Mac OS X: LACP required for Link Aggregation
Link aggregation allows you to aggregate or combine multiple physical links that connect your Mac to a link aggregation device (a switch or another Mac) into a single logical link. The result is a fault-tolerant link with a bandwidth equal to the sum of the bandwidths of the physical links.
Mac OS X uses the Link Aggregation Control Protocol (LACP) to negotiate the link aggregation. LACP must be supported on all link aggregation devices involved.