-.\" Jean II - HPLB - 96
+.\" Jean II - HPLB - 1996 => HPL - 2004
.\" iwconfig.8
.\"
-.TH IWCONFIG 8 "31 October 1996" "net-tools" "Linux Programmer's Manual"
+.TH IWCONFIG 8 "22 June 2004" "wireless-tools" "Linux Programmer's Manual"
.\"
.\" NAME part
.\"
.br
.BI " [sens " S "] [mode " M "] [ap " A "] [nick " NN ]
.br
-.BI " [rate " R "] [rts " RT "] [frag " FT ]
+.BI " [rate " R "] [rts " RT "] [frag " FT "] [txpower " T ]
.br
-.BI " [enc " E "] [key " K "] [power " P ]
+.BI " [enc " E "] [key " K "] [power " P "] [retry " R ]
+.br
+.BI " [commit]
+.br
+.BI "iwconfig --help"
+.br
+.BI "iwconfig --version"
.\"
.\" DESCRIPTION part
.\"
statistics (extracted from
.IR /proc/net/wireless ).
.PP
-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
+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.
.\"
.\" PARAMETER part
.SH PARAMETERS
.TP
.B 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.
-.br
-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
+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.
+.br
+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.
+.br
+With some cards, you may disable the ESSID checking (ESSID
+promiscuous) with
.IR off " or " any " (and " on
to reenable it).
.br
.I " iwconfig eth0 essid ""My Network""
.TP
.BR nwid / domain
-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
+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.
+.br
+This parameter is only used for pre-802.11 hardware, the 802.11
+protocol uses the ESSID and AP Address for this function.
+.br
+With some cards, you may disable the Network ID checking (NWID
+promiscuous) with
.IR off " (and " on
to reenable it).
.br
.I " iwconfig eth0 nwid off"
.TP
.BR freq / channel
-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 '0'.
-.br
-Channels are usually numbered starting at 1,
-and you may use
-.IR iwpriv (8)
-to get the total number of channels and list the available
-frequencies. Depending on regulations, some frequencies/channels may
-not be available.
+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'.
+.br
+Channels are usually numbered starting at 1, and you may use
+.IR iwlist (8)
+to get the total number of channels, list the available frequencies,
+and display the current frequency as a channel. Depending on
+regulations, some frequencies/channels may not be available.
.br
.B Examples :
.br
+.I " iwconfig eth0 freq 2422000000"
+.br
.I " iwconfig eth0 freq 2.422G"
.br
.I " iwconfig eth0 channel 3"
.TP
.B 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
+which the hardware attempt packet reception, signals weaker than this
+are ignored. 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.
.br
-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).
+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).
.br
.B Example :
.br
.B mode
Set the operating mode of the device, which depends on the network
topology. The mode can be
-.I Ad-hoc
+.I Ad-Hoc
(network composed of only one cell and without Access Point),
.I Managed
-(network composed of many cells, with roaming or with an Access Point),
+(node connects to a network composed of many Access Points, with roaming),
.I Master
-(the node is the synchronisation master or act as an Access Point),
+(the node is the synchronisation master or acts as an Access Point),
.I Repeater
-(the node forward packets on the air),
+(the node forwards packets between other wireless nodes),
.I Secondary
-(the node act as a backup master/repeater) or
+(the node acts as a backup master/repeater),
+.I Monitor
+(the node acts as a passive monitor and only receives packets) or
.IR Auto .
.br
.B Example :
.br
.I " iwconfig eth0 mode Managed"
+.br
+.I " iwconfig eth0 mode Ad-Hoc"
.TP
.B ap
-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.
+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).
+.br
+You may also use
+.I off
+to re-enable automatic mode without changing the current Access Point,
+or you may use
+.I any
+or
+.I auto
+to force the card to reassociate with the currently best Access Point.
.br
.B Example :
.br
.I " iwconfig eth0 ap 00:60:1D:01:23:45"
+.br
+.I " iwconfig eth0 ap any"
+.br
+.I " iwconfig eth0 ap off"
.TP
.BR nick [name]
-Set the nickname, or the station name. Most 802.11 products do define
+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 accessory as far as configuration goes. In
-fact only some diagnostic tools may use it.
+concerned and completely useless as far as configuration goes. Only
+some diagnostic tools may use it.
.br
.B Example :
.br
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.
+various overhead.
.br
-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
+You may 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
.I auto
-to select the automatic bit-rate mode (fallback to lower rate on noisy
+to select automatic bit-rate mode (fallback to lower rate on noisy
channels), which is the default for most cards, and
.I fixed
to revert back to fixed setting. If you specify a bit-rate value and append
.IR auto ,
-the driver will use all bit lower and equal than this value.
+the driver will use all bit-rates lower and equal than this value.
.br
.B Examples :
.br
.I " iwconfig eth0 rate 11M"
.br
.I " iwconfig eth0 rate auto"
+.br
+.I " iwconfig eth0 rate 5.5M auto"
.TP
.BR rts [_threshold]
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 disable
-the scheme. You may also set this parameter to
+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 maximum packet size disable
+the mechanism. You may also set this parameter to
.IR auto ", " fixed " or " off .
.br
.B Examples :
.I " iwconfig eth0 rts off"
.TP
.BR frag [mentation_threshold]
-Fragmentation allow to split a IP packet in a burst of smaller
+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 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
+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
.IR auto ", " fixed " or " off .
.br
.B Examples :
.I " iwconfig eth0 frag off"
.TP
.BR key / enc [ryption]
-Used to manipulate encryption or scrambling keys and encryption mode.
+Used to manipulate encryption or scrambling keys and security mode.
.br
To set the current encryption key, just enter the key in hex digits as
.IR XXXX-XXXX-XXXX-XXXX " or " XXXXXXXX .
-To set a key other than the current key, append
+To set a key other than the current key, prepend or append
.I [index]
-to the key itself. You can also enter the key as an ASCII string by
-using the
+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
.I s:
-prefix.
+prefix. Passphrase is currently not supported.
.br
-To change which key is the current active key, just enter
+To change which key is the currently active key, just enter
.I [index]
(without entering any key value).
.br
.IR off " and " on
-disable and reenable encryption,
+disable and reenable encryption.
+.br
+The security mode may be
+.I open
+or
+.IR restricted ,
+and its meaning depends on the card used. With most cards, in
.I open
-set the system in open mode (accept non-encrypted packets) and
+mode no authentication is used and the card may also accept
+non-encrypted sessions, whereas in
.I restricted
-discard non-encrypted packets.
+mode only encrypted sessions are accepted and the card will use
+authentication if available.
+.br
+If you need to set multiple keys, or set a key and change the active
+key, you need to use multiple
+.B key
+directives. Arguments can be put in any order, the last one will take
+precedence.
.br
.B Examples :
.br
.I " iwconfig eth0 key 0123-4567-89"
.br
+.I " iwconfig eth0 key [3] 0123-4567-89"
+.br
.I " iwconfig eth0 key s:password [2]"
.br
-.I " iwconfig eth0 key [2] open"
+.I " iwconfig eth0 key [2]"
+.br
+.I " iwconfig eth0 key open"
.br
.I " iwconfig eth0 key off"
+.br
+.I " iwconfig eth0 key restricted [3] 0123456789"
+.br
+.I " iwconfig eth0 key 01-23 key 45-67 [4] key [4]"
.TP
.BR power
Used to manipulate power management scheme parameters and mode.
.br
-To set the period between wake up, enter
+To set the period between wake ups, enter
.IR "period `value'" .
To set the timeout before going back to sleep, enter
.IR "timeout `value'" .
-By defaults, those values are in seconds, append the suffix m or u to
-specify values un milliseconds or microseconds.
+You can also add the
+.IR min " and " max
+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).
.br
.IR off " and " on
disable and reenable power management. Finally, you may set the power
.I " iwconfig eth0 power timeout 300u all"
.br
.I " iwconfig eth0 power off"
+.br
+.I " iwconfig eth0 power min period 2 power max period 4"
+.TP
+.BR txpower
+For cards supporting multiple transmit powers, set the transmit power in dBm. If
+.I W
+is the power in Watt, the power in dBm is
+.IR "P = 30 + 10.log(W)" .
+If the value is postfixed by
+.IR mW ,
+it will be automatically converted to dBm.
+.br
+In addition,
+.IR on " and " off
+enable and disable the radio, and
+.IR auto " and " fixed
+enable and disable power control (if those features are available).
+.br
+.B Examples :
+.br
+.I " iwconfig eth0 txpower 15"
+.br
+.I " iwconfig eth0 txpower 30mW"
+.br
+.I " iwconfig eth0 txpower auto"
+.br
+.I " iwconfig eth0 txpower off"
+.TP
+.BR retry
+Most cards have MAC retransmissions, and some allow to set the
+behaviour of the retry mechanism.
+.br
+To set the maximum number of retries, enter
+.IR "limit `value'" .
+This is an absolute value (without unit).
+The set the maximum length of time the MAC should retry, enter
+.IR "lifetime `value'" .
+By defaults, this value in in seconds, append the suffix m or u to
+specify values in milliseconds or microseconds.
+.br
+You can also add the
+.IR min " and " max
+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
+.I min limit
+is the short retry limit (non RTS/CTS packets).
+.br
+.B Examples :
+.br
+.I " iwconfig eth0 retry 16"
+.br
+.I " iwconfig eth0 retry lifetime 300m"
+.br
+.I " iwconfig eth0 retry min limit 8"
+.TP
+.BR 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) forces the card to apply all pending changes.
+.br
+This is normally not needed, because the card will eventually apply
+the changes, but can be useful for debugging.
.\"
.\" DISPLAY part
.\"
.SH DISPLAY
-For each device which support wireless extensions,
+For each device which supports wireless extensions,
.I iwconfig
will display the name of the
.B MAC protocol
and the
.B power management
settings (depending on availability).
+.PP
+The parameters displayed have the same meaning and values as the
+parameter you can set, please refer to the previous part for a
+detailed explanation of them.
.br
-See above for explanations of what these parameters mean.
+Some parameters are only displayed in short/abreviated form (such as
+encryption). You may use
+.IR iwlist (8)
+to get all the details.
.br
-If the label for bitrate is followed by
+Some parameters have two modes (such as bitrate). If the value is
+prefixed by
.RB ` = ',
it means that the parameter is fixed and forced to that value, if it
-is followed by
-.RB ` : '
-it is only the current value (device in normal auto mode).
+is prefixed by
+.RB ` : ',
+the parameter is in automatic mode and the current value is shown (and
+may change).
+.TP
+.BR "Access Point" / Cell
+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
+.B Access Point
+parameter will be shown as
+.B Cell
+in ad-hoc mode (for obvious reasons), but otherwise works the same.
.PP
If
.I /proc/net/wireless
exists,
.I iwconfig
-will also display its content :
+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.
.TP
.B Link quality
-Quality of the link or the modulation (what is the level of contention
-or interference, or how good the received signal is).
+Overall quality of the link. May be based on the level of contention
+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.
.TP
.B Signal level
-Received signal strength (how strong the received signal is).
+Received signal strength (RSSI - how strong the received signal
+is). May be arbitrary units or dBm,
+.I iwconfig
+uses driver meta information to interpret the raw value given by
+.I /proc/net/wireless
+and display the proper unit or maximum value (using 8 bit arithmetic). In
+.I Ad-Hoc
+mode, this may be undefined and you should use
+.IR iwspy .
.TP
.B Noise level
-Background noise level (when no packet is transmited).
+Background noise level (when no packet is transmitted). Similar
+comments as for
+.BR "Signal level" .
+.TP
+.B Rx invalid nwid
+Number of packets received with a different NWID or ESSID. Used to
+detect configuration problems or adjacent network existence (on the
+same frequency).
.TP
-.B invalid nwid
-Number of packets received with a different NWID. Used to detect
-configuration problems or adjacent network existence.
+.B Rx invalid crypt
+Number of packets that the hardware was unable to decrypt. This can be
+used to detect invalid encryption settings.
.TP
-.B invalid crypt
-Number of packets that the hardware was unable to decrypt.
+.B Rx invalid frag
+Number of packets for which the hardware was not able to properly
+re-assemble the link layer fragments (most likely one was missing).
.TP
-.B invalid misc
+.B Tx excessive retries
+Number of packets that the hardware failed to deliver. Most MAC
+protocols will retry the packet a number of times before giving up.
+.TP
+.B Invalid misc
Other packets lost in relation with specific wireless operations.
+.TP
+.B Missed beacon
+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.
.\"
.\" AUTHOR part
.\"
.SH SEE ALSO
.BR ifconfig (8),
.BR iwspy (8),
+.BR iwlist (8),
+.BR iwevent (8),
.BR iwpriv (8),
-.BR wavelan (4),
-.BR wavelan_cs (4),
-.BR xircnw_cs (4).
+.BR wireless (7).
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