Abstract: A network includes a first plurality of routers that do not implement a desired protocol in communication with a second plurality of routers that implement at least the desired protocol and a tunneling protocol. Routers implementing the tunneling protocol are preferably implemented at the boundaries of domains, i.e., in those routers that serve as interfaces between domains. Each router automatically determines whether it is proper to forward a received message in either a format native to the desired protocol or encapsulated using a legacy protocol. The tunneling protocol can be disabled in a given router as deployment of the desired protocol increases. Conversely, if deployment of the desired protocol decreases, the tunneling protocol may be resumed in a given router. Using this progressive deployment feature, the tunneling protocol in accordance with the instant disclosure maximizes use of the desired protocol while minimizing, in an automatic fashion, use of tunnels.