RTW(4) FreeBSD Kernel Interfaces Manual RTW(4)
NAME
rtw - Realtek RTL8180L IEEE 802.11b wireless network device
SYNOPSIS
rtw* at cardbus?
rtw* at pci?
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.
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.
The rtw driver can be configured to use software Wired Equivalent Privacy
(WEP). It is strongly recommended that WEP not be used as the sole
mechanism to secure wireless communication, due to serious weaknesses in
it.
The rtw driver can be configured at runtime with ifconfig(8) or on boot
with hostname.if(5).
HARDWARE
The following adapters should work:
Card Radio Bus
Allnet ALL0182 SA2400 CardBus
Belkin F5D6020 V3 SA2400 CardBus
Buffalo WLI-CB-B11 SA2400 CardBus
Corega CG-WLCB11V3 SA2400 CardBus
D-Link DWL-610 ? CardBus
Edimax EW-7106 SA2400 CardBus
GigaFast WF721-AEX (R* serial) GRF5101 CardBus
Jensen AirLink 6011 GRF5101 CardBus
Level-One WPC-0101 SA2400 CardBus
Linksys WPC11 v4 MAX2820 CardBus
Netgear MA521 SA2400 CardBus
Ovislink AirLive WL-1120PCM SA2400 CardBus
Planet WL-3553 SA2400 CardBus
Q-Tec 770WC SA2400 CardBus
Q-Tec 775WC SA2400 CardBus
Roper FreeLan 802.11b SA2400 CardBus
SAFECOM SWLCR-1100 SA2400 CardBus
TRENDnet TEW-226PC ? CardBus
VCTnet PC-11B1 SA2400 CardBus
Winstron CB-200B SA2400 CardBus
Zonet ZEW1000 GRF5101 CardBus
EXAMPLES
The following example scans for available networks:
# ifconfig rtw0 scan
The following hostname.if(5) example configures rtw0 to join network
"mynwid", using WEP key "mywepkey", obtaining an IP address using DHCP:
nwid mynwid nwkey mywepkey
inet autoconf
The following hostname.if(5) example creates a host-based access point on
boot:
mediaopt hostap
nwid mynwid nwkey mywepkey
inet 192.168.1.1 255.255.255.0
SEE ALSO
arp(4), cardbus(4), ifmedia(4), intro(4), netintro(4), pci(4),
hostname.if(5), hostapd(8), ifconfig(8)
Realtek, https://www.realtek.com/en.
HISTORY
The rtw device driver first appeared in OpenBSD 3.7.
AUTHORS
The rtw driver was written by David Young <
[email protected]> and ported
to OpenBSD by Jonathan Gray <
[email protected]>.
CAVEATS
GCT refuse to release any documentation on their GRF5101 RF transceiver.
While PCI devices will attach, most of them are not able to transmit.
Host AP mode doesn't support power saving. Clients attempting to use
power saving mode may experience significant packet loss (disabling power
saving on the client will fix this).
FreeBSD 14.1-RELEASE-p8 March 27, 2025 FreeBSD 14.1-RELEASE-p8