RTWN(4) FreeBSD Kernel Interfaces Manual RTWN(4)
NAME
rtwn - Realtek RTL8188CE/RTL8188EE/RTL8192CE/RTL8723AE PCIe IEEE
802.11b/g/n wireless network device
SYNOPSIS
rtwn* at pci? port ?
DESCRIPTION
The rtwn driver supports PCIe wireless network devices based on the
Realtek RTL8188CE, RTL8188EE, RTL8192CE and RTL8723AE chipsets.
The RTL8188CE, RTL8188EE and RTL8723AE are highly integrated 802.11n
adapters that combine a MAC, a 1T1R capable baseband and an RF in a
single chip. The RTL8723AE also includes a Bluetooth 2.1/3.0/4.0
controller.
The RTL8192CE 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.
These devices operate in the 2GHz spectrum only.
These are the modes the rtwn 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 rtwn 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 rtwn driver can be configured at runtime with ifconfig(8) or on boot
with hostname.if(5).
FILES
The adapter needs firmware files to run, which are loaded on demand by
the driver when the device is attached:
/etc/firmware/rtwn-rtl8188e
/etc/firmware/rtwn-rtl8192cU
/etc/firmware/rtwn-rtl8192cU_B
/etc/firmware/rtwn-rtl8723
/etc/firmware/rtwn-rtl8723_B
EXAMPLES
The following example scans for available networks:
# ifconfig rtwn0 scan
The following hostname.if(5) example configures rtwn0 to join network
"mynwid", using WPA key "mywpakey", obtaining an IP address using DHCP:
join mynwid wpakey mywpakey
inet autoconf
DIAGNOSTICS
rtwn0: 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.
rtwn0: 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), pci(4), hostname.if(5),
ifconfig(8)
HISTORY
The rtwn driver first appeared in OpenBSD 5.8.
AUTHORS
The rtwn driver was written by Stefan Sperling <
[email protected]>. It
was based on the urtwn(4) driver written by Damien Bergamini
<
[email protected]>.
CAVEATS
The rtwn 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.
FreeBSD 14.1-RELEASE-p8 March 27, 2025 FreeBSD 14.1-RELEASE-p8