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NetBSD 6.1.5 - man page for ifconfig (netbsd section 8)

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IFCONFIG(8)			   BSD System Manager's Manual			      IFCONFIG(8)

NAME
     ifconfig -- configure network interface parameters

SYNOPSIS
     ifconfig [-N] interface address_family [address [dest_address]] [parameters]
     ifconfig [-hLmNvz] interface [protocol_family]
     ifconfig -a [-bdhLNmsuvz] [protocol_family]
     ifconfig -l [-bdsu]
     ifconfig -s interface
     ifconfig -C

DESCRIPTION
     ifconfig is used to assign an address to a network interface and/or configure network inter-
     face parameters.  ifconfig must be used at boot time to define the network address of each
     interface present on a machine; it may also be used at a later time to redefine an inter-
     face's address or other operating parameters.

     Available operands for ifconfig:

     address
	     For the DARPA-Internet family, the address is either a host name present in the host
	     name data base, hosts(5), or a DARPA Internet address expressed in the Internet
	     standard ``dot notation''.  For the Xerox Network Systems(tm) family, addresses are
	     net:a.b.c.d.e.f, where net is the assigned network number (in decimal), and each of
	     the six bytes of the host number, a through f, are specified in hexadecimal.  The
	     host number may be omitted on Ethernet interfaces, which use the hardware physical
	     address, and on interfaces other than the first.  For the ISO family, addresses are
	     specified as a long hexadecimal string, as in the Xerox family.  However, two con-
	     secutive dots imply a zero byte, and the dots are optional, if the user wishes to
	     (carefully) count out long strings of digits in network byte order.

     address_family
	     Specifies the address_family which affects interpretation of the remaining parame-
	     ters.  Since an interface can receive transmissions in differing protocols with dif-
	     ferent naming schemes, specifying the address family is recommended.  The address or
	     protocol families currently supported are ``inet'', ``inet6'', ``atalk'', ``iso'',
	     and ``link''.

     interface
	     The interface parameter is a string of the form ``name unit'', for example, ``en0''

     The following parameters may be set with ifconfig:

     active	     This keyword applies when ifconfig adds or modifies any link-layer address.
		     It indicates that ifconfig should ``activate'' the address.  Activation
		     makes an address the default source for transmissions on the interface.  You
		     may not delete the active address from an interface.  You must activate some
		     other address, first.

     advbase n	     If the driver is a carp(4) pseudo-device, set the base advertisement inter-
		     val to n seconds.	This ia an 8-bit number; the default value is 1 second.

     advskew n	     If the driver is a carp(4) pseudo-device, skew the advertisement interval by
		     n.  This is an 8-bit number; the default value is 0.

		     Taken together the advbase indicate how frequently, in seconds, the host
		     will advertise the fact that it considers itself the master of the virtual
		     host.  The formula is advbase + (advskew / 256).  If the master does not
		     advertise within three times this interval, this host will begin advertising
		     as master.

     alias	     Establish an additional network address for this interface.  This is some-
		     times useful when changing network numbers, and one wishes to accept packets
		     addressed to the old interface.

     -alias	     Remove the specified network address alias.

     arp	     Enable the use of the Address Resolution Protocol in mapping between network
		     level addresses and link level addresses (default).  This is currently
		     implemented for mapping between DARPA Internet addresses and Ethernet
		     addresses.

     -arp	     Disable the use of the Address Resolution Protocol.

     anycast	     (inet6 only) Set the IPv6 anycast address bit.

     -anycast	     (inet6 only) Clear the IPv6 anycast address bit.

     broadcast mask  (Inet only) Specify the address to use to represent broadcasts to the net-
		     work.  The default broadcast address is the address with a host part of all
		     1's.

     carpdev iface   If the driver is a carp(4) pseudo-device, attach it to iface.  If not speci-
		     fied, the kernel will attempt to select an interface with a subnet matching
		     that of the carp interface.

     debug	     Enable driver dependent debugging code; usually, this turns on extra console
		     error logging.

     -debug	     Disable driver dependent debugging code.

     delete	     Remove the network address specified.  This would be used if you incorrectly
		     specified an alias, or it was no longer needed.  If you have incorrectly set
		     an NS address having the side effect of specifying the host portion, remov-
		     ing all NS addresses will allow you to respecify the host portion.  delete
		     does not work for IPv6 addresses.	Use -alias with explicit IPv6 address
		     instead.

     dest_address    Specify the address of the correspondent on the other end of a point to
		     point link.

     down	     Mark an interface ``down''.  When an interface is marked ``down'', the sys-
		     tem will not attempt to transmit messages through that interface.	If possi-
		     ble, the interface will be reset to disable reception as well.  This action
		     does not automatically disable routes using the interface.

     ipdst	     This is used to specify an Internet host who is willing to receive ip pack-
		     ets encapsulating NS packets bound for a remote network.  An apparent point
		     to point link is constructed, and the address specified will be taken as the
		     NS address and network of the destination.  IP encapsulation of CLNP packets
		     is done differently.

     media type      Set the media type of the interface to type.  Some interfaces support the
		     mutually exclusive use of one of several different physical media connec-
		     tors.  For example, a 10Mb/s Ethernet interface might support the use of
		     either AUI or twisted pair connectors.  Setting the media type to
		     ``10base5'' or ``AUI'' would change the currently active connector to the
		     AUI port.	Setting it to ``10baseT'' or ``UTP'' would activate twisted pair.
		     Refer to the interfaces' driver specific man page for a complete list of the
		     available types and the ifmedia(4) manual page for a list of media types.
		     See the -m flag below.

     mediaopt opts   Set the specified media options on the interface.	opts is a comma delimited
		     list of options to apply to the interface.  Refer to the interfaces' driver
		     specific man page for a complete list of available options.  Also see the
		     ifmedia(4) manual page for a list of media options.

     -mediaopt opts  Disable the specified media options on the interface.

     mode mode	     If the driver supports the media selection system, set the specified operat-
		     ing mode on the interface to mode.  For IEEE 802.11 wireless interfaces that
		     support multiple operating modes this directive is used to select between
		     802.11a (``11a''), 802.11b (``11b''), and 802.11g (``11g'') operating modes.

     instance minst  Set the media instance to minst.  This is useful for devices which have mul-
		     tiple physical layer interfaces (PHYs).  Setting the instance on such
		     devices may not be strictly required by the network interface driver as the
		     driver may take care of this automatically; see the driver's manual page for
		     more information.

     metric n	     Set the routing metric of the interface to n, default 0.  The routing metric
		     is used by the routing protocol (routed(8)).  Higher metrics have the effect
		     of making a route less favorable; metrics are counted as addition hops to
		     the destination network or host.

     mtu n	     Set the maximum transmission unit of the interface to n.  Most interfaces
		     don't support this option.

     netmask mask    (inet, inet6, and ISO) Specify how much of the address to reserve for subdi-
		     viding networks into sub-networks.  The mask includes the network part of
		     the local address and the subnet part, which is taken from the host field of
		     the address.  The mask can be specified as a single hexadecimal number with
		     a leading 0x, with a dot-notation Internet address, or with a pseudo-network
		     name listed in the network table networks(5).  The mask contains 1's for the
		     bit positions in the 32-bit address which are to be used for the network and
		     subnet parts, and 0's for the host part.  The mask should contain at least
		     the standard network portion, and the subnet field should be contiguous with
		     the network portion.

		     For INET and INET6 addresses, the netmask can also be given with slash-nota-
		     tion after the address (e.g 192.168.17.3/24).

     nsellength n    (ISO only) This specifies a trailing number of bytes for a received NSAP
		     used for local identification, the remaining leading part of which is taken
		     to be the NET (Network Entity Title).  The default value is 1, which is con-
		     formant to US GOSIP.  When an ISO address is set in an ifconfig command, it
		     is really the NSAP which is being specified.  For example, in US GOSIP, 20
		     hex digits should be specified in the ISO NSAP to be assigned to the inter-
		     face.  There is some evidence that a number different from 1 may be useful
		     for AFI 37 type addresses.

     state state     Explicitly force the carp(4) pseudo-device to enter this state.  Valid
		     states are init, backup, and master.

     frag threshold  (IEEE 802.11 devices only) Configure the fragmentation threshold for IEEE
		     802.11-based wireless network interfaces.

     rts threshold   (IEEE 802.11 devices only) Configure the RTS/CTS threshold for IEEE
		     802.11-based wireless network interfaces.	This controls the number of bytes
		     used for the RTS/CTS handshake boundary.  The threshold can be any value
		     between 0 and 2347.  The default is 2347, which indicates the RTS/CTS mecha-
		     nism should not be used.

     ssid id	     (IEEE 802.11 devices only) Configure the Service Set Identifier (a.k.a. the
		     network name) for IEEE 802.11-based wireless network interfaces.  The id can
		     either be any text string up to 32 characters in length, or a series of up
		     to 64 hexadecimal digits preceded by ``0x''.  Setting id to the empty string
		     allows the interface to connect to any available access point.

     nwid id	     Synonym for ``ssid''.

     hidessid	     (IEEE 802.11 devices only) When operating as an access point, do not broad-
		     cast the SSID in beacon frames or respond to probe request frames unless
		     they are directed to the ap (i.e., they include the ap's SSID).  By default,
		     the SSID is included in beacon frames and undirected probe request frames
		     are answered.

     -hidessid	     (IEEE 802.11 devices only) When operating as an access point, broadcast the
		     SSID in beacon frames and answer and respond to undirected probe request
		     frames (default).

     nwkey key	     (IEEE 802.11 devices only) Enable WEP encryption for IEEE 802.11-based wire-
		     less network interfaces with the key.  The key can either be a string, a
		     series of hexadecimal digits preceded by ``0x'', or a set of keys in the
		     form n:k1,k2,k3,k4, where n specifies which of keys will be used for all
		     transmitted packets, and four keys, k1 through k4, are configured as WEP
		     keys.  Note that the order must be match within same network if multiple
		     keys are used.  For IEEE 802.11 wireless network, the length of each key is
		     restricted to 40 bits, i.e. 5-character string or 10 hexadecimal digits,
		     while the WaveLAN/IEEE Gold cards accept the 104 bits (13 characters) key.

     nwkey persist   (IEEE 802.11 devices only) Enable WEP encryption for IEEE 802.11-based wire-
		     less network interfaces with the persistent key written in the network card.

     nwkey persist:key
		     (IEEE 802.11 devices only) Write the key to the persistent memory of the
		     network card, and enable WEP encryption for IEEE 802.11-based wireless net-
		     work interfaces with the key.

     -nwkey	     (IEEE 802.11 devices only) Disable WEP encryption for IEEE 802.11-based
		     wireless network interfaces.

     apbridge	     (IEEE 802.11 devices only) When operating as an access point, pass packets
		     between wireless clients directly (default).

     -apbridge	     (IEEE 802.11 devices only) When operating as an access point, pass packets
		     through the system so that they can be forwared using some other mechanism.
		     Disabling the internal bridging is useful when traffic is to be processed
		     with packet filtering.

     pass passphrase
		     If the driver is a carp(4) pseudo-device, set the authentication key to
		     passphrase.  There is no passphrase by default

     powersave	     (IEEE 802.11 devices only) Enable 802.11 power saving mode.

     -powersave      (IEEE 802.11 devices only) Disable 802.11 power saving mode.

     powersavesleep duration
		     (IEEE 802.11 devices only) Set the receiver sleep duration in milliseconds
		     for 802.11 power saving mode.

     bssid bssid     (IEEE 802.11 devices only) Set the desired BSSID for IEEE 802.11-based wire-
		     less network interfaces.

     -bssid	     (IEEE 802.11 devices only) Unset the desired BSSID for IEEE 802.11-based
		     wireless network interfaces.  The interface will automatically select a
		     BSSID in this mode, which is the default.

     chan chan	     (IEEE 802.11 devices only) Select the channel (radio frequency) to be used
		     for IEEE 802.11-based wireless network interfaces.

     -chan	     (IEEE 802.11 devices only) Unset the desired channel to be used for IEEE
		     802.11-based wireless network interfaces.	It doesn't affect the channel to
		     be created for IBSS or hostap mode.

     list scan	     (IEEE 802.11 devices only) Display the access points and/or ad-hoc neighbors
		     located in the vicinity.  The -v flag may be used to display long SSIDs.  -v
		     also causes received information elements to be displayed symbolically.
		     Only the super-user can use this command.

     tunnel src_addr[,src_port]
		     dest_addr[,dest_port] (IP tunnel devices only) Configure the physical source
		     and destination address for IP tunnel interfaces, including gif(4).  The
		     arguments src_addr and dest_addr are interpreted as the outer source/desti-
		     nation for the encapsulating IPv4/IPv6 header.

		     On a gre(4) interface in UDP mode, the arguments src_port and dest_port are
		     interpreted as the outer source/destination port for the encapsulating UDP
		     header.

     deletetunnel    Unconfigure the physical source and destination address for IP tunnel inter-
		     faces previously configured with tunnel.

     create	     Create the specified network pseudo-device.

     destroy	     Destroy the specified network pseudo-device.

     pltime n	     (inet6 only) Set preferred lifetime for the address.

     prefixlen n     (inet and inet6 only) Effect is similar to netmask.  but you can specify by
		     prefix length by digits.

     deprecated      (inet6 only) Set the IPv6 deprecated address bit.

     -deprecated     (inet6 only) Clear the IPv6 deprecated address bit.

     tentative	     (inet6 only) Set the IPv6 tentative address bit.

     -tentative      (inet6 only) Clear the IPv6 tentative address bit.

     eui64	     (inet6 only) Fill interface index (lowermost 64bit of an IPv6 address) auto-
		     matically.

     link[0-2]	     Enable special processing of the link level of the interface.  These three
		     options are interface specific in actual effect, however, they are in gen-
		     eral used to select special modes of operation.  An example of this is to
		     enable SLIP compression, or to select the connector type for some Ethernet
		     cards.  Refer to the man page for the specific driver for more information.

     -link[0-2]      Disable special processing at the link level with the specified interface.

     linkstr	     Set a link-level string parameter for the interface.  This functionality
		     varies from interface to interface.  Refer to the man page for the specific
		     driver for more information.

     -linkstr	     Remove an interface link-level string parameter.

     up 	     Mark an interface ``up''.	This may be used to enable an interface after an
		     ``ifconfig down.''  It happens automatically when setting the first address
		     on an interface.  If the interface was reset when previously marked down,
		     the hardware will be re-initialized.

     vhid n	     If the driver is a carp(4) pseudo-device, set the virtual host ID to n.
		     Acceptable values are 1 to 255.

     vlan vid	     If the interface is a vlan(4) pseudo-interface, set the VLAN identifier to
		     vid.  These are the first 12 bits (0-4095) from a 16-bit integer used to
		     create an 802.1Q VLAN header for packets sent from the vlan(4) interface.
		     Note that vlan and vlanif must be set at the same time.

     vlanif iface    If the interface is a vlan(4) pseudo-interface, associate the physical
		     interface iface with it.  Packets transmitted through the vlan(4) interface
		     will be diverted to the specified physical interface iface with 802.1Q VLAN
		     encapsulation.  Packets with 802.1Q encapsulation received by the physical
		     interface with the correct VLAN tag will be diverted to the associated
		     vlan(4) pseudo-interface.	The VLAN interface is assigned a copy of the
		     physical interface's flags and Ethernet address.  If the vlan(4) interface
		     already has a physical interface associated with it, this command will fail.
		     To change the association to another physical interface, the existing asso-
		     ciation must be cleared first.  Note that vlanif and vlan must be set at the
		     same time.

     agrport iface   Add iface to the agr(4) interface.

     -agrport iface  Remove iface from the agr(4) interface.

     vltime n	     (inet6 only) Set valid lifetime for the address.

     ip4csum	     Shorthand of ``ip4csum-tx ip4csum-rx''

     -ip4csum	     Shorthand of ``-ip4csum-tx -ip4csum-rx''

     tcp4csum	     Shorthand of ``tcp4csum-tx tcp4csum-rx''

     -tcp4csum	     Shorthand of ``-tcp4csum-tx -tcp4csum-rx''

     udp4csum	     Shorthand of ``udp4csum-tx udp4csum-rx''

     -udp4csum	     Shorthand of ``-udp4csum-tx -udp4csum-rx''

     tcp6csum	     Shorthand of ``tcp6csum-tx tcp6csum-rx''

     -tcp6csum	     Shorthand of ``-tcp6csum-tx -tcp6csum-rx''

     udp6csum	     Shorthand of ``udp6csum-tx udp6csum-rx''

     -udp6csum	     Shorthand of ``-udp6csum-tx -udp6csum-rx''

     ip4csum-tx      Enable hardware-assisted IPv4 header checksums for the out-bound direction.

     -ip4csum-tx     Disable hardware-assisted IPv4 header checksums for the out-bound direction.

     ip4csum-rx      Enable hardware-assisted IPv4 header checksums for the in-bound direction.

     -ip4csum-rx     Disable hardware-assisted IPv4 header checksums for the in-bound direction.

     tcp4csum-tx     Enable hardware-assisted TCP/IPv4 checksums for the out-bound direction.

     -tcp4csum-tx    Disable hardware-assisted TCP/IPv4 checksums for the out-bound direction.

     tcp4csum-rx     Enable hardware-assisted TCP/IPv4 checksums for the in-bound direction.

     -tcp4csum-rx    Disable hardware-assisted TCP/IPv4 checksums for the in-bound direction.

     udp4csum-tx     Enable hardware-assisted UDP/IPv4 checksums for the out-bound direction.

     -udp4csum-tx    Disable hardware-assisted UDP/IPv4 checksums for the out-bound direction.

     udp4csum-rx     Enable hardware-assisted UDP/IPv4 checksums for the in-bound direction.

     -udp4csum-rx    Disable hardware-assisted UDP/IPv4 checksums for the in-bound direction.

     tcp6csum-tx     Enable hardware-assisted TCP/IPv6 checksums for the out-bound direction.

     -tcp6csum-tx    Disable hardware-assisted TCP/IPv6 checksums for the out-bound direction.

     tcp6csum-rx     Enable hardware-assisted TCP/IPv6 checksums for the in-bound direction.

     -tcp6csum-rx    Disable hardware-assisted TCP/IPv6 checksums for the in-bound direction.

     udp6csum-tx     Enable hardware-assisted UDP/IPv6 checksums for the out-bound direction.

     -udp6csum-tx    Disable hardware-assisted UDP/IPv6 checksums for the out-bound direction.

     udp6csum-rx     Enable hardware-assisted UDP/IPv6 checksums for the in-bound direction.

     -udp6csum-rx    Disable hardware-assisted UDP/IPv6 checksums for the in-bound direction.

     tso4	     Enable hardware-assisted TCP/IPv4 segmentation on interfaces that support
		     it.

     -tso4	     Disable hardware-assisted TCP/IPv4 segmentation on interfaces that support
		     it.

     tso6	     Enable hardware-assisted TCP/IPv6 segmentation on interfaces that support
		     it.

     -tso6	     Disable hardware-assisted TCP/IPv6 segmentation on interfaces that support
		     it.

     maxupd n	     If the driver is a pfsync(4) pseudo-device, indicate the maximum number of
		     updates for a single state which can be collapsed into one.  This is an
		     8-bit number; the default value is 128.

     syncdev iface   If the driver is a pfsync(4) pseudo-device, use the specified interface to
		     send and receive pfsync state synchronisation messages.

     -syncdev	     If the driver is a pfsync(4) pseudo-device, stop sending pfsync state syn-
		     chronisation messages over the network.

     syncpeer peer_address
		     If the driver is a pfsync(4) pseudo-device, make the pfsync link point-to-
		     point rather than using multicast to broadcast the state synchronisation
		     messages.	The peer_address is the IP address of the other host taking part
		     in the pfsync cluster.  With this option, pfsync(4) traffic can be protected
		     using ipsec(4).

     -syncpeer	     If the driver is a pfsync(4) pseudo-device, broadcast the packets using mul-
		     ticast.

     ifconfig displays the current configuration for a network interface when no optional parame-
     ters are supplied.  If a protocol family is specified, ifconfig will report only the details
     specific to that protocol family.

     If the -s flag is passed before an interface name, ifconfig will attempt to query the inter-
     face for its media status.  If the interface supports reporting media status, and it reports
     that it does not appear to be connected to a network, ifconfig will exit with status of 1
     (false); otherwise, it will exit with a zero (true) exit status.  Not all interface drivers
     support media status reporting.

     If the -m flag is passed before an interface name, ifconfig will display all of the sup-
     ported media for the specified interface.	If the -L flag is supplied, address lifetime is
     displayed for IPv6 addresses, as time offset string.

     Optionally, the -a flag may be used instead of an interface name.	This flag instructs
     ifconfig to display information about all interfaces in the system.  This is also the
     default behaviour when no arguments are given to ifconfig on the command line.  When -a is
     used, the output can be modified by adding more flags: -d limits this to interfaces that are
     down, -u limits this to interfaces that are up, -b limits this to broadcast interfaces, and
     -s omits interfaces which appear not to be connected to a network.

     The -l flag may be used to list all available interfaces on the system, with no other addi-
     tional information.  Use of this flag is mutually exclusive with all other flags and com-
     mands, except for -d (only list interfaces that are down), -u (only list interfaces that are
     up), -s (only list interfaces that may be connected), -b (only list broadcast interfaces).

     The -C flag may be used to list all of the interface cloners available on the system, with
     no additional information.  Use of this flag is mutually exclusive with all other flags and
     commands.

     The -v flag prints statistics on packets sent and received on the given interface.  If -h is
     used in conjunction with -v, the byte statistics will be printed in "human-readable" format.
     The -z flag is identical to the -v flag except that it zeros the interface input and output
     statistics after printing them.

     The -N flag is just the opposite of the -n flag in netstat(1) or in route(8): it tells
     ifconfig to try to resolve numbers to hostnames or to service names.  The default ifconfig
     behavior is to print numbers instead of names.

     Only the super-user may modify the configuration of a network interface.

EXAMPLES
     Add a link-layer (MAC) address to an Ethernet:

     ifconfig sip0 link 00:11:22:33:44:55

     Add and activate a link-layer (MAC) address:

     ifconfig sip0 link 00:11:22:33:44:55 active

DIAGNOSTICS
     Messages indicating the specified interface does not exist, the requested address is
     unknown, or the user is not privileged and tried to alter an interface's configuration.

SEE ALSO
     netstat(1), agr(4), carp(4), ifmedia(4), netintro(4), pfsync(4), vlan(4), ifconfig.if(5),
     rc(8), routed(8)

HISTORY
     The ifconfig command appeared in 4.2BSD.

BSD					 January 28, 2012				      BSD
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