With the BloxOne DDI application, you can configure DHCP properties at the global level. You can also configure properties to the DHCP configuration profile. Properties can also be assigned to IP space, DHCP host, address block, subnet, address range, and fixed address levels. The DHCP properties follow a top-down inheritance hierarchy in which child objects automatically inherit DHCP properties from their parent objects. Thus, global DHCP properties remain at the top of the hierarchy and are inheritable to all child objects unless you override them at the object level.
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Inheritance Hierarchy
The DHCP inheritance chain is based on a parent-child relationship where all objects above an object are considered parent objects to that object. All objects below the object are considered child objects to the object. A child object inherits the properties of its parent objects. When an object’s inheritance is overridden, the default, global  hierarchical chain is broken, and properties may be assigned directly to the object at the object level.
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(2) Outside the context of a given DHCP Host. In this case, the inheritance chain is: Global DHCP Configuration > IP Space > Address Block > Subnet. In this scenario, since a DHCP Host has not been configured, all child objects, in this example, the Subnet inherits from the DHCP Conf ProfileAddress Block or IP Space.