What is LACP Networking? Everything You Need to Know

Introduction

In this article, we’re going to take a detailed look at LACP networking - what exactly it is, how it works, some use cases, and a general guide to configuration and setup.

What is LACP? 

LACP (Link Aggregation Control Protocol) is an IEEE 802.3ad standard for negotiating and maintaining LAGs (Link Aggregation Groups). A LAG consists of aggregating multiple network links into a single, logical channel. LACP is how these links are then automatically managed. A LAG can be static and configured without LACP, however this then means that manual configuration is required on all devices.

How does LACP Work?

LACP works by allowing devices to send Link Aggregation Control Protocol Data Units (LACPDUs) to each other, which creates a link aggregation connection. LACP is an active monitoring protocol, and once this connection has been established, LACP constantly monitors the links to reconfigure the single logical channel.

It does this by re-routing traffic, and adding or removing ports as required, which in turn helps to increase bandwidth and reliability.

One of the main reasons LACP is used is to ensure there is minimal disruption when any individual links fail.

The process of link aggregation occurs through two different modes, active or passive:

Active

Packets are actively sent to create an LACP connection

Passive

In passive mode, a response can be given to an LACP but it cannot self-initiate.

The Core Components of LACP

Devices will send out LACPDUs when the negotiation process starts, and these contain information about the specific link such as the:

System priority

Each device is assigned a system priority, set automatically or manually via the command line interface (CLI). The system priority is then combined with its MAC address which creates a system ID. The switch with the lowest system priority controls the aggregation and is deemed as the active device.

Port priority

Every switch port needs to also have a port priority, which, similar to the system priority, can be configured automatically or manually through the CLI. The port priority and port number create a port identifier. With this, the switch is able to select which ports are to remain active if there are a surplus number of ports than required.

Benefits of LACP in Networking

There are a number of benefits of LACP in networking, such as:

Increased bandwidth

This is arguably one of the key benefits of LACP, as several network links can be combined to form just one single link. This increases the bandwidth available to the network, and is especially beneficial where large amounts of data needs to be transmitted quickly.

Link redundancy and failover protection

If a particular link in the aggregation goes down, there is no interruption in the transmission of data, as the other links are available.  

Load balancing

As network traffic is distributed automatically across the links, performance is enhanced as no one link in particular is overloaded.

Simpler management of aggregated links

Network management is much easier when using LACP, as links are consolidated, which makes it more simple and efficient to run the network.

Easy to scale

Minimal reconfiguration is required when adding links to the existing aggregation, so the network can be expanded quickly and easily.

Increased reliability

The automatic nature of LACP means that any network changes are taken care of, be it links being added or removed, so the network can run efficiently without any outages or errors.

LACP vs Static Link Aggregation

Links can either be aggregated automatically via LACP, or manually via static link aggregation. The outcome is the same - a single logical link, however they differ in configuration and how they operate.

Common Use Cases for LACP

Enterprise networks

Enterprise networks are a prime example of where LACP is used. With large, complex networks and the need for reliability, LACP is the ideal choice.

Security and surveillance systems

Security and surveillance systems have high bandwidth requirements, especially when it comes to the data requirements associated with video surveillance and live monitoring.

Transportation

Transportation and logistics are another example where reliability and real time communication is a necessity. Whether it is tracking vehicles, or managing day to day operations, the complexity of the industry means that LACP is the right choice.

Practical Implementation of LACP in 2025

Step 1: Physically connect the devices:

Firstly, you will need to connect the ports between the devices you would like to aggregate

Step 2. Configure the devices

To configure the devices, you must log in to the command line interface (CLI) of the initial device and enter global configuration mode

Step 3. Create an aggregation group

Create a single logical interface for the LACP channel.

Step 4. Configure each physical port

Enter configuration mode and configure each individual port you would like to use.

Step 5. Assign ports

Assign the physical port to the newly created channel group.

Step 6. Set LACP Mode:

On one device, set the channel to “active” mode - this will commence LACP negotiation

On the other device, set the channel to “passive” mode - this will then respond to the LACP negotiation

Step 7. Verify the configuration

Check the configuration and confirm the aggregation is live

Step 8. Save the configuration:

Save the configuration to the startup-config so it persists after a reboot

How Comnet Supports LACP

Our switches support LACP and IEEE 802.3ad, and are therefore compatible with other devices that are LACP enabled. We also pride ourselves on manufacturing switches that are of the highest standard, and able to withstand harsh conditions and extreme temperatures.

Our switches consist of a strong aluminum housing design which can be DIN-rail or wall mounted, and we provide a lifetime warranty on our products.                                      

Conclusion

LACP networking is a highly innovative solution that can truly streamline multiple network links into a single, logical channel. Not only does this simplify networks, there are a number of benefits from increased bandwidth, better reliability, and a network that can be scaled easily and without hassle.

Whilst static link aggregation can also be carried out to create a single network link, the lack of automation not only in configuring, but also maintaining the network means it may not be suitable for many organisations.

LACP networking is an excellent option for enterprise networks, or any network that requires a high degree of reliability and scalability, along with the benefit of increased bandwidth.

For more information on our LACP compatible products please contact us and our sales team can discuss options with you.