What Is an Onboard LAN?

By Heather Lindsay

A LAN (local area network) interconnects several computers using Ethernet technology. As technology advances, networking capabilities have begun shipping as a standard feature on most motherboards. Onboard LAN is a specialized chipset on the motherboard designed to handle networking responsibilities for the computer, such as home networking and Internet connectivity.

Local Area Networking

Local area networks connect several computers within a limited physical proximity via Ethernet cables or wireless Ethernet, such as in homes, schools or businesses. In early computers, this capability was not a standard feature and required the installation of a network interface card (NIC). NIC installation was necessary until LANs became more common, requiring more efficient and less expensive networking capabilities. Onboard LAN controllers support numerous built-in hardware and software enhancements for networking, such as power management and input/output (I/O) scalability.

Onboard LAN

As transistor technology advanced, it became easier to integrate certain functions into motherboards, such as onboard LAN and sound. Physically, onboard LAN is enabled through a small chip embedded on the computer's motherboard. This configuration allows for an Ethernet port to be available on the rear side of the motherboard without using an expansion slot. Onboard LANs also allow software to be run on the computer itself that handles more advanced networking tasks and could be enhanced via software as needed.

Onboard LAN Performance

Onboard local area networking capabilities do not completely replace the need for add-in networking cards. These onboard counterparts are adequate for home networking tasks and Internet connectivity, but use CPU resources. The onboard motherboard firmware also provides auto-detection capabilities and auto-configuration to ease the creation of a home network. These networking implementations, however, do not possess advanced features such as quality of service and switching capabilities. Therefore, mission-critical applications such as enterprise networking still require dedicated networking hardware.

Onboard LAN Teaming

Due to their simple implementation and relatively cheap cost of embedding, newer computers are often supplied with multiple onboard LAN chipsets. This in turn allows for multiple Ethernet ports on a single motherboard. These motherboards often provide a feature known as teaming. Teaming allows for both Ethernet ports to act as one single port. This has the effect of nearly doubling the available bandwidth to the computer motherboard itself. This solution is often employed on enthusiast-class motherboards to increase the network transfer capabilities without increasing the overall cost of infrastructure.