We investigate the problem of management and control in a large and, for simplicity, homogeneous packet-switched network. Specifically we focus on routing, an important function of network management. The network consists of several individually controlled domains. Domains are interconnected via gateway links. Each domain is controlled by its own Network Control Center, while the overall network performance is managed by an Integrated Network Control Center. Each Center has only a portion of the information required for global routing. We investigate the impact of the reduced information available at each center on network performance (average delay in our case). We present a general approach to designing a hierarchical algorithm for routing in multidomain networks. We propose a heuristic procedure suitable for packet-switched networks. Several numerical examples will illustrate the impact of incomplete information on the network. Performance is compared with a lower bound obtained, which is not differentiating destinations in other domains. Therefore, for this bound, each domain is perceived as a single node in a simplified model of the network.