There is provided a network device disposed at an interface between an access segment and an interconnecting layer of a data center. The network device includes an address cache and an address resolution processor configured to receive an address request addressed to virtual machines in a transmission domain of the network device. The address request requesting a layer 2 address of a target virtual machine in the data center, and specifying a layer 3 address of the target virtual machine. In response to receiving a reply, the network device updates the address cache to include an entry specifying the layer 2 address of an edge device of an access segment which has the target virtual machine having a respective layer 3 address corresponding to the specified layer 3 address.