Trunk load balancing using Layer 4 ports allows the use of TCP/UDP source and destination port number for trunk load balancing. This is in addition to the current use of source and destination IP address and MAC addresses. Configuration of Layer 4 load balancing would apply to all trunks on the switch. Only non-fragmented packets will have their TCP/UDP port number used by load balancing. This ensures that all frames associated with a fragmented IP packet are sent through the same trunk on the same physical link.
The priority for using Layer 4 packets when this feature is enabled is as follows: