Equal-Cost Multipath Traffic (ECMP)

Equal-Cost Multipath, or ECMP, is a routing method that distributes network traffic across multiple available paths with identical routing costs. Instead of forwarding all traffic through a single route, routers or Layer 3 switches can use several equivalent connections simultaneously. Traffic is typically distributed based on specific flow characteristics, such as source and destination IP addresses and port information. ECMP enables more efficient utilisation of available network resources and can support the scalability and resilience of an IT infrastructure. If one available path fails, traffic can be forwarded through the remaining routes. The technology is commonly used in data centres, spine-leaf architectures, enterprise networks and large IP networks.