.\" $OpenBSD: urtw.4,v 1.2 2008/12/03 10:44:17 jsg Exp $
.\"
.\" Copyright (c) 2008 Weongyo Jeong <weongyo@FreeBSD.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: December 3 2008 $
.Os
.Dt URTW 4
.Sh NAME
.Nm urtw
.Nd Realtek RTL8187L USB IEEE 802.11b/g wireless network device
.Sh SYNOPSIS
.Cd "urtw* at uhub? port ?"
.Sh DESCRIPTION
The
.Nm
driver supports USB 802.11b/g wireless adapters based on the
Realtek RTL8187L.
.Pp
These are the modes the
.Nm
driver can operate in:
.Bl -tag -width "IBSS-masterXX"
.It BSS mode
Also known as
.Em infrastructure
mode, this is used when associating with an access point, through
which all traffic passes.
This mode is the default.
.It IBSS mode
Also known as
.Em IEEE ad-hoc
mode or
.Em peer-to-peer
mode.
This is the standardized method of operating without an access point.
Stations associate with a service set.
However, actual connections between stations are peer-to-peer.
.It 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.
.El
.Pp
The
.Nm
driver can be configured to use
Wireless 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
.Nm
driver relies on the software 802.11 stack for both encryption and decryption
of data frames.
.Pp
The
.Nm
driver can be configured at runtime with
.Xr ifconfig 8
or on boot with
.Xr hostname.if 5 .
.Sh HARDWARE
The following adapters should work:
.Pp
.Bl -tag -width Ds -offset indent -compact
.It Netgear WG111v2
.It Shuttle XPC Accessory PN20
.El
.Sh EXAMPLES
The following
.Xr hostname.if 5
example configures urtw0 to join whatever network is available on boot,
using WEP key
.Dq 0x1deadbeef1 ,
channel 11, obtaining an IP address using DHCP:
.Bd -literal -offset indent
dhcp NONE NONE NONE nwkey 0x1deadbeef1 chan 11
.Ed
.Pp
The following
.Xr hostname.if 5
example creates a host-based access point on boot:
.Bd -literal -offset indent
inet 192.168.1.1 255.255.255.0 NONE media autoselect \e
	mediaopt hostap nwid my_net chan 11
.Ed
.Pp
Configure urtw0 to join network
.Dq my_net
using WPA-PSK with passphrase
.Dq my_passphrase :
.Bd -literal -offset indent
# ifconfig urtw0 nwid my_net wpa wpapsk \e
	$(wpa-psk my_net my_passphrase)
.Ed
.Pp
Return urtw0 to its default settings:
.Bd -literal -offset indent
# ifconfig urtw0 -bssid -chan media autoselect \e
	nwid "" -nwkey -wpa -wpapsk
.Ed
.Pp
Join an existing BSS network,
.Dq my_net :
.Bd -literal -offset indent
# ifconfig urtw0 192.168.1.1 netmask 0xffffff00 nwid my_net
.Ed
.Sh SEE ALSO
.Xr arp 4 ,
.Xr ifmedia 4 ,
.Xr intro 4 ,
.Xr netintro 4 ,
.Xr usb 4 ,
.Xr hostname.if 5 ,
.Xr hostapd 8 ,
.Xr ifconfig 8 ,
.Xr wpa-psk 8
.Pp
RealTek Semiconductor:
.Pa http://www.realtek.com.tw/
.Sh HISTORY
The
.Nm
device driver first appeared in
.Ox 4.5 .
.Sh AUTHORS
The
.Nm
driver was written by
.An Weongyo Jeong Aq weongyo@FreeBSD.org .