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 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 rxcsum , txcsum 306If the driver supports user-configurable checksum offloading, 307enable receive (or transmit) checksum offloading on the interface. 308Some drivers may not be able to enable these flags independently 309of each other, so setting one may also set the other. 310The driver will offload as much checksum work as it can reliably 311support, the exact level of offloading varies between drivers. 312.It Fl rxcsum , Fl txcsum 313If the driver supports user-configurable checksum offloading, 314disable receive (or transmit) checksum offloading on the interface. 315These settings may not always be independent of each other. 316.It Cm tunnel Ar src_addr dest_addr 317(IP tunnel devices only.) 318Configure the physical source and destination address for IP tunnel 319interfaces 320.Pq Xr gif 4 . 321The arguments 322.Ar src_addr 323and 324.Ar dest_addr 325are interpreted as the outer source/destination for the encapsulating 326IPv4/IPv6 header. 327.It Cm deletetunnel 328Unconfigure the physical source and destination address for IP tunnel 329interfaces previously configured with 330.Cm tunnel . 331.It Cm create 332Create the specified network pseudo-device. 333If the interface is given without a unit number, try to create a new 334device with an arbitrary unit number. 335If creation of an arbitrary device is successful, the new device name is 336printed to standard output. 337.It Cm destroy 338Destroy the specified network pseudo-device. 339.It Cm plumb 340Another name for the 341.Cm create 342parameter. 343Included for 344.Tn Solaris 345compatibility. 346.It Cm unplumb 347Another name for the 348.Cm destroy 349parameter. 350Included for 351.Tn Solaris 352compatibility. 353.It Cm vlan Ar vlan_tag 354If the interface is a vlan pseudo interface, set the vlan tag value 355to 356.Ar vlan_tag . 357This value is a 16-bit number which is used to create an 802.1Q 358vlan header for packets sent from the vlan interface. 359Note that 360.Cm vlan 361and 362.Cm vlandev 363must both be set at the same time. 364.It Cm vlandev Ar iface 365If the interface is a vlan pseudo device, associate physical interface 366.Ar iface 367with it. 368Packets transmitted through the vlan interface will be 369diverted to the specified physical interface 370.Ar iface 371with 802.1Q vlan encapsulation. 372Packets with 802.1Q encapsulation received 373by the parent interface with the correct vlan tag will be diverted to 374the associated vlan pseudo-interface. 375The vlan interface is assigned a 376copy of the parent interface's flags and the parent's ethernet address. 377The 378.Cm vlandev 379and 380.Cm vlan 381must both be set at the same time. 382If the vlan interface already has 383a physical interface associated with it, this command will fail. 384To 385change the association to another physical interface, the existing 386association must be cleared first. 387.Pp 388Note: if the hardware tagging capability 389is set on the vlan interface, the vlan pseudo 390interface's behavior changes: 391the vlan interface recognizes that the 392parent interface supports insertion and extraction of vlan tags on its 393own (usually in firmware) and that it should pass packets to and from 394the parent unaltered. 395.It Fl vlandev Ar iface 396If the driver is a vlan pseudo device, disassociate the physical interface 397.Ar iface 398from it. 399This breaks the link between the vlan interface and its parent, 400clears its vlan tag, flags and its link address and shuts the interface down. 401.It Cm metric Ar n 402Set the routing metric of the interface to 403.Ar n , 404default 0. 405The routing metric is used by the routing protocol 406.Pq Xr routed 8 . 407Higher metrics have the effect of making a route 408less favorable; metrics are counted as addition hops 409to the destination network or host. 410.It Cm mtu Ar n 411Set the maximum transmission unit of the interface to 412.Ar n , 413default is interface specific. 414The MTU is used to limit the size of packets that are transmitted on an 415interface. 416Not all interfaces support setting the MTU, and some interfaces have 417range restrictions. 418.It Cm netmask Ar mask 419.\" (Inet and ISO.) 420(Inet only.) 421Specify how much of the address to reserve for subdividing 422networks into sub-networks. 423The mask includes the network part of the local address 424and the subnet part, which is taken from the host field of the address. 425The mask can be specified as a single hexadecimal number 426with a leading 427.Ql 0x , 428with a dot-notation Internet address, 429or with a pseudo-network name listed in the network table 430.Xr networks 5 . 431The mask contains 1's for the bit positions in the 32-bit address 432which are to be used for the network and subnet parts, 433and 0's for the host part. 434The mask should contain at least the standard network portion, 435and the subnet field should be contiguous with the network 436portion. 437.Pp 438The netmask can also be specified in CIDR notation after the address. 439See the 440.Ar address 441option above for more information. 442.It Cm prefixlen Ar len 443(Inet6 only.) 444Specify that 445.Ar len 446bits are reserved for subdividing networks into sub-networks. 447The 448.Ar len 449must be integer, and for syntactical reason it must be between 0 to 128. 450It is almost always 64 under the current IPv6 assignment rule. 451If the parameter is omitted, 64 is used. 452.Pp 453The prefix can also be specified using the slash notation after the address. 454See the 455.Ar address 456option above for more information. 457.\" see 458.\" Xr eon 5 . 459.\" .It Cm nsellength Ar n 460.\" .Pf ( Tn ISO 461.\" only) 462.\" This specifies a trailing number of bytes for a received 463.\" .Tn NSAP 464.\" used for local identification, the remaining leading part of which is 465.\" taken to be the 466.\" .Tn NET 467.\" (Network Entity Title). 468.\" The default value is 1, which is conformant to US 469.\" .Tn GOSIP . 470.\" When an ISO address is set in an ifconfig command, 471.\" it is really the 472.\" .Tn NSAP 473.\" which is being specified. 474.\" For example, in 475.\" .Tn US GOSIP , 476.\" 20 hex digits should be 477.\" specified in the 478.\" .Tn ISO NSAP 479.\" to be assigned to the interface. 480.\" There is some evidence that a number different from 1 may be useful 481.\" for 482.\" .Tn AFI 483.\" 37 type addresses. 484.It Cm range Ar netrange 485Under appletalk, set the interface to respond to a 486.Ar netrange 487of the form 488.Ar startnet Ns - Ns Ar endnet . 489Appletalk uses this scheme instead of 490netmasks though 491.Fx 492implements it internally as a set of netmasks. 493.It Cm remove 494Another name for the 495.Fl alias 496parameter. 497Introduced for compatibility 498with 499.Bsx . 500.It Cm phase 501The argument following this specifies the version (phase) of the 502Appletalk network attached to the interface. 503Values of 1 or 2 are permitted. 504.Sm off 505.It Cm link Op Cm 0 No - Cm 2 506.Sm on 507Enable special processing of the link level of the interface. 508These three options are interface specific in actual effect, however, 509they are in general used to select special modes of operation. 510An example 511of this is to enable SLIP compression, or to select the connector type 512for some Ethernet cards. 513Refer to the man page for the specific driver 514for more information. 515.Sm off 516.It Fl link Op Cm 0 No - Cm 2 517.Sm on 518Disable special processing at the link level with the specified interface. 519.It Cm monitor 520Put the interface in monitor mode. 521No packets are transmitted, and received packets are discarded after 522.Xr bpf 4 523processing. 524.It Fl monitor 525Take the interface out of monitor mode. 526.It Cm up 527Mark an interface 528.Dq up . 529This may be used to enable an interface after an 530.Dq Nm Cm down . 531It happens automatically when setting the first address on an interface. 532If the interface was reset when previously marked down, 533the hardware will be re-initialized. 534.It Cm ssid Ar ssid 535For IEEE 802.11 wireless interfaces, set the desired Service Set 536Identifier (aka network name). 537The SSID is a string up to 32 characters 538in length and may be specified as either a normal string or in 539hexadecimal when proceeded by 540.Ql 0x . 541Additionally, the SSID may be cleared by setting it to 542.Ql - . 543.It Cm nwid Ar ssid 544Another name for the 545.Cm ssid 546parameter. 547Included for 548.Nx 549compatibility. 550.It Cm stationname Ar name 551For IEEE 802.11 wireless interfaces, set the name of this station. 552It appears that the station name is not really part of the IEEE 802.11 553protocol though all interfaces seem to support it. 554As such it only 555seems to be meaningful to identical or virtually identical equipment. 556Setting the station name is identical in syntax to setting the SSID. 557.It Cm station Ar name 558Another name for the 559.Cm stationname 560parameter. 561Included for 562.Bsx 563compatibility. 564.It Cm channel Ar number 565For IEEE 802.11 wireless interfaces, set the desired channel. 566Channels range from 1 to 14, but the exact selection available 567depends on the region your adaptor was manufactured for. 568Setting 569the channel to 0 will give you the default for your adaptor. 570Many 571adaptors ignore this setting unless you are in ad-hoc mode. 572.It Cm authmode Ar mode 573For IEEE 802.11 wireless interfaces, set the desired authentication mode 574in infrastructure mode. 575Not all adaptors support all modes. 576The set of 577valid modes is 578.Dq none , 579.Dq open , 580and 581.Dq shared . 582Modes are case insensitive. 583.It Cm powersave 584For IEEE 802.11 wireless interfaces, enable powersave mode. 585.It Fl powersave 586For IEEE 802.11 wireless interfaces, disable powersave mode. 587.It Cm powersavesleep Ar sleep 588For IEEE 802.11 wireless interfaces, set the desired max powersave sleep 589time in milliseconds. 590.It Cm wepmode Ar mode 591For IEEE 802.11 wireless interfaces, set the desired WEP mode. 592Not all adaptors support all modes. 593The set of valid modes is 594.Dq off , 595.Dq on , 596and 597.Dq mixed . 598.Dq Mixed 599mode explicitly tells the adaptor to allow association with access 600points which allow both encrypted and unencrypted traffic. 601On these adaptors, 602.Dq on 603means that the access point must only allow encrypted connections. 604On other adaptors, 605.Dq on 606is generally another name for 607.Dq mixed . 608Modes are case insensitive. 609.It Cm weptxkey Ar index 610For IEEE 802.11 wireless interfaces, set the WEP key to be used for 611transmission. 612.It Cm wepkey Ar key Ns | Ns Ar index : Ns Ar key 613For IEEE 802.11 wireless interfaces, set the selected WEP key. 614If an 615.Ar index 616is not given, key 1 is set. 617A WEP key will be either 5 or 13 618characters (40 or 104 bits) depending of the local network and the 619capabilities of the adaptor. 620It may be specified either as a plain 621string or as a string of hexadecimal digits proceeded by 622.Ql 0x . 623For maximum portability, hex keys are recommended; 624the mapping of text keys to WEP encryption is usually driver-specific. 625In particular, the 626.Tn Windows 627drivers do this mapping differently to 628.Fx . 629A key may be cleared by setting it to 630.Ql - . 631If WEP is supported then there are at least four keys. 632Some adaptors support more than four keys. 633If that is the case, then the first four keys 634(1-4) will be the standard temporary keys and any others will be adaptor 635specific keys such as permanent keys stored in NVRAM. 636.It Cm wep 637Another way of saying 638.Cm wepmode on . 639Included for 640.Bsx 641compatibility. 642.It Fl wep 643Another way of saying 644.Cm wepmode off . 645Included for 646.Bsx 647compatibility. 648.It Cm nwkey key 649Another way of saying: 650.Pp 651.Dq Li "wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-" . 652.Pp 653Included for 654.Nx 655compatibility. 656.It Cm nwkey Xo 657.Sm off 658.Ar n : k1 , k2 , k3 , k4 659.Sm on 660.Xc 661Another way of saying 662.Pp 663.Dq Li "wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4" . 664.Pp 665Included for 666.Nx 667compatibility. 668.It Fl nwkey 669Another way of saying 670.Cm wepmode off . 671.Pp 672Included for 673.Nx 674compatibility. 675.El 676.Pp 677The 678.Nm 679utility displays the current configuration for a network interface 680when no optional parameters are supplied. 681If a protocol family is specified, 682.Nm 683will report only the details specific to that protocol family. 684.Pp 685If the driver does supports the media selection system, the supported 686media list will be included in the output. 687.Pp 688If the 689.Fl m 690flag is passed before an interface name, 691.Nm 692will display all 693of the supported media for the specified interface. 694If 695.Fl L 696flag is supplied, address lifetime is displayed for IPv6 addresses, 697as time offset string. 698.Pp 699Optionally, the 700.Fl a 701flag may be used instead of an interface name. 702This flag instructs 703.Nm 704to display information about all interfaces in the system. 705The 706.Fl d 707flag limits this to interfaces that are down, and 708.Fl u 709limits this to interfaces that are up. 710When no arguments are given, 711.Fl a 712is implied. 713.Pp 714The 715.Fl l 716flag may be used to list all available interfaces on the system, with 717no other additional information. 718Use of this flag is mutually exclusive 719with all other flags and commands, except for 720.Fl d 721(only list interfaces that are down) 722and 723.Fl u 724(only list interfaces that are up). 725.Pp 726The 727.Fl C 728flag may be used to list all of the interface cloners available on 729the system, with no additional information. 730Use of this flag is mutually exclusive with all other flags and commands. 731.Pp 732Only the super-user may modify the configuration of a network interface. 733.Sh NOTES 734The media selection system is relatively new and only some drivers support 735it (or have need for it). 736.Sh DIAGNOSTICS 737Messages indicating the specified interface does not exist, the 738requested address is unknown, or the user is not privileged and 739tried to alter an interface's configuration. 740.Sh BUGS 741IPv6 link-local addresses are required for several basic communication 742between IPv6 node. 743If they are deleted by 744.Nm 745manually, the kernel might show very strange behavior. 746So, such manual deletions are strongly discouraged. 747.Sh SEE ALSO 748.Xr netstat 1 , 749.Xr netintro 4 , 750.\" .Xr eon 5 , 751.Xr rc 8 , 752.Xr routed 8 753.Sh HISTORY 754The 755.Nm 756utility appeared in 757.Bx 4.2 . 758