Definition
Link Aggregation, often referred to as LAG, is a networking technique that combines multiple physical network connections into a single logical link. This is achieved by using protocols like Link Aggregation Control Protocol (LACP) to negotiate and manage the aggregated links. LAG is crucial on the job as it significantly increases bandwidth and provides redundancy, ensuring network uptime even if one link fails. For instance, a server might have two 1 Gbps Ethernet ports aggregated into a single 2 Gbps logical link. A common confusion is with simple port mirroring, which only duplicates traffic, whereas LAG actively forwards traffic across multiple links. This technology is vital for high-throughput network environments.