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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.
50 supports multi-mode devices capable of
51 operating in both 2.4GHz and 5GHz bands and supports numerous
52 802.11 standards: 802.11a, 802.11b, 802.11g, 802.11n, and 802.11s (Draft 3.0).
53 The WPA, 802.11i, and 802.1x security protocols are supported
54 through a combination of in-kernel code and user-mode applications.
55 The WME/WMM multi-media protocols are supported entirely within
58 module but require a suitably capable hardware device.
59 Likewise the 802.11h specification is supported only by suitably
62 Drivers provide 802.11 functionality through
64 interfaces that are created at runtime using interface cloning.
72 Some drivers support the creation of multiple
74 interfaces that share the same underlying device;
75 this is the way by which ``multi-bss support'' is provided but it
76 can also be used to create WDS links and other interesting applications.
78 There are several types of
80 interfaces that may be created:
81 .Bl -tag -width monitor
83 A client station in an infrastructure bss
84 (i.e. one that associates to an access point).
86 An access point in an infrastructure bss.
88 A mesh station in an MBSS network.
90 A station in an IBSS network.
92 A station operating in ``adhoc demo mode''.
93 This is essentially an IBSS station that does not use management
94 frames (e.g. no beacons are transmitted).
97 interface is especially useful for applications that want to transmit
98 and receive raw 802.11 packets.
100 An interface used exclusively for capturing 802.11 frames.
101 In particular this specified to have read-only properties
102 which enables it to be operated on frequencies where one
103 would otherwise not be allowed.
105 A station that passes 4-address 802.11 traffic for the purpose
106 of tunneling traffic over a wireless link.
107 Typically this station would share the same MAC address as a
110 It may be possible to create
112 interfaces without a companion
114 interface but that is not guaranteed; one may need to create a
116 interface that does not send beacon frames before
118 interfaces may be created.
121 Note that an interface's type cannot be changed once it is created.
124 defines several mechanisms by which plugin modules may
125 be used to extend its' functionality.
126 Cryptographic support such as WEP, TKIP, and AES-CCMP are implemented
127 as standalone modules (if not statically configured into a system)
130 Similarly there is an authenticator framework for defining 802.11
131 authentication services and a framework for integrating access
132 control mechanisms specific to the 802.11 protocol.
134 .\"Join an existing BSS network (i.e., connect to an access point):
136 .\".Dl "ifconfig iface 192.168.0.20/24"
138 .\"Join a specific BSS network with network name
141 .\".Dl "ifconfig iface 192.168.0.20/24 ssid my_net"
143 .\"Join a specific BSS network with 64 bit WEP encryption:
144 .\".Bd -literal -offset indent
145 .\"ifconfig iface 192.168.0.20/24 ssid my_net wepmode on \e
146 .\" wepkey 0x1234567890 weptxkey 1
149 .\"Join a specific BSS network with 128 bit WEP encryption:
150 .\".Bd -literal -offset indent
151 .\"ifconfig iface 192.168.0.20/24 ssid my_net wepmode on \e
152 .\" wepkey 0x01020304050607080910111213 weptxkey 1
155 .\"Join/create an 802.11b IBSS network:
156 .\".Bd -literal -offset indent
157 .\"ifconfig iface 192.168.0.20/24 ssid my_net mediaopt adhoc
160 .\"To debug a network setup, you may wish to enable interface debugging:
161 .\".Bd -literal -offset indent
162 .\"ifconfig iface down debug up
165 .\"To disable debugging, you may simply use:
166 .\".Bd -literal -offset indent
167 .\"ifconfig iface down -debug up
170 .\"Create an 802.11g host-based access point:
171 .\".Bd -literal -offset indent
172 .\"ifconfig iface 192.168.0.20/24 ssid my_net mode 11g mediaopt hostap
175 .\"Create an 802.11a host-based access point with WEP enabled:
176 .\".Bd -literal -offset indent
177 .\"ifconfig iface 192.168.0.20/24 ssid my_net wepmode on \e
178 .\" wepkey 0x1234567890 weptxkey 1 mode 11a mediaopt hostap
181 .\"Create a host-based wireless bridge to fxp0:
182 .\".Bd -literal -offset indent
183 .\"ifconfig iface up ssid my_net media DS/11Mbps mediaopt hostap
184 .\"sysctl net.inet.ip.check_interface=0
185 .\"ifconfig bridge0 create
186 .\"ifconfig bridge0 addm iface1 addm iface2 up
189 .\"This will give you the same functionality as an access point.
193 option is included in the kernel configuration,
194 debugging controls are available using:
196 .Dl "sysctl net.wlan.X.debug=mask"
202 instance and mask is a bit-or of control bits that determine which
203 debugging messages to enable.
206 .Dl "sysctl net.wlan.0.debug=0x00200000"
208 enables debugging messages related to scanning for an access point,
209 adhoc neighbor, or an unoccupied channel when operation as an access point.
212 tool provides a more user-friendly mechanism for doing the same thing.
215 .Dl "sysctl net.wlan.debug=mask"
217 defines the initial value of the debugging flags for each cloned
219 interface; this is useful to enable debug messages during interface creation.
223 was used to be compatible with
226 Mesh stations follow the 802.11s Draft 3.0 specification which is
227 not ratified and subject to change.
228 Beware that this specification is incompatible with earlier drafts;
229 and stations implementing earlier drafts (e.g. Linux)
230 may not interoperate.
259 More information can be found in the IEEE 802.11 Standards.
263 driver first appeared in
266 Atsushi Onoe is the author of original
268 software from which this work began.
271 brought the code into
273 and then rewrote it to support multi-mode devices,
274 802.11g, 802.11n, WPA/802.11i, WME, multi-bss, and
275 add the extensible frameworks
276 for cryptographic, authentication, and access control plugins.
277 This manual page was written by
278 .An Tom Rhodes Aq trhodes@FreeBSD.org .