the present invention is in the field of virtualization of network interface cards and controllers that connect to for example a host computer that can have multiple functions and os &# 39 ; s running on it simultaneously and , in particular , relates to the virtualization of the operation of a single nic such that it can be used simultaneously by multiple guests in such a manner that memory references due to the network traffic originating from and destined to a particular guest is kept separate from other network traffic , and that allows the media access controller within the nic to operate such that it only accepts network packets that are destined to one of the guest - functions or guest - os &# 39 ; s , and the mac is not required to operate in promiscuous mode where it accept all incoming packets in order to implement the virtualization features .