What protocol or technology uses source IP to destination IP as a load-balancing mechanism?

The protocol or technology that uses source IP to destination IP as a load-balancing mechanism is EtherChannel. EtherChannel can use various load-balancing methods, and one common method involves hashing the source and destination IP addresses to determine which physical link within the EtherChannel to use for a particular packet. This way, the traffic between specific source and destination IP pairs can be consistently forwarded over the same physical link, which helps prevent out-of-order packet delivery. EtherChannel is a link aggregation technology that combines several physical links to create a single logical link for increased bandwidth and redundancy.