Application mobility is a unique feature of the edge computing to support relocation of application instance across edge computing hosts or between edge computing host and cloud computing over underlying mobile network. With the active-standby mode application instance implementation with support of L2 networks, the application mobility could achieve the service continuity with low latency switching time. An application mobility mechanism can be implemented in the data plane of edge computing host under the control of edge computing platform and management. It can be also implemented in L2 switching function of the User Plane Function in 5G networks.