The src-dst-port load balancing method ensures that frames in the same flow (identified by the source and destination ports) follow the same links in a port channel. This method is effective in environments with Cisco MDS 9000 Series Switches because it maintains the order of frame delivery within a flow, which is crucial for storage traffic. Subsequent flows can use different links, allowing for efficient utilization of the port channel bandwidth. References: Implementing and Operating Cisco Data Center Core Technologies (DCCOR) course materials.