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 75The 76.Nm 77utility is used to assign an address 78to a network interface and/or configure 79network interface parameters. 80The 81.Nm 82utility must be used at boot time to define the network address 83of each interface present on a machine; it may also be used at 84a later time to redefine an interface's address 85or other operating parameters. 86.Pp 87The following options are available: 88.Bl -tag -width indent 89.It Ar address 90For the 91.Tn DARPA Ns -Internet 92family, 93the address is either a host name present in the host name data 94base, 95.Xr hosts 5 , 96or a 97.Tn DARPA 98Internet address expressed in the Internet standard 99.Dq dot notation . 100.Pp 101It is also possible to use the CIDR notation (also known as the 102slash notation) to include the netmask. 103That is, one can specify an address like 104.Li 192.168.0.1/16 . 105.Pp 106For 107.Dq inet6 108family, it is also possible to specify the prefix length using the slash 109notation, like 110.Li ::1/128 . 111See the 112.Cm prefixlen 113parameter below for more information. 114.\" For the Xerox Network Systems(tm) family, 115.\" addresses are 116.\" .Ar net:a.b.c.d.e.f , 117.\" where 118.\" .Ar net 119.\" is the assigned network number (in decimal), 120.\" and each of the six bytes of the host number, 121.\" .Ar a 122.\" through 123.\" .Ar f , 124.\" are specified in hexadecimal. 125.\" The host number may be omitted on IEEE 802 protocol 126.\" (Ethernet, FDDI, and Token Ring) interfaces, 127.\" which use the hardware physical address, 128.\" and on interfaces other than the first. 129.\" For the 130.\" .Tn ISO 131.\" family, addresses are specified as a long hexadecimal string, 132.\" as in the Xerox family. 133.\" However, two consecutive dots imply a zero 134.\" byte, and the dots are optional, if the user wishes to (carefully) 135.\" count out long strings of digits in network byte order. 136.Pp 137The link-level 138.Pq Dq link 139address 140is specified as a series of colon-separated hex digits. 141This can be used to 142e.g. set a new MAC address on an ethernet interface, though the 143mechanism used is not ethernet-specific. 144If the interface is already 145up when this option is used, it will be briefly brought down and 146then brought back up again in order to ensure that the receive 147filter in the underlying ethernet hardware is properly reprogrammed. 148.It Ar address_family 149Specify the 150address family 151which affects interpretation of the remaining parameters. 152Since an interface can receive transmissions in differing protocols 153with different naming schemes, specifying the address family is recommended. 154The address or protocol families currently 155supported are 156.Dq inet , 157.Dq inet6 , 158.Dq atalk , 159.Dq ipx , 160.\" .Dq iso , 161and 162.Dq link . 163.\" and 164.\" .Dq ns . 165The default is 166.Dq inet . 167.Dq ether 168and 169.Dq lladdr 170are synonyms for 171.Dq link . 172.It Ar dest_address 173Specify the address of the correspondent on the other end 174of a point to point link. 175.It Ar interface 176This 177parameter is a string of the form 178.Dq name unit , 179for example, 180.Dq Li ed0 . 181.El 182.Pp 183The following parameters may be set with 184.Nm : 185.Bl -tag -width indent 186.It Cm add 187Another name for the 188.Cm alias 189parameter. 190Introduced for compatibility 191with 192.Bsx . 193.It Cm alias 194Establish an additional network address for this interface. 195This is sometimes useful when changing network numbers, and 196one wishes to accept packets addressed to the old interface. 197If the address is on the same subnet as the first network address 198for this interface, a non-conflicting netmask must be given. 199Usually 200.Li 0xffffffff 201is most appropriate. 202.It Fl alias 203Remove the network address specified. 204This would be used if you incorrectly specified an alias, or it 205was no longer needed. 206If you have incorrectly set an NS address having the side effect 207of specifying the host portion, removing all NS addresses will 208allow you to respecify the host portion. 209.It Cm anycast 210(Inet6 only.) 211Specify that the address configured is an anycast address. 212Based on the current specification, 213only routers may configure anycast addresses. 214Anycast address will not be used as source address of any of outgoing 215IPv6 packets. 216.It Cm arp 217Enable the use of the Address Resolution Protocol 218.Pq Xr arp 4 219in mapping 220between network level addresses and link level addresses (default). 221This is currently implemented for mapping between 222.Tn DARPA 223Internet 224addresses and 225.Tn IEEE 226802 48-bit MAC addresses (Ethernet, FDDI, and Token Ring addresses). 227.It Fl arp 228Disable the use of the Address Resolution Protocol 229.Pq Xr arp 4 . 230.It Cm broadcast 231(Inet only.) 232Specify the address to use to represent broadcasts to the 233network. 234The default broadcast address is the address with a host part of all 1's. 235.It Cm debug 236Enable driver dependent debugging code; usually, this turns on 237extra console error logging. 238.It Fl debug 239Disable driver dependent debugging code. 240.It Cm promisc 241Put interface into permanently promiscuous mode. 242.It Fl promisc 243Disable permanently promiscuous mode. 244.It Cm delete 245Another name for the 246.Fl alias 247parameter. 248.It Cm down 249Mark an interface 250.Dq down . 251When an interface is marked 252.Dq down , 253the system will not attempt to 254transmit messages through that interface. 255If possible, the interface will be reset to disable reception as well. 256This action does not automatically disable routes using the interface. 257.It Cm eui64 258(Inet6 only.) 259Fill interface index 260(lowermost 64bit of an IPv6 address) 261automatically. 262.\" .It Cm ipdst 263.\" This is used to specify an Internet host who is willing to receive 264.\" ip packets encapsulating NS packets bound for a remote network. 265.\" An apparent point to point link is constructed, and 266.\" the address specified will be taken as the NS address and network 267.\" of the destination. 268.\" IP encapsulation of 269.\" .Tn CLNP 270.\" packets is done differently. 271.It Cm maclabel Ar label 272If Mandatory Access Control support is enabled in the kernel, 273set the MAC label to 274.Ar label . 275.\" (see 276.\" .Xr maclabel 7 ) . 277.It Cm media Ar type 278If the driver supports the media selection system, set the media type 279of the interface to 280.Ar type . 281Some interfaces support the mutually exclusive use of one of several 282different physical media connectors. 283For example, a 10Mb/s Ethernet 284interface might support the use of either 285.Tn AUI 286or twisted pair connectors. 287Setting the media type to 288.Dq 10base5/AUI 289would change the currently active connector to the AUI port. 290Setting it to 291.Dq 10baseT/UTP 292would activate twisted pair. 293Refer to the interfaces' driver 294specific documentation or man page for a complete list of the 295available types. 296.It Cm mediaopt Ar opts 297If the driver supports the media selection system, set the specified 298media options on the interface. 299The 300.Ar opts 301argument 302is a comma delimited list of options to apply to the interface. 303Refer to the interfaces' driver specific man page for a complete 304list of available options. 305.It Fl mediaopt Ar opts 306If the driver supports the media selection system, disable the 307specified media options on the interface. 308.It Cm tunnel Ar src_addr dest_addr 309(IP tunnel devices only.) 310Configure the physical source and destination address for IP tunnel 311interfaces 312.Pq Xr gif 4 . 313The arguments 314.Ar src_addr 315and 316.Ar dest_addr 317are interpreted as the outer source/destination for the encapsulating 318IPv4/IPv6 header. 319.It Cm deletetunnel 320Unconfigure the physical source and destination address for IP tunnel 321interfaces previously configured with 322.Cm tunnel . 323.It Cm create 324Create the specified network pseudo-device. 325If the interface is given without a unit number, try to create a new 326device with an arbitrary unit number. 327If creation of an arbitrary device is successful, the new device name is 328printed to standard output. 329.It Cm destroy 330Destroy the specified network pseudo-device. 331.It Cm plumb 332Another name for the 333.Cm create 334parameter. 335Included for 336.Tn Solaris 337compatibility. 338.It Cm unplumb 339Another name for the 340.Cm destroy 341parameter. 342Included for 343.Tn Solaris 344compatibility. 345.It Cm vlan Ar vlan_tag 346If the interface is a vlan pseudo interface, set the vlan tag value 347to 348.Ar vlan_tag . 349This value is a 16-bit number which is used to create an 802.1Q 350vlan header for packets sent from the vlan interface. 351Note that 352.Cm vlan 353and 354.Cm vlandev 355must both be set at the same time. 356.It Cm vlandev Ar iface 357If the interface is a vlan pseudo device, associate physical interface 358.Ar iface 359with it. 360Packets transmitted through the vlan interface will be 361diverted to the specified physical interface 362.Ar iface 363with 802.1Q vlan encapsulation. 364Packets with 802.1Q encapsulation received 365by the parent interface with the correct vlan tag will be diverted to 366the associated vlan pseudo-interface. 367The vlan interface is assigned a 368copy of the parent interface's flags and the parent's ethernet address. 369The 370.Cm vlandev 371and 372.Cm vlan 373must both be set at the same time. 374If the vlan interface already has 375a physical interface associated with it, this command will fail. 376To 377change the association to another physical interface, the existing 378association must be cleared first. 379.Pp 380Note: if the 381.Cm link0 382flag is set on the vlan interface, the vlan pseudo 383interface's behavior changes: the 384.Cm link0 385tells the vlan interface that the 386parent interface supports insertion and extraction of vlan tags on its 387own (usually in firmware) and that it should pass packets to and from 388the parent unaltered. 389.It Fl vlandev Ar iface 390If the driver is a vlan pseudo device, disassociate the physical interface 391.Ar iface 392from it. 393This breaks the link between the vlan interface and its parent, 394clears its vlan tag, flags and its link address and shuts the interface down. 395.It Cm metric Ar n 396Set the routing metric of the interface to 397.Ar n , 398default 0. 399The routing metric is used by the routing protocol 400.Pq Xr routed 8 . 401Higher metrics have the effect of making a route 402less favorable; metrics are counted as addition hops 403to the destination network or host. 404.It Cm mtu Ar n 405Set the maximum transmission unit of the interface to 406.Ar n , 407default is interface specific. 408The MTU is used to limit the size of packets that are transmitted on an 409interface. 410Not all interfaces support setting the MTU, and some interfaces have 411range restrictions. 412.It Cm netmask Ar mask 413.\" (Inet and ISO.) 414(Inet only.) 415Specify how much of the address to reserve for subdividing 416networks into sub-networks. 417The mask includes the network part of the local address 418and the subnet part, which is taken from the host field of the address. 419The mask can be specified as a single hexadecimal number 420with a leading 421.Ql 0x , 422with a dot-notation Internet address, 423or with a pseudo-network name listed in the network table 424.Xr networks 5 . 425The mask contains 1's for the bit positions in the 32-bit address 426which are to be used for the network and subnet parts, 427and 0's for the host part. 428The mask should contain at least the standard network portion, 429and the subnet field should be contiguous with the network 430portion. 431.Pp 432The netmask can also be specified in CIDR notation after the address. 433See the 434.Ar address 435option above for more information. 436.It Cm prefixlen Ar len 437(Inet6 only.) 438Specify that 439.Ar len 440bits are reserved for subdividing networks into sub-networks. 441The 442.Ar len 443must be integer, and for syntactical reason it must be between 0 to 128. 444It is almost always 64 under the current IPv6 assignment rule. 445If the parameter is omitted, 64 is used. 446.Pp 447The prefix can also be specified using the slash notation after the address. 448See the 449.Ar address 450option above for more information. 451.\" see 452.\" Xr eon 5 . 453.\" .It Cm nsellength Ar n 454.\" .Pf ( Tn ISO 455.\" only) 456.\" This specifies a trailing number of bytes for a received 457.\" .Tn NSAP 458.\" used for local identification, the remaining leading part of which is 459.\" taken to be the 460.\" .Tn NET 461.\" (Network Entity Title). 462.\" The default value is 1, which is conformant to US 463.\" .Tn GOSIP . 464.\" When an ISO address is set in an ifconfig command, 465.\" it is really the 466.\" .Tn NSAP 467.\" which is being specified. 468.\" For example, in 469.\" .Tn US GOSIP , 470.\" 20 hex digits should be 471.\" specified in the 472.\" .Tn ISO NSAP 473.\" to be assigned to the interface. 474.\" There is some evidence that a number different from 1 may be useful 475.\" for 476.\" .Tn AFI 477.\" 37 type addresses. 478.It Cm range Ar netrange 479Under appletalk, set the interface to respond to a 480.Ar netrange 481of the form 482.Ar startnet Ns - Ns Ar endnet . 483Appletalk uses this scheme instead of 484netmasks though 485.Fx 486implements it internally as a set of netmasks. 487.It Cm remove 488Another name for the 489.Fl alias 490parameter. 491Introduced for compatibility 492with 493.Bsx . 494.It Cm phase 495The argument following this specifies the version (phase) of the 496Appletalk network attached to the interface. 497Values of 1 or 2 are permitted. 498.Sm off 499.It Cm link Op Cm 0 No - Cm 2 500.Sm on 501Enable special processing of the link level of the interface. 502These three options are interface specific in actual effect, however, 503they are in general used to select special modes of operation. 504An example 505of this is to enable SLIP compression, or to select the connector type 506for some Ethernet cards. 507Refer to the man page for the specific driver 508for more information. 509.Sm off 510.It Fl link Op Cm 0 No - Cm 2 511.Sm on 512Disable special processing at the link level with the specified interface. 513.It Cm monitor 514.Sm on 515Put the interface in monitor mode. 516No packets are transmitted and received packets are discarded after 517.Xr bpf 4 518processing. 519.Sm off 520.It Fl monitor 521.Sm on 522Take the interface out of monitor mode. 523.Sm off 524.It Cm up 525Mark an interface 526.Dq up . 527This may be used to enable an interface after an 528.Dq Nm Cm down . 529It happens automatically when setting the first address on an interface. 530If the interface was reset when previously marked down, 531the hardware will be re-initialized. 532.It Cm ssid Ar ssid 533For IEEE 802.11 wireless interfaces, set the desired Service Set 534Identifier (aka network name). 535The SSID is a string up to 32 characters 536in length and may be specified as either a normal string or in 537hexadecimal when proceeded by 538.Ql 0x . 539Additionally, the SSID may be cleared by setting it to 540.Ql - . 541.It Cm nwid Ar ssid 542Another name for the 543.Cm ssid 544parameter. 545Included for 546.Nx 547compatibility. 548.It Cm stationname Ar name 549For IEEE 802.11 wireless interfaces, set the name of this station. 550It appears that the station name is not really part of the IEEE 802.11 551protocol though all interfaces seem to support it. 552As such it only 553seems to be meaningful to identical or virtually identical equipment. 554Setting the station name is identical in syntax to setting the SSID. 555.It Cm station Ar name 556Another name for the 557.Cm stationname 558parameter. 559Included for 560.Bsx 561compatibility. 562.It Cm channel Ar number 563For IEEE 802.11 wireless interfaces, set the desired channel. 564Channels range from 1 to 14, but the exact selection available 565depends on the region your adaptor was manufactured for. 566Setting 567the channel to 0 will give you the default for your adaptor. 568Many 569adaptors ignore this setting unless you are in ad-hoc mode. 570.It Cm authmode Ar mode 571For IEEE 802.11 wireless interfaces, set the desired authentication mode 572in infrastructure mode. 573Not all adaptors support all modes. 574The set of 575valid modes is 576.Dq none , 577.Dq open , 578and 579.Dq shared . 580Modes are case insensitive. 581.It Cm powersave 582For IEEE 802.11 wireless interfaces, enable powersave mode. 583.It Fl powersave 584For IEEE 802.11 wireless interfaces, disable powersave mode. 585.It Cm powersavesleep Ar sleep 586For IEEE 802.11 wireless interfaces, set the desired max powersave sleep 587time in milliseconds. 588.It Cm wepmode Ar mode 589For IEEE 802.11 wireless interfaces, set the desired WEP mode. 590Not all adaptors support all modes. 591The set of valid modes is 592.Dq off , 593.Dq on , 594and 595.Dq mixed . 596.Dq Mixed 597mode explicitly tells the adaptor to allow association with access 598points which allow both encrypted and unencrypted traffic. 599On these adaptors, 600.Dq on 601means that the access point must only allow encrypted connections. 602On other adaptors, 603.Dq on 604is generally another name for 605.Dq mixed . 606Modes are case insensitive. 607.It Cm weptxkey Ar index 608For IEEE 802.11 wireless interfaces, set the WEP key to be used for 609transmission. 610.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key 611For IEEE 802.11 wireless interfaces, set the selected WEP key. 612If an 613.Ar index 614is not given, key 1 is set. 615A WEP key will be either 5 or 13 616characters (40 or 104 bits) depending of the local network and the 617capabilities of the adaptor. 618It may be specified either as a plain 619string or as a string of hexadecimal digits proceeded by 620.Ql 0x . 621For maximum portability, hex keys are recommended; 622the mapping of text keys to WEP encryption is usually driver-specific. 623In particular, the Windows drivers do this mapping differently to 624.Fx . 625A key may be cleared by setting it to 626.Ql - . 627If WEP is supported then there are at least four keys. 628Some adaptors support more than four keys. 629If that is the case, then the first four keys 630(1-4) will be the standard temporary keys and any others will be adaptor 631specific keys such as permanent keys stored in NVRAM. 632.It Cm wep 633Another way of saying 634.Cm wepmode on . 635Included for 636.Bsx 637compatibility. 638.It Fl wep 639Another way of saying 640.Cm wepmode off . 641Included for 642.Bsx 643compatibility. 644.It Cm nwkey key 645Another way of saying: 646.Pp 647.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" . 648.Pp 649Included for 650.Nx 651compatibility. 652.It Cm nwkey Xo 653.Sm off 654.Ar n : k1 , k2 , k3 , k4 655.Sm on 656.Xc 657Another way of saying 658.Pp 659.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" . 660.Pp 661Included for 662.Nx 663compatibility. 664.It Fl nwkey 665Another way of saying 666.Cm wepmode off . 667.Pp 668Included for 669.Nx 670compatibility. 671.El 672.Pp 673The 674.Nm 675utility displays the current configuration for a network interface 676when no optional parameters are supplied. 677If a protocol family is specified, 678.Nm 679will report only the details specific to that protocol family. 680.Pp 681If the driver does supports the media selection system, the supported 682media list will be included in the output. 683.Pp 684If the 685.Fl m 686flag is passed before an interface name, 687.Nm 688will display all 689of the supported media for the specified interface. 690If 691.Fl L 692flag is supplied, address lifetime is displayed for IPv6 addresses, 693as time offset string. 694.Pp 695Optionally, the 696.Fl a 697flag may be used instead of an interface name. 698This flag instructs 699.Nm 700to display information about all interfaces in the system. 701The 702.Fl d 703flag limits this to interfaces that are down, and 704.Fl u 705limits this to interfaces that are up. 706When no arguments are given, 707.Fl a 708is implied. 709.Pp 710The 711.Fl l 712flag may be used to list all available interfaces on the system, with 713no other additional information. 714Use of this flag is mutually exclusive 715with all other flags and commands, except for 716.Fl d 717(only list interfaces that are down) 718and 719.Fl u 720(only list interfaces that are up). 721.Pp 722The 723.Fl C 724flag may be used to list all of the interface cloners available on 725the system, with no additional information. 726Use of this flag is mutually exclusive with all other flags and commands. 727.Pp 728Only the super-user may modify the configuration of a network interface. 729.Sh NOTES 730The media selection system is relatively new and only some drivers support 731it (or have need for it). 732.Sh DIAGNOSTICS 733Messages indicating the specified interface does not exist, the 734requested address is unknown, or the user is not privileged and 735tried to alter an interface's configuration. 736.Sh BUGS 737IPv6 link-local addresses are required for several basic communication 738between IPv6 node. 739If they are deleted by 740.Nm 741manually, the kernel might show very strange behavior. 742So, such manual deletions are strongly discouraged. 743.Sh SEE ALSO 744.Xr netstat 1 , 745.Xr netintro 4 , 746.\" .Xr eon 5 , 747.Xr rc 8 , 748.Xr routed 8 749.Sh HISTORY 750The 751.Nm 752utility appeared in 753.Bx 4.2 . 754