In this paper, we present an optimization-based approach to control the outbound interdomain traffic for stub ASes. Our approach allows the network operator to define multiple traffic objectives. We ...present a genetic algorithm to specify a provider for destination prefix sets with the objective of minimizing configure changes , minimum cost and load balancing. In solving the assignment problem with constrains in combinatorial optimization, we consider AS relationships between remote ASes to avoid the conflict of routing polices. An example demonstrates the availability and effectiveness of the algorithm.