1.\" $NetBSD: ifconfig.8,v 1.130 2024/08/20 08:18:24 ozaki-r Exp $ 2.\" 3.\" Copyright (c) 1983, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)ifconfig.8 8.4 (Berkeley) 6/1/94 31.\" 32.Dd August 20, 2024 33.Dt IFCONFIG 8 34.Os 35.Sh NAME 36.Nm ifconfig 37.Nd configure network interface parameters 38.Sh SYNOPSIS 39.Nm 40.Op Fl N 41.Ar interface address_family 42.Oo 43.Ar address 44.Op Ar dest_address 45.Oc 46.Op Ar parameters 47.Nm 48.Op Fl hLmNvz 49.Ar interface 50.Op Ar protocol_family 51.Nm 52.Fl a 53.Op Fl bdhLNmsuvz 54.Op Ar protocol_family 55.Nm 56.Fl l 57.Op Fl bdsu 58.Nm 59.Fl s 60.Ar interface 61.Nm 62.Fl w 63.Ar secs 64.Op Fl W Ar secs 65.Nm 66.Fl C 67.Sh DESCRIPTION 68.Nm 69is used to assign an address 70to a network interface and/or configure 71network interface parameters. 72.Nm 73must be used at boot time to define the network address 74of each interface present on a machine; it may also be used at 75a later time to redefine an interface's address 76or other operating parameters. 77.Pp 78Available operands for 79.Nm : 80.Bl -tag -width Ds 81.It Ar address 82For the 83.Tn DARPA-Internet 84family, 85the address is either a host name present in the host name data 86base, 87.Xr hosts 5 , 88or a 89.Tn DARPA 90Internet address expressed in the Internet standard 91.Dq dot notation . 92.It Ar address_family 93Specifies the 94.Ar address_family 95which affects interpretation of the remaining parameters. 96Since an interface can receive transmissions in differing protocols 97with different naming schemes, specifying the address family is recommended. 98The address or protocol families currently 99supported are 100.Dq inet , 101.Dq inet6 , 102.Dq atalk , 103and 104.Dq link . 105.It Ar interface 106The 107.Ar interface 108parameter is a string of the form 109.Dq name unit , 110for example, 111.Dq en0 112.El 113.Pp 114The following parameters may be set with 115.Nm : 116.Bl -tag -width dest_addressxx 117.It Cm active 118This keyword applies when 119.Nm 120adds or modifies any link-layer address. 121It indicates that 122.Nm 123should 124.Dq activate 125the address. 126Activation makes an address the default source for transmissions 127on the interface. 128You may not delete the active address from an interface. 129You must activate some other address, first. 130.It Cm advbase Ar n 131If the driver is a 132.Xr carp 4 133pseudo-device, set the base advertisement interval to 134.Ar n 135seconds. 136This ia an 8-bit number; the default value is 1 second. 137.It Cm advskew Ar n 138If the driver is a 139.Xr carp 4 140pseudo-device, skew the advertisement interval by 141.Ar n . 142This is an 8-bit number; the default value is 0. 143.Pp 144Taken together the 145.Cm advbase 146indicate how frequently, in seconds, the host will advertise the fact that it 147considers itself the master of the virtual host. 148The formula is 149.Cm advbase 150+ 151.Pf ( Cm advskew 152/ 256). 153If the master does not advertise within three times this interval, this host 154will begin advertising as master. 155.It Cm alias 156Establish an additional network address for this interface. 157This is sometimes useful when changing network numbers, and 158one wishes to accept packets addressed to the old interface. 159.It Fl alias 160Remove the specified network address alias. 161.It Cm arp 162Enable the use of the Address Resolution Protocol in mapping 163between network level addresses and link level addresses 164.Pq default . 165This is currently implemented for mapping between 166.Tn DARPA 167Internet 168addresses and Ethernet addresses. 169.It Fl arp 170Disable the use of the Address Resolution Protocol. 171.It Cm anycast 172.Pq inet6 only 173Set the IPv6 anycast address bit. 174.It Fl anycast 175.Pq inet6 only 176Clear the IPv6 anycast address bit. 177.It Cm broadcast Ar mask 178.Pq Inet only 179Specify the address to use to represent broadcasts to the 180network. 181The default broadcast address is the address with a host part of all 1's. 182.It Cm carpdev Ar iface 183If the driver is a 184.Xr carp 4 185pseudo-device, attach it to 186.Ar iface . 187If not specified, the kernel will attempt to select an interface with 188a subnet matching that of the carp interface. 189.It Cm description Ar description , Cm descr Ar description 190Set a description of the interface. (0-63 characters) 191.It Cm -description , Cm -descr 192Clear the description of the interface. 193.It Cm debug 194Enable driver dependent debugging code; usually, this turns on 195extra console error logging. 196.It Fl debug 197Disable driver dependent debugging code. 198.It Cm delete 199Remove the network address specified. 200This would be used if you incorrectly specified an alias, or it 201was no longer needed. 202If you have incorrectly set an NS address having the side effect 203of specifying the host portion, removing all NS addresses will 204allow you to respecify the host portion. 205.Cm delete 206does not work for IPv6 addresses. 207Use 208.Fl alias 209with explicit IPv6 address instead. 210.It Ar dest_address 211Specify the address of the correspondent on the other end 212of a point to point link. 213.It Cm down 214Mark an interface ``down''. 215When an interface is 216marked ``down'', the system will not attempt to 217transmit messages through that interface. 218If possible, the interface will be reset to disable reception as well. 219This action does not automatically disable routes using the interface. 220.It Cm media Ar type 221Set the media type of the interface to 222.Ar type . 223Some interfaces support the mutually exclusive use of one of several 224different physical media connectors. 225For example, a 10Mb/s Ethernet 226interface might support the use of either 227.Tn AUI 228or twisted pair connectors. 229Setting the media type to 230.Dq 10base5 231or 232.Dq AUI 233would change the currently active connector to the AUI port. 234Setting it to 235.Dq 10baseT 236or 237.Dq UTP 238would activate twisted pair. 239Refer to the interfaces' driver 240specific man page for a complete list of the available types 241and the 242.Xr ifmedia 4 243manual page for a list of media types. 244See the 245.Fl m 246flag below. 247.It Cm mediaopt Ar opts 248Set the specified media options on the interface. 249.Ar opts 250is a comma delimited list of options to apply to the interface. 251Refer to the interfaces' driver specific man page for a complete 252list of available options. 253Also see the 254.Xr ifmedia 4 255manual page for a list of media options. 256.It Fl mediaopt Ar opts 257Disable the specified media options on the interface. 258.It Cm mode Ar mode 259If the driver supports the media selection system, set the specified 260operating mode on the interface to 261.Ar mode . 262For IEEE 802.11 wireless interfaces that support multiple operating modes 263this directive is used to select between 802.11a 264.Pq Dq 11a , 265802.11b 266.Pq Dq 11b , 267and 802.11g 268.Pq Dq 11g 269operating modes. 270.It Cm instance Ar minst 271Set the media instance to 272.Ar minst . 273This is useful for devices which have multiple physical layer interfaces 274.Pq PHYs . 275Setting the instance on such devices may not be strictly required 276by the network interface driver as the driver may take care of this 277automatically; see the driver's manual page for more information. 278.It Cm metric Ar n 279Set the routing metric of the interface to 280.Ar n , 281default 0. 282The routing metric is used by the routing protocol 283.Pq Xr routed 8 . 284Higher metrics have the effect of making a route 285less favorable; metrics are counted as addition hops 286to the destination network or host. 287.It Cm mtu Ar n 288Set the maximum transmission unit of the interface to 289.Ar n . 290Most interfaces do not support this option. 291.It Cm netmask Ar mask 292.Pq inet and inet6 293Specify how much of the address to reserve for subdividing 294networks into sub-networks. 295The mask includes the network part of the local address 296and the subnet part, which is taken from the host field of the address. 297The mask can be specified as a single hexadecimal number 298with a leading 0x, with a dot-notation Internet address, 299or with a pseudo-network name listed in the network table 300.Xr networks 5 . 301The mask contains 1's for the bit positions in the 32-bit address 302which are to be used for the network and subnet parts, 303and 0's for the host part. 304The mask should contain at least the standard network portion, 305and the subnet field should be contiguous with the network 306portion. 307.Pp 308For INET and INET6 addresses, the netmask can also be given with 309slash-notation after the address 310.Pq e.g 192.168.17.3/24 . 311.\" see 312.\" Xr eon 5 . 313.It Cm state Ar state 314Explicitly force the 315.Xr carp 4 316pseudo-device to enter this state. 317Valid states are 318.Ar INIT , 319.Ar BACKUP , 320and 321.Ar MASTER . 322.It Cm frag Ar threshold 323.Pq IEEE 802.11 devices only 324Configure the fragmentation threshold for IEEE 802.11-based wireless 325network interfaces. 326.It Cm rts Ar threshold 327.Pq IEEE 802.11 devices only 328Configure the RTS/CTS threshold for IEEE 802.11-based wireless 329network interfaces. 330This controls the number of bytes used for the RTS/CTS handshake boundary. 331The 332.Ar threshold 333can be any value between 0 and 2347. 334The default is 2347, which indicates the RTS/CTS mechanism should not be used. 335.It Cm ssid Ar id 336.Pq IEEE 802.11 devices only 337Configure the Service Set Identifier (aka the network name) 338for IEEE 802.11-based wireless network interfaces. 339The 340.Ar id 341can either be any text string up to 32 characters in length, 342or a series of up to 64 hexadecimal digits preceded by 343.Dq 0x . 344Setting 345.Ar id 346to the empty string allows the interface to connect to any available 347access point. 348.It Cm nwid Ar id 349Synonym for 350.Dq ssid . 351.It Cm hidessid 352.Pq IEEE 802.11 devices only 353When operating as an access point, do not broadcast the SSID 354in beacon frames or respond to probe request frames unless 355they are directed to the ap (i.e., they include the ap's SSID). 356By default, the SSID is included in beacon frames and 357undirected probe request frames are answered. 358.It Fl hidessid 359.Pq IEEE 802.11 devices only 360When operating as an access point, broadcast the SSID 361in beacon frames and answer and respond to undirected probe 362request frames (default). 363.It Cm nwkey Ar key 364.Pq IEEE 802.11 devices only 365Enable WEP encryption for IEEE 802.11-based wireless network interfaces 366with the 367.Ar key . 368The 369.Ar key 370can either be a string, a series of hexadecimal digits preceded by 371.Dq 0x , 372or a set of keys in the form 373.Ar n:k1,k2,k3,k4 , 374where 375.Ar n 376specifies which of keys will be used for all transmitted packets, 377and four keys, 378.Ar k1 379through 380.Ar k4 , 381are configured as WEP keys. 382Note that the order must be match within same network if multiple keys 383are used. 384For IEEE 802.11 wireless network, the length of each key is restricted to 38540 bits, i.e., 5-character string or 10 hexadecimal digits, 386while the WaveLAN/IEEE Gold cards accept the 104 bits 387.Pq 13 characters 388key. 389.It Cm nwkey Cm persist 390.Pq IEEE 802.11 devices only 391Enable WEP encryption for IEEE 802.11-based wireless network interfaces 392with the persistent key written in the network card. 393.It Cm nwkey Cm persist : Ns Ar key 394.Pq IEEE 802.11 devices only 395Write the 396.Ar key 397to the persistent memory of the network card, and 398enable WEP encryption for IEEE 802.11-based wireless network interfaces 399with the 400.Ar key . 401.It Fl nwkey 402.Pq IEEE 802.11 devices only 403Disable WEP encryption for IEEE 802.11-based wireless network interfaces. 404.It Cm apbridge 405.Pq IEEE 802.11 devices only 406When operating as an access point, pass packets between 407wireless clients directly (default). 408.It Fl apbridge 409.Pq IEEE 802.11 devices only 410When operating as an access point, pass packets through 411the system so that they can be forwarded using some other mechanism. 412Disabling the internal bridging is useful when traffic 413is to be processed with packet filtering. 414.It Cm pass Ar passphrase 415If the driver is a 416.Xr carp 4 417pseudo-device, set the authentication key to 418.Ar passphrase . 419There is no passphrase by default 420.It Cm powersave 421.Pq IEEE 802.11 devices only 422Enable 802.11 power saving mode. 423.It Fl powersave 424.Pq IEEE 802.11 devices only 425Disable 802.11 power saving mode. 426.It Cm powersavesleep Ar duration 427.Pq IEEE 802.11 devices only 428Set the receiver sleep duration in milliseconds for 802.11 power saving mode. 429.It Cm bssid Ar bssid 430.Pq IEEE 802.11 devices only 431Set the desired BSSID for IEEE 802.11-based wireless network interfaces. 432.It Fl bssid 433.Pq IEEE 802.11 devices only 434Unset the desired BSSID for IEEE 802.11-based wireless network interfaces. 435The interface will automatically select a BSSID in this mode, which is 436the default. 437.It Cm chan Ar chan 438.Pq IEEE 802.11 devices only 439Select the channel 440.Pq radio frequency 441to be used for IEEE 802.11-based wireless network interfaces. 442.It Fl chan 443.Pq IEEE 802.11 devices only 444Unset the desired channel to be used 445for IEEE 802.11-based wireless network interfaces. 446It does not affect the channel to be created for IBSS or hostap mode. 447.It Cm list scan 448.Pq IEEE 802.11 devices only 449Display the access points and/or ad-hoc neighbors 450located in the vicinity. 451The 452.Fl v 453flag may be used to display long SSIDs. 454.Fl v 455also causes received information elements to be displayed symbolically. 456The interface must be up before any scanning operation. 457Only the super-user can use this command. 458.It Cm tunnel Ar src_addr Ns Oo Ar ,src_port Oc Ar dest_addr Ns Oo Ar ,dest_port Oc 459.Pq IP tunnel devices only 460Configure the physical source and destination address for IP tunnel 461interfaces, including 462.Xr gif 4 . 463The arguments 464.Ar src_addr 465and 466.Ar dest_addr 467are interpreted as the outer source/destination for the encapsulating 468IPv4/IPv6 header. 469.Pp 470On a 471.Xr gre 4 472interface in UDP mode, the arguments 473.Ar src_port 474and 475.Ar dest_port 476are interpreted as the outer source/destination port for the encapsulating 477UDP header. 478.It Cm deletetunnel 479Unconfigure the physical source and destination address for IP tunnel 480interfaces previously configured with 481.Cm tunnel . 482.It Cm session Ar local_session Ar remote_session 483.Pq L2TPv3 devices only 484Configure local session id and remote session id for L2TPv3 485interface. 486The length of session id is 4 bytes. 487.It Cm deletesession 488Unconfigure the local session id and remote session id for 489L2TPv3 interface previously configured with 490.Cm session . 491.It Cm cookie Ar local_cookie_length Ar local_cookie Ar remote_cookie_length Ar remote_cookie 492.Pq L2TPv3 devices only 493Configure local cookie and remote cookie for L2TPv3 interface. 494The cookie length must be 4 or 8 bytes. 495Generally, cookies are managed by daemon. 496So, this command would be used for test or debug only. 497.It Cm deletecookie 498Unconfigure the local cookie and remote cookie for L2TPv3 499interface previously configured with 500.Cm cookie . 501.It Cm create 502Create the specified network pseudo-device. 503.It Cm destroy 504Destroy the specified network pseudo-device. 505.It Cm pltime Ar n 506.Pq inet6 only 507Set preferred lifetime for the address. 508.It Cm prefixlen Ar n 509.Pq inet and inet6 only 510Effect is similar to 511.Cm netmask . 512but you can specify by prefix length by digits. 513.It Cm deprecated 514.Pq inet6 only 515Set the IPv6 deprecated address bit. 516.It Fl deprecated 517.Pq inet6 only 518Clear the IPv6 deprecated address bit. 519.It Cm eui64 520.Pq inet6 only 521Fill interface index 522.Pq lowermost 64bit of an IPv6 address 523automatically. 524.It Cm link[0-2] 525Enable special processing of the link level of the interface. 526These three options are interface specific in actual effect, however, 527they are in general used to select special modes of operation. 528An example 529of this is to enable SLIP compression, or to select the connector type 530for some Ethernet cards. 531Refer to the man page for the specific driver 532for more information. 533.It Fl link[0-2] 534Disable special processing at the link level with the specified interface. 535.It Cm linkstr Ar str 536Set a link-level string parameter for the interface. 537This functionality varies from interface to interface. 538Refer to the man page for the specific driver 539for more information. 540.It Fl linkstr 541Remove an interface link-level string parameter. 542.It Cm up 543Mark an interface ``up''. 544This may be used to enable an interface after an ``ifconfig down.'' 545It happens automatically when setting the first address on an interface. 546If the interface was reset when previously marked down, 547the hardware will be re-initialized. 548.It Cm vhid Ar n 549If the driver is a 550.Xr carp 4 551pseudo-device, set the virtual host ID to 552.Ar n . 553Acceptable values are 1 to 255. 554.It Cm vlan Ar vid 555If the interface is a 556.Xr vlan 4 557pseudo-interface, set the VLAN identifier to 558.Ar vid . 559These are the first 12 bits (0-4095) from a 16-bit integer used 560to create an 802.1Q VLAN header for packets sent from the 561.Xr vlan 4 562interface. 563Note that 564.Cm vlan 565and 566.Cm vlanif 567must be set at the same time. 568.It Cm vlanif Ar iface 569If the interface is a 570.Xr vlan 4 571pseudo-interface, associate the physical interface 572.Ar iface 573with it. 574Packets transmitted through the 575.Xr vlan 4 576interface will be diverted to the specified physical interface 577.Ar iface 578with 802.1Q VLAN encapsulation. 579Packets with 802.1Q encapsulation received 580by the physical interface with the correct VLAN tag will be diverted to the 581associated 582.Xr vlan 4 583pseudo-interface. 584The VLAN interface is assigned a copy of the physical 585interface's flags and 586.Tn Ethernet 587address. 588If the 589.Xr vlan 4 590interface already has a physical interface associated with it, this command 591will fail. 592To change the association to another physical interface, the 593existing association must be cleared first. 594Note that 595.Cm vlanif 596and 597.Cm vlan 598must be set at the same time. 599.It Cm -vlanif Ar iface 600Dissociate 601.Ar iface 602from the 603.Xr vlan 4 604interface. 605.It Cm agrport Ar iface 606Add 607.Ar iface 608to the 609.Xr agr 4 610interface. 611.It Cm -agrport Ar iface 612Remove 613.Ar iface 614from the 615.Xr agr 4 616interface. 617.It Cm laggport Ar interface Oo Cm pri Ar n Oc 618Add the interface named by 619.Ar interface 620as a port of the 621.Xr lagg 4 622interface, 623and set the priority of 624.Ar interface 625to 626.Ar n . 627.It Cm -laggport Ar interface 628Remove the interface named by 629.Ar interface 630from the 631.Xr lagg 4 632interface. 633.It Cm laggportpri Ar interface Ar n 634If the interface is a 635.Xr lagg 4 636pseudo-interface, set the priority of 637.Ar interface 638to 639.Ar n 640.It Cm laggproto Ar proto 641Set the aggregation protocol of 642.Xr lagg 4 . 643The default is 644.Li none . 645The available options are 646.Li failover , 647.Li lacp , 648.Li loadbalance , 649and 650.Li none . 651.It Cm eee 652Enable IEEE 802.3az Energy Efficiency Ethernet function. 653.It Cm -eee 654Disable IEEE 802.3az Energy Efficiency Ethernet function. 655.It Cm vltime Ar n 656.Pq inet6 only 657Set valid lifetime for the address. 658.It Cm ip4csum 659Shorthand of 660.Dq ip4csum-tx ip4csum-rx 661.It Cm -ip4csum 662Shorthand of 663.Dq -ip4csum-tx -ip4csum-rx 664.It Cm tcp4csum 665Shorthand of 666.Dq tcp4csum-tx tcp4csum-rx 667.It Cm -tcp4csum 668Shorthand of 669.Dq -tcp4csum-tx -tcp4csum-rx 670.It Cm udp4csum 671Shorthand of 672.Dq udp4csum-tx udp4csum-rx 673.It Cm -udp4csum 674Shorthand of 675.Dq -udp4csum-tx -udp4csum-rx 676.It Cm tcp6csum 677Shorthand of 678.Dq tcp6csum-tx tcp6csum-rx 679.It Cm -tcp6csum 680Shorthand of 681.Dq -tcp6csum-tx -tcp6csum-rx 682.It Cm udp6csum 683Shorthand of 684.Dq udp6csum-tx udp6csum-rx 685.It Cm -udp6csum 686Shorthand of 687.Dq -udp6csum-tx -udp6csum-rx 688.It Cm ip4csum-tx 689Enable hardware-assisted IPv4 header checksums for the out-bound direction. 690.It Cm -ip4csum-tx 691Disable hardware-assisted IPv4 header checksums for the out-bound direction. 692.It Cm ip4csum-rx 693Enable hardware-assisted IPv4 header checksums for the in-bound direction. 694.It Cm -ip4csum-rx 695Disable hardware-assisted IPv4 header checksums for the in-bound direction. 696.It Cm tcp4csum-tx 697Enable hardware-assisted TCP/IPv4 checksums for the out-bound direction. 698.It Cm -tcp4csum-tx 699Disable hardware-assisted TCP/IPv4 checksums for the out-bound direction. 700.It Cm tcp4csum-rx 701Enable hardware-assisted TCP/IPv4 checksums for the in-bound direction. 702.It Cm -tcp4csum-rx 703Disable hardware-assisted TCP/IPv4 checksums for the in-bound direction. 704.It Cm udp4csum-tx 705Enable hardware-assisted UDP/IPv4 checksums for the out-bound direction. 706.It Cm -udp4csum-tx 707Disable hardware-assisted UDP/IPv4 checksums for the out-bound direction. 708.It Cm udp4csum-rx 709Enable hardware-assisted UDP/IPv4 checksums for the in-bound direction. 710.It Cm -udp4csum-rx 711Disable hardware-assisted UDP/IPv4 checksums for the in-bound direction. 712.It Cm tcp6csum-tx 713Enable hardware-assisted TCP/IPv6 checksums for the out-bound direction. 714.It Cm -tcp6csum-tx 715Disable hardware-assisted TCP/IPv6 checksums for the out-bound direction. 716.It Cm tcp6csum-rx 717Enable hardware-assisted TCP/IPv6 checksums for the in-bound direction. 718.It Cm -tcp6csum-rx 719Disable hardware-assisted TCP/IPv6 checksums for the in-bound direction. 720.It Cm udp6csum-tx 721Enable hardware-assisted UDP/IPv6 checksums for the out-bound direction. 722.It Cm -udp6csum-tx 723Disable hardware-assisted UDP/IPv6 checksums for the out-bound direction. 724.It Cm udp6csum-rx 725Enable hardware-assisted UDP/IPv6 checksums for the in-bound direction. 726.It Cm -udp6csum-rx 727Disable hardware-assisted UDP/IPv6 checksums for the in-bound direction. 728.It Cm tso4 729Enable hardware-assisted TCP/IPv4 segmentation on interfaces that 730support it. 731.It Cm -tso4 732Disable hardware-assisted TCP/IPv4 segmentation on interfaces that 733support it. 734.It Cm tso6 735Enable hardware-assisted TCP/IPv6 segmentation on interfaces that 736support it. 737.It Cm -tso6 738Disable hardware-assisted TCP/IPv6 segmentation on interfaces that 739support it. 740.It Cm vlan-hwfilter 741Enable hardware-assisted VLAN frame filter on interfaces that support it. 742.It Cm -vlan-hwfilter 743Disable hardware-assisted VLAN frame filter on interfaces that support it. 744.It Cm vlan-hwtagging 745Enable hardware-assisted VLAN tag insertion/removal on interfaces that 746support it. 747.It Cm -vlan-hwtagging 748Disable hardware-assisted VLAN tag insertion/removal on interfaces that 749support it. 750.It Cm maxupd Ar n 751If the driver is a 752.Xr pfsync 4 753pseudo-device, indicate the maximum number 754of updates for a single state which can be collapsed into one. 755This is an 8-bit number; the default value is 128. 756.It Cm syncdev Ar iface 757If the driver is a 758.Xr pfsync 4 759pseudo-device, use the specified interface 760to send and receive pfsync state synchronisation messages. 761.It Fl syncdev 762If the driver is a 763.Xr pfsync 4 764pseudo-device, stop sending pfsync state 765synchronisation messages over the network. 766.It Cm syncpeer Ar peer_address 767If the driver is a 768.Xr pfsync 4 769pseudo-device, make the pfsync link point-to-point rather than using 770multicast to broadcast the state synchronisation messages. 771The peer_address is the IP address of the other host taking part in 772the pfsync cluster. 773With this option, 774.Xr pfsync 4 775traffic can be protected using 776.Xr ipsec 4 . 777.It Fl syncpeer 778If the driver is a 779.Xr pfsync 4 780pseudo-device, broadcast the packets using multicast. 781.It Cm unnumbered 782Treat the interface as unnumbered. 783.It Cm -unnumbered 784Don't treat the interface as unnumbered. 785.El 786.Pp 787.Nm 788displays the current configuration for a network interface 789when no optional parameters are supplied. 790If a protocol family is specified, 791.Nm 792will report only the details specific to that protocol 793family. 794.Pp 795If the 796.Fl s 797flag is passed before an interface name, 798.Nm 799will attempt to query the interface for its media status. 800If the 801interface supports reporting media status, and it reports that it does 802not appear to be connected to a network, 803.Nm 804will exit with status of 1 805.Pq false ; 806otherwise, it will exit with a zero 807.Pq true 808exit status. 809For interface drivers that do not support media status reporting. 810then if the link state is not reported to be up, 811.Nm 812will exit with a status of 1 813.Pq false ; 814otherwise, it will exit with a zero 815.Pq true 816exit status. 817.Pp 818If the 819.Fl m 820flag is passed before an interface name, 821.Nm 822will display all of the supported media for the specified interface. 823If the 824.Fl L 825flag is supplied, address lifetime is displayed for IPv6 addresses, 826as time offset string. 827.Pp 828Optionally, the 829.Fl a 830flag may be used instead of an interface name. 831This flag instructs 832.Nm 833to display information about all interfaces in the system. 834This is also the default behaviour when no arguments are given to 835.Nm 836on the command line. 837When 838.Fl a 839is used, the output can be modified by adding more flags: 840.Fl d 841limits this to interfaces that are down, 842.Fl u 843limits this to interfaces that are up, 844.Fl b 845limits this to broadcast interfaces, and 846.Fl s 847omits interfaces which appear not to be connected to a network. 848.Pp 849The 850.Fl l 851flag may be used to list all available interfaces on the system, with 852no other additional information. 853Use of this flag is mutually exclusive 854with all other flags and commands, except for 855.Fl d 856.Pq only list interfaces that are down , 857.Fl u 858.Pq only list interfaces that are up , 859.Fl s 860.Pq only list interfaces that may be connected , 861.Fl b 862.Pq only list broadcast interfaces . 863.Pp 864The 865.Fl C 866flag may be used to list all of the interface cloners available on 867the system, with no additional information. 868Use of this flag is 869mutually exclusive with all other flags and commands. 870.Pp 871The 872.Fl v 873flag prints additional information like statistics on packets sent and received 874on the interface and the link state of the interface. 875If 876.Fl h 877is used in conjunction with 878.Fl v , 879the byte statistics will be printed in "human-readable" format. 880The 881.Fl z 882flag is identical to the 883.Fl v 884flag except that it zeros the interface input and output statistics 885after printing them. 886.Pp 887The 888.Fl w 889flag may be used to wait 890.Ar seconds 891seconds for the 892.Cm tentative 893flag to be removed from all addresses. 8940 seconds means to wait indefinitely until all addresses no longer have the 895.Cm tentative 896flag. 897The optional 898.Fl W 899flag may be used to wait 900.Ar seconds 901seconds during the above time for the detached flag to be removed from all 902addresses whose interface is marked ``up'' as well. 903The detached flag is set when the interface does not have a carrier. 904.Pp 905The 906.Fl N 907flag is just the opposite of the 908.Fl n 909flag in 910.Xr netstat 1 911or in 912.Xr route 8 : 913it tells 914.Nm 915to try to resolve numbers to hostnames or to service names. 916The default 917.Nm 918behavior is to print numbers instead of names. 919.Pp 920Only the super-user may modify the configuration of a network interface. 921.Sh EXAMPLES 922Add a link-layer (MAC) address to an Ethernet: 923.Pp 924.Ic ifconfig sip0 link 00:11:22:33:44:55 925.Pp 926Add and activate a link-layer (MAC) address: 927.Pp 928.Ic ifconfig sip0 link 00:11:22:33:44:55 active 929.Sh DIAGNOSTICS 930Messages indicating the specified interface does not exist, the 931requested address is unknown, or the user is not privileged and 932tried to alter an interface's configuration. 933.Sh SEE ALSO 934.Xr netstat 1 , 935.Xr agr 4 , 936.Xr lagg 4 , 937.Xr carp 4 , 938.Xr ifmedia 4 , 939.Xr netintro 4 , 940.Xr pfsync 4 , 941.Xr vlan 4 , 942.Xr ifconfig.if 5 , 943.\" .Xr eon 5 , 944.Xr ifmcstat 8 , 945.Xr rc 8 , 946.Xr routed 8 947.Sh BUGS 948Due to hardware limitations some of the capabilities cannot be turned on 949and off individually and need to be specified together. 950For example the 951.Xr ixg 4 952driver can't enable separately tcp and udp, or the transmit and receive 953checksumming capabilities. 954Unfortunately the diagnostic messages in this case are lacking. 955.Sh HISTORY 956The 957.Nm 958command appeared in 959.Bx 4.2 . 960