1. A method of path determination in an optical network, the method comprising: detecting a fault on a link between two nodes of the optical network, the two nodes being on an original path between a source node and a destination node of the optical network, the original path having a set of operational links and the faulty link; for each node on the original path, assigning, after the fault is detected, one of a first value and a second value as an adjoint weight to each operational link connected to the node; determining a connection cost associated with each node on the original path, a connection cost associated with a node being based on the adjoint weights of the links connected to the node; and determining the new path between the source node and the destination node based at least in part on the adjoint weights and the connection costs.