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 rxcsum , txcsum 309If the driver supports user-configurable checksum offloading, 310enable receive (or transmit) checksum offloading on the interface. 311Some drivers may not be able to enable these flags independently 312of each other, so setting one may also set the other. 313The driver will offload as much checksum work as it can reliably 314support, the exact level of offloading varies between drivers. 315.It Fl rxcsum , Fl txcsum 316If the driver supports user-configurable checksum offloading, 317disable receive (or transmit) checksum offloading on the interface. 318These settings may not always be independent of each other. 319.It Cm tunnel Ar src_addr dest_addr 320(IP tunnel devices only.) 321Configure the physical source and destination address for IP tunnel 322interfaces 323.Pq Xr gif 4 . 324The arguments 325.Ar src_addr 326and 327.Ar dest_addr 328are interpreted as the outer source/destination for the encapsulating 329IPv4/IPv6 header. 330.It Cm deletetunnel 331Unconfigure the physical source and destination address for IP tunnel 332interfaces previously configured with 333.Cm tunnel . 334.It Cm create 335Create the specified network pseudo-device. 336If the interface is given without a unit number, try to create a new 337device with an arbitrary unit number. 338If creation of an arbitrary device is successful, the new device name is 339printed to standard output. 340.It Cm destroy 341Destroy the specified network pseudo-device. 342.It Cm plumb 343Another name for the 344.Cm create 345parameter. 346Included for 347.Tn Solaris 348compatibility. 349.It Cm unplumb 350Another name for the 351.Cm destroy 352parameter. 353Included for 354.Tn Solaris 355compatibility. 356.It Cm vlan Ar vlan_tag 357If the interface is a vlan pseudo interface, set the vlan tag value 358to 359.Ar vlan_tag . 360This value is a 16-bit number which is used to create an 802.1Q 361vlan header for packets sent from the vlan interface. 362Note that 363.Cm vlan 364and 365.Cm vlandev 366must both be set at the same time. 367.It Cm vlandev Ar iface 368If the interface is a vlan pseudo device, associate physical interface 369.Ar iface 370with it. 371Packets transmitted through the vlan interface will be 372diverted to the specified physical interface 373.Ar iface 374with 802.1Q vlan encapsulation. 375Packets with 802.1Q encapsulation received 376by the parent interface with the correct vlan tag will be diverted to 377the associated vlan pseudo-interface. 378The vlan interface is assigned a 379copy of the parent interface's flags and the parent's ethernet address. 380The 381.Cm vlandev 382and 383.Cm vlan 384must both be set at the same time. 385If the vlan interface already has 386a physical interface associated with it, this command will fail. 387To 388change the association to another physical interface, the existing 389association must be cleared first. 390.Pp 391Note: if the hardware tagging capability 392is set on the vlan interface, the vlan pseudo 393interface's behavior changes: 394the vlan interface recognizes that the 395parent interface supports insertion and extraction of vlan tags on its 396own (usually in firmware) and that it should pass packets to and from 397the parent unaltered. 398.It Fl vlandev Ar iface 399If the driver is a vlan pseudo device, disassociate the physical interface 400.Ar iface 401from it. 402This breaks the link between the vlan interface and its parent, 403clears its vlan tag, flags and its link address and shuts the interface down. 404.It Cm metric Ar n 405Set the routing metric of the interface to 406.Ar n , 407default 0. 408The routing metric is used by the routing protocol 409.Pq Xr routed 8 . 410Higher metrics have the effect of making a route 411less favorable; metrics are counted as addition hops 412to the destination network or host. 413.It Cm mtu Ar n 414Set the maximum transmission unit of the interface to 415.Ar n , 416default is interface specific. 417The MTU is used to limit the size of packets that are transmitted on an 418interface. 419Not all interfaces support setting the MTU, and some interfaces have 420range restrictions. 421.It Cm netmask Ar mask 422.\" (Inet and ISO.) 423(Inet only.) 424Specify how much of the address to reserve for subdividing 425networks into sub-networks. 426The mask includes the network part of the local address 427and the subnet part, which is taken from the host field of the address. 428The mask can be specified as a single hexadecimal number 429with a leading 430.Ql 0x , 431with a dot-notation Internet address, 432or with a pseudo-network name listed in the network table 433.Xr networks 5 . 434The mask contains 1's for the bit positions in the 32-bit address 435which are to be used for the network and subnet parts, 436and 0's for the host part. 437The mask should contain at least the standard network portion, 438and the subnet field should be contiguous with the network 439portion. 440.Pp 441The netmask can also be specified in CIDR notation after the address. 442See the 443.Ar address 444option above for more information. 445.It Cm prefixlen Ar len 446(Inet6 only.) 447Specify that 448.Ar len 449bits are reserved for subdividing networks into sub-networks. 450The 451.Ar len 452must be integer, and for syntactical reason it must be between 0 to 128. 453It is almost always 64 under the current IPv6 assignment rule. 454If the parameter is omitted, 64 is used. 455.Pp 456The prefix can also be specified using the slash notation after the address. 457See the 458.Ar address 459option above for more information. 460.\" see 461.\" Xr eon 5 . 462.\" .It Cm nsellength Ar n 463.\" .Pf ( Tn ISO 464.\" only) 465.\" This specifies a trailing number of bytes for a received 466.\" .Tn NSAP 467.\" used for local identification, the remaining leading part of which is 468.\" taken to be the 469.\" .Tn NET 470.\" (Network Entity Title). 471.\" The default value is 1, which is conformant to US 472.\" .Tn GOSIP . 473.\" When an ISO address is set in an ifconfig command, 474.\" it is really the 475.\" .Tn NSAP 476.\" which is being specified. 477.\" For example, in 478.\" .Tn US GOSIP , 479.\" 20 hex digits should be 480.\" specified in the 481.\" .Tn ISO NSAP 482.\" to be assigned to the interface. 483.\" There is some evidence that a number different from 1 may be useful 484.\" for 485.\" .Tn AFI 486.\" 37 type addresses. 487.It Cm range Ar netrange 488Under appletalk, set the interface to respond to a 489.Ar netrange 490of the form 491.Ar startnet Ns - Ns Ar endnet . 492Appletalk uses this scheme instead of 493netmasks though 494.Fx 495implements it internally as a set of netmasks. 496.It Cm remove 497Another name for the 498.Fl alias 499parameter. 500Introduced for compatibility 501with 502.Bsx . 503.It Cm phase 504The argument following this specifies the version (phase) of the 505Appletalk network attached to the interface. 506Values of 1 or 2 are permitted. 507.Sm off 508.It Cm link Op Cm 0 No - Cm 2 509.Sm on 510Enable special processing of the link level of the interface. 511These three options are interface specific in actual effect, however, 512they are in general used to select special modes of operation. 513An example 514of this is to enable SLIP compression, or to select the connector type 515for some Ethernet cards. 516Refer to the man page for the specific driver 517for more information. 518.Sm off 519.It Fl link Op Cm 0 No - Cm 2 520.Sm on 521Disable special processing at the link level with the specified interface. 522.It Cm monitor 523Put the interface in monitor mode. 524No packets are transmitted, and received packets are discarded after 525.Xr bpf 4 526processing. 527.It Fl monitor 528Take the interface out of monitor mode. 529.It Cm up 530Mark an interface 531.Dq up . 532This may be used to enable an interface after an 533.Dq Nm Cm down . 534It happens automatically when setting the first address on an interface. 535If the interface was reset when previously marked down, 536the hardware will be re-initialized. 537.It Cm ssid Ar ssid 538For IEEE 802.11 wireless interfaces, set the desired Service Set 539Identifier (aka network name). 540The SSID is a string up to 32 characters 541in length and may be specified as either a normal string or in 542hexadecimal when proceeded by 543.Ql 0x . 544Additionally, the SSID may be cleared by setting it to 545.Ql - . 546.It Cm nwid Ar ssid 547Another name for the 548.Cm ssid 549parameter. 550Included for 551.Nx 552compatibility. 553.It Cm stationname Ar name 554For IEEE 802.11 wireless interfaces, set the name of this station. 555It appears that the station name is not really part of the IEEE 802.11 556protocol though all interfaces seem to support it. 557As such it only 558seems to be meaningful to identical or virtually identical equipment. 559Setting the station name is identical in syntax to setting the SSID. 560.It Cm station Ar name 561Another name for the 562.Cm stationname 563parameter. 564Included for 565.Bsx 566compatibility. 567.It Cm channel Ar number 568For IEEE 802.11 wireless interfaces, set the desired channel. 569Channels range from 1 to 14, but the exact selection available 570depends on the region your adaptor was manufactured for. 571Setting 572the channel to 0 will give you the default for your adaptor. 573Many 574adaptors ignore this setting unless you are in ad-hoc mode. 575.It Cm authmode Ar mode 576For IEEE 802.11 wireless interfaces, set the desired authentication mode 577in infrastructure mode. 578Not all adaptors support all modes. 579The set of 580valid modes is 581.Dq none , 582.Dq open , 583and 584.Dq shared . 585Modes are case insensitive. 586.It Cm powersave 587For IEEE 802.11 wireless interfaces, enable powersave mode. 588.It Fl powersave 589For IEEE 802.11 wireless interfaces, disable powersave mode. 590.It Cm powersavesleep Ar sleep 591For IEEE 802.11 wireless interfaces, set the desired max powersave sleep 592time in milliseconds. 593.It Cm wepmode Ar mode 594For IEEE 802.11 wireless interfaces, set the desired WEP mode. 595Not all adaptors support all modes. 596The set of valid modes is 597.Dq off , 598.Dq on , 599and 600.Dq mixed . 601.Dq Mixed 602mode explicitly tells the adaptor to allow association with access 603points which allow both encrypted and unencrypted traffic. 604On these adaptors, 605.Dq on 606means that the access point must only allow encrypted connections. 607On other adaptors, 608.Dq on 609is generally another name for 610.Dq mixed . 611Modes are case insensitive. 612.It Cm weptxkey Ar index 613For IEEE 802.11 wireless interfaces, set the WEP key to be used for 614transmission. 615.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key 616For IEEE 802.11 wireless interfaces, set the selected WEP key. 617If an 618.Ar index 619is not given, key 1 is set. 620A WEP key will be either 5 or 13 621characters (40 or 104 bits) depending of the local network and the 622capabilities of the adaptor. 623It may be specified either as a plain 624string or as a string of hexadecimal digits proceeded by 625.Ql 0x . 626For maximum portability, hex keys are recommended; 627the mapping of text keys to WEP encryption is usually driver-specific. 628In particular, the 629.Tn Windows 630drivers do this mapping differently to 631.Fx . 632A key may be cleared by setting it to 633.Ql - . 634If WEP is supported then there are at least four keys. 635Some adaptors support more than four keys. 636If that is the case, then the first four keys 637(1-4) will be the standard temporary keys and any others will be adaptor 638specific keys such as permanent keys stored in NVRAM. 639.It Cm wep 640Another way of saying 641.Cm wepmode on . 642Included for 643.Bsx 644compatibility. 645.It Fl wep 646Another way of saying 647.Cm wepmode off . 648Included for 649.Bsx 650compatibility. 651.It Cm nwkey key 652Another way of saying: 653.Pp 654.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" . 655.Pp 656Included for 657.Nx 658compatibility. 659.It Cm nwkey Xo 660.Sm off 661.Ar n : k1 , k2 , k3 , k4 662.Sm on 663.Xc 664Another way of saying 665.Pp 666.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" . 667.Pp 668Included for 669.Nx 670compatibility. 671.It Fl nwkey 672Another way of saying 673.Cm wepmode off . 674.Pp 675Included for 676.Nx 677compatibility. 678.El 679.Pp 680The 681.Nm 682utility displays the current configuration for a network interface 683when no optional parameters are supplied. 684If a protocol family is specified, 685.Nm 686will report only the details specific to that protocol family. 687.Pp 688If the driver does supports the media selection system, the supported 689media list will be included in the output. 690.Pp 691If the 692.Fl m 693flag is passed before an interface name, 694.Nm 695will display all 696of the supported media for the specified interface. 697If 698.Fl L 699flag is supplied, address lifetime is displayed for IPv6 addresses, 700as time offset string. 701.Pp 702Optionally, the 703.Fl a 704flag may be used instead of an interface name. 705This flag instructs 706.Nm 707to display information about all interfaces in the system. 708The 709.Fl d 710flag limits this to interfaces that are down, and 711.Fl u 712limits this to interfaces that are up. 713When no arguments are given, 714.Fl a 715is implied. 716.Pp 717The 718.Fl l 719flag may be used to list all available interfaces on the system, with 720no other additional information. 721Use of this flag is mutually exclusive 722with all other flags and commands, except for 723.Fl d 724(only list interfaces that are down) 725and 726.Fl u 727(only list interfaces that are up). 728.Pp 729The 730.Fl C 731flag may be used to list all of the interface cloners available on 732the system, with no additional information. 733Use of this flag is mutually exclusive with all other flags and commands. 734.Pp 735Only the super-user may modify the configuration of a network interface. 736.Sh NOTES 737The media selection system is relatively new and only some drivers support 738it (or have need for it). 739.Sh DIAGNOSTICS 740Messages indicating the specified interface does not exist, the 741requested address is unknown, or the user is not privileged and 742tried to alter an interface's configuration. 743.Sh BUGS 744IPv6 link-local addresses are required for several basic communication 745between IPv6 node. 746If they are deleted by 747.Nm 748manually, the kernel might show very strange behavior. 749So, such manual deletions are strongly discouraged. 750.Sh SEE ALSO 751.Xr netstat 1 , 752.Xr netintro 4 , 753.\" .Xr eon 5 , 754.Xr rc 8 , 755.Xr routed 8 756.Sh HISTORY 757The 758.Nm 759utility appeared in 760.Bx 4.2 . 761