Hard zoning is zoning which is implemented in hardware switches.
In a storage area network (SAN), zoning is the allocation of resources for device load balancing and for selectively allowing access to data only to certain users. Essentially, zoning allows an administrator to control who can see what in a SAN. With hard zoning, switch port numbers are used to set up the zones and each device in the SAN is assigned a permanent zone.
In comparison, soft zoning uses World Wide Names (WWNs) to set up the zone, and device assignments can be changed to respond to the varying demands of servers in a network. Because administrators need to specify both the switch domain ID and the port number of the switch, hard zoning is more secure than soft zoning.