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

       iwconfig - configure a wireless network interface

       iwconfig [interface]
       iwconfig interface [essid X] [nwid N] [freq F] [channel C]
			  [sens S] [mode M] [ap A] [nick NN]
			  [rate R] [rts RT] [frag FT] [txpower T]
			  [enc E] [key K] [power P] [retry R]
       iwconfig --help
       iwconfig --version

       Iwconfig  is  similar  to  ifconfig(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  frequency).   Iwconfig may also be used to display those
       parameters, and the wireless statistics (extracted from /proc/net/wireless).

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

       essid  Set the ESSID (or Network Name - in some products it may also  called  Domain  ID).
	      The ESSID is used to identify cells which are part of the same virtual network.
	      As  opposed  to  the NWID which defines a single cell, the ESSID defines a group of
	      cell connected via repeaters or infrastructure, where the user may roam.	With some
	      card,  you  may disable the ESSID checking (ESSID promiscuous) with off or any (and
	      on to reenable it).
	      Examples :
		   iwconfig eth0 essid any
		   iwconfig eth0 essid "My Network"

	      Set the Network ID (in some products it is also 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 belonguing to the  same
	      cell.  With  some  card, you may disable the Network ID checking (NWID promiscuous)
	      with off (and on to reenable it).
	      Examples :
		   iwconfig eth0 nwid AB34
		   iwconfig eth0 nwid off

	      Set the operating frequency or channel in the device.  Value  below  1000  are  the
	      channel  number, value over this is the frequency in Hz. You must append the suffix
	      k, M or G to the value (for example, "2.46G" for 2.46 GHz frequency), or add enough
	      Channels	are  usually numbered starting at 1, and you may use iwpriv(8) to get the
	      total number of channels and list the available frequencies. Depending  on  regula-
	      tions, some frequencies/channels may not be available.
	      Examples :
		   iwconfig eth0 freq 2.422G
		   iwconfig eth0 channel 3

       sens   Set the sensitivity threshold. This is the lowest signal level for which we attempt
	      a packet reception, signal lower than this are not received. This is used to  avoid
	      receiving  background  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 control the defer threshold (lowest signal
	      level for which we consider the channel busy) and the  handover  threshold  (lowest
	      signal level where we stay associated with the current access point).
	      Example :
		   iwconfig eth0 sens -80

       mode   Set  the	operating  mode of the device, which depends on the network topology. The
	      mode can be Ad-hoc (network composed of only one cell and  without  Access  Point),
	      Managed  (node connects to a network composed of many Access Points, with roaming),
	      Master (the node is the synchronisation master or act as an Access Point), Repeater
	      (the node forward packets between other wireless nodes), Secondary (the node act as
	      a backup master/repeater), Monitor (the node act as  a  passive  monitor	and  only
	      receives packets) or Auto.
	      Example :
		   iwconfig eth0 mode Managed
		   iwconfig eth0 mode Ad-Hoc

       ap     Force  the card to register to the Access Point given by the address, if it is pos-
	      sible. When the quality of the connection goes too low, the driver may revert  back
	      to automatic mode (the card finds the best Access Point in range).
	      You  may	also  use  off	to  re-enable automatic mode without changing the current
	      Access Point, or you may use any or auto to force the card to reassociate with  the
	      current best Access Point.
	      Example :
		   iwconfig eth0 ap 00:60:1D:01:23:45
		   iwconfig eth0 ap any
		   iwconfig eth0 ap off

	      Set  the nickname, or the station name. Most 802.11 products do define it, but this
	      is not used as far as the protocols (MAC, IP, TCP)  are  concerned  and  completely
	      accessory  as far as configuration goes. In fact only some diagnostic tools may use
	      Example :
		   iwconfig eth0 nickname "My Linux Node"

	      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 overhead.
	      You must append the suffix k, M or G to the value (decimal multiplier : 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 auto to select the automatic bit-rate  mode  (fall-
	      back  to	lower  rate  on noisy channels), which is the default for most cards, and
	      fixed to revert back to fixed setting. If you specify a bit-rate value  and  append
	      auto, the driver will use all bit lower and equal than this value.
	      Examples :
		   iwconfig eth0 rate 11M
		   iwconfig eth0 rate auto
		   iwconfig eth0 rate 5.5M auto

	      RTS/CTS  adds  a	handshake  before  each packet transmission to make sure that the
	      channel is clear. This adds overhead, but increase performance in  case  of  hidden
	      nodes or large number of active nodes. This parameters set the size of the smallest
	      packet for which the node sends RTS, a value equal to the maximum packet size  dis-
	      able the scheme. You may also set this parameter to auto, fixed or off.
	      Examples :
		   iwconfig eth0 rts 250
		   iwconfig eth0 rts off

	      Fragmentation  allow to split a IP packet in a burst of smaller fragments transmit-
	      ted on the medium. In most cases this adds overhead, but in very noisy  environment
	      this  reduce  the  error	penalty.  This parameter set the maximum fragment size, a
	      value equal to the maximum packet size disable the scheme. You may  also	set  this
	      parameter to auto, fixed or off.
	      Examples :
		   iwconfig eth0 frag 512
		   iwconfig eth0 frag off

	      Used to manipulate encryption or scrambling keys and encryption mode.
	      To  set  the current encryption key, just enter the key in hex digits as XXXX-XXXX-
	      XXXX-XXXX or XXXXXXXX.  To set a key other than the current key, prepend or  append
	      [index] 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 current active key, just enter [index] (without entering
	      any key value).
	      off and on disable and reenable encryption,  open  set  the  system  in  open  mode
	      (accept non-encrypted packets) and restricted discard non-encrypted packets.
	      If  you need to set multiple keys, or set a key and change the active key, you need
	      to use multiple key directives. Arguments can be put in any  order,  the	last  one
	      will take precendence.
	      Examples :
		   iwconfig eth0 key 0123-4567-89
		   iwconfig eth0 key s:password [2]
		   iwconfig eth0 key [2] open
		   iwconfig eth0 key off
		   iwconfig eth0 key restricted [3] 0123456789
		   iwconfig eth0 key 01-23 key 45-67 [4] key [4]

       power  Used to manipulate power management scheme parameters and mode.
	      To set the period between wake up, enter period `value'.	To set the timeout before
	      going back to sleep, enter timeout `value'.  You can also add the min and max modi-
	      fiers.  By defaults, those values are in seconds, append the suffix m or u to spec-
	      ify values un milliseconds or microseconds. Sometimes,  those  values  are  without
	      units (number of dwell or the like).
	      off  and	on  disable and reenable power management. Finally, you may set the power
	      management mode to all (receive all  packets),  unicast  (receive  unicast  packets
	      only,  discard multicast and broadcast) and multicast (receive multicast and broad-
	      cast only, discard unicast packets).
	      Examples :
		   iwconfig eth0 power period 2
		   iwconfig eth0 power 500m unicast
		   iwconfig eth0 power timeout 300u all
		   iwconfig eth0 power off
		   iwconfig eth0 power min period 2 power max period 4

	      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 = 30 + 10.log(W).  If the value is
	      postfixed by mW, it will be automatically converted to dBm.
	      In addition, on and off enable and disable the radio, and auto and fixed enable and
	      disable power control (if those features are available).
	      Examples :
		   iwconfig eth0 txpower 15
		   iwconfig eth0 txpower 30mW
		   iwconfig eth0 txpower auto
		   iwconfig eth0 txpower off

       retry  Most  cards  have  MAC  retransmissions, and some allow to set the behaviour of the
	      retry mechanism.
	      To set the maximum number of retries, enter limit `value'.   This  is  an  absolute
	      value  (without  unit).	The  set the maximum length of time the MAC should retry,
	      enter lifetime `value'.  By defaults, this value in in seconds, append the suffix m
	      or u to specify values un milliseconds or microseconds.
	      You  can	also  add  the min and max modifiers. If the card support 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 min limit is the short retry
	      limit (non RTS/CTS packets).
	      Examples :
		   iwconfig eth0 retry 16
		   iwconfig eth0 retry lifetime 300m
		   iwconfig eth0 retry min limit 8

       commit Some cards may not apply changes done through Wireless Extensions immediately (they
	      may  wait  to agregate the changes or apply it only when the card is brought up via
	      ifconfig). This command (when available)	force  the  card  to  apply  all  pending
	      This  is	normally  not needed, because the card will eventually apply the changes,
	      but can be usefull for debugging.

       For each device which support wireless extensions, iwconfig will display the name  of  the
       MAC  protocol  used  (name of device for proprietary protocols), the ESSID (Network Name),
       the NWID, the frequency (or channel), the sensitivity, the mode of operation,  the  Access
       Point address, the bit-rate the RTS threshold, the fragmentation threshold, the encryption
       key and the power management settings (depending on availability).
       See above for explanations of what these parameters mean.
       If the label for bitrate is followed by `=', it means that  the	parameter  is  fixed  and
       forced  to  that  value,  if it is followed by `:' it is only the current value (device in
       normal auto mode).

       If /proc/net/wireless exists, iwconfig will also display its content :

       Link quality
	      Quality of the link or the modulation (what is the level of contention or interfer-
	      ence, or how good the received signal is).

       Signal level
	      Received signal strength (how strong the received signal is).

       Noise level
	      Background noise level (when no packet is transmited).

       invalid nwid
	      Number  of  packets  received  with  a different NWID. Used to detect configuration
	      problems or adjacent network existence.

       invalid crypt
	      Number of packets that the hardware was unable to decrypt.

       invalid misc
	      Other packets lost in relation with specific wireless operations.

       Jean Tourrilhes - jt@hpl.hp.com


       ifconfig(8), iwspy(8), iwlist(8), iwpriv(8), wavelan(4), wavelan_cs(4), wvlan_cs(4),  net-

net-tools				 31 October 1996			      IWCONFIG(8)
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