NAME
rtwn
—
Realtek RTL8188CE/RTL8192CE 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 and RTL8192CE chipsets.
The RTL8188CE is a highly integrated 802.11n adapter that combines a MAC, a 1T1R capable baseband and an RF in a single chip.
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 (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 rtwn
driver can be configured at
runtime with
ifconfig(8) or on boot with
hostname.if(5).
FILES
The driver needs at least version 1.0 of the following firmware files, which are loaded when an interface is brought up:
- /etc/firmware/rtwn-rtl8192cfwU
- /etc/firmware/rtwn-rtl8192cfwU_B
A prepackaged version of the firmware can be installed using fw_update(1).
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:
nwid mynwid wpakey mywpakey dhcp
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
<stsp@openbsd.org>.
It was based on the
urtwn(4) driver written by Damien Bergamini
<damien.bergamini@free.fr>.
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.