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

# pgt(4)

Conexant/Intersil Prism GT Full-MAC IEEE 802.11a/b/g wireless network device

## NAME

**pgt** – Conexant/Intersil Prism GT Full-MAC IEEE 802.11a/b/g wireless network device

## SYNOPSIS

**pgt\* at cardbus?** **pgt\* at pci?**

## DESCRIPTION

The **pgt** driver provides support for Conexant/Intersil GT-series devices which can support the Full-MAC firmware, using the ISL3877, ISL3880, and ISL3890 chips. The **pgt** driver will not (yet) work on similar devices using the ISL3886 or similar chips which use the Soft-MAC firmware.

These are the modes the **pgt** 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 **pgt** driver can be configured to use hardware 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.

In BSS mode, the driver supports powersave mode, which can be enabled via [ifconfig(8)](/ifconfig/8.md).

The **pgt** 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 driver needs a set of firmware files which are loaded when an interface is brought up:

- */etc/firmware/pgt-isl3877*

  - */etc/firmware/pgt-isl3890*

  These firmware files are not free because Conexant refuses to grant distribution rights. In fact they have rebuffed thousands of attempts to start a dialogue on this issue. As a result, even though OpenBSD includes the driver, the firmware files cannot be included and users have to download these files on their own.

A prepackaged version of the firmware can be installed using [fw\_update(8)](/fw_update/8.md).

## HARDWARE

The following cards are among those supported by the **pgt** driver:

| | | |
| --- | --- | --- |
| *Card* | *Chip* | *Bus* |
| 3COM 3CRWE154G72 | ISL3880 | CardBus |
| D-Link DWL-g650 A1 | ISL3890 | PCI |
| I-O Data WN-G54/CB | ISL3890 | PCI |
| I4 Z-Com XG-600 | ISL3890 | PCI |
| I4 Z-Com XG-900 | ISL3890 | PCI |
| Intersil PRISM Indigo | ISL3877 | PCI |
| Intersil PRISM Duette | ISL3890 | PCI |
| NETGEAR WG511 (Taiwanese, not Chinese) | ISL3890 | CardBus |
| PLANEX GW-DS54G | ISL3890 | PCI |
| SMC EZ Connect g 2.4GHz SMC2802W | ISL3890 | PCI |
| SMC EZ Connect g 2.4GHz SMC2835W-v2 | ISL3890 | CardBus |
| SMC 2802Wv2 | ISL3890 | PCI |
| Soyo Aerielink | ISL3890 | CardBus |
| ZyXEL ZyAIR G-100 | ISL3890 | CardBus |

## EXAMPLES

The following example scans for available networks:

```
# ifconfig pgt0 scan
```

The following [hostname.if(5)](/hostname.if/5.md) example configures pgt0 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)](/hostname.if/5.md) 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)](/arp/4.md), [cardbus(4)](/cardbus/4.md), [ifmedia(4)](/ifmedia/4.md), [intro(4)](/intro/4.md), [netintro(4)](/netintro/4.md), [pci(4)](/pci/4.md), [hostname.if(5)](/hostname.if/5.md), [hostapd(8)](/hostapd/8.md), [ifconfig(8)](/ifconfig/8.md)

## HISTORY

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

## AUTHORS

The **pgt** driver was originally written for FreeBSD by Brian Fundakowski, and then rewritten for OpenBSD by Marcus Glocker and Claudio Jeker.

## CAVEATS

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).