This is the index, from 1 to 4, identifying which slot in the unit's small 4-entry management-access allow-list a given IP/mask pair occupies. Since the table only holds 4 entries total, an admin managing more than 4 authorized management stations has to consolidate them into broader subnet entries rather than listing individual hosts. For example, index 1 might hold the primary NOC's subnet while index 2 holds a backup monitoring station's address, leaving only two more slots available for future additions.