RTWN(4)

NAME
rtwn - Realtek RTL8188CE/RTL8192CE PCIe IEEE 802.11b/g/n wireless network device

SYNOPSIS
rtwn* at pci? dev ? function ?

DESCRIPTION
The rtwn driver supports PCIe wireless network devices based on the Realtek 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 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 ifconfig.if(5).

FILES
The driver needs the following firmware files, which are loaded when an interface is brought up:

/libdata/firmware/if_rtwn/rtl8192cfw.bin
/libdata/firmware/if_rtwn/rtl8192cfwU.bin
/libdata/firmware/if_rtwn/rtl8192cfwU_B.bin

EXAMPLES
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
    dhcp

Join an existing BSS network, “my_net”:

    # ifconfig rtwn0 192.168.1.1 netmask 0xffffff00 nwid my_net

DIAGNOSTICS

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 transmission did not complete in time. The driver will reset the hardware. This should not happen.

SEE ALSO
arp(4), netintro(4), pci(4), ifconfig.if(5), wpa_supplicant.conf(5), ifconfig(8), wpa_supplicant(8)

HISTORY
The rtwn driver first appeared in OpenBSD 5.8 and in NetBSD 8.0.

AUTHORS
-nosplit The rtwn driver was written by Stefan Sperling <stsp@openbsd.org> for OpenBSD and ported to NetBSD by NONAKA Kimihiro <nonaka@NetBSD.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.