Link aggregation

Link Aggregation

Diagram of link aggregation

Link aggregation is a method used in computer networking to combine multiple network connections in parallel in order to increase throughput beyond what a single connection could sustain, and to provide redundancy in case one of the links should fail. This technique is also known as port trunking, channel bonding, or NIC teaming.

Link aggregation is commonly used in Ethernet networks, where it is implemented using the IEEE 802.3ad standard, also known as Link Aggregation Control Protocol (LACP). This protocol allows for the dynamic negotiation of link aggregation between network devices, ensuring that the aggregated links are used efficiently and that traffic is distributed evenly across them.

Benefits of Link Aggregation

Link aggregation offers several benefits, including:

• Increased Bandwidth: By combining multiple links, the total available bandwidth is increased, allowing for higher data transfer rates.
• Redundancy and Fault Tolerance: If one link in the aggregation fails, the remaining links can continue to carry traffic, providing a level of fault tolerance.
• Load Balancing: Traffic can be distributed across the aggregated links, preventing any single link from becoming a bottleneck.

Implementation

Link aggregation can be implemented in both hardware and software. In hardware, network switches and routers often support link aggregation natively, allowing for easy configuration and management. In software, operating systems and network drivers can be configured to aggregate links at the network interface card (NIC) level.

Configuration

To configure link aggregation, the following steps are typically involved:

1. Identify the Links: Determine which network interfaces will be aggregated. 2. Configure the Devices: Set up the network devices (such as switches and routers) to support link aggregation, often using LACP. 3. Test the Configuration: Ensure that the aggregated links are functioning correctly and that traffic is being distributed as expected.

Use Cases

Link aggregation is used in various scenarios, including:

• Data Centers: To provide high-speed connections between servers and switches.
• Enterprise Networks: To increase the bandwidth and reliability of connections between network devices.
• Home Networks: For advanced users who require higher bandwidth and redundancy.

Related Pages

• Ethernet
• IEEE 802.3ad
• Network interface card
• Load balancing (computing)