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

NAME
     ifconfig -- configure network interface parameters

SYNOPSIS
     ifconfig [-L] [-k] [-m] interface [create] [address_family] [address
              [dest_address]] [parameters]
     ifconfig interface destroy
     ifconfig -a [-L] [-d] [-m] [-u] [-v] [address_family]
     ifconfig -l [-d] [-u] [address_family]
     ifconfig [-L] [-d] [-k] [-m] [-u] [-v] [-C]

DESCRIPTION
     The ifconfig utility is used to assign an address to a network interface
     and/or configure network interface parameters.  The ifconfig utility 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
     interface's address or other operating parameters.

     The following options are available:

     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''.

             It is also possible to use the CIDR notation (also known as the
             slash notation) to include the netmask.  That is, one can specify
             an address like 192.168.0.1/16.

             For ``inet6'' family, it is also possible to specify the prefix
             length using the slash notation, like ::1/128.  See the prefixlen
             parameter below for more information.

             The link-level (``link'') address is specified as a series of
             colon-separated hex digits.  This can be used to e.g. set a new
             MAC address on an ethernet interface, though the mechanism used
             is not ethernet-specific.  If the interface is already up when
             this option is used, it will be briefly brought down and then
             brought back up again in order to ensure that the receive filter
             in the underlying ethernet hardware is properly reprogrammed.

     address_family
             Specify the address family which affects interpretation of the
             remaining parameters.  Since an interface can receive transmis-
             sions in differing protocols with different naming schemes, spec-
             ifying the address family is recommended.  The address or proto-
             col families currently supported are ``inet'', ``inet6'',
             ``atalk'', ``ipx'', and ``link''.  The default is ``inet''.
             ``ether'' and ``lladdr'' are synonyms for ``link''.

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

     interface
             This parameter is a string of the form ``name unit'', for exam-
             ple, ``ed0''.

     The following parameters may be set with ifconfig:

     add     Another name for the alias parameter.  Introduced for compatibil-
             ity with BSD/OS.

     alias   Establish an additional network address for this interface.  This
             is sometimes useful when changing network numbers, and one wishes
             to accept packets addressed to the old interface.  If the address
             is on the same subnet as the first network address for this
             interface, a non-conflicting netmask must be given.  Usually
             0xffffffff is most appropriate.

     -alias  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, removing all NS addresses will allow
             you to respecify the host portion.

     anycast
             (Inet6 only.)  Specify that the address configured is an anycast
             address.  Based on the current specification, only routers may
             configure anycast addresses.  Anycast address will not be used as
             source address of any of outgoing IPv6 packets.

     arp     Enable the use of the Address Resolution Protocol (arp(4)) in
             mapping between network level addresses and link level addresses
             (default).  This is currently implemented for mapping between
             DARPA Internet addresses and IEEE 802 48-bit MAC addresses (Eth-
             ernet, FDDI, and Token Ring addresses).

     -arp    Disable the use of the Address Resolution Protocol (arp(4)).

     staticarp
             If the Address Resolution Protocol is enabled, the host will only
             reply to requests for its addresses, and will never send any
             requests.

     -staticarp
             If the Address Resolution Protocol is enabled, the host will per-
             form normally, sending out requests and listening for replies.

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

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

     -debug  Disable driver dependent debugging code.

     promisc
             Put interface into permanently promiscuous mode.

     -promisc
             Disable permanently promiscuous mode.

     delete  Another name for the -alias parameter.

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

     eui64   (Inet6 only.)  Fill interface index (lowermost 64bit of an IPv6
             address) automatically.

     ipdst   This is used to specify an Internet host who is willing to
             receive IP packets encapsulating IPX packets bound for a remote
             network.  An apparent point to point link is constructed, and the
             address specified will be taken as the IPX address and network of
             the destination.

     maclabel label
             If Mandatory Access Control support is enabled in the kernel, set
             the MAC label to label.

     media type
             If the driver supports the media selection system, set the media
             type of the interface to type.  Some interfaces support the mutu-
             ally exclusive use of one of several different physical media
             connectors.  For example, a 10Mbit/s Ethernet interface might
             support the use of either AUI or twisted pair connectors.  Set-
             ting the media type to 10base5/AUI would change the currently
             active connector to the AUI port.  Setting it to 10baseT/UTP
             would activate twisted pair.  Refer to the interfaces' driver
             specific documentation or man page for a complete list of the
             available types.

     mediaopt opts
             If the driver supports the media selection system, set the speci-
             fied media options on the interface.  The opts argument 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.

     -mediaopt opts
             If the driver supports the media selection system, disable the
             specified media options on the interface.

     mode mode
             If the driver supports the media selection system, set the speci-
             fied operating 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.

     name name
             Set the interface name to name.

     rxcsum, txcsum
             If the driver supports user-configurable checksum offloading,
             enable receive (or transmit) checksum offloading on the inter-
             face.  Some drivers may not be able to enable these flags inde-
             pendently of each other, so setting one may also set the other.
             The driver will offload as much checksum work as it can reliably
             support, the exact level of offloading varies between drivers.

     -rxcsum, -txcsum
             If the driver supports user-configurable checksum offloading,
             disable receive (or transmit) checksum offloading on the inter-
             face.  These settings may not always be independent of each
             other.

     vlanmtu, vlanhwtag
             If the driver offers user-configurable VLAN support, enable
             reception of extended frames or tag processing in hardware,
             respectively.  Note that this must be issued on a physical inter-
             face associated with vlan(4), not on a vlan(4) interface itself.

     -vlanmtu, -vlanhwtag
             If the driver offers user-configurable VLAN support, disable
             reception of extended frames or tag processing in hardware,
             respectively.

     polling
             Turn on polling(4) feature and disable interrupts on the inter-
             face, if driver supports this mode.

     -polling
             Turn off polling(4) feature and enable interrupt mode on the
             interface.

     create  Create the specified network pseudo-device.  If the interface is
             given without a unit number, try to create a new device with an
             arbitrary unit number.  If creation of an arbitrary device is
             successful, the new device name is printed to standard output
             unless the interface is renamed or destroyed in the same ifconfig
             invocation.

     destroy
             Destroy the specified network pseudo-device.

     plumb   Another name for the create parameter.  Included for Solaris com-
             patibility.

     unplumb
             Another name for the destroy parameter.  Included for Solaris
             compatibility.

     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, default
             is interface specific.  The MTU is used to limit the size of
             packets that are transmitted on an interface.  Not all interfaces
             support setting the MTU, and some interfaces have range restric-
             tions.

     netmask mask
             (Inet only.)  Specify how much of the address to reserve for sub-
             dividing networks into sub-networks.  The mask includes the net-
             work part of the local address and the subnet part, which is
             taken from the host field of the address.  The mask can be speci-
             fied 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.

             The netmask can also be specified in CIDR notation after the
             address.  See the address option above for more information.

     prefixlen len
             (Inet6 only.)  Specify that len bits are reserved for subdividing
             networks into sub-networks.  The len must be integer, and for
             syntactical reason it must be between 0 to 128.  It is almost
             always 64 under the current IPv6 assignment rule.  If the parame-
             ter is omitted, 64 is used.

             The prefix can also be specified using the slash notation after
             the address.  See the address option above for more information.

     range netrange
             Under appletalk, set the interface to respond to a netrange of
             the form startnet-endnet.  Appletalk uses this scheme instead of
             netmasks though FreeBSD implements it internally as a set of net-
             masks.

     remove  Another name for the -alias parameter.  Introduced for compati-
             bility with BSD/OS.

     phase   The argument following this specifies the version (phase) of the
             Appletalk network attached to the interface.  Values of 1 or 2
             are permitted.

     link[0-2]
             Enable special processing of the link level of the interface.
             These three options are interface specific in actual effect, how-
             ever, they are in general used to select special modes of opera-
             tion.  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.

     monitor
             Put the interface in monitor mode.  No packets are transmitted,
             and received packets are discarded after bpf(4) processing.

     -monitor
             Take the interface out of monitor mode.

     up      Mark an interface ``up''.  This may be used to enable an inter-
             face 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-ini-
             tialized.

     The following parameters are specific to IEEE 802.11 wireless interfaces:

     apbridge
             When operating as an access point, pass packets between wireless
             clients directly (default).  To instead let them pass up through
             the system and be forwarded using some other mechanism, use
             -apbridge.  Disabling the internal bridging is useful when traf-
             fic is to be processed with packet filtering.

     authmode mode
             Set the desired authentication mode in infrastructure mode.  Not
             all adaptors support all modes.  The set of valid modes is none,
             open, shared (shared key), 8021x (IEEE 802.1x), and wpa (IEEE
             WPA/WPA2/802.11i).  The 8021x and wpa modes are only useful when
             using an authentication service (a supplicant for client opera-
             tion or an authenticator when operating as an access point).
             Modes are case insensitive.

     bintval interval
             Set the interval at which beacon frames are sent when operating
             in ad-hoc or ap mode.  The interval parameter is specified in
             TU's (1/1024 msecs).  By default beacon frames are transmitted
             every 100 TU's.

     bmissthreshold count
             Set the number of consecutive missed beacons at which the station
             will attempt to roam (i.e. search for a new access point).  The
             count parameter is must be in the range 1 to 255; though the
             upper bound may be reduced according to device capabilities..
             The default threshold is 7 consecutive missed beacons; but this
             may be overridden by the device driver.  Another name for the
             bmissthreshold parameter is bmiss.

     bssid address
             Specify the MAC address of the access point to use when operating
             as a station in a BSS network.  This overrides any automatic
             selection done by the system.  To disable a previously selected
             access point, supply any, none, or - for the address.  This
             option is useful when more than one access points have the same
             SSID.  Another name for the bssid parameter is ap.

     burst   Enable packet bursting.  Packet bursting is a transmission tech-
             nique whereby the wireless medium is acquired once to send multi-
             ple frames and the interframe spacing is reduced.  This technique
             can significantly increase throughput by reducing transmission
             overhead.  Packet bursting is supported by the 802.11e QoS speci-
             fication and some devices that do not support QoS may still be
             capable.  By default packet bursting is enabled if a device is
             capable of doing it.  To disable packet bursting, use -burst.

     chanlist channels
             Set the desired channels to use when scanning for access points,
             neighbors in an IBSS network, or looking for unoccupied channels
             when operating as an access point.  The set of channels is speci-
             fied as a comma-separated list with each element in the list rep-
             resenting either a single channel number or a range of the form
             ``a-b''.  Channel numbers must be in the range 1 to 255 and be
             permissible according to the operating characteristics of the
             device.

     channel number
             Set a single desired channel.  Channels range from 1 to 255, but
             the exact selection available depends on the region your adaptor
             was manufactured for.  Setting the channel to 0, any, or - will
             give you the default for your adaptor.  Some adaptors ignore this
             setting unless you are in ad-hoc mode.  Alternatively the fre-
             quency, in megahertz, may be specified instead of the channel
             number.

     deftxkey index
             Set the default key to use for transmission.  Typically this is
             only set when using WEP encryption.  The weptxkey is an alias for
             this request; it is provided for backwards compatibility.

     dtimperiod period
             Set the DTIM period for transmitting buffered multicast data
             frames when operating in ap mode.  The period specifies the num-
             ber of beacon intervals between DTIM and must be in the range 1
             to 15.  By default DTIM is 1 (i.e., DTIM occurs at each beacon).

     fragthreshold length
             Set the threshold for which transmitted frames are broken into
             fragments.  The length argument is the frame size in bytes and
             must be in the range 256 to 2346.  Setting length to 2346, any,
             or - disables transmit fragmentation.  Not all adaptors honor the
             fragmentation threshold.

     hidessid
             When operating as an access point, do not broadcast 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.  To re-enable the broadcast of
             the SSID etc., use -hidessid.

     list active
             Display the list of channels available for use taking into
             account any restrictions set with the chanlist directive.  See
             the description of list chan for more information.

     list caps
             Display the adaptor's capabilities, including the operating modes
             supported.

     list chan
             Display the list of channels available for use.  Channels are
             shown with their IEEE channel number, equivalent frequency, and
             usage modes.  Channels identified as `11g' are also usable in
             `11b' mode.  Channels identified as `11a Turbo' may be used only
             for Atheros' Static Turbo mode (specified with mediaopt turbo).
             Channels marked with a `*' have a regulatory constraint that they
             be passively scanned.  This means a station is not permitted to
             transmit on the channel until it identifies the channel is being
             used for 802.11 communication; typically by hearing a beacon
             frame from an access point operating on the channel.  list freq
             is another way of requesting this information.

     list mac
             Display the current MAC Access Control List state.  Each address
             is prefixed with a character that indicates the current policy
             applied to it: `+' indicates the address is allowed access, `-'
             indicates the address is denied access, `*' indicates the address
             is present but the current policy open (so the ACL is not con-
             sulted).

     list scan
             Display the access points and/or ad-hoc neighbors located in the
             vicinity.  The -v flag may be used to display long SSIDs.  This
             information may be updated automatically by the adaptor and/or
             with a scan request.  list ap is another way of requesting this
             information.

     list sta
             When operating as an access point display the stations that are
             currently associated.  When operating in ad-hoc mode display sta-
             tions identified as neighbors in the IBSS.  Capabilities adver-
             tised by the stations are described under the scan request.
             Depending on the capabilities of the stations the following flags
             can be included in the output:

             A    Authorized.  Indicates that the station is permitted to
                  send/receive data frames.

             E    Extended Rate Phy (ERP).  Indicates that the station is
                  operating in an 802.11g network using extended transmit
                  rates.

             P    Power Save.  Indicates that the station is operating in
                  power save mode.

             Q    Quality of Service (QoS).  Indicates that the station is
                  using QoS encapsulation for data frame.  QoS encapsulation
                  is enabled only when WME mode is enabled.

     list wme
             Display the current parameters to use when operating in WME mode.
             When WME mode is enabled for an adaptor this information will be
             displayed with the regular status; this command is mostly useful
             for examining parameters when WME mode is disabled.  See the
             description of the wme directive for information on the various
             parameters.

     mcastrate rate
             Set the rate for transmitting multicast/broadcast frames.  Rates
             are specified as megabits/second in decimal; e.g. 5.5 for 5.5
             Mb/s.  This rate should be valid for the current operating condi-
             tions; if an invalid rate is specified drivers are free to chose
             an appropriate rate.

     powersave
             Enable powersave operation.  When operating as a client, the sta-
             tion will conserve power by periodically turning off the radio
             and listening for messages from the access point telling it there
             are packets waiting.  The station must then retrieve the packets.
             When operating as an access point, the station must honor power
             save operation of associated clients.  Not all devices support
             power save operation, either as a client or as an access point.
             Use -powersave to disable powersave operation.

     powersavesleep sleep
             Set the desired max powersave sleep time in milliseconds.

     protmode technique
             For interfaces operating in 802.11g, use the specified technique
             for protecting OFDM frames in a mixed 11b/11g network.  The set
             of valid techniques is off, cts (CTS to self), and rtscts
             (RTS/CTS).  Technique names are case insensitive.

     pureg   When operating as an access point in 802.11g mode allow only 11g-
             capable stations to associate (11b-only stations are not permit-
             ted to associate).  To allow both 11g and 11b-only stations to
             associate, use -pureg.

     roaming mode
             When operating as a station, control how the system will behave
             when communication with the current access point is broken.  The
             mode argument may be one of device (leave it to the hardware
             device to decide), auto (handle either in the device or the oper-
             ating system--as appropriate), manual (do nothing until explic-
             itly instructed).  By default, the device is left to handle this
             if it is capable; otherwise, the operating system will automati-
             cally attempt to reestablish communication.  Manual mode is
             mostly useful when an application wants to control the selection
             of an access point.

     rtsthreshold length
             Set the threshold for which transmitted frames are preceded by
             transmission of an RTS control frame.  The length argument is the
             frame size in bytes and must be in the range 1 to 2346.  Setting
             length to 2346, any, or - disables transmission of RTS frames.
             Not all adaptors support setting the RTS threshold.

     ssid ssid
             Set the desired Service Set Identifier (aka network name).  The
             SSID is a string up to 32 characters in length and may be speci-
             fied as either a normal string or in hexadecimal when preceded by
             `0x'.  Additionally, the SSID may be cleared by setting it to
             `-'.

     scan    Initiate a scan of neighboring stations, wait for it to complete,
             and display all stations found.  Only the super-user can initiate
             a scan.  Depending on the capabilities of the APs, the following
             flags can be included in the output:

             E    Extended Service Set (ESS).  Indicates that the station is
                  part of an infrastructure network (in contrast to an
                  IBSS/ad-hoc network).

             I    IBSS/ad-hoc network.  Indicates that the station is part of
                  an ad-hoc network (in contrast to an ESS network).

             P    Privacy.  Data confidentiality is required for all data
                  frames exchanged within the BSS.  This means that this BSS
                  requires the station to use cryptographic means such as WEP,
                  TKIP or AES-CCMP to encrypt/decrypt data frames being
                  exchanged with others.

             S    Short Preamble.  Indicates that the network is using short
                  preambles (defined in 802.11b High Rate/DSSS PHY, short pre-
                  amble utilizes a 56 bit sync field in contrast to a 128 bit
                  field used in long preamble mode).

             s    Short slot time.  Indicates that the network is using a
                  short slot time.

             The list scan request can be used to show recent scan results
             without initiating a new scan.

             The -v flag may be used to prevent the shortening of long SSIDs.

     stationname name
             Set the name of this station.  It appears that the station name
             is not really part of the IEEE 802.11 protocol though all inter-
             faces seem to support it.  As such it only seems to be meaningful
             to identical or virtually identical equipment.  Setting the sta-
             tion name is identical in syntax to setting the SSID.

     txpower power
             Set the power used to transmit frames.  The power argument is a
             unitless value in the range 0 to 100 that is interpreted by driv-
             ers to derive a device-specific value.  Out of range values are
             truncated.  Typically only a few discreet power settings are
             available and the driver will use the setting closest to the
             specified value.  Not all adaptors support changing the transmit
             power.

     wepmode mode
             Set the desired WEP mode.  Not all adaptors support all modes.
             The set of valid modes is off, on, and mixed.  The mixed mode
             explicitly tells the adaptor to allow association with access
             points which allow both encrypted and unencrypted traffic.  On
             these adaptors, on means that the access point must only allow
             encrypted connections.  On other adaptors, on is generally
             another name for mixed.  Modes are case insensitive.

     weptxkey index
             Set the WEP key to be used for transmission.  This is the same as
             setting the default transmission key with deftxkey.

     wepkey key|index:key
             Set the selected WEP key.  If an index is not given, key 1 is
             set.  A WEP key will be either 5 or 13 characters (40 or 104
             bits) depending of the local network and the capabilities of the
             adaptor.  It may be specified either as a plain string or as a
             string of hexadecimal digits preceded by `0x'.  For maximum
             portability, hex keys are recommended; the mapping of text keys
             to WEP encryption is usually driver-specific.  In particular, the
             Windows drivers do this mapping differently to FreeBSD.  A key
             may be cleared by setting it to `-'.  If WEP is supported then
             there are at least four keys.  Some adaptors support more than
             four keys.  If that is the case, then the first four keys (1-4)
             will be the standard temporary keys and any others will be adap-
             tor specific keys such as permanent keys stored in NVRAM.

     wme     Enable Wireless Multimedia Extensions (WME) support, if avail-
             able, for the specified interface.  WME is a subset of the IEEE
             802.11e standard to support the efficient communication of real-
             time and multimedia data.  To disable WME support, use -wme.

             The following parameters are meaningful only when WME support is
             in use.  Parameters are specified per-AC (Access Category) and
             split into those that are used by a station when acting as an
             access point and those for client stations in the BSS.  The lat-
             ter are received from the access point and may not be changed (at
             the station).  The following Access Categories are recognized:

             AC_BE  (or BE) best effort delivery,
             AC_BK  (or BK) background traffic,
             AC_VI  (or VI) video traffic,
             AC_VO  (or VO) voice traffic.

             AC parameters are case-insensitive.  Traffic classification is
             done in the operating system using the vlan priority associated
             with data frames or the ToS (Type of Service) indication in IP-
             encapsulated frames.  If neither information is present, traffic
             is assigned to the Best Effort (BE) category.

             ack ac  Set the ACK policy for QoS transmissions by the local
                     station; this controls whether or not data frames trans-
                     mitted by a station require an ACK response from the
                     receiving station.  To disable waiting for an ACK use
                     -ack.  This parameter is applied only to the local sta-
                     tion.

             acm ac  Enable the Admission Control Mandatory (ACM) mechanism
                     for transmissions by the local station.  To disable the
                     ACM use -acm.  On stations in a BSS this parameter is
                     read-only and indicates the setting received from the
                     access point.  NB: ACM is not supported right now.

             aifs ac count
                     Set the Arbitration Inter Frame Spacing (AIFS) channel
                     access parameter to use for transmissions by the local
                     station.  On stations in a BSS this parameter is read-
                     only and indicates the setting received from the access
                     point.

             cwmin ac count
                     Set the CWmin channel access parameter to use for trans-
                     missions by the local station.  On stations in a BSS this
                     parameter is read-only and indicates the setting received
                     from the access point.

             cwmax ac count
                     Set the CWmax channel access parameter to use for trans-
                     missions by the local station.  On stations in a BSS this
                     parameter is read-only and indicates the setting received
                     from the access point.

             txoplimit ac limit
                     Set the Transmission Opportunity Limit channel access
                     parameter to use for transmissions by the local station.
                     This parameter defines an interval of time when a WME
                     station has the right to initiate transmissions onto the
                     wireless medium.  On stations in a BSS this parameter is
                     read-only and indicates the setting received from the
                     access point.

             bss:aifs ac count
                     Set the AIFS channel access parameter to send to stations
                     in a BSS.  This parameter is meaningful only when operat-
                     ing in ap mode.

             bss:cwmin ac count
                     Set the CWmin channel access parameter to send to sta-
                     tions in a BSS.  This parameter is meaningful only when
                     operating in ap mode.

             bss:cwmax ac count
                     Set the CWmax channel access parameter to send to sta-
                     tions in a BSS.  This parameter is meaningful only when
                     operating in ap mode.

             bss:txoplimit ac limit
                     Set the TxOpLimit channel access parameter to send to
                     stations in a BSS.  This parameter is meaningful only
                     when operating in ap mode.

     The following parameters support an optional access control list feature
     available with some adaptors when operating in ap mode; see wlan_acl(4).
     This facility allows an access point to accept/deny association requests
     based on the MAC address of the station.  Note that this feature does not
     significantly enhance security as MAC address spoofing is easy to do.

     mac:add address
             Add the specified MAC address to the database.  Depending on the
             policy setting association requests from the specified station
             will be allowed or denied.

     mac:allow
             Set the ACL policy to permit association only by stations regis-
             tered in the database.

     mac:del address
             Delete the specified MAC address from the database.

     mac:deny
             Set the ACL policy to deny association only by stations regis-
             tered in the database.

     mac:kick address
             Force the specified station to be deauthenticated.  This typi-
             cally is done to block a station after updating the address data-
             base.

     mac:open
             Set the ACL policy to allow all stations to associate.

     mac:flush
             Delete all entries in the database.

     The following parameters are for compatibility with other systems:

     nwid ssid
             Another name for the ssid parameter.  Included for NetBSD compat-
             ibility.

     station name
             Another name for the stationname parameter.  Included for BSD/OS
             compatibility.

     wep     Another way of saying wepmode on.  Included for BSD/OS compati-
             bility.

     -wep    Another way of saying wepmode off.  Included for BSD/OS compati-
             bility.

     nwkey key
             Another way of saying: ``wepmode on weptxkey 1 wepkey 1:key
             wepkey 2:- wepkey 3:- wepkey 4:-''.  Included for NetBSD compati-
             bility.

     nwkey n:k1,k2,k3,k4
             Another way of saying ``wepmode on weptxkey n wepkey 1:k1 wepkey
             2:k2 wepkey 3:k3 wepkey 4:k4''.  Included for NetBSD compatibil-
             ity.

     -nwkey  Another way of saying wepmode off.  Included for NetBSD compati-
             bility.

     The following parameters are specific to bridge interfaces:

     addm interface
             Add the interface named by interface as a member of the bridge.
             The interface is put into promiscuous mode so that it can receive
             every packet sent on the network.

     deletem interface
             Remove the interface named by interface from the bridge.  Promis-
             cuous mode is disabled on the interface when it is removed from
             the bridge.

     maxaddr size
             Set the size of the bridge address cache to size.  The default is
             100 entries.

     timeout seconds
             Set the timeout of address cache entries to seconds seconds.  If
             seconds is zero, then address cache entries will not be expired.
             The default is 240 seconds.

     addr    Display the addresses that have been learned by the bridge.

     static interface-name address
             Add a static entry into the address cache pointing to
             interface-name.  Static entries are never aged out of the cache
             or re-placed, even if the address is seen on a different inter-
             face.

     deladdr address
             Delete address from the address cache.

     flush   Delete all dynamically-learned addresses from the address cache.

     flushall
             Delete all addresses, including static addresses, from the
             address cache.

     discover interface
             Mark an interface as a ``discovering'' interface.  When the
             bridge has no address cache entry (either dynamic or static) for
             the destination address of a packet, the bridge will forward the
             packet to all member interfaces marked as ``discovering''.  This
             is the default for all interfaces added to a bridge.

     -discover interface
             Clear the ``discovering'' attribute on a member interface.  For
             packets without the ``discovering'' attribute, the only packets
             forwarded on the interface are broadcast or multicast packets and
             packets for which the destination address is known to be on the
             interface's segment.

     learn interface
             Mark an interface as a ``learning'' interface.  When a packet
             arrives on such an interface, the source address of the packet is
             entered into the address cache as being a destination address on
             the interface's segment.  This is the default for all interfaces
             added to a bridge.

     -learn interface
             Clear the ``learning'' attribute on a member interface.

     span interface
             Add the interface named by interface as a span port on the
             bridge.  Span ports transmit a copy of every frame received by
             the bridge.  This is most useful for snooping a bridged network
             passively on another host connected to one of the span ports of
             the bridge.

     -span interface
             Delete the interface named by interface from the list of span
             ports of the bridge.

     stp interface
             Enable Spanning Tree protocol on interface.  The if_bridge(4)
             driver has support for the IEEE 802.1D Spanning Tree protocol
             (STP).  Spanning Tree is used to detect and remove loops in a
             network topology.

     -stp interface
             Disable Spanning Tree protocol on interface.  This is the default
             for all interfaces added to a bridge.

     maxage seconds
             Set the time that a Spanning Tree protocol configuration is
             valid.  The default is 20 seconds.  The minimum is 1 second and
             the maximum is 255 seconds.

     fwddelay seconds
             Set the time that must pass before an interface begins forwarding
             packets when Spanning Tree is enabled.  The default is 15 sec-
             onds.  The minimum is 1 second and the maximum is 255 seconds.

     hellotime seconds
             Set the time between broadcasting of Spanning Tree protocol con-
             figuration messages.  The default is 2 seconds.  The minimum is 1
             second and the maximum is 255 seconds.

     priority value
             Set the bridge priority for Spanning Tree.  The default is 32768.
             The minimum is 0 and the maximum is 65536.

     ifpriority interface value
             Set the Spanning Tree priority of interface to value.  The
             default is 128.  The minimum is 0 and the maximum is 255.

     ifpathcost interface value
             Set the Spanning Tree path cost of interface to value.  The
             default is 55.  The minimum is 0 and the maximum is 65535.

     The following parameters are specific to IP tunnel interfaces, gif(4):

     tunnel src_addr dest_addr
             Configure the physical source and destination address for IP tun-
             nel interfaces.  The arguments src_addr and dest_addr are inter-
             preted as the outer source/destination for the encapsulating
             IPv4/IPv6 header.

     -tunnel
             Unconfigure the physical source and destination address for IP
             tunnel interfaces previously configured with tunnel.

     deletetunnel
             Another name for the -tunnel parameter.

     The following parameters are specific to pfsync(4) interfaces:

     maxupd n
             Set 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.

     The following parameters are specific to vlan(4) interfaces:

     vlan vlan_tag
             Set the VLAN tag value to vlan_tag.  This value is a 16-bit num-
             ber which is used to create an 802.1Q VLAN header for packets
             sent from the vlan(4) interface.  Note that vlan and vlandev must
             both be set at the same time.

     vlandev iface
             Associate the physical interface iface with a vlan(4) interface.
             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 parent interface with the correct VLAN tag will be
             diverted to the associated vlan(4) pseudo-interface.  The vlan(4)
             interface is assigned a copy of the parent interface's flags and
             the parent's ethernet address.  The vlandev and vlan must both be
             set at the same time.  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 association must be cleared first.

             Note: if the hardware tagging capability is set on the parent
             interface, the vlan(4) pseudo interface's behavior changes: the
             vlan(4) interface recognizes that the parent interface supports
             insertion and extraction of VLAN tags on its own (usually in
             firmware) and that it should pass packets to and from the parent
             unaltered.

     -vlandev [iface]
             If the driver is a vlan(4) pseudo device, disassociate the parent
             interface from it.  This breaks the link between the vlan(4)
             interface and its parent, clears its VLAN tag, flags and its link
             address and shuts the interface down.  The iface argument is use-
             less and hence deprecated.

     The following parameters are specific to carp(4) interfaces:

     advbase seconds
             Specifies the base of the advertisement interval in seconds.  The
             acceptable values are 1 to 255.  The default value is 1.

     advskew interval
             Specifies the skew to add to the base advertisement interval to
             make one host advertise slower than another host.  It is speci-
             fied in 1/256 of seconds.  The acceptable values are 1 to 254.
             The default value is 0.

     pass phrase
             Set the authentication key to phrase.

     vhid n  Set the virtual host ID.  This is a required setting.  Acceptable
             values are 1 to 255.

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

     If the -m flag is passed before an interface name, ifconfig will display
     the capability list and all of the supported media for the specified
     interface.  If -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.  The -d flag limits this to interfaces that are down, and -u
     limits this to interfaces that are up.  When no arguments are given, -a
     is implied.

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

     The -v flag may be used to get more verbose status for an interface.

     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 -k flag causes keying information for the interface, if available, to
     be printed.  For example, the values of 802.11 WEP keys will be printed,
     if accessible to the current user.  This information is not printed by
     default, as it may be considered sensitive.

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

NOTES
     The media selection system is relatively new and only some drivers sup-
     port it (or have need for it).

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), carp(4), netintro(4), pfsync(4), polling(4), vlan(4), rc(8),
     routed(8), sysctl(8)

HISTORY
     The ifconfig utility appeared in 4.2BSD.

BUGS
     Basic IPv6 node operation requires a link-local address on each interface
     configured for IPv6.  Normally, such an address is automatically config-
     ured by the kernel on each interface added to the system; this behaviour
     may be disabled by setting the sysctl MIB variable
     net.inet6.ip6.auto_linklocal to 0.

     If you delete such an address using ifconfig, the kernel may act very
     oddly.  Do this at your own risk.

FreeBSD 6.2                     October 9, 2006                    FreeBSD 6.2

NAME | SYNOPSIS | DESCRIPTION | NOTES | DIAGNOSTICS | SEE ALSO | HISTORY | BUGS

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