The index of this DHCP range. DHCP ranges are stored in a list which is ordered by range name. The index gives the place in the list. Note that if ranges are added or deleted, the index for a given range will change. Since this table is read-only, this will not have an undue effect, but if in future this table is made read-write, a mechanism will have to be created to lock the indices of the range table while SET operations are proceeding.