---
name: "aggr"
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/aggr"
---

# aggr(4)

IEEE 802.1AX Link Aggregation (LACP) network interface

## NAME

**aggr** – IEEE 802.1AX Link Aggregation (LACP) network interface

## SYNOPSIS

**pseudo-device aggr**

## DESCRIPTION

The **aggr** driver implements IEEE 802.1AX (formerly 802.3ad) Link Aggregation for combining one or more Ethernet interfaces into a single logical interface. The Link Aggregation Control Protocol (*LACP*) is used to negotiate the aggregation of member interfaces with a partner device.

**aggr** interfaces must be configured to use one or more Ethernet interfaces as ports, and communicate with a partner device over those ports using *LACP*. Member interfaces that negotiate with a partner device are aggregated into a single logical link. Packets transmitted through an **aggr** interface select an aggregated interface for transmission. Packets received by an aggregated device appear to be received by the **aggr** interface it is a member of.

**aggr** interfaces can be created at runtime using the **ifconfig** **aggr***N* **create** command or by setting up a [hostname.if(5)](/hostname.if/5.md) configuration file for [netstart(8)](/netstart/8.md). The interface itself can be configured with [ifconfig(8)](/ifconfig/8.md); see its manual page for more information.

A random MAC address is generated when an **aggr** interface is created. A specific MAC address can be assigned using the [ifconfig(8)](/ifconfig/8.md) command **lladdr** *etheraddr*.

Other forms of aggregation of Ethernet interfaces are available using the [trunk(4)](/trunk/4.md) driver.

## EXAMPLES

Create an **aggr** virtual interface on top of two physical interfaces:

```
# ifconfig aggr0 create
# ifconfig aggr0 trunkport em0
# ifconfig aggr0 trunkport em1
# ifconfig aggr0 10.1.1.100/24
# ifconfig aggr0 up
```

## SEE ALSO

[inet(4)](/inet/4.md), [ip(4)](/ip/4.md), [netintro(4)](/netintro/4.md), [trunk(4)](/trunk/4.md), [hostname.if(5)](/hostname.if/5.md), [ifconfig(8)](/ifconfig/8.md), [netstart(8)](/netstart/8.md)

## STANDARDS

*IEEE 802.1AX Link Aggregation*.

## HISTORY

The **aggr** driver first appeared in OpenBSD 6.6.