Techniques are disclosed for disseminating network service-specific mapping information across administrative domains. In one example, a network device receives an indication of a route target and one or more underlay tunnels configured to support a service route. The service route is configured to transport network traffic associated with a first network service of a plurality of network services. The network device defines, based on the indication, a first transport class of a plurality of transport classes. The network device receives a service route for the first network service and stores a correspondence between the service route and the first transport class. The network device receives network traffic associated with the first network service and forwards, based on the correspondence, the network traffic along the underlay tunnels specified by the first transport class.