1. An access masking structure, comprising: a mode selection mechanism selectable between a learn mode and an operational mode; a processor operably connected to the mode selection mechanism; computer code located on a non-transitory computer readable medium accessed by the processor responsive to selection of the learn mode by the mode selection mechanism to automatically configure an access restriction set based upon detected activity between enabled storage units and enabled computers on a network, wherein the access restriction set comprises the enabled storage units and enabled computers and does not comprise computers and storage units that are not enabled on the network during the learning mode; and computer code located on a non-transitory computer readable medium accessed by the processor responsive to selection of the operational mode to enforce the access restriction set by blocking access between storage units and computers on the network that are not in the access restriction set.