.Cm stationname 535parameter. 536Included for 537.Bsx 538compatibility. 539.It Cm channel Ar number 540For IEEE 802.11 wireless interfaces, set the desired channel. 541Channels range from 1 to 14, but the exact selection available 542depends on the region your adaptor was manufactured for. 543Setting 544the channel to 0 will give you the default for your adaptor. 545Many 546adaptors ignore this setting unless you are in ad-hoc mode. 547.It Cm authmode Ar mode 548For IEEE 802.11 wireless interfaces, set the desired authentication mode 549in infrastructure mode. 550Not all adaptors support all modes. 551The set of 552valid modes is 553.Dq none , 554.Dq open , 555and 556.Dq shared . 557Modes are case insensitive. 558.It Cm powersave 559For IEEE 802.11 wireless interfaces, enable powersave mode. 560.It Fl powersave 561For IEEE 802.11 wireless interfaces, disable powersave mode. 562.It Cm powersavesleep Ar sleep 563For IEEE 802.11 wireless interfaces, set the desired max powersave sleep 564time in milliseconds. 565.It Cm wepmode Ar mode 566For IEEE 802.11 wireless interfaces, set the desired WEP mode. 567Not all adaptors support all modes. 568The set of valid modes is 569.Dq off , 570.Dq on , 571and 572.Dq mixed . 573.Dq Mixed 574mode explicitly tells the adaptor to allow association with access 575points which allow both encrypted and unencrypted traffic. 576On these adaptors, 577.Dq on 578means that the access point must only allow encrypted connections. 579On other adaptors, 580.Dq on 581is generally another name for 582.Dq mixed . 583Modes are case insensitive. 584.It Cm weptxkey Ar index 585For IEEE 802.11 wireless interfaces, set the WEP key to be used for 586transmission. 587.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key 588For IEEE 802.11 wireless interfaces, set the selected WEP key. 589If an 590.Ar index 591is not given, key 1 is set. 592A WEP key will be either 5 or 13 593characters (40 or 104 bits) depending of the local network and the 594capabilities of the adaptor. 595It may be specified either as a plain 596string or as a string of hexadecimal digits proceeded by 597.Ql 0x . 598A key may be cleared by setting it to 599.Ql - . 600If WEP is supported then there are at least four keys. 601Some adaptors support more than four keys. 602If that is the case, then the first four keys 603(1-4) will be the standard temporary keys and any others will be adaptor 604specific keys such as permanent keys stored in NVRAM. 605.It Cm wep 606Another way of saying 607.Cm wepmode on . 608Included for 609.Bsx 610compatibility. 611.It Fl wep 612Another way of saying 613.Cm wepmode off . 614Included for 615.Bsx 616compatibility. 617.It Cm nwkey key 618Another way of saying: 619.Pp 620.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" . 621.Pp 622Included for 623.Nx 624compatibility. 625.It Cm nwkey Xo 626.Sm off 627.Ar n : k1 , k2 , k3 , k4 628.Sm on 629.Xc 630Another way of saying 631.Pp 632.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" . 633.Pp 634Included for 635.Nx 636compatibility. 637.It Fl nwkey 638Another way of saying 639.Cm wepmode off . 640.Pp 641Included for 642.Nx 643compatibility. 644.El 645.Pp 646.Nm Ifconfig 647displays the current configuration for a network interface 648when no optional parameters are supplied. 649If a protocol family is specified, 650.Nm 651will report only the details specific to that protocol family. 652.Pp 653If the driver does supports the media selection system, the supported 654media list will be included in the output. 655.Pp 656If the 657.Fl m 658flag is passed before an interface name, 659.Nm 660will display all 661of the supported media for the specified interface. 662If 663.Fl L 664flag is supplied, address lifetime is displayed for IPv6 addresses, 665as time offset string. 666.Pp 667Optionally, the 668.Fl a 669flag may be used instead of an interface name. 670This flag instructs 671.Nm 672to display information about all interfaces in the system. 673The 674.Fl d 675flag limits this to interfaces that are down, and 676.Fl u 677limits this to interfaces that are up. 678When no arguments are given, 679.Fl a 680is implied. 681.Pp 682The 683.Fl l 684flag may be used to list all available interfaces on the system, with 685no other additional information. 686Use of this flag is mutually exclusive 687with all other flags and commands, except for 688.Fl d 689(only list interfaces that are down) 690and 691.Fl u 692(only list interfaces that are up). 693.Pp 694The 695.Fl C 696flag may be used to list all of the interface cloners available on 697the system, with no additional information. 698Use of this flag is mutually exclusive with all other flags and commands. 699.Pp 700Only the super-user may modify the configuration of a network interface. 701.Sh NOTES 702The media selection system is relatively new and only some drivers support 703it (or have need for it). 704.Sh DIAGNOSTICS 705Messages indicating the specified interface does not exist, the 706requested address is unknown, or the user is not privileged and 707tried to alter an interface's configuration. 708.Sh BUGS 709IPv6 link-local addresses are required for several basic communication 710between IPv6 node. 711If they are deleted by 712.Nm 713manually, the kernel might show very strange behavior. 714So, such manual deletions are strongly discouraged. 715.Sh SEE ALSO 716.Xr netstat 1 , 717.Xr netintro 4 , 718.\" .Xr eon 5 , 719.Xr rc 8 , 720.Xr routed 8 721.Sh HISTORY 722The 723.Nm 724command appeared in 725.Bx 4.2 . 726