1. A method implemented in at least one fat tree network node for improved load distribution, wherein the node is one of a plurality of fat tree network nodes in a fat tree network each of which implement a tie-breaking process to produce minimum cost trees, the method comprising the steps of: performing a spanning tree computation for each root node of the fat tree network in order from a lowest ranked root node to a highest ranked node by, determining if there are at least one failure affecting one root node of the fat tree network, if there are no failures, calculating spanning trees for all of the roots to generate the trees, if there is only one failure, calculating spanning trees for all of the roots excluding the affected root from lowest ranked to highest ranked to generate the trees for the unaffected roots, and for the affected root, performing a some pairs calculation, and if there is more than one failure, calculating spanning trees for all of the roots excluding the affected roots from lowest ranked to highest ranked to generate the trees for the unaffected roots, and for the affected roots, performing an all pairs calculation for all but the highest ranked affected root in order from lowest to highest ranked, and performing a some pairs calculation for the highest ranked affected root; generating a filtering database for each root node of the fat tree network, wherein the filtering database includes a set of media access control (MAC) addresses of the leaf nodes of the fat tree network; and adding link utilization for each computed tree to use as a prefix to link identifiers used for at least one tie-breaking algorithm.