ancontrol(8)
NAME
ancontrol - configure Aironet 4500/4800 devices
SYNOPSIS
ancontrol -i iface -A ancontrol -i iface -N ancontrol -i iface -S ancontrol -i iface -I ancontrol -i iface -T ancontrol -i iface -C ancontrol -i iface -Q ancontrol -i iface -Z ancontrol -i iface -R ancontrol -i iface -t 0-4 ancontrol -i iface -s 0-3 ancontrol -i iface [-v 1-4] -a AP ancontrol -i iface -b beacon_period ancontrol -i iface [-v 0 | 1] -d 0-3 ancontrol -i iface -e 0-4 ancontrol -i iface [-v 0-8] -k key ancontrol -i iface -K 0-2 ancontrol -i iface -W 0-2 ancontrol -i iface -L user_name ancontrol -i iface -j netjoin_timeout ancontrol -i iface -l station_name ancontrol -i iface -m mac_address ancontrol -i iface [-v 1-3] -n SSID ancontrol -i iface -o 0 | 1 ancontrol -i iface -p tx_power ancontrol -i iface -c frequency ancontrol -i iface -f fragmentation_threshold ancontrol -i iface -r RTS_threshold ancontrol -i iface -M 0-15 ancontrol -h
DESCRIPTION
- The ancontrol utility controls the operation of Aironet
- wireless networking devices via the an(4) driver. Most of the parameters
- that can be
changed relate to the IEEE 802.11 protocol which the Aironet - cards implement. This includes such things as the station name,
- whether the station
is operating in ad-hoc (point to point) or infrastructure - mode, and the
network name of a service set to join. The ancontrol utili - ty can also be
used to view the current NIC status, configuration and to - dump out the
values of the card's statistics counters. - The iface argument given to ancontrol should be the logical
- interface
name associated with the Aironet device (an0, an1, etc.). - If one is not
specified the device ``an0'' will be assumed. - The ancontrol utility is not designed to support the combi
- nation of arguments from different SYNOPSIS lines in a single ancontrol
- invocation, and
such combinations are not recommended.
OPTIONS
The options are as follows:
- -i iface -A
- Display the preferred access point list. The AP
- list can be used
by stations to specify the MAC address of access - points with
which it wishes to associate. If no AP list is - specified (the
default) then the station will associate with the - first access
point that it finds which serves the SSID(s) speci - fied in the
SSID list. The AP list can be modified with the -a - option.
- -i iface -N
- Display the SSID list. This is a list of service
- set IDs (i.e.,
network names) with which the station wishes to as - sociate. There
may be up to three SSIDs in the list: the station - will go through
the list in ascending order and associate with the - first matching
SSID that it finds. - -i iface -S
- Display NIC status information. This includes the
- current operating status, current BSSID, SSID, channel, beacon
- period and
currently associated access point. The operating - mode indicates
the state of the NIC, MAC status and receiver sta - tus. When the
"synced" keyword appears, it means the NIC has suc - cessfully associated with an access point, associated with an ad
- hoc ``master''
station, or become a ``master'' itself. The beacon - period can be
anything between 20 and 976 milliseconds. The de - fault is 100.
- -i iface -I
- Display NIC capability information. This shows the
- device type,
frequency, speed and power level capabilities and - firmware revision levels.
- -i iface -T
- Display the NIC's internal statistics counters.
- -i iface -C
- Display current NIC configuration. This shows the
- current operation mode, receive mode, MAC address, power save
- settings, various timing settings, channel selection, diversity,
- transmit power
and transmit speed. - -i iface -Q
- Display the cached signal strength information main
- tained by the
an(4) driver. The driver retains information about - signal
strength and noise level for packets received from - different
hosts. The signal strength and noise level values - are displayed
in units of dBms by default. The - hw.an.an_cache_mode sysctl(8)
variable can be set to raw, dbm or per. - -i iface -Z
- Clear the signal strength cache maintained internal
- ly by the
an(4) driver. - -i iface -R
- Display RSSI map that converts from the RSSI index
- to percent and
dBm. - -i iface -t 0-4
- Select transmit speed. The available settings are
- as follows:
TX rate NIC speed
0 Auto -- NIC selects optimalspeed
1 1Mbps fixed
2 2Mbps fixed
3 5.5Mbps fixed
4 11Mbps fixed - Note that the 5.5 and 11Mbps settings are only sup
- ported on the
4800 series adapters: the 4500 series adapters have - a maximum
speed of 2Mbps. - -i iface -s 0-3
- Set power save mode. Valid selections are as fol
- lows:
Selection Power save mode 0 None - power save disabled
1 Constantly awake mode (CAM)
2 Power Save Polling (PSP)
3 Fast Power Save Polling (PSPCAM) - Note that for IBSS (ad-hoc) mode, only PSP mode is
- supported, and
only if the ATIM window is non-zero. - -i iface [-v 1-4] -a AP
- Set preferred access point. The AP is specified as
- a MAC address
consisting of 6 hexadecimal values separated by - colons. By
default, the -a option only sets the first entry in - the AP list.
The -v modifier can be used to specify exactly which - AP list
entry is to be modified. If the -v flag is not - used, the first
AP list entry will be changed. - -i iface -b beacon_period
- Set the ad-hoc mode beacon period. The
- beacon_period is specified in milliseconds. The default is 100ms.
- -i iface [-v 0 | 1] -d 0-3
- Select the antenna diversity. Aironet devices can
- be configured
with up to two antennas, and transmit and receive - diversity can
be configured accordingly. Valid selections are as - follows:
Selection Diversity 0 Select factory default diversity
1 Antenna 1 only
2 Antenna 2 only
3 Antenna 1 and 2 - The receive and transmit diversity can be set inde
- pendently. The
user must specify which diversity setting is to be - modified by
using the -v option: selection 0 sets the receive - diversity and 1
sets the transmit diversity. - -i iface -e 0-4
- Set the transmit WEP key to use. Note that until
- this command is
issued, the device will use the last key programmed. - The transmit key is stored in NVRAM. Currently set transmit
- key can be
checked via -C option. Selection 4 sets the card in - ``Home
Network Mode'' and uses the home key. - -i iface [-v 0-8] -k key
- Set a WEP key. For 40 bit prefix 10 hex character
- with 0x. For
128 bit prefix 26 hex character with 0x. Use "" as - the key to
erase the key. Supports 4 keys; even numbers are - for permanent
keys and odd number are for temporary keys. For ex - ample, -v 1
sets the first temporary key. (A ``permanent'' key - is stored in
NVRAM; a ``temporary'' key is not.) Note that the - device will
use the most recently-programmed key by default. - Currently set
keys can be checked via -C option, only the sizes of - the keys are
returned. The value of 8 is for the home key. Note - that the
value for the home key can be read back from - firmware.
- -i iface -K 0-2
- Set authorization type. Use 0 for none, 1 for
- ``Open'', 2 for
``Shared Key''. - -i iface -W 0-2
- Enable WEP. Use 0 for no WEP, 1 to enable full WEP,
- 2 for mixed
cell. - -i iface -L user_name
- Enable LEAP and query for password. It will check
- to see if it
has authenticated for up to 60s. To disable LEAP, - set WEP mode.
- -i iface -j netjoin_timeout
- Set the ad-hoc network join timeout. When a station
- is first
activated in ad-hoc mode, it will search out a - ``master'' station
with the desired SSID and associate with it. If the - station is
unable to locate another station with the same SSID - after a suitable timeout, it sets itself up as the ``master'' so
- that other
stations may associate with it. This timeout de - faults to 10000
milliseconds (10 seconds) but may be changed with - this option.
The timeout should be specified in milliseconds. - -i iface -l station_name
- Set the station name used internally by the NIC.
- The
station_name can be any text string up to 16 charac - ters in
length. The default name is set by the driver to - ``FreeBSD''.
- -i iface -m mac_address
- Set the station address for the specified interface.
- The
mac_address is specified as a series of six hexadec - imal values
separated by colons, e.g.: 00:60:1d:12:34:56. This - programs the
new address into the card and updates the interface - as well.
- -i iface [-v 1-3] -n SSID
- Set the desired SSID (network name). There are
- three SSIDs which
allows the NIC to work with access points at several - locations
without needing to be reconfigured. The NIC checks - each SSID in
sequence when searching for a match. The SSID to be - changed can
be specified with the -v modifier option. If the -v - flag is not
used, the first SSID in the list is set. - -i iface -o 0 | 1
- Set the operating mode of the Aironet interface.
- Valid selections are 0 for ad-hoc mode and 1 for infrastructure
- mode. The
default driver setting is for infrastructure mode. - -i iface -p tx_power
- Set the transmit power level in milliwatts. Valid
- power settings
vary depending on the actual NIC and can be viewed - by dumping the
device capabilities with the -I flag. Typical val - ues are 1, 5,
20, 50 and 100mW. Selecting 0 sets the factory de - fault.
- -i iface -c frequency
- Set the radio frequency of a given interface. The
- frequency
should be specified as a channel ID as shown in the - table below.
The list of available frequencies is dependent on - radio regulations specified by regional authorities. Recognized
- regulatory
authorities include the FCC (United States), ETSI - (Europe),
France and Japan. Frequencies in the table are - specified in MHz.
Channel ID FCC ETSI FranceJapan
1 2412 24122 2417 24173 2422 24224 2427 24275 2432 24326 2437 24377 2442 24428 2447 24479 2452 245210 2457 2457 245711 2462 2462 246212 - 2467 246713 - 2472 247214 - -2484 - If an illegal channel is specified, the NIC will re
- vert to its
default channel. For NICs sold in the United States - and Europe,
the default channel is 3. For NICs sold in France, - the default
channel is 11. For NICs sold in Japan, the only - available channel is 14. Note that two stations must be set to
- the same channel in order to communicate.
- -i iface -f fragmentation_threshold
- Set the fragmentation threshold in bytes. This
- threshold controls the point at which outgoing packets will be
- split into multiple fragments. If a single fragment is not sent
- successfully,
only that fragment will need to be retransmitted in - stead of the
whole packet. The fragmentation threshold can be - anything from
64 to 2312 bytes. The default is 2312. - -i iface -r RTS_threshold
- Set the RTS/CTS threshold for a given interface.
- This controls
the number of bytes used for the RTS/CTS handshake - boundary. The
RTS_threshold can be any value between 0 and 2312. - The default
is 2312. - -i iface -M 0-15
- Set monitor mode via bit mask, meaning:
Bit Meaning
0 to not dump 802.11 packet.
1 to enable 802.11 monitor.
2 to monitor any SSID.
4 to not skip beacons, monitor beaconsproduces ahigh system load.8 to enable full Aironet header returnedvia BPF.Note it appears that a SSID must beset. - -h Print a list of available options and sample usage.
SECURITY NOTES
- WEP (``wired equivalent privacy'') is based on the RC4 algo
- rithm, using a
24 bit initialization vector. - RC4 is supposedly vulnerable to certain known plaintext at
- tacks, especially with 40 bit keys. So the security of WEP in part de
- pends on how
much known plaintext is transmitted. - Because of this, although counter-intuitive, using ``shared
- key'' authentication (which involves sending known plaintext) is less
- secure than
using ``open'' authentication when WEP is enabled. - Devices may alternate among all of the configured WEP keys
- when transmitting packets. Therefore, all configured keys (up to four)
- must agree.
EXAMPLES
- ancontrol -i an0 -v 0 -k 0x12345678901234567890123456
ancontrol -i an0 -K 2
ancontrol -i an0 -W 1
ancontrol -i an0 -e 0 - Sets a WEP key 0, enables ``Shared Key'' authentication, en
- ables full WEP
and uses transmit key 0.
SEE ALSO
HISTORY
The ancontrol utility first appeared in FreeBSD 4.0.
AUTHORS
- The ancontrol utility was written by Bill Paul
- <wpaul@ee.columbia.edu>.
BUGS
- The statistics counters do not seem to show the amount of
- transmit and
received frames as increasing. This is likely due to the - fact that the
an(4) driver uses unmodified packet mode instead of letting - the NIC perform 802.11/ethernet encapsulation itself.
- Setting the channel does not seem to have any effect.
- BSD September 10, 1999