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 April 28, 2003 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 263This is used to specify an Internet host who is willing to receive 264IP packets encapsulating IPX packets bound for a remote network. 265An apparent point to point link is constructed, and 266the address specified will be taken as the IPX address and network 267of the destination. 268.It Cm maclabel Ar label 269If Mandatory Access Control support is enabled in the kernel, 270set the MAC label to 271.Ar label . 272.\" (see 273.\" .Xr maclabel 7 ) . 274.It Cm media Ar type 275If the driver supports the media selection system, set the media type 276of the interface to 277.Ar type . 278Some interfaces support the mutually exclusive use of one of several 279different physical media connectors. 280For example, a 10Mb/s Ethernet 281interface might support the use of either 282.Tn AUI 283or twisted pair connectors. 284Setting the media type to 285.Dq 10base5/AUI 286would change the currently active connector to the AUI port. 287Setting it to 288.Dq 10baseT/UTP 289would activate twisted pair. 290Refer to the interfaces' driver 291specific documentation or man page for a complete list of the 292available types. 293.It Cm mediaopt Ar opts 294If the driver supports the media selection system, set the specified 295media options on the interface. 296The 297.Ar opts 298argument 299is a comma delimited list of options to apply to the interface. 300Refer to the interfaces' driver specific man page for a complete 301list of available options. 302.It Fl mediaopt Ar opts 303If the driver supports the media selection system, disable the 304specified media options on the interface. 305.It Cm mode Ar mode 306If the driver supports the media selection system, set the specified 307operating mode on the interface to 308.Ar mode . 309For IEEE 802.11 wireless interfaces that support multiple operating modes 310this directive is used to select between 802.11a (\c 311.Dq 11a ), 312802.11b (\c 313.Dq 11b ), 314and 802.11g (\c 315.Dq 11g ) 316operating modes. 317.It Cm rxcsum , txcsum 318If the driver supports user-configurable checksum offloading, 319enable receive (or transmit) checksum offloading on the interface. 320Some drivers may not be able to enable these flags independently 321of each other, so setting one may also set the other. 322The driver will offload as much checksum work as it can reliably 323support, the exact level of offloading varies between drivers. 324.It Fl rxcsum , Fl txcsum 325If the driver supports user-configurable checksum offloading, 326disable receive (or transmit) checksum offloading on the interface. 327These settings may not always be independent of each other. 328.It Cm tunnel Ar src_addr dest_addr 329(IP tunnel devices only.) 330Configure the physical source and destination address for IP tunnel 331interfaces 332.Pq Xr gif 4 . 333The arguments 334.Ar src_addr 335and 336.Ar dest_addr 337are interpreted as the outer source/destination for the encapsulating 338IPv4/IPv6 header. 339.It Cm deletetunnel 340Unconfigure the physical source and destination address for IP tunnel 341interfaces previously configured with 342.Cm tunnel . 343.It Cm create 344Create the specified network pseudo-device. 345If the interface is given without a unit number, try to create a new 346device with an arbitrary unit number. 347If creation of an arbitrary device is successful, the new device name is 348printed to standard output. 349.It Cm destroy 350Destroy the specified network pseudo-device. 351.It Cm plumb 352Another name for the 353.Cm create 354parameter. 355Included for 356.Tn Solaris 357compatibility. 358.It Cm unplumb 359Another name for the 360.Cm destroy 361parameter. 362Included for 363.Tn Solaris 364compatibility. 365.It Cm vlan Ar vlan_tag 366If the interface is a vlan pseudo interface, set the vlan tag value 367to 368.Ar vlan_tag . 369This value is a 16-bit number which is used to create an 802.1Q 370vlan header for packets sent from the vlan interface. 371Note that 372.Cm vlan 373and 374.Cm vlandev 375must both be set at the same time. 376.It Cm vlandev Ar iface 377If the interface is a vlan pseudo device, associate physical interface 378.Ar iface 379with it. 380Packets transmitted through the vlan interface will be 381diverted to the specified physical interface 382.Ar iface 383with 802.1Q vlan encapsulation. 384Packets with 802.1Q encapsulation received 385by the parent interface with the correct vlan tag will be diverted to 386the associated vlan pseudo-interface. 387The vlan interface is assigned a 388copy of the parent interface's flags and the parent's ethernet address. 389The 390.Cm vlandev 391and 392.Cm vlan 393must both be set at the same time. 394If the vlan interface already has 395a physical interface associated with it, this command will fail. 396To 397change the association to another physical interface, the existing 398association must be cleared first. 399.Pp 400Note: if the hardware tagging capability 401is set on the vlan interface, the vlan pseudo 402interface's behavior changes: 403the vlan interface recognizes that the 404parent interface supports insertion and extraction of vlan tags on its 405own (usually in firmware) and that it should pass packets to and from 406the parent unaltered. 407.It Fl vlandev Ar iface 408If the driver is a vlan pseudo device, disassociate the physical interface 409.Ar iface 410from it. 411This breaks the link between the vlan interface and its parent, 412clears its vlan tag, flags and its link address and shuts the interface down. 413.It Cm metric Ar n 414Set the routing metric of the interface to 415.Ar n , 416default 0. 417The routing metric is used by the routing protocol 418.Pq Xr routed 8 . 419Higher metrics have the effect of making a route 420less favorable; metrics are counted as addition hops 421to the destination network or host. 422.It Cm mtu Ar n 423Set the maximum transmission unit of the interface to 424.Ar n , 425default is interface specific. 426The MTU is used to limit the size of packets that are transmitted on an 427interface. 428Not all interfaces support setting the MTU, and some interfaces have 429range restrictions. 430.It Cm netmask Ar mask 431.\" (Inet and ISO.) 432(Inet only.) 433Specify how much of the address to reserve for subdividing 434networks into sub-networks. 435The mask includes the network part of the local address 436and the subnet part, which is taken from the host field of the address. 437The mask can be specified as a single hexadecimal number 438with a leading 439.Ql 0x , 440with a dot-notation Internet address, 441or with a pseudo-network name listed in the network table 442.Xr networks 5 . 443The mask contains 1's for the bit positions in the 32-bit address 444which are to be used for the network and subnet parts, 445and 0's for the host part. 446The mask should contain at least the standard network portion, 447and the subnet field should be contiguous with the network 448portion. 449.Pp 450The netmask can also be specified in CIDR notation after the address. 451See the 452.Ar address 453option above for more information. 454.It Cm prefixlen Ar len 455(Inet6 only.) 456Specify that 457.Ar len 458bits are reserved for subdividing networks into sub-networks. 459The 460.Ar len 461must be integer, and for syntactical reason it must be between 0 to 128. 462It is almost always 64 under the current IPv6 assignment rule. 463If the parameter is omitted, 64 is used. 464.Pp 465The prefix can also be specified using the slash notation after the address. 466See the 467.Ar address 468option above for more information. 4693\" see 470.\" Xr eon 5 . 471.\" .It Cm nsellength Ar n 472.\" .Pf ( Tn ISO 473.\" only) 474.\" This specifies a trailing number of bytes for a received 475.\" .Tn NSAP 476.\" used for local identification, the remaining leading part of which is 477.\" taken to be the 478.\" .Tn NET 479.\" (Network Entity Title). 480.\" The default value is 1, which is conformant to US 481.\" .Tn GOSIP . 482.\" When an ISO address is set in an ifconfig command, 483.\" it is really the 484.\" .Tn NSAP 485.\" which is being specified. 486.\" For example, in 487.\" .Tn US GOSIP , 488.\" 20 hex digits should be 489.\" specified in the 490.\" .Tn ISO NSAP 491.\" to be assigned to the interface. 492.\" There is some evidence that a number different from 1 may be useful 493.\" for 494.\" .Tn AFI 495.\" 37 type addresses. 496.It Cm range Ar netrange 497Under appletalk, set the interface to respond to a 498.Ar netrange 499of the form 500.Ar startnet Ns - Ns Ar endnet . 501Appletalk uses this scheme instead of 502netmasks though 503.Fx 504implements it internally as a set of netmasks. 505.It Cm remove 506Another name for the 507.Fl alias 508parameter. 509Introduced for compatibility 510with 511.Bsx . 512.It Cm phase 513The argument following this specifies the version (phase) of the 514Appletalk network attached to the interface. 515Values of 1 or 2 are permitted. 516.Sm off 517.It Cm link Op Cm 0 No - Cm 2 518.Sm on 519Enable special processing of the link level of the interface. 520These three options are interface specific in actual effect, however, 521they are in general used to select special modes of operation. 522An example 523of this is to enable SLIP compression, or to select the connector type 524for some Ethernet cards. 525Refer to the man page for the specific driver 526for more information. 527.Sm off 528.It Fl link Op Cm 0 No - Cm 2 529.Sm on 530Disable special processing at the link level with the specified interface. 531.It Cm monitor 532Put the interface in monitor mode. 533No packets are transmitted, and received packets are discarded after 534.Xr bpf 4 535processing. 536.It Fl monitor 537Take the interface out of monitor mode. 538.It Cm up 539Mark an interface 540.Dq up . 541This may be used to enable an interface after an 542.Dq Nm Cm down . 543It happens automatically when setting the first address on an interface. 544If the interface was reset when previously marked down, 545the hardware will be re-initialized. 546.It Cm ssid Ar ssid 547For IEEE 802.11 wireless interfaces, set the desired Service Set 548Identifier (aka network name). 549The SSID is a string up to 32 characters 550in length and may be specified as either a normal string or in 551hexadecimal when proceeded by 552.Ql 0x . 553Additionally, the SSID may be cleared by setting it to 554.Ql - . 555.It Cm nwid Ar ssid 556Another name for the 557.Cm ssid 558parameter. 559Included for 560.Nx 561compatibility. 562.It Cm stationname Ar name 563For IEEE 802.11 wireless interfaces, set the name of this station. 564It appears that the station name is not really part of the IEEE 802.11 565protocol though all interfaces seem to support it. 566As such it only 567seems to be meaningful to identical or virtually identical equipment. 568Setting the station name is identical in syntax to setting the SSID. 569.It Cm station Ar name 570Another name for the 571.Cm stationname 572parameter. 573Included for 574.Bsx 575compatibility. 576.It Cm channel Ar number 577For IEEE 802.11 wireless interfaces, set the desired channel. 578Channels range from 1 to 14, but the exact selection available 579depends on the region your adaptor was manufactured for. 580Setting 581the channel to 0 will give you the default for your adaptor. 582Many 583adaptors ignore this setting unless you are in ad-hoc mode. 584.It Cm authmode Ar mode 585For IEEE 802.11 wireless interfaces, set the desired authentication mode 586in infrastructure mode. 587Not all adaptors support all modes. 588The set of 589valid modes is 590.Dq none , 591.Dq open , 592and 593.Dq shared . 594Modes are case insensitive. 595.It Cm powersave 596For IEEE 802.11 wireless interfaces, enable powersave mode. 597.It Fl powersave 598For IEEE 802.11 wireless interfaces, disable powersave mode. 599.It Cm powersavesleep Ar sleep 600For IEEE 802.11 wireless interfaces, set the desired max powersave sleep 601time in milliseconds. 602.It Cm wepmode Ar mode 603For IEEE 802.11 wireless interfaces, set the desired WEP mode. 604Not all adaptors support all modes. 605The set of valid modes is 606.Dq off , 607.Dq on , 608and 609.Dq mixed . 610.Dq Mixed 611mode explicitly tells the adaptor to allow association with access 612points which allow both encrypted and unencrypted traffic. 613On these adaptors, 614.Dq on 615means that the access point must only allow encrypted connections. 616On other adaptors, 617.Dq on 618is generally another name for 619.Dq mixed . 620Modes are case insensitive. 621.It Cm weptxkey Ar index 622For IEEE 802.11 wireless interfaces, set the WEP key to be used for 623transmission. 624.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key 625For IEEE 802.11 wireless interfaces, set the selected WEP key. 626If an 627.Ar index 628is not given, key 1 is set. 629A WEP key will be either 5 or 13 630characters (40 or 104 bits) depending of the local network and the 631capabilities of the adaptor. 632It may be specified either as a plain 633string or as a string of hexadecimal digits proceeded by 634.Ql 0x . 635For maximum portability, hex keys are recommended; 636the mapping of text keys to WEP encryption is usually driver-specific. 637In particular, the 638.Tn Windows 639drivers do this mapping differently to 640.Fx . 641A key may be cleared by setting it to 642.Ql - . 643If WEP is supported then there are at least four keys. 644Some adaptors support more than four keys. 645If that is the case, then the first four keys 646(1-4) will be the standard temporary keys and any others will be adaptor 647specific keys such as permanent keys stored in NVRAM. 648.It Cm wep 649Another way of saying 650.Cm wepmode on . 651Included for 652.Bsx 653compatibility. 654.It Fl wep 655Another way of saying 656.Cm wepmode off . 657Included for 658.Bsx 659compatibility. 660.It Cm nwkey key 661Another way of saying: 662.Pp 663.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" . 664.Pp 665Included for 666.Nx 667compatibility. 668.It Cm nwkey Xo 669.Sm off 670.Ar n : k1 , k2 , k3 , k4 671.Sm on 672.Xc 673Another way of saying 674.Pp 675.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" . 676.Pp 677Included for 678.Nx 679compatibility. 680.It Fl nwkey 681Another way of saying 682.Cm wepmode off . 683.Pp 684Included for 685.Nx 686compatibility. 687.El 688.Pp 689The 690.Nm 691utility displays the current configuration for a network interface 692when no optional parameters are supplied. 693If a protocol family is specified, 694.Nm 695will report only the details specific to that protocol family. 696.Pp 697If the driver does supports the media selection system, the supported 698media list will be included in the output. 699.Pp 700If the 701.Fl m 702flag is passed before an interface name, 703.Nm 704will display all 705of the supported media for the specified interface. 706If 707.Fl L 708flag is supplied, address lifetime is displayed for IPv6 addresses, 709as time offset string. 710.Pp 711Optionally, the 712.Fl a 713flag may be used instead of an interface name. 714This flag instructs 715.Nm 716to display information about all interfaces in the system. 717The 718.Fl d 719flag limits this to interfaces that are down, and 720.Fl u 721limits this to interfaces that are up. 722When no arguments are given, 723.Fl a 724is implied. 725.Pp 726The 727.Fl l 728flag may be used to list all available interfaces on the system, with 729no other additional information. 730Use of this flag is mutually exclusive 731with all other flags and commands, except for 732.Fl d 733(only list interfaces that are down) 734and 735.Fl u 736(only list interfaces that are up). 737.Pp 738The 739.Fl C 740flag may be used to list all of the interface cloners available on 741the system, with no additional information. 742Use of this flag is mutually exclusive with all other flags and commands. 743.Pp 744Only the super-user may modify the configuration of a network interface. 745.Sh NOTES 746The media selection system is relatively new and only some drivers support 747it (or have need for it). 748.Sh DIAGNOSTICS 749Messages indicating the specified interface does not exist, the 750requested address is unknown, or the user is not privileged and 751tried to alter an interface's configuration. 752.Sh BUGS 753IPv6 link-local addresses are required for several basic communication 754between IPv6 node. 755If they are deleted by 756.Nm 757manually, the kernel might show very strange behavior. 758So, such manual deletions are strongly discouraged. 759.Sh SEE ALSO 760.Xr netstat 1 , 761.Xr netintro 4 , 762.\" .Xr eon 5 , 763.Xr rc 8 , 764.Xr routed 8 765.Sh HISTORY 766The 767.Nm 768utility appeared in 769.Bx 4.2 . 770