BWI(4) OpenBSD Programmer's Manual BWI(4)NAMEbwi - Broadcom AirForce IEEE 802.11b/g wireless network device
SYNOPSIS
bwi* at cardbus?
bwi* at pci?
DESCRIPTION
The bwi driver provides support for Broadcom AirForce based PCI/Cardbus
network adapters.
These are the modes the bwi driver can operate in:
BSS mode Also known as infrastructure mode, this is used when
associating with an access point, through which all
traffic passes. This mode is the default.
monitor mode In this mode the driver is able to receive packets without
associating with an access point. This disables the
internal receive filter and enables the card to capture
packets from networks which it wouldn't normally have
access to, or to scan for access points.
The bwi driver can be configured to use Wired Equivalent Privacy (WEP) or
Wi-Fi Protected Access (WPA-PSK and WPA2-PSK). WPA is the de facto
encryption standard for wireless networks. It is strongly recommended
that WEP not be used as the sole mechanism to secure wireless
communication, due to serious weaknesses in it. The bwi driver relies on
the software 802.11 stack for both encryption and decryption of data
frames.
The transmit speed is user-selectable or can be adapted automatically by
the driver depending on the received signal strength and on the number of
hardware transmission retries.
The bwi driver can be configured at runtime with ifconfig(8) or on boot
with hostname.if(5).
FILES
The driver needs a firmware file which is loaded when an interface is
brought up:
/etc/firmware/bwi-airforce
A prepackaged version of the firmware, designed to be used with
pkg_add(1), can be found at:
http://www.nazgul.ch/bwi/bwi-firmware-1.4.tgz
HARDWARE
The following cards are among those supported by the bwi driver:
Card Chip Bus Standard
Apple Airport Extreme BCM4306 PCI b/g
Apple Airport Extreme BCM4318 PCI b/g
ASUS WL-138g BCM4318 PCI b/g
Buffalo WLI-CB-G54 BCM4306 CardBus b/g
Compaq R4035 onboard BCM4306 PCI b/g
HP nx6125 BCM4319 PCI b/g
Linksys WPC54G Ver 3 BCM4318 CardBus b/g
Linksys WPC54GS Ver 2 BCM4318 CardBus b/g
TRENDnet TEW-401PCplus
BCM4306 CardBus b/g
US Robotics 5411 BCM4318 CardBus b/g
EXAMPLES
The following hostname.if(5) example configures bwi0 to join whatever
network is available on boot, using WEP key ``0x1deadbeef1'', channel 11,
obtaining an IP address using DHCP:
dhcp NONE NONE NONE nwkey 0x1deadbeef1 chan 11
Configure bwi0 to join network ``my_net'' using WPA with passphrase
``my_passphrase'':
# ifconfig bwi0 nwid my_net wpakey my_passphrase
Join an existing BSS network, ``my_net'':
# ifconfig bwi0 192.168.1.1 netmask 0xffffff00 nwid my_net
SEE ALSOarp(4), cardbus(4), ifmedia(4), intro(4), netintro(4), pci(4),
hostname.if(5), ifconfig(8)HISTORY
The bwi driver first appeared in OpenBSD 4.3.
AUTHORS
The bwi driver was written for DragonFlyBSD by Sepherosa Ziehau and
ported to OpenBSD by Jonathan Gray and Marcus Glocker.
CAVEATS
Some chips are incorrectly calibrated due to the lack of documentation,
which can slow the amount of traffic to the point of being unusable.
Furthermore this driver only supports firmware version 3.
OpenBSD 4.9 November 1, 2010 OpenBSD 4.9
