MTW(4) FreeBSD Kernel Interfaces Manual MTW(4)
NAME
mtw - MediaTek USB IEEE 802.11b/g/n wireless network device
SYNOPSIS
mtw* at uhub? port ?
DESCRIPTION
The mtw driver supports USB 2.0 wireless adapters based on the MediaTek
MT7601U chipset.
These are the modes the mtw 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 mtw driver can be configured to use Wired Equivalent Privacy (WEP) or
Wi-Fi Protected Access (WPA1 and WPA2). WPA2 is currently the most
secure encryption standard for wireless networks supported by OpenBSD.
It is strongly recommended that neither WEP nor WPA1 are used as the sole
mechanism to secure wireless communication, due to serious weaknesses.
WPA1 is disabled by default and may be enabled using the option
"wpaprotos wpa1,wpa2". For standard WPA networks which use pre-shared
keys (PSK), keys are configured using the "wpakey" option. WPA-
Enterprise networks require use of the wpa_supplicant package. The mtw
driver offloads both encryption and decryption of data frames to the
hardware for the WEP40, WEP104, TKIP(+MIC) and CCMP ciphers.
The mtw driver can be configured at runtime with ifconfig(8) or on boot
with hostname.if(5).
FILES
The driver needs the following firmware files, which are loaded when an
interface is brought up:
/etc/firmware/mtw-mt7601u
HARDWARE
The following adapters should work:
ASUS USB-N10 v2
D-Link DWA-127 rev B1
Edimax EW-7711UAn v2
Edimax EW-7711ULn v2
Foxconn WFU03
Tenda U2
Tenda W311MI v2
TP-LINK TL-WN727N v4
Yealink WF40
EXAMPLES
The following example scans for available networks:
# ifconfig mtw0 scan
The following hostname.if(5) example configures mtw0 to join network
"mynwid", using WPA key "mywpakey", obtaining an IP address using DHCP:
join mynwid wpakey mywpakey
inet autoconf
DIAGNOSTICS
mtw0: 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.
mtw0: could not load firmware An error occurred while attempting to
upload the microcode to the onboard 8051 microcontroller unit.
mtw0: 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.
SEE ALSO
arp(4), ifmedia(4), intro(4), netintro(4), usb(4), hostname.if(5),
ifconfig(8)
HISTORY
The mtw driver first appeared in OpenBSD 7.1.
AUTHORS
The mtw driver was written by James Hastings <
[email protected]> based
on the run(4) driver by Damien Bergamini <
[email protected]>.
CAVEATS
The mtw driver does not support any of the 802.11n capabilities offered
by the MT7601U chipset. Additional work is required in ieee80211(9)
before those features can be supported.
FreeBSD 14.1-RELEASE-p8 March 27, 2025 FreeBSD 14.1-RELEASE-p8