Abstract: A method is given for deriving a backup path routing spare capacity template that is feasible, scalable, adaptive, much faster, and near global optimal in redundancy reduction. The method includes determining working paths, aggregating the working paths into a first matrix, determining backup paths, aggregating the backup paths into a second matrix, and deriving the template from the first and second matrices. A method is also given for successively approximating the optimal spare capacity allocation needed for a network. The method includes, determining the link cost associated with a selected traffic flow's backup path, determining an updated link cost that is less than the current link cost, determining a backup path with the updated link cost, and notifying the rest of the network of the backup path.