Systems and methodologies are described that facilitate enabling multiple address access between two or more networks. A home agent can update a binding cache with a particular proxy binding update (PBU) to include two or more network gateway IP addresses associated with a user equipment (UE) within two or more networks or systems. When the UE in idle mode moves between networks or systems to which registration has occurred, an attachment procedure is not performed since the home agent includes the network gateway IP addresses related to such UE. Thus, inter-system idle mode mobility is enabled without having to perform a full attachment, re-registration, or de-registration based on the network location of the UE.