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RTWN(4) NetBSD Kernel Interfaces Manual RTWN(4)
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rtwn -- Realtek RTL8188CE/RTL8192CE PCIe IEEE 802.11b/g/n wireless net-
rtwn* at pci? dev ? function ?
The rtwn driver supports PCIe wireless network devices based on the Real-
tek RTL8188CE and RTL8192CE chipset.
The RTL8188CE is a highly integrated 802.11n adapter that combines a MAC,
a 1T1R capable baseband and an RF in a single chip. It operates in the
2GHz spectrum only.
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. It operates 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 asso-
ciating 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 (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 communica-
tion, due to serious weaknesses in it.
The rtwn 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 brought up:
The following ifconfig.if(5) example configures rtwn0 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 rtwn0 192.168.1.1 netmask 0xffffff00 nwid my_net
rtwn%d: 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.
rtwn%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), pci(4), ifconfig.if(5), wpa_supplicant.conf(5),
The rtwn driver first appeared in OpenBSD 5.8 and in NetBSD 8.0.
The rtwn driver was written by Stefan Sperling <email@example.com> for
OpenBSD and ported to NetBSD by NONAKA Kimihiro <nonaka@NetBSD.org>. It
was based on the urtwn(4) driver written by Damien Bergamini
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.
NetBSD 9.1 August 27, 2015 NetBSD 9.1