Which statement best describes equal-cost load balancing?

• A. There are multiple equal-cost paths to the same destination, and traffic is distributed among them.
• B. There is a single best path used exclusively
• C. All paths to the destination are equally used regardless of metric
• D. It only applies to static routes

Answer: (A)

Equal-cost load balancing means there are multiple routes to the same destination that have the same metric, and the router distributes traffic across those paths rather than using just one. When a router learns several equal-cost options, it can install more than one next-hop and split the traffic among them, usually using a hashing method on packet headers to decide which path a given packet takes. This approach makes better use of available links, improves redundancy, and helps absorb failures without dropping traffic, because other equal-cost paths can carry the load.

This isn’t about dictating that all paths are used exactly the same amount or about paths with different metrics. If the metrics aren’t equal, those paths aren’t part of equal-cost load balancing. And ECMP isn’t limited to static routes; dynamic routing protocols can also advertise multiple equal-cost routes for load balancing.