URTWN(4) Device Drivers Manual URTWN(4)
urtwn - Realtek RTL8188CU/RTL8188EU/RTL8192CU 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
Realtek RTL8188CU, RTL8188CE-VAU, RTL8188EU, RTL8188RU and RTL8192CU
The RTL8188CU and RTL8188EU 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 RTL8188CU. The RTL8188CE-VAU is a PCI Express Mini Card adapter
that attaches to the USB interface.
The RTL8192CU is a highly integrated multiple-in, multiple-out (MIMO)
802.11n adapter that combines 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
associating with an access point, through which all
traffic passes. This mode is the default.
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 current
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 urtwn driver can be configured at runtime with ifconfig(8) or on boot
The driver needs at least version 1.1p0 of the following firmware files,
which are loaded when an interface is attached:
A prepackaged version of the firmware can be installed using
The following adapters should work:
Approx APPUSB300NANO V1
Aus. Linx AL-9604R1S
Belkin F7D1102 Surf Wireless Micro
D-Link DWA-123 rev D1
D-Link DWA-125 rev D1
D-Link DWA-131 rev B
Full River FR-W100NUL
Hercules Wireless N USB Pico HWNUp-150
ISY IWL4000 USB Wireless Micro Adapter
On Networks N300MA
Sitecom WLA-2100 v2
TP-LINK TL-WN723N v3
TP-LINK TL-WN725N v2
TP-Link TL-WN821N v4
The following example scans for available networks:
# ifconfig urtwn0 scan
The following hostname.if(5) example configures urtwn0 to join network
"mynwid", using WPA key "mywpakey", obtaining an IP address using DHCP:
urtwn0: error N, could not read firmware ... For some reason, the driver
was unable to read the microcode file from the filesystem. The file
might be missing or corrupted.
urtwn0: device timeout A frame dispatched to the hardware for
transmission did not complete in time. The driver will reset the
hardware. This should not happen.
arp(4), ifmedia(4), intro(4), netintro(4), usb(4), hostname.if(5),
The urtwn driver first appeared in OpenBSD 4.9.
The urtwn driver was written by Damien Bergamini
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.
OpenBSD 6.2 July 12, 2017 OpenBSD 6.2
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