How is traffic load-balanced from a WLC to a switch using LAG?

When a LAG is created between a switch and a WLC, the method of load balancing used is hash-based, using layer 4 source and destination ports. Round-robin load balancing cannot be configured on the WLC or switch side of a LAG. First in, first out (FIFO) is a buffer mechanism used to send data out as it comes in, and it is not used in load balancing scenarios. Spill and fill is a method of saturating one link before the other link is used; it is not used in load balancing scenarios.