One embodiment of a method for migrating a multi-region network including multiple autonomous systems into a single autonomous system comprises allocating a unique identifier to each autonomous system of a plurality of autonomous systems, wherein each autonomous system includes a corresponding regional route reflector; tagging the routing instruction advertised to a global route reflector by a regional route reflector included in one of the plurality of autonomous systems with the unique identifier of the autonomous system corresponding to the regional route reflector that advertised the routing instruction; instructing the regional route reflectors included in the plurality of autonomous systems to ignore routing instructions received from the global route reflector that are tagged with one of the unique identifiers allocated to the plurality of autonomous systems; and migrating one autonomous system of the plurality of autonomous systems by: removing the unique identifier from routing instructions advertised to the global route reflector from the regional route reflector; and instructing the regional route reflector to apply routing instructions received from the global route reflector that are tagged with the unique identifier.