In this paper, we present the Multihomed Mobile Network Architecture (MMNA), a comprehensive multihomed mobility solution for complex nested mobility scenarios. It provides a multihoming management mechanism for gateway discovery and selection, on top of an efficient multihomed mobility model integrating different mobility and multihoming protocols. We describe how the MMNA was experimentally implemented and evaluated in a testbed setup. We first validated the capabilities of the solution in terms of different multihoming features, namely load sharing, link failure recovery, and preference setting. We then examined the effectiveness and feasibility of the MMNA solution considering a use case example of a search and rescue scenario. The results highlight the practicality and advantages of deploying the MMNA solution into realistic scenarios.