Huawei Technologies Co.,Ltd Huawei Technologies Co.,Ltd CNNIC China Mobile A Host Identity Protocol (HIP) proxy is a host that holds the keying material, and participates in HIP-based communications, on behalf of one or more hosts. HIP proxies play an important role in the transition from the current Internet architecture to the HIP architecture. A core objective of a HIP proxy is to facilitate the communication between legacy (or Non- HIP) hosts and HIP hosts while not modifying the host protocol stacks. In this document, the legacy hosts served by proxies are referred to as Legacy Hosts (LHs). Currently, various design solutions of HIP proxies have been proposed. These solutions may be applicable in different working circumstances. In this document, these solutions are investigated in detail to compare their effectiveness in different scenarios.