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 February 13, 1996 36.Dt IFCONFIG 8 37.Os BSD 4.2 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 Ar address_family 47.Oo 48.Ar address Ns Op Cm / Ns Ar prefixlength 49.Op Ar dest_address 50.Oc 51.Op Ar parameters 52.Nm 53.Fl a 54.Op Fl L 55.Op Fl d 56.Op Fl m 57.Op Fl u 58.Op Ar address_family 59.Nm 60.Fl l 61.Op Fl d 62.Op Fl u 63.Op Ar address_family 64.Nm 65.Op Fl L 66.Op Fl d 67.Op Fl m 68.Op Fl u 69.Sh DESCRIPTION 70.Nm Ifconfig 71is used to assign an address 72to a network interface and/or configure 73network interface parameters. 74.Nm Ifconfig 75must be used at boot time to define the network address 76of each interface present on a machine; it may also be used at 77a later time to redefine an interface's address 78or other operating parameters. 79.Pp 80The following options are available: 81.Bl -tag -width indent 82.It Ar address 83For the 84.Tn DARPA Ns -Internet 85family, 86the address is either a host name present in the host name data 87base, 88.Xr hosts 5 , 89or a 90.Tn DARPA 91Internet address expressed in the Internet standard 92.Dq dot notation . 93.Pp 94It is also possible to use the CIDR notation (also known as the 95slash notation) to include the netmask. 96That is, one can specify an address like 97.Li 192.168.0.1/16 . 98.\" For the Xerox Network Systems(tm) family, 99.\" addresses are 100.\" .Ar net:a.b.c.d.e.f , 101.\" where 102.\" .Ar net 103.\" is the assigned network number (in decimal), 104.\" and each of the six bytes of the host number, 105.\" .Ar a 106.\" through 107.\" .Ar f , 108.\" are specified in hexadecimal. 109.\" The host number may be omitted on IEEE 802 protocol 110.\" (Ethernet, FDDI, and Token Ring) interfaces, 111.\" which use the hardware physical address, 112.\" and on interfaces other than the first. 113.\" For the 114.\" .Tn ISO 115.\" family, addresses are specified as a long hexadecimal string, 116.\" as in the Xerox family. However, two consecutive dots imply a zero 117.\" byte, and the dots are optional, if the user wishes to (carefully) 118.\" count out long strings of digits in network byte order. 119.It Ar address_family 120Specify the 121.Ar "address family" 122which affects interpretation of the remaining parameters. 123Since an interface can receive transmissions in differing protocols 124with different naming schemes, specifying the address family is recommended. 125The address or protocol families currently 126supported are 127.Dq inet , 128.Dq inet6 , 129.Dq atalk , 130.Dq ether , 131.\" .Dq iso , 132and 133.Dq ipx . 134.\" and 135.\" .Dq ns . 136.It Ar dest_address 137Specify the address of the correspondent on the other end 138of a point to point link. 139.It Ar interface 140This 141parameter is a string of the form 142.Dq name unit , 143for example, 144.Dq en0 . 145.El 146.Pp 147The following parameters may be set with 148.Nm : 149.Bl -tag -width indent 150.It Cm add 151Another name for the 152.Cm alias 153parameter. 154Introduced for compatibility 155with BSD/OS. 156.It Cm alias 157Establish an additional network address for this interface. 158This is sometimes useful when changing network numbers, and 159one wishes to accept packets addressed to the old interface. 160If the address is on the same subnet as the first network address 161for this interface, a netmask of 0xffffffff has to be specified. 162.It Fl alias 163Remove the network address specified. 164This would be used if you incorrectly specified an alias, or it 165was no longer needed. 166If you have incorrectly set an NS address having the side effect 167of specifying the host portion, removing all NS addresses will 168allow you to respecify the host portion. 169.It Cm anycast 170(Inet6 only) 171Specify that the address configured is an anycast address. 172Based on the current specification, 173only routers may configure anycast addresses. 174Anycast address will not be used as source address of any of outgoing 175IPv6 packets. 176.It Cm arp 177Enable the use of the Address Resolution Protocol in mapping 178between network level addresses and link level addresses (default). 179This is currently implemented for mapping between 180.Tn DARPA 181Internet 182addresses and 183.Tn IEEE 184802 48-bit MAC addresses (Ethernet, FDDI, and Token Ring addresses). 185.It Fl arp 186Disable the use of the Address Resolution Protocol. 187.It Cm broadcast 188(Inet only) 189Specify the address to use to represent broadcasts to the 190network. 191The default broadcast address is the address with a host part of all 1's. 192.It Cm debug 193Enable driver dependent debugging code; usually, this turns on 194extra console error logging. 195.It Fl debug 196Disable driver dependent debugging code. 197.It Cm delete 198Another name for the 199.Fl alias 200parameter. 201.It Cm down 202Mark an interface 203.Dq down . 204When an interface is marked 205.Dq down , 206the system will not attempt to 207transmit messages through that interface. 208If possible, the interface will be reset to disable reception as well. 209This action does not automatically disable routes using the interface. 210.It Cm ether 211Another name for the 212.Dq lladdr 213parameter. 214.\" .It Cm ipdst 215.\" This is used to specify an Internet host who is willing to receive 216.\" ip packets encapsulating NS packets bound for a remote network. 217.\" An apparent point to point link is constructed, and 218.\" the address specified will be taken as the NS address and network 219.\" of the destination. 220.\" IP encapsulation of 221.\" .Tn CLNP 222.\" packets is done differently. 223.It Cm lladdr Ar addr 224Set the link-level address on an interface. This can be used to 225e.g. set a new MAC address on an ethernet interface, though the 226mechanism used is not ethernet-specific. The address 227.Ar addr 228is specified as a series of colon-separated hex digits. 229If the interface is already 230up when this option is used, it will be briefly brought down and 231then brought back up again in order to insure that the receive 232filter in the underlying ethernet hardware is properly reprogrammed. 233.It Cm media Ar type 234If the driver supports the media selection system, set the media type 235of the interface to 236.Ar type . 237Some interfaces support the mutually exclusive use of one of several 238different physical media connectors. For example, a 10Mb/s Ethernet 239interface might support the use of either 240.Tn AUI 241or twisted pair connectors. Setting the media type to 242.Dq 10base5/AUI 243would change the currently active connector to the AUI port. 244Setting it to 245.Dq 10baseT/UTP 246would activate twisted pair. Refer to the interfaces' driver 247specific documentation or man page for a complete list of the 248available types. 249.It Cm mediaopt Ar opts 250If the driver supports the media selection system, set the specified 251media options on the interface. 252.Ar Opts 253is a comma delimited list of options to apply to the interface. 254Refer to the interfaces' driver specific man page for a complete 255list of available options. 256.It Fl mediaopt Ar opts 257If the driver supports the media selection system, disable the 258specified media options on the interface. 259.It Cm tunnel Ar src_addr Ar dest_addr 260(IP tunnel devices only) 261Configure the physical source and destination address for IP tunnel 262interfaces (gif). The arguments 263.Ar src_addr 264and 265.Ar dest_addr 266are interpreted as the outer source/destination for the encapsulating 267IPv4/IPv6 header. 268.It Cm deletetunnel 269Unconfigure the physical source and destination address for IP tunnel 270interfaces previously configured with 271.Cm tunnel . 272.It Cm vlan Ar vlan_tag 273If the interface is a vlan pseudo interface, set the vlan tag value 274to 275.Ar vlan_tag . 276This value is a 16-bit number which is used to create an 802.1Q 277vlan header for packets sent from the vlan interface. 278Note that 279.Cm vlan 280and 281.Cm vlandev 282must both be set at the same time. 283.It Cm vlandev Ar iface 284If the interface is a vlan pseudo device, associate physical interface 285.Ar iface 286with it. 287Packets transmitted through the vlan interface will be 288diverted to the specified physical interface 289.Ar iface 290with 802.1Q vlan encapsulation. 291Packets with 802.1Q encapsulation received 292by the parent interface with the correct vlan tag will be diverted to 293the associated vlan pseudo-interface. 294The vlan interface is assigned a 295copy of the parent interface's flags and the parent's ethernet address. 296The 297.Cm vlandev 298and 299.Cm vlan 300must both be set at the same time. 301If the vlan interface already has 302a physical interface associated with it, this command will fail. 303To 304change the association to another physical interface, the existing 305association must be cleared first. 306.Pp 307Note: if the 308.Ar link0 309flag is set on the vlan interface, the vlan pseudo 310interface's behavior changes: the 311.Ar link0 312tells the vlan interface that the 313parent interface supports insertion and extraction of vlan tags on its 314own (usually in firmware) and that it should pass packets to and from 315the parent unaltered. 316.It Fl vlandev Ar iface 317If the driver is a vlan pseudo device, disassociate the physical interface 318.Ar iface 319from it. 320This breaks the link between the vlan interface and its parent, 321clears its vlan tag, flags and its link address and shuts the interface down. 322.It Cm metric Ar n 323Set the routing metric of the interface to 324.Ar n , 325default 0. 326The routing metric is used by the routing protocol 327.Pq Xr routed 8 . 328Higher metrics have the effect of making a route 329less favorable; metrics are counted as addition hops 330to the destination network or host. 331.It Cm mtu Ar n 332Set the maximum transmission unit of the interface to 333.Ar n , 334default is interface specific. 335The mtu is used to limit the size of packets that are transmitted on an 336interface. 337Not all interfaces support setting the mtu, and some interfaces have 338range restrictions. 339.It Cm netmask Ar mask 340.\" (Inet and ISO) 341(Inet only) 342Specify how much of the address to reserve for subdividing 343networks into sub-networks. 344The mask includes the network part of the local address 345and the subnet part, which is taken from the host field of the address. 346The mask can be specified as a single hexadecimal number 347with a leading 0x, with a dot-notation Internet address, 348or with a pseudo-network name listed in the network table 349.Xr networks 5 . 350The mask contains 1's for the bit positions in the 32-bit address 351which are to be used for the network and subnet parts, 352and 0's for the host part. 353The mask should contain at least the standard network portion, 354and the subnet field should be contiguous with the network 355portion. 356.Pp 357The netmask can also be specified in CIDR notation after the address. 358See the 359.Ar address 360option above for more information. 361.It Cm prefixlen Ar len 362(Inet6 only) 363Specify that 364.Ar len 365bits are reserved for subdividing networks into sub-networks. 366The 367.Ar len 368must be integer, and for syntactical reason it must be between 0 to 128. 369It is almost always 64 under the current IPv6 assignment rule. 370If the parameter is ommitted, 64 is used. 371.\" see 372.\" Xr eon 5 . 373.\" .It Cm nsellength Ar n 374.\" .Pf ( Tn ISO 375.\" only) 376.\" This specifies a trailing number of bytes for a received 377.\" .Tn NSAP 378.\" used for local identification, the remaining leading part of which is 379.\" taken to be the 380.\" .Tn NET 381.\" (Network Entity Title). 382.\" The default value is 1, which is conformant to US 383.\" .Tn GOSIP . 384.\" When an ISO address is set in an ifconfig command, 385.\" it is really the 386.\" .Tn NSAP 387.\" which is being specified. 388.\" For example, in 389.\" .Tn US GOSIP , 390.\" 20 hex digits should be 391.\" specified in the 392.\" .Tn ISO NSAP 393.\" to be assigned to the interface. 394.\" There is some evidence that a number different from 1 may be useful 395.\" for 396.\" .Tn AFI 397.\" 37 type addresses. 398.It Cm range Ar netrange 399Under appletalk, set the interface to respond to a 400.Ar netrange 401of the form 402.Ar startnet Ns - Ns Ar endnet . 403Appletalk uses this scheme instead of 404netmasks though 405.Fx 406implements it internally as a set of netmasks. 407.It Cm remove 408Another name for the 409.Fl alias 410parameter. 411Introduced for compatibility 412with BSD/OS. 413.It Cm phase 414The argument following this specifies the version (phase) of the 415Appletalk network attached to the interface. 416Values of 1 or 2 are permitted. 417.It Cm link Ns Xo 418.Op Cm 0 Ns - Ns Cm 2 419.Xc 420Enable special processing of the link level of the interface. 421These three options are interface specific in actual effect, however, 422they are in general used to select special modes of operation. 423An example 424of this is to enable SLIP compression, or to select the connector type 425for some Ethernet cards. Refer to the man page for the specific driver 426for more information. 427.It Fl link Ns Xo 428.Op Cm 0 Ns - Ns Cm 2 429.Xc 430Disable special processing at the link level with the specified interface. 431.It Cm up 432Mark an interface 433.Dq up . 434This may be used to enable an interface after an 435.Dq ifconfig down . 436It happens automatically when setting the first address on an interface. 437If the interface was reset when previously marked down, 438the hardware will be re-initialized. 439.It Cm ssid Ar ssid 440For IEEE 802.11 wireless interfaces, set the desired Service Set 441Identifier (aka network name.) The SSID is a string up to 32 characters 442in length and may be specified as either a normal string or in 443hexadecimal when proceeded by 444.Sq 0x . 445Additionally, the SSID may be cleared by setting it to 446.Sq - . 447.It Cm nwid Ar ssid 448Another name for the 449.Dq ssid 450parameter. Included for NetBSD compatibility. 451.It Cm stationname Ar name 452For IEEE 802.11 wireless interfaces, set the name of this station. 453It appears that the station name is not really part of the IEEE 802.11 454protocol though all interfaces seem to support it. As such it only 455seems to be meaningful to identical or virtually identical equipment. 456Setting the station name is identical in syntax to setting the SSID. 457.It Cm station Ar name 458Another name for the 459.Dq stationname 460parameter. Included for BSD/OS compatibility. 461.It Cm channel Ar number 462For IEEE 802.11 wireless interfaces, set the desired channel. 463Channels range from 1 to 14, but the exact selection available 464depends on the region your adaptor was manufactured for. Setting 465the channel to 0 will give you the default for your adaptor. Many 466adaptors ignore this setting unless you are in ad-hoc mode. 467.It Cm authmode Ar mode 468For IEEE 802.11 wireless interfaces, set the desired authentication mode 469in infrastructure mode. Not all adaptors support all modes. The set of 470valid modes is 471.Dq none , 472.Dq open , 473and 474.Dq shared . 475Modes are case insensitive. 476.It Cm powersave 477For IEEE 802.11 wireless interfaces, enable powersave mode. 478.It Cm -powersave 479For IEEE 802.11 wireless interfaces, disable powersave mode. 480.It Cm powersavesleep Ar sleep 481For IEEE 802.11 wireless interfaces, set the desired max powersave sleep 482time in milliseconds. 483.It Cm wepmode Ar mode 484For IEEE 802.11 wireless interfaces, set the desired WEP mode. Not all 485adaptors support all modes. The set of valid modes is 486.Dq off , 487.Dq on , 488and 489.Dq mixed . 490.Dq Mixed 491mode explicitly tells the adaptor to allow association with access 492points which allow both encrypted and unencrypted traffic. On these 493adaptors, 494.Dq on 495means that the access point must only allow encrypted connections. On 496other adaptors, 497.Dq on 498is generally another name for 499.Dq mixed . 500Modes are case insensitive. 501.It Cm weptxkey Ar index 502For IEEE 802.11 wireless interfaces, set the WEP key to be used for 503transmission. 504.It Cm wepkey Ar key|index:key 505For IEEE 802.11 wireless interfaces, set the selected WEP key. If 506an 507.Ar index 508is not given, key 1 is set. A WEP key will be either 5 or 13 509characters (40 or 104 bits) depending of the local network and the 510capabilities of the adaptor. It may be specified either as a plain 511string or as a string of hexadecimal digits proceeded by 512.Sq 0x . 513A key may be cleared by setting it to 514.Sq - . 515If WEP is supported then there are at least four keys. Some adaptors 516support more then four keys. If that is the case, then the first four keys 517(1-4) will be the standard temporary keys and any others will be adaptor 518specific keys such as permanent keys stored in NVRAM. 519.It Cm wep 520Another way of saying 521.Dq wepmode on . 522Included for BSD/OS compatibility. 523.It Cm -wep 524Another way of saying 525.Dq wepmode off . 526Included for BSD/OS compatibility. 527.It Cm nwkey key 528Another way of saying: 529.Pp 530``wepmode on weptxkey 1 wepkey 1:key wepkey 2:- wepkey 3:- wepkey 4:-''. 531.Pp 532Included for NetBSD compatibility. 533.It Cm nwkey n:k1,k2,k3,k4 534Another way of saying 535.Pp 536``wepmode on weptxkey n wepkey 1:k1 wepkey 2:k2 wepkey 3:k3 wepkey 4:k4''. 537.Pp 538Included for NetBSD compatibility. 539.It Cm -nwkey 540Another way of saying 541.Dq wepmode off . 542.Pp 543Included for NetBSD compatibility. 544.El 545.Pp 546.Nm Ifconfig 547displays the current configuration for a network interface 548when no optional parameters are supplied. 549If a protocol family is specified, 550.Nm 551will report only the details specific to that protocol family. 552.Pp 553If the driver does supports the media selection system, the supported 554media list will be included in the output. 555.Pp 556If the 557.Fl m 558flag is passed before an interface name, ifconfig will display all 559of the supported media for the specified interface. 560If 561.Fl L 562flag is supplied, address lifetime is displayed for IPv6 addresses, 563as time offset string. 564.Pp 565Optionally, the 566.Fl a 567flag may be used instead of an interface name. This flag instructs 568.Nm 569to display information about all interfaces in the system. 570The 571.Fl d 572flag limits this to interfaces that are down, and 573.Fl u 574limits this to interfaces that are up. 575When no arguments are given, 576.Fl a 577is implied. 578.Pp 579The 580.Fl l 581flag may be used to list all available interfaces on the system, with 582no other additional information. Use of this flag is mutually exclusive 583with all other flags and commands, except for 584.Fl d 585(only list interfaces that are down) 586and 587.Fl u 588(only list interfaces that are up). 589.Pp 590Only the super-user may modify the configuration of a network interface. 591.Sh NOTES 592The media selection system is relatively new and only some drivers support 593it (or have need for it). 594.Sh DIAGNOSTICS 595Messages indicating the specified interface does not exist, the 596requested address is unknown, or the user is not privileged and 597tried to alter an interface's configuration. 598.Sh BUGS 599IPv6 link-local addresses are required for several basic communication 600between IPv6 node. 601If they are deleted by 602.Nm 603manually, the kernel might show very strange behavior. 604So, such manual deletions are strongly discouraged. 605.Sh SEE ALSO 606.Xr netstat 1 , 607.Xr netintro 4 , 608.Xr rc 8 , 609.Xr routed 8 610.\" .Xr eon 5 611.Sh HISTORY 612The 613.Nm 614command appeared in 615.Bx 4.2 . 616