A method in a first mobile router configured for establishing communications within a mobile network having a top level mobile router as the root of a tree topology and at least two mobile routers (30, 30a, 30b) attached to the top level mobile router, the method comprising: detecting a router advertisement message (34a, 34b) that includes a source address identifying a corresponding second mobile router having sent the router advertisement message, and a tree information option field having attributes (68a-68f) specifying a network topology model of the corresponding second mobile router, wherein the tree information option field includes a tree group identifier for a corresponding tree group within the tree topology; determining a priority of the network topology model relative to identified priorities stored in the first mobile router; and selectively attaching to the second mobile router having sent the router advertisement message based on the determined priority of the corresponding network topology model relative to the identified priorities stored in the first mobile router, the selectively attaching step including selecting the second mobile router having sent the router advertisement based on: identifying a tree group, based on its corresponding tree group identifier, having a highest aggregated priority, wherein the aggregated priority is based on a network interface type preference and a tree group preference; and identifying a router within the tree group having a highest corresponding preference value and the highest aggregated priority. detecting a router advertisement message (34a, 34b) that includes a source address identifying a corresponding second mobile router having sent the router advertisement message, and a tree information option field having attributes (68a-68f) specifying a network topology model of the corresponding second mobile router, wherein the tree information option field includes a tree group identifier for a corresponding tree group within the tree topology; determining a priority of the network topology model relative to identified priorities stored in the first mobile router; and selectively attaching to the second mobile router having sent the router advertisement message based on the determined priority of the corresponding network topology model relative to the identified priorities stored in the first mobile router, the selectively attaching step including selecting the second mobile router having sent the router advertisement based on: identifying a tree group, based on its corresponding tree group identifier, having a highest aggregated priority, wherein the aggregated priority is based on a network interface type preference and a tree group preference; and identifying a router within the tree group having a highest corresponding preference value and the highest aggregated priority. identifying a tree group, based on its corresponding tree group identifier, having a highest aggregated priority, wherein the aggregated priority is based on a network interface type preference and a tree group preference; and identifying a router within the tree group having a highest corresponding preference value and the highest aggregated priority.