---
name: "rum"
section: "4"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["freebsd", "openbsd"]
url: "https://new.carta.tech/rum"
---

# rum(4)

Ralink Technology/MediaTek USB IEEE 802.11a/b/g wireless network device

## NAME

**rum** – Ralink Technology/MediaTek USB IEEE 802.11a/b/g wireless network device

## SYNOPSIS

**rum\* at uhub? port ?**

## DESCRIPTION

The **rum** driver supports USB 2.0 and PCI Express Mini Card wireless adapters based on the Ralink RT2501USB and RT2601USB chipsets.

Ralink PCI Express Mini Card adapters show up as normal USB 2.0 devices and are thus handled by the **rum** driver.

The RT2501USB chipset is the second generation of 802.11a/b/g adapters from Ralink. It consists of two integrated chips, an RT2571W MAC/BBP and an RT2528 or RT5226 radio transceiver.

The RT2601USB chipset consists of two integrated chips, an RT2671 MAC/BBP and an RT2527 or RT5225 radio transceiver. This chipset uses the MIMO (multiple-input multiple-output) technology with multiple antennas to extend the operating range of the adapter and to achieve higher throughput.

These are the modes the **rum** 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 **rum** driver can be configured to use Wired Equivalent Privacy (WEP) or Wi-Fi Protected Access (WPA1 and WPA2). WPA2 is currently the most secure encryption standard for wireless networks supported by OpenBSD. It is strongly recommended that neither WEP nor WPA1 are used as the sole mechanism to secure wireless communication, due to serious weaknesses. WPA1 is disabled by default and may be enabled using the option "**wpaprotos** *wpa1,wpa2*". For standard WPA networks which use pre-shared keys (PSK), keys are configured using the "**wpakey**" option. WPA-Enterprise networks require use of the wpa\_supplicant package. The **rum** driver relies on the software 802.11 stack for both encryption and decryption of data frames.

The **rum** driver can be configured at runtime with [ifconfig(8)](/ifconfig/8.md) or on boot with [hostname.if(5)](/hostname.if/5.md).

## FILES

The following firmware file is loaded when an interface is brought up:

- /etc/firmware/rum-rt2573

  ## HARDWARE

The following adapters should work:

- 3Com Aolynk WUB320g

  - Abocom WUG2700

  - Airlink101 AWLL5025

  - ASUS WL-167g ver 2

  - Atlantis Land A02-UP1-W54

  - Belkin F5D7050 ver 3

  - Belkin F5D9050 ver 3

  - Belkin F5D9050C

  - Buffalo WLI-U2-SG54HG

  - Buffalo WLI-U2-SG54HP

  - Buffalo WLI-U2-G54HP

  - CNet CWD-854 ver F

  - Conceptronic C54RU ver 2

  - Corega CG-WLUSB2GL

  - Corega CG-WLUSB2GO

  - Corega CG-WLUSB2GPX

  - D-Link DWA-110

  - D-Link DWA-111

  - D-Link DWL-G122 rev C1

  - D-Link WUA-1340

  - Digitus DN-7003GR

  - Edimax EW-7318Ug

  - Edimax EW-7318USg

  - Edimax EW-7618Ug

  - Gigabyte GN-WB01GS

  - Gigabyte GN-WI05GS

  - Hawking HWUG1

  - Hawking HWU54DM

  - Hercules HWGUSB2-54-LB

  - Hercules HWGUSB2-54V2-AP

  - LevelOne WNC-0301USB v3

  - Linksys WUSB200

  - Linksys WUSB54G rev C

  - Linksys WUSB54GR

  - Planex GW-US54HP

  - Planex GW-US54Mini2

  - Planex GW-USMM

  - Senao NUB-3701

  - Sitecom WL-113 ver 2

  - Sitecom WL-172

  - Sweex LW053

  - TP-LINK TL-WN321G

  ## EXAMPLES

The following example scans for available networks:

```
# ifconfig rum0 scan
```

The following [hostname.if(5)](/hostname.if/5.md) example configures rum0 to join network “mynwid”, using WPA key “mywpakey”, obtaining an IP address using DHCP:

```
nwid mynwid wpakey mywpakey
inet autoconf
```

The following [hostname.if(5)](/hostname.if/5.md) example creates a host-based access point on boot:

```
mediaopt hostap
nwid mynwid wpakey mywpakey
inet 192.168.1.1 255.255.255.0
```

## DIAGNOSTICS

- rum0: error N, 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.

- rum0: could not load 8051 microcode

  An error occurred while attempting to upload the microcode to the onboard 8051 microcontroller unit.

- rum0: 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)](/arp/4.md), [ifmedia(4)](/ifmedia/4.md), [intro(4)](/intro/4.md), [netintro(4)](/netintro/4.md), [usb(4)](/usb/4.md), [hostname.if(5)](/hostname.if/5.md), [hostapd(8)](/hostapd/8.md), [ifconfig(8)](/ifconfig/8.md)

## HISTORY

The **rum** driver first appeared in OpenBSD 4.0.

## AUTHORS

The **rum** driver was written by Niall O'Higgins ⟨*niallo@openbsd.org*⟩ and Damien Bergamini ⟨*damien.bergamini@free.fr*⟩.

## CAVEATS

The **rum** driver supports automatic control of the transmit speed in BSS mode only. Therefore the use of a **rum** adapter in Host AP mode is discouraged.