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WLAN(4)			 BSD Kernel Interfaces Manual		       WLAN(4)

     wlan -- generic 802.11 link-layer support

     device wlan

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

     The wlan 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 ap-
     plications.  The WME and WMM multi-media protocols	are supported entirely
     within the	wlan module but	require	a suitably capable hardware device.

     The wlan 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 authentica-
     tor framework for defining	802.11 authentication services and a framework
     for integrating access control mechanisms specific	to the 802.11 proto-

     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 wlan instance	and mask is a bit-or of	con-
     trol bits that determine which debugging messages to enable.  For exam-

	   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 80211debug 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;

	   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	wlan was used to be compatible with NetBSD.

     an(4), ath(4), awi(4), netintro(4), wi(4),	wlan_acl(4), wlan_ccmp(4),
     wlan_tkip(4), wlan_wep(4),	wlan_xauth(4)

     More information can be found in the IEEE 802.11 Standard.

     The wlan driver first appeared in FreeBSD 5.0.

     Atsushi Onoe is the author	of original NetBSD software from which this
     work began.  Sam Leffler brought the code into FreeBSD 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 con-
     trol plugins.  This manual	page was written by Tom	Rhodes

BSD			       December	7, 2004				   BSD


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