Methods and Gateways (GWs) are provided for efficiently sending a router advertisement message to a User Equipment (UE). The GW comprises an interface, a processor, and an instructions repository that stores instructions that when executed by the processor cause the later to determine the UE is in idle mode, and responsive thereto, to delay a transmission of the router advertisement message to the UE until the UE transitions from the idle mode to an active mode. This is achieved by delaying a paging of the UE. In another embodiment, a method and GW is provided. The GW's processor detects a router advertisement message needs to be sent to the UE, determines the UE is in idle mode and delays a paging of the UE until detecting the UE transitions from the idle mode into an active mode, when the router advertisement message is sent to the UE.