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URTWN(4) NetBSD Kernel Interfaces Manual URTWN(4)
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urtwn -- Realtek RTL8188CU/RTL8188EU/RTL8192CU/RTL8192EU USB IEEE
802.11b/g/n wireless network device
urtwn* at uhub? port ?
The urtwn driver supports USB 2.0 wireless network devices based on Real-
tek RTL8188CUS, RTL8188CE-VAU, RTL8188EUS, RTL8188RU, RTL8192CU and
The RTL8188CUS and RTL8188EUS are highly integrated 802.11n adapters that
combine a MAC, a 1T1R capable baseband and an RF in a single chip. They
operate in the 2GHz spectrum only. The RTL8188RU is a high-power variant
of the RTL8188CUS. The RTL8188CE-VAU is a PCI Express Mini Card adapter
that attaches to the USB interface.
The RTL8192CU and RTL8192EU are highly integrated multiple-in, multiple-
out (MIMO) 802.11n adapters that combine a MAC, a 2T2R capable baseband
and an RF in a single chip. It operates in the 2GHz spectrum only.
These are the modes the urtwn driver can operate in:
BSS mode Also known as infrastructure mode, this is used when asso-
ciating with an access point, through which all traffic
passes. This mode is the default.
IBSS mode Also known as IEEE ad-hoc mode or 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.
Host AP In this mode the driver acts as an access point (base sta-
tion) for other cards.
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.
The urtwn driver can be configured to use Wired 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 communica-
tion, due to serious weaknesses in it.
The urtwn driver can be configured at runtime with ifconfig(8) or on boot
The driver needs the following firmware files, which are loaded when an
interface is attached:
The following adapters should work:
Aus. Linx AL-9604R1S
ASUSTeK USB-N10 NANO
Belkin F7D1102 Surf Wireless Micro
Full River FR-W100NUL
Hercules Wireless N USB Pico HWNUp-150
Sitecom N300 USB (WLA-2102 v1)
TP-LINK TL-WN723N v3
TP-LINK TL-WN725N v2
The following ifconfig.if(5) example configures urtwn0 to join whatever
network is available on boot, using WEP key ``0x1deadbeef1'', channel 11,
obtaining an IP address using DHCP:
nwkey 0x1deadbeef1 chan 11
Join an existing BSS network, ``my_net'':
# ifconfig urtwn0 192.168.1.1 netmask 0xffffff00 nwid my_net
urtwn%d: error %d, could not read firmware %s For some reason, the
driver was unable to read the microcode file from the filesystem. The
file might be missing or corrupted.
urtwn%d: device timeout A frame dispatched to the hardware for transmis-
sion did not complete in time. The driver will reset the hardware. This
should not happen.
arp(4), netintro(4), usb(4), ifconfig.if(5), wpa_supplicant.conf(5),
The urtwn device driver first appeared in OpenBSD 4.9 and in NetBSD 6.0.
The urtwn driver was written by Damien Bergamini <email@example.com> for
OpenBSD and ported to NetBSD by NONAKA Kimihiro <nonaka@NetBSD.org>.
The urtwn driver does not support any of the 802.11n capabilities offered
by the adapters. Additional work is required in ieee80211(9) before
those features can be supported.
NetBSD 9.3 December 17, 2018 NetBSD 9.3