---
name: "if_mgb"
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/if_mgb"
---

# if\_mgb(4)

Microchip LAN743x PCIe Gigabit Ethernet driver

## NAME

**mgb** – Microchip LAN743x PCIe Gigabit Ethernet driver

## SYNOPSIS

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

```
if_mgb_load="YES"
```

## DESCRIPTION

The **mgb** driver is experimental, and has a number of caveats and limitations. It is currently available only as a kernel module.

The **mgb** device driver provides support for PCIe Gigabit Ethernet adapters based on Microchip's LAN7430 and LAN7431.

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

## HARDWARE

The **mgb** driver supports Microchip PCIe Gigabit Ethernet interfaces, including:

- Microchip LAN7430 PCIe Gigabit Ethernet controller with PHY

- Microchip LAN7431 PCIe Gigabit Ethernet controller with RGMII interface

## SEE ALSO

[arp(4)](/arp/4.md), [miibus(4)](/miibus/4.md), [ifconfig(8)](/ifconfig/8.md)

## CAVEATS

The driver does not yet implement support for many hardware features, including:

- Multiple RX queue support

- RX and TX checksum offload

- Hardware VLAN tagging or untagging

- Multicast receive packet filtering

- Wake on LAN (WoL)

- LSO

- RSS

LAN7431 support is completely untested.