Support of disparate addressing plans and dynamic ha address allocation in mobile ip

Methods and apparatus for enhancing Mobile IP signaling and to support use of disparate addressing plans and dynamic Home Agent allocation in Mobile IP Regional Tunneling are described. The enhanced methods of signaling use an intermediate node (104), e.g., a Gateway Foreign Agent, straddling different addressing domains, when the signaling controls a process between the intermediate node (104) and an upstream node (106). The specific intermediate node, its interfaces and upstream addresses can be dynamically selected. The Enhanced MIP signaling includes dynamic allocation of: a regional node at a Foreign Agent, the upstream address of a regional node by the regional node, a Home Agent for a regional node prior to dynamic allocation of the regional node. A method is supported to indicate to a Mobile Node that a dynamically allocated regional node has become invalid triggering enhanced MIP signaling dynamically allocating a new regional node and upstream interface address.