A method, mobile node (MN), home agent and system for handover of a MN from a first access network supporting network-based mobility to a second access network not supporting network-based mobility in a packet switched communication network including at least the MN, a mobile access gateway (MAG), a correspondent node and a home agent. The method includes performing proxy route optimization towards the correspondent node by the MAG on behalf of the MN. Handover from the first access network to the second access network is performed when the MN moves out of the first access network. A determination is made as to whether the proxy route optimization is to be maintained after the handover, and if so, information regarding the proxy route optimization is sent to the MN by the home agent.