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33 .Nd generic 802.11 link-layer support
39 module provides generic code to support 802.11 drivers.
40 Where a device does not directly support 802.11 functionality
44 module is required by all native 802.11 drivers as well as the
49 supports multi-mode devices capable of
50 operating in both 2.4GHz and 5GHz bands and supports numerous
51 802.11 standards: 802.11a, 802.11b, 802.11g, 802.11n, and 802.11s (Draft 3.0).
52 The WPA, 802.11i, and 802.1x security protocols are supported
53 through a combination of in-kernel code and user-mode applications.
54 The WME/WMM multi-media protocols are supported entirely within
57 module but require a suitably capable hardware device.
58 Likewise the 802.11h specification is supported only by suitably
61 Drivers provide 802.11 functionality through
63 interfaces that are created at runtime using interface cloning.
71 Some drivers support the creation of multiple
73 interfaces that share the same underlying device;
74 this is the way by which ``multi-bss support'' is provided but it
75 can also be used to create WDS links and other interesting applications.
77 There are several types of
79 interfaces that may be created:
80 .Bl -tag -width monitor
82 A client station in an infrastructure bss
83 (i.e. one that associates to an access point).
85 An access point in an infrastructure bss.
87 A mesh station in an MBSS network.
89 A station in an IBSS network.
91 A station operating in ``adhoc demo mode''.
92 This is essentially an IBSS station that does not use management
93 frames (e.g. no beacons are transmitted).
96 interface is especially useful for applications that want to transmit
97 and receive raw 802.11 packets.
99 An interface used exclusively for capturing 802.11 frames.
100 In particular this specified to have read-only properties
101 which enables it to be operated on frequencies where one
102 would otherwise not be allowed.
104 A station that passes 4-address 802.11 traffic for the purpose
105 of tunneling traffic over a wireless link.
106 Typically this station would share the same MAC address as a
109 It may be possible to create
111 interfaces without a companion
113 interface but that is not guaranteed; one may need to create a
115 interface that does not send beacon frames before
117 interfaces may be created.
120 Note that an interface's type cannot be changed once it is created.
123 defines several mechanisms by which plugin modules may
124 be used to extend its' functionality.
125 Cryptographic support such as WEP, TKIP, and AES-CCMP are implemented
126 as standalone modules (if not statically configured into a system)
129 Similarly there is an authenticator framework for defining 802.11
130 authentication services and a framework for integrating access
131 control mechanisms specific to the 802.11 protocol.
133 .\"Join an existing BSS network (i.e., connect to an access point):
135 .\".Dl "ifconfig iface 192.168.0.20/24"
137 .\"Join a specific BSS network with network name
140 .\".Dl "ifconfig iface 192.168.0.20/24 ssid my_net"
142 .\"Join a specific BSS network with 64 bit WEP encryption:
143 .\".Bd -literal -offset indent
144 .\"ifconfig iface 192.168.0.20/24 ssid my_net wepmode on \e
145 .\" wepkey 0x1234567890 weptxkey 1
148 .\"Join a specific BSS network with 128 bit WEP encryption:
149 .\".Bd -literal -offset indent
150 .\"ifconfig iface 192.168.0.20/24 ssid my_net wepmode on \e
151 .\" wepkey 0x01020304050607080910111213 weptxkey 1
154 .\"Join/create an 802.11b IBSS network:
155 .\".Bd -literal -offset indent
156 .\"ifconfig iface 192.168.0.20/24 ssid my_net mediaopt adhoc
159 .\"To debug a network setup, you may wish to enable interface debugging:
160 .\".Bd -literal -offset indent
161 .\"ifconfig iface down debug up
164 .\"To disable debugging, you may simply use:
165 .\".Bd -literal -offset indent
166 .\"ifconfig iface down -debug up
169 .\"Create an 802.11g host-based access point:
170 .\".Bd -literal -offset indent
171 .\"ifconfig iface 192.168.0.20/24 ssid my_net mode 11g mediaopt hostap
174 .\"Create an 802.11a host-based access point with WEP enabled:
175 .\".Bd -literal -offset indent
176 .\"ifconfig iface 192.168.0.20/24 ssid my_net wepmode on \e
177 .\" wepkey 0x1234567890 weptxkey 1 mode 11a mediaopt hostap
180 .\"Create a host-based wireless bridge to fxp0:
181 .\".Bd -literal -offset indent
182 .\"ifconfig iface up ssid my_net media DS/11Mbps mediaopt hostap
183 .\"sysctl net.inet.ip.check_interface=0
184 .\"ifconfig bridge0 create
185 .\"ifconfig bridge0 addm iface1 addm iface2 up
188 .\"This will give you the same functionality as an access point.
192 option is included in the kernel configuration,
193 debugging controls are available using:
195 .Dl "sysctl net.wlan.X.debug=mask"
201 instance and mask is a bit-or of control bits that determine which
202 debugging messages to enable.
205 .Dl "sysctl net.wlan.0.debug=0x00200000"
207 enables debugging messages related to scanning for an access point,
208 adhoc neighbor, or an unoccupied channel when operation as an access point.
211 tool provides a more user-friendly mechanism for doing the same thing.
214 .Dl "sysctl net.wlan.debug=mask"
216 defines the initial value of the debugging flags for each cloned
218 interface; this is useful to enable debug messages during interface creation.
222 was used to be compatible with
225 Mesh stations follow the 802.11s Draft 3.0 specification which is
226 not ratified and subject to change.
227 Beware that this specification is incompatible with earlier drafts;
228 and stations implementing earlier drafts (e.g. Linux)
229 may not interoperate.
261 More information can be found in the IEEE 802.11 Standards.
265 driver first appeared in
270 is the author of the original
272 software from which this work began.
274 brought the code into
276 and then rewrote it to support multi-mode devices,
277 802.11g, 802.11n, WPA/802.11i, WME, multi-bss, and
278 add the extensible frameworks
279 for cryptographic, authentication, and access control plugins.
280 This manual page was written by
281 .An Tom Rhodes Aq Mt trhodes@FreeBSD.org .