NAME
rtw
—
Realtek RTL8180L IEEE 802.11b wireless
network driver
SYNOPSIS
rtw* at cardbus? function ?
rtw* at pci? dev ? function ?
DESCRIPTION
The rtw
driver supports PCI/CardBus
802.11b wireless adapters based on the Realtek RTL8180L.
A variety of radio transceivers can be found in these devices, including the Philips SA2400A, Maxim MAX2820, and GCT GRF5101, though not all of them are currently supported.
These are the modes the rtw
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.
- IBSS mode
- Also known as IEEE ad-hoc mode or peer-to-peer mode. This is the standardized method of operating without an access point. Stations associate with a service set. However, actual connections between stations are peer-to-peer.
- Host AP
- In this mode the driver acts as an access point (base station) for other cards.
- 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.
rtw
supports software WEP. Wired
Equivalent Privacy (WEP) is the de facto encryption standard for wireless
networks. It can be typically configured in one of three modes: no
encryption; 40-bit encryption; or 104-bit encryption. Unfortunately, due to
serious weaknesses in WEP protocol it is strongly recommended that it not be
used as the sole mechanism to secure wireless communication. WEP is not
enabled by default.
CONFIGURATION
The rtw
driver can be configured at
runtime with
ifconfig(8) or on boot with
ifconfig.if(5) using the following parameters:
bssid
bssid- Set the desired BSSID.
-bssid
- Unset the desired BSSID. The interface will automatically select a BSSID in this mode, which is the default.
chan
n- Set the channel (radio frequency) to be used by the driver based on the given channel ID n.
-chan
- Unset the desired channel to be used by the driver. The driver will automatically select a channel in this mode, which is the default.
media
media- The
rtw
driver supports the following media types:autoselect
- Enable autoselection of the media type and options.
DS1
- Set 802.11b DS 1Mbps operation.
DS2
- Set 802.11b DS 2Mbps operation.
DS5
- Set 802.11b DS 5.5Mbps operation.
DS11
- Set 802.11b DS 11Mbps operation.
mediaopt
opts- The
rtw
driver supports the following media options:hostap
- Select Host AP operation.
ibss
- Select IBSS operation.
monitor
- Select monitor mode.
-mediaopt
opts- Disable the specified media options on the driver and return it to the default mode of operation (BSS).
ssid
id- Set the network ID. The id can either be any text
string up to 32 characters in length, or a series of hexadecimal digits up
to 64 digits. An empty id string allows the
interface to connect to any available access points. By default the
rtw
driver uses an empty string. Note that network ID is synonymous with Extended Service Set ID (ESSID). nwkey
key- Enable WEP encryption using the specified key. The
key can either be a string, a series of hexadecimal
digits (preceded by ‘0x’), or a set of keys of the form
“n:k1,k2,k3,k4”, where ‘n’ specifies which of
the keys will be used for transmitted packets, and the four keys,
“k1” through “k4”, are configured as WEP keys.
If a set of keys is specified, a comma (‘,’) within the key
must be escaped with a backslash. Note that if multiple keys are used,
their order must be the same within the network.
rtw
is capable of using both 40-bit (5 characters or 10 hexadecimal digits) or 104-bit (13 characters or 26 hexadecimal digits) keys. -nwkey
- Disable WEP encryption. This is the default mode of operation.
nwkey persist
- Enable WEP encryption with the persistent key stored in the network card.
HARDWARE
The following adapters should work:
Card | Bus |
Belkin F5D6020
V3 |
CardBus |
Buffalo
WLI-CB-B11 |
CardBus |
Corega
CG-WLCB11V3 |
CardBus |
D-Link
DWL-610 |
CardBus |
Level-One
WPC-0101 |
CardBus |
Linksys WPC11
v4 |
CardBus |
Netgear
MA521 |
CardBus |
Ovislink AirLive
WL-1120PCM |
CardBus |
Planet
WL-3553 |
CardBus |
TrendNET
TEW-266PC |
CardBus |
VCTnet
PC-11B1 |
CardBus |
EXAMPLES
The following ifconfig.if(5) example creates a host-based access point on boot:
inet 192.168.1.1 255.255.255.0 NONE media autoselect \ mediaopt hostap ssid my_net chan 11
Configure rtw0 for WEP, using hex key “0x1deadbeef1”:
# ifconfig rtw0 nwkey 0x1deadbeef1
Return rtw0 to its default settings:
# ifconfig rtw0 -bssid -chan media autoselect \ ssid "" -nwkey
Join an existing BSS network, “my_net”:
# ifconfig rtw0 192.168.1.1 netmask 0xffffff00 ssid my_net
SEE ALSO
arp(4), cardbus(4), ifmedia(4), intro(4), netintro(4), pci(4), ifconfig.if(5), ifconfig(8)
Realtek, http://www.realtek.com.tw.
HISTORY
The rtw
device driver first appeared in
NetBSD 3.0 and then in OpenBSD
3.7.
AUTHORS
The rtw
driver was written by
David Young ⟨dyoung@NetBSD.org⟩ and
ported to OpenBSD by Jonathan
Gray
<jsg@openbsd.org>, who
wrote this man page.
BUGS
Only the Philips SA2400A and Maxim MAX2820 RF transceivers are known to work. Devices incorporating a GCT RF transceiver are not supported due to a lack of documentation from GCT.
While PCI devices will attach most of them are not able to transmit.