---
name: "ae"
section: "4"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/ae/4"
---

# ae(4)

Attansic/Atheros L2 FastEthernet controller driver

## NAME

**ae** – Attansic/Atheros L2 FastEthernet controller driver

## SYNOPSIS

To compile this driver into the kernel, place the following lines in your kernel configuration file:

**device miibus** **device ae**

Alternatively, to load the driver as a module at boot time, place the following line in [loader.conf(5)](/loader.conf/5.md):

```
if_ae_load="YES"
```

## DESCRIPTION

The **ae** device driver provides support for Attansic/Atheros L2 PCIe FastEthernet controllers.

The controller supports hardware Ethernet checksum processing, hardware VLAN tag stripping/insertion and an interrupt moderation mechanism. Attansic L2 also features a 64-bit multicast hash filter.

The **ae** driver supports the following media types:

- **autoselect**

  Enable autoselection of the media type and options. The user can manually override the autoselected mode by adding media options to [rc.conf(5)](/rc.conf/5.md).

- **10baseT/UTP**

  Select 10Mbps operation.

- **100baseTX**

  Set 100Mbps (FastEthernet) operation.

The **ae** driver provides support for the following media options:

- **full-duplex**

  Force full duplex operation.

- **half-duplex**

  Force half duplex operation.

For more information on configuring this device, see [ifconfig(8)](/ifconfig/8.md).

## HARDWARE

The **ae** driver supports Attansic/Atheros L2 PCIe FastEthernet controllers, and is known to support the following hardware:

- ASUS EeePC 701

- ASUS EeePC 900

Other hardware may or may not work with this driver.

## LOADER TUNABLES

Tunables can be set at the [loader(8)](/loader/8.md) prompt before booting the kernel or stored in [loader.conf(5)](/loader.conf/5.md).

- *hw.ae.msi\_disable*

  This tunable disables MSI support on the Ethernet hardware. The default value is 0.

## SYSCTL VARIABLES

The **ae** driver collects a number of useful MAC counter during the work. The statistics is available via the *dev.ae.%d.stats* [sysctl(8)](/sysctl/8.md) tree, where %d corresponds to the controller number.

## DIAGNOSTICS

- ae%d: watchdog timeout.

  The device has stopped responding to the network, or there is a problem with the network connection (cable).

- ae%d: reset timeout.

  The card reset operation has been timed out.

- ae%d: Generating random ethernet address.

  No valid Ethernet address was found in the controller NVRAM and registers. Random locally administered address with ASUS OUI identifier will be used instead.

## SEE ALSO

[altq(4)](/altq/4.md), [arp(4)](/arp/4.md), [miibus(4)](/miibus/4.md), [netintro(4)](/netintro/4.md), [ng\_ether(4)](/ng_ether/4.md), [vlan(4)](/vlan/4.md), [ifconfig(8)](/ifconfig/8.md)

## HISTORY

The **ae** driver and this manual page was written by Stanislav Sedov ⟨*stas@FreeBSD.org*⟩. It first appeared in FreeBSD 7.1.

## BUGS

The Attansic L2 FastEthernet controller supports DMA but does not use a descriptor based transfer mechanism via scatter-gather DMA. Thus the data should be copied to/from the controller memory on each transmit/receive. Furthermore, a lot of data alignment restrictions apply. This may introduce a high CPU load on systems with heavy network activity. Luckily enough this should not be a problem on modern hardware as L2 does not support speeds faster than 100Mbps.