This paper studies heterogeneous networks of nonlinear systems in the presence of bounded perturbations. We proposed a framework based on semi-passivity of the nodes, interconnected according to a static consensus protocol, to guarantee global uniform ultimate boundedness as well as global uniform ultimate boundedness. These conclusions allow us to ensure global practical synchronization when the coupling gain is allowed to be large. Our may contribution shows that network-wide input perturbations, that can affect the entire network, can be handled provided that a single, well-located, node possesses the right robustness properties. The obtained results are illustrated in simulation on a network of mobile robots.