1. A method comprising: sending a problem solving request to a plurality of network domains that have a potential path between a source node and the destination node, the problem solving request including one or more constraints associated with a routing function for traffic between the source node and the destination node; receiving local path solutions from domains in response to the problem solving request, the local path solutions representing possible paths from a previous neighbor network domain to a next neighbor network domain that satisfy the one or more constraints; and determining whether there is at least one path from the source node to the destination node that satisfies the one or more constraints based on the local path solutions.