Patent attributes
Mechanisms are described by which link state “path” information can be collected from networks and shared with external components, such as routers or centralized controllers or path computation elements, using an exterior gateway protocol, such as the Border Gateway Protocol. That is, the link state information for multiple interior gateway protocol (IGP) routing domains is shared between external components using the exterior gateway protocol, such as BGP. As such, the techniques described herein allow link state information to be shared across different routing domains, such as routing and reachability information shared between different autonomous systems. The extensions described herein allow an exterior gateway protocol to be used to signal explicit path segments within IPG routing domains so as to set up an overall path that spans the multiple IPG routing domains.
