Langue: en

Version: 300852 (debian - 07/07/09)

Section: 4 (Pilotes et protocoles réseau)

BSD mandoc


wlan - generic 802.11 link-layer support


device wlan


The module provides generic code to support 802.11 drivers. Where a device does not directly support 802.11 functionality this layer fills in. The is required for the an(4), ath(4), awi(4), ipw(4), iwi(4), ral(4), rum(4), ural(4), wi(4), and zyd(4) drivers, with other drivers to follow.

The module supports multi-mode devices capable of operating in both 2.4GHz and 5GHz bands and supports numerous 802.11 protocols: 802.11a, 802.11b, and 802.11g. The WPA, 802.11i, and 802.1x security protocols are supported through a combination of in-kernel code and user-mode applications. The WME and WMM multi-media protocols are supported entirely within the module but require a suitably capable hardware device.

The module defines several mechanisms by which plugin modules may be used to extend functionality. Cryptographic support such as WEP, TKIP, and AES-CCMP are implemented as modules that are loaded on demand (if not statically configured into a system). Similarly there is an authenticator framework for defining 802.11 authentication services and a framework for integrating access control mechanisms specific to the 802.11 protocol.


If the associated interface is marked for debugging with, for example,
"ifconfig wi0 debug"

then messages describing the operation of the 802.11 protocol will be sent to the console. Complete debugging controls are available using:

"sysctl net.wlan.X.debug=mask"

where X is the number of the instance and mask is a bit-or of control bits that determine which debugging messages to enable. For example,

"sysctl net.wlan.0.debug=0x00200000"

enables debugging messages related to scanning for an access point, adhoc neighbor, or an unoccupied channel when operation as an access point. The wlandebug tool provides a more user-friendly mechanism for doing the same thing.

Many drivers will also display the contents of each 802.11 frame sent and received when the interface is marked with both debugging and link2 e.g.,

"ifconfig wi0 debug link2"

Beware however that some management frames may be processed entirely within the device and not be received by the host.


The module name of was used to be compatible with Nx .


an(4), ath(4), awi(4), ipw(4), iwi(4), netintro(4), ral(4), rum(4), ural(4), wi(4), wlan_acl4, wlan_ccmp4, wlan_tkip4, wlan_wep4, wlan_xauth4, zyd(4), wlandebug(8)


More information can be found in the IEEE 802.11 Standard.


The driver first appeared in Fx 5.0 .


Atsushi Onoe is the author of original Nx software from which this work began. An -nosplit An Sam Leffler brought the code into Fx and then rewrote it to support multi-mode devices, 802.11g, WPA/802.11i, WME, and add the extensible frameworks for cryptographic, authentication, and access control plugins. This manual page was written by An Tom Rhodes Aq trhodes@FreeBSD.org .