IWCONFIG(8)                Linux Programmer's Manual
IWCONFIG(8)



NNAAMMEE
       iwconfig - configure a wireless network interface

SSYYNNOOPPSSIISS
       iiwwccoonnffiigg
       [[_i_n_t_e_r_f_a_c_e]]
       iiwwccoonnffiigg _i_n_t_e_r_f_a_c_e
       [[eessssiidd _X]] [[nnwwiidd _N]]
       [[ffrreeqq _F]] [[cchhaannnneell _C]]
                          [[sseennss _S]]
                          [[mmooddee _M]] [[aapp
                          _A]] [[nniicckk _N_N]]
                          [[rraattee _R]] [[rrttss
                          _R_T]] [[ffrraagg _F_T]]
                          [[ttxxppoowweerr _T]]
                          [[eenncc _E]] [[kkeeyy
                          _K]] [[ppoowweerr _P]]
                          [[rreettrryy _R]]
                          [[ccoommmmiitt]]
       iiwwccoonnffiigg ----hheellpp
       iiwwccoonnffiigg ----vveerrssiioonn

DDEESSCCRRIIPPTTIIOONN
       IIwwccoonnffiigg  is  similar  to
       _i_f_c_o_n_f_i_g(8), but is dedicated to
       the wireless interfaces. It is used to set the
       parameters of the  network  interface which  are
       specific  to the wireless operation (for example
       : the fre‐ quency).  IIwwccoonnffiigg
       may also be used to display  those  parameters,
       and the wireless statistics (extracted from
       _/_p_r_o_c_/_n_e_t_/_w_i_r_e_l_e_s_s).

       All  these  parameters and statistics are device
       dependent. Each driver will provide only some of them
       depending on hardware support,  and  the range of
       values may change. Please refer to the man page of
       each device for details.

PPAARRAAMMEETTEERRSS
       eessssiidd  Set the ESSID (or Network Name -
       in some products it may also be
              called Domain ID). The ESSID is used to identify
              cells which are part of the same virtual network.
              As opposed to the AP Address or NWID which define
              a single cell, the  ESSID  defines  a group of
              cells connected via repeaters or infrastructure,
              where the user may roam transparently.  With some
              cards, you may disable the ESSID checking
              (ESSID  pro‐ miscuous) with _o_f_f
              or _a_n_y (and _o_n to reenable it).
              EExxaammpplleess ::
                   _i_w_c_o_n_f_i_g
                   _e_t_h_0 _e_s_s_i_d
                   _a_n_y _i_w_c_o_n_f_i_g
                   _e_t_h_0 _e_s_s_i_d _"_M_y
                   _N_e_t_w_o_r_k_"

       nnwwiidd/ddoommaaiinn
              Set  the  Network  ID  (in  some  products it
              may also be called Domain ID). As all adjacent
              wireless  networks  share  the  same medium,
              this  parameter  is  used to differenciate
              them (create logical colocated networks) and
              identify nodes belonging to  the same cell.
              This  parameter is only used for pre-802.11
              hardware, the 802.11 protocol uses the ESSID
              and AP Address for this function.  With some
              cards, you may disable the Network ID  checking
              (NWID promiscuous) with _o_f_f (and _o_n
              to reenable it).  EExxaammpplleess ::
                   _i_w_c_o_n_f_i_g
                   _e_t_h_0 _n_w_i_d _A_B_3_4
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _n_w_i_d _o_f_f

       ffrreeqq/cchhaannnneell
              Set  the  operating  frequency or channel in
              the device. A value below 1000 indicates a
              channel number, a value greater than 1000 is a
              frequency in Hz. You may append the suffix k,
              M or G to the value (for example, "2.46G" for
              2.46  GHz  frequency),  or  add enough '0'.
              Channels  are  usually  numbered  starting
              at 1, and you may use _i_w_l_i_s_t(8)
              to get the total number of channels, list  the
              avail‐ able  frequencies,  and display the
              current frequency as a chan‐ nel. Depending
              on regulations, some frequencies/channels may
              not be available.  EExxaammpplleess ::
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _f_r_e_q _2_4_2_2_0_0_0_0_0_0
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _f_r_e_q _2_._4_2_2_G
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _c_h_a_n_n_e_l _3

       sseennss   Set  the  sensitivity threshold. This
       is the lowest signal level
              for which the hardware attempt packet reception,
              signals  weaker than  this  are  ignored.
              This is used to avoid receiving back‐ ground
              noise, so you should set  it  according  to
              the  average noise  level.  Positive  values
              are assumed to be the raw value used by the
              hardware  or  a  percentage,  negative  values
              are assumed to be dBm.  With  some  hardware,
              this  parameter  also  controls the defer
              threshold (lowest signal level for which the
              hardware  consider the channel busy) and the
              handover threshold (signal level where the
              hardware start looking for a new access point).
              EExxaammppllee ::
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _s_e_n_s _-_8_0

       mmooddee   Set the operating mode of the device,
       which depends on the  net‐
              work  topology. The mode can be
              _A_d_-_H_o_c (network composed of
              only one cell and without Access Point),
              _M_a_n_a_g_e_d (node connects to  a
              network  composed  of  many Access Points,
              with roaming), _M_a_s_t_e_r (the node
              is the synchronisation master or  acts  as  an
              Access Point),  _R_e_p_e_a_t_e_r (the
              node forwards packets between other wire‐ less
              nodes),  _S_e_c_o_n_d_a_r_y  (the  node
              acts  as  a  backup   mas‐ ter/repeater),
              _M_o_n_i_t_o_r  (the node acts as a
              passive monitor and only receives packets)
              or _A_u_t_o.  EExxaammppllee ::
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _m_o_d_e _M_a_n_a_g_e_d
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _m_o_d_e _A_d_-_H_o_c

       aapp     Force the card to register to the  Access
       Point  given  by  the
              address,  if  it is possible. When the quality
              of the connection goes too low, the driver may
              revert back to automatic mode  (the card selects
              the best Access Point in range).  You  may also
              use _o_f_f to re-enable automatic mode without
              chang‐ ing the current Access Point, or you
              may  use  _a_n_y  or  _a_u_t_o  to force
              the  card  to  reassociate with the currently
              best Access Point.  EExxaammppllee ::
                   _i_w_c_o_n_f_i_g _e_t_h_0 _a_p
                   _0_0_:_6_0_:_1_D_:_0_1_:_2_3_:_4_5
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _a_p _a_n_y _i_w_c_o_n_f_i_g
                   _e_t_h_0 _a_p _o_f_f

       nniicckk[name]
              Set the nickname, or the station name. Some
              802.11  products  do define  it,  but  this is
              not used as far as the protocols (MAC, IP, TCP)
              are concerned and completely useless as far as
              configu‐ ration goes. Only some diagnostic
              tools may use it.  EExxaammppllee ::
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _n_i_c_k_n_a_m_e _"_M_y
                   _L_i_n_u_x _N_o_d_e_"

       rraattee/bbiitt[rate]
              For  cards  supporting  multiple  bit rates,
              set the bit-rate in b/s. The bit-rate is the
              speed at  which  bits  are  transmitted over
              the  medium,  the  user  speed of the link is
              lower due to medium sharing and various overhead.
              You may append the suffix k, M or G to the value
              (decimal multi‐ plier  :  10^3,  10^6  and
              10^9 b/s), or add enough '0'. Values below 1000
              are card specific, usually an index in  the
              bit-rate list.  Use  _a_u_t_o  to select
              automatic bit-rate mode (fallback to lower rate
              on noisy channels), which is  the  default  for
              most cards, and _f_i_x_e_d to revert back to
              fixed setting. If you specify a bit-rate value
              and append _a_u_t_o, the driver will use
              all  bit- rates lower and equal than this value.
              EExxaammpplleess ::
                   _i_w_c_o_n_f_i_g
                   _e_t_h_0 _r_a_t_e
                   _1_1_M _i_w_c_o_n_f_i_g
                   _e_t_h_0 _r_a_t_e _a_u_t_o
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _r_a_t_e _5_._5_M _a_u_t_o

       rrttss[_threshold]
              RTS/CTS adds a handshake before each
              packet transmission to make sure  that  the
              channel  is  clear.  This  adds  overhead,
              but increases  performance in case of hidden
              nodes or a large number of active nodes. This
              parameter sets the size  of  the  smallest
              packet for which the node sends RTS ; a value
              equal to the maxi‐ mum packet size disable the
              mechanism. You  may  also  set  this parameter
              to _a_u_t_o, _f_i_x_e_d or _o_f_f.
              EExxaammpplleess ::
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _r_t_s _2_5_0 _i_w_c_o_n_f_i_g
                   _e_t_h_0 _r_t_s _o_f_f

       ffrraagg[mentation_threshold]
              Fragmentation allows to split an IP packet
              in a burst of smaller fragments transmitted
              on the medium. In  most  cases  this  adds
              overhead, but in a very noisy environment
              this reduces the error penalty and allow
              packets to get  through  interference  bursts.
              This parameter sets the maximum fragment size ;
              a value equal to the maximum packet size disable
              the mechanism. You may also  set this parameter
              to _a_u_t_o, _f_i_x_e_d or _o_f_f.
              EExxaammpplleess ::
                   _i_w_c_o_n_f_i_g
                   _e_t_h_0 _f_r_a_g _5_1_2
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _f_r_a_g _o_f_f

       kkeeyy/eenncc[ryption]
              Used  to  manipulate  encryption or
              scrambling keys and security mode.
              To set the current encryption key,
              just enter  the  key  in  hex digits  as
              _X_X_X_X_-_X_X_X_X_-_X_X_X_X_-_X_X_X_X
              or _X_X_X_X_X_X_X_X.  To set a key
              other than the current key, prepend  or  append
              _[_i_n_d_e_x_]  to  the  key itself (this
              won't change which is the active key). You can
              also enter the key as  an  ASCII  string  by
              using  the  _s_:  prefix.  Passphrase is
              currently not supported.  To  change  which
              key  is  the currently active key, just enter
              _[_i_n_d_e_x_] (without entering any
              key value).  _o_f_f and _o_n disable and
              reenable encryption.  The security mode may be
              _o_p_e_n or  _r_e_s_t_r_i_c_t_e_d,
              and  its  meaning depends  on  the  card  used.
              With  most cards, in _o_p_e_n mode no
              authentication is  used  and  the  card
              may  also  accept  non- encrypted  sessions,
              whereas  in _r_e_s_t_r_i_c_t_e_d mode
              only encrypted sessions are accepted and the
              card will  use  authentication  if available.
              If  you  need  to set multiple keys, or set a
              key and change the active key, you need to use
              multiple kkeeyy  directives.  Arguments can
              be put in any order, the last one will take
              precedence.  EExxaammpplleess ::
                   _i_w_c_o_n_f_i_g
                   _e_t_h_0 _k_e_y
                   _0_1_2_3_-_4_5_6_7_-_8_9
                   _i_w_c_o_n_f_i_g
                   _e_t_h_0 _k_e_y _[_3_]
                   _0_1_2_3_-_4_5_6_7_-_8_9
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _k_e_y _s_:_p_a_s_s_w_o_r_d
                   _[_2_] _i_w_c_o_n_f_i_g
                   _e_t_h_0 _k_e_y _[_2_]
                   _i_w_c_o_n_f_i_g
                   _e_t_h_0 _k_e_y _o_p_e_n
                   _i_w_c_o_n_f_i_g
                   _e_t_h_0 _k_e_y _o_f_f
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _k_e_y _r_e_s_t_r_i_c_t_e_d
                   _[_3_] _0_1_2_3_4_5_6_7_8_9
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _k_e_y _0_1_-_2_3 _k_e_y
                   _4_5_-_6_7 _[_4_] _k_e_y
                   _[_4_]

       ppoowweerr  Used to manipulate power management
       scheme parameters and mode.
              To  set  the  period between wake ups, enter
              _p_e_r_i_o_d _`_v_a_l_u_e_'.
              To set the timeout  before  going  back
              to  sleep,  enter  _t_i_m_e_o_u_t
              _`_v_a_l_u_e_'.   You  can  also  add  the
              _m_i_n  and  _m_a_x modifiers. By default,
              those values are in seconds, append the suffix
              m  or  u to  specify  values  in milliseconds
              or microseconds. Sometimes, those values are
              without units (number of beacon periods,  dwell
              or similar).  _o_f_f  and  _o_n disable and
              reenable power management. Finally, you may set
              the power management mode to _a_l_l (receive
              all  packets), _u_n_i_c_a_s_t  (receive
              unicast  packets  only, discard multicast and
              broadcast) and _m_u_l_t_i_c_a_s_t
              (receive multicast and broadcast  only, discard
              unicast packets).  EExxaammpplleess ::
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _p_o_w_e_r _p_e_r_i_o_d
                   _2 _i_w_c_o_n_f_i_g
                   _e_t_h_0 _p_o_w_e_r
                   _5_0_0_m _u_n_i_c_a_s_t
                   _i_w_c_o_n_f_i_g
                   _e_t_h_0 _p_o_w_e_r
                   _t_i_m_e_o_u_t _3_0_0_u
                   _a_l_l _i_w_c_o_n_f_i_g
                   _e_t_h_0 _p_o_w_e_r
                   _o_f_f _i_w_c_o_n_f_i_g
                   _e_t_h_0 _p_o_w_e_r _m_i_n
                   _p_e_r_i_o_d _2 _p_o_w_e_r
                   _m_a_x _p_e_r_i_o_d _4

       ttxxppoowweerr
              For  cards supporting multiple transmit powers,
              set the transmit power in dBm. If _W is the
              power in Watt, the power in dBm is _P _= _3_0
              _+  _1_0_._l_o_g_(_W_).   If  the value
              is postfixed by _m_W, it will be automatically
              converted to dBm.  In addition, _o_n and
              _o_f_f enable and disable the radio,  and
              _a_u_t_o and  _f_i_x_e_d  enable  and
              disable power control (if those features are
              available).  EExxaammpplleess ::
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _t_x_p_o_w_e_r _1_5
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _t_x_p_o_w_e_r _3_0_m_W
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _t_x_p_o_w_e_r _a_u_t_o
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _t_x_p_o_w_e_r _o_f_f

       rreettrryy  Most cards have MAC retransmissions,
       and some allow to  set  the
              behaviour of the retry mechanism.  To set the
              maximum number of retries, enter _l_i_m_i_t
              _`_v_a_l_u_e_'.  This is an absolute
              value (without unit).  The set the maximum
              length of  time  the  MAC  should  retry,  enter
              _l_i_f_e_t_i_m_e _`_v_a_l_u_e_'.
              By defaults, this value in in seconds, append the
              suffix m or u  to specify values in milliseconds
              or microseconds.  You can also add the _m_i_n
              and _m_a_x modifiers. If the card supports
              automatic mode, they define the bounds of the
              limit or lifetime.  Some  other  cards  define
              different values depending on packet size, for
              example in 802.11 _m_i_n _l_i_m_i_t is
              the short  retry  limit (non RTS/CTS packets).
              EExxaammpplleess ::
                   _i_w_c_o_n_f_i_g
                   _e_t_h_0 _r_e_t_r_y _1_6
                   _i_w_c_o_n_f_i_g _e_t_h_0
                   _r_e_t_r_y _l_i_f_e_t_i_m_e
                   _3_0_0_m _i_w_c_o_n_f_i_g
                   _e_t_h_0 _r_e_t_r_y _m_i_n
                   _l_i_m_i_t _8

       ccoommmmiitt Some  cards  may  not apply changes
       done through Wireless Exten‐
              sions immediately (they may wait  to  agregate
              the  changes  or apply  it  only  when the
              card is brought up via ifconfig). This command
              (when available) forces the card to  apply
              all  pending changes.  This  is  normally  not
              needed, because the card will eventually apply
              the changes, but can be useful for debugging.

DDIISSPPLLAAYY
       For each device which supports wireless extensions,
       _i_w_c_o_n_f_i_g will  dis‐ play  the
       name of the MMAACC pprroottooccooll used
       (name of device for proprietary protocols), the
       EESSSSIIDD (Network Name), the NNWWIIDD,
       the ffrreeqquueennccyy (or chan‐
       nel), the sseennssiittiivviittyy, the
       mmooddee of operation, the AAcccceessss
       PPooiinntt address, the bbiitt--rraattee
       the  RRTTSS  tthhrreesshhoolldd,
       the  ffrraaggmmeennttaattiioonn
       tthhrreesshhoolldd,  the
       eennccrryyppttiioonn  kkeeyy  and the
       ppoowweerr mmaannaaggeemmeenntt settings
       (depending on avail‐ ability).

       The parameters displayed have the same meaning and
       values as the param‐ eter  you  can  set,  please
       refer to the previous part for a detailed explanation
       of them.  Some parameters are only displayed in
       short/abreviated  form  (such  as encryption). You
       may use _i_w_l_i_s_t(8) to get all the details.
       Some  parameters have two modes (such as bitrate). If
       the value is pre‐ fixed by `==', it means that the
       parameter is fixed and forced  to  that value, if it
       is prefixed by `::', the parameter is in automatic
       mode and the current value is shown (and may change).

       AAcccceessss PPooiinntt/CCeellll
              An address equal to 00:00:00:00:00:00 means that
              the card failed to  associate  with an Access
              Point (most likely a configuration issue). The
              AAcccceessss PPooiinntt parameter will
              be shown as CCeellll in  ad- hoc mode (for
              obvious reasons), but otherwise works the same.

       If
       _/_p_r_o_c_/_n_e_t_/_w_i_r_e_l_e_s_s
       exists, _i_w_c_o_n_f_i_g will also display
       its content.  Note that those values will depend  on
       the  driver  and  the  hardware specifics, so you
       need to refer to your driver documentation for proper
       interpretation of those values.

       LLiinnkk qquuaalliittyy
              Overall quality of the link. May be based on the
              level  of  con‐ tention  or  interference, the
              bit or frame error rate, how good the received
              signal is, some timing  synchronisation,  or
              other hardware metric. This is an aggregate
              value, and depends totally on the driver and
              hardware.

       SSiiggnnaall lleevveell
              Received signal strength (RSSI - how strong the
              received  signal is).  May  be  arbitrary units
              or dBm, _i_w_c_o_n_f_i_g uses driver meta
              information to interpret the raw value given by
              _/_p_r_o_c_/_n_e_t_/_w_i_r_e_‐
              _l_e_s_s  and  display the proper unit or
              maximum value (using 8 bit arithmetic). In
              _A_d_-_H_o_c mode,  this  may  be
              undefined  and  you should use _i_w_s_p_y.

       NNooiissee lleevveell
              Background  noise level (when no packet
              is transmitted). Similar comments as for
              SSiiggnnaall lleevveell.

       RRxx iinnvvaalliidd nnwwiidd
              Number of packets received with a different
              NWID or ESSID.  Used to  detect  configuration
              problems or adjacent network existence (on the
              same frequency).

       RRxx iinnvvaalliidd ccrryypptt
              Number of packets that the hardware was unable
              to decrypt.  This can be used to detect invalid
              encryption settings.

       RRxx iinnvvaalliidd ffrraagg
              Number  of  packets for which the hardware was
              not able to prop‐ erly re-assemble the link
              layer fragments (most likely  one  was missing).

       TTxx eexxcceessssiivvee rreettrriieess
              Number  of packets that the hardware failed
              to deliver. Most MAC protocols will retry the
              packet a number of times before  giving up.

       IInnvvaalliidd mmiisscc
              Other  packets  lost  in  relation with specific
              wireless opera‐ tions.

       MMiisssseedd bbeeaaccoonn
              Number of periodic beacons from the Cell or
              the Access Point  we have  missed.  Beacons are
              sent at regular intervals to maintain the cell
              coordination, failure to receive them usually
              indicates that the card is out of range.

AAUUTTHHOORR
       Jean Tourrilhes - jt@hpl.hp.com

FFIILLEESS
       _/_p_r_o_c_/_n_e_t_/_w_i_r_e_l_e_s_s

SSEEEE AALLSSOO
       iiffccoonnffiigg(8), iiwwssppyy(8),
       iiwwlliisstt(8), iiwweevveenntt(8),
       iiwwpprriivv(8), wwiirreelleessss(7).



wireless-tools                   22 June 2004
IWCONFIG(8)
