1. A method for providing an RDMA access to a physical memory of a physical machine using multiple mapping tables, the physical memory including a plurality of physical memory regions, at least some of the physical memory regions being associated with a virtual memory region of a virtual machine running on the physical machine, the method comprising: mapping memory region identifiers, each of which is adapted to identify a virtual memory region and an associated physical memory region, to virtual memory regions and to the associated physical memory regions based on a mapping table, wherein the mapping table is selected from multiple mapping tables based on a network identifier of the virtual machine, each of the mapping tables being indexed using a plurality of memory region identifiers, each of the plurality of memory region identifiers being associated with one of the virtual memory regions and one of the physical memory regions, receiving an access request from a client for accessing one of the physical memory regions being associated with one of the virtual memory regions of the virtual machine, wherein the access request includes one of the plurality of memory region identifiers identifying the virtual memory region and the associated physical memory region, and providing access for the client to the virtual memory region and the associated physical memory region using the information contained in the selected mapping table and using the received memory region identifier.