---
name: "mlx5ib"
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/mlx5ib"
---

# mlx5ib(4)

Mellanox ConnectX-4 and ConnectX-4 LX based 100Gb, 50Gb, 40Gb, 25Gb and 10Gb network adapter driver

## NAME

**mlx5ib** – Mellanox ConnectX-4 and ConnectX-4 LX based 100Gb, 50Gb, 40Gb, 25Gb and 10Gb network adapter driver

## SYNOPSIS

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

**options COMPAT\_LINUXKPI** **device mlx5** **device mlx5ib**

To load the driver as a module at run-time, run this command as root:

```
kldload mlx5ib
```

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

```
mlx5ib_load="YES"
```

## DESCRIPTION

The **mlx5ib** driver provides support for infiniband and Remote DMA over Converged Ethernet, RoCE, for PCI Express network adapters based on ConnectX-4 and ConnectX-4 LX.\
 For further hardware information and questions related to hardware requirements, see *http://www.mellanox.com/*.

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

## HARDWARE

The **mlx5ib** driver supports 100Gb, 50Gb, 40Gb, 25Gb and 10Gb network adapters. ConnectX-4 supports: 10/20/25/40/50/56/100Gb/s speeds. ConnectX-4 LX supports: 10/25/40/50Gb/s speeds (and reduced power consumption):

- Mellanox MCX455A-ECAT

- Mellanox MCX456A-ECAT

- Mellanox MCX415A-CCAT

- Mellanox MCX416A-CCAT

- Mellanox MCX455A-FCAT

- Mellanox MCX456A-FCAT

- Mellanox MCX415A-BCAT

- Mellanox MCX416A-BCAT

- Mellanox MCX4131A-GCAT

- Mellanox MCX4131A-BCAT

- Mellanox MCX4121A-ACAT

- Mellanox MCX4111A-ACAT

- Mellanox MCX4121A-XCAT

- Mellanox MCX4111A-XCAT

## SUPPORT

For general information and support, go to the Mellanox support website at: *http://www.mellanox.com/*.

If an issue is identified with this driver with a supported adapter, email all the specific information related to the issue to ⟨*freebsd-drivers@mellanox.com*⟩.

## SEE ALSO

[mlx5en(4)](/mlx5en/4.md), [ifconfig(8)](/ifconfig/8.md)

## HISTORY

The **mlx5ib** device driver first appeared in FreeBSD 12.0.

## AUTHORS

The **mlx5ib** driver was written by Mellanox Technologies \<freebsd-drivers@mellanox.com\>.