This read-only Integer32 (1..65535) uniquely identifies an Ethernet Management Port within a card, and together with the neIndex, shelfIndex, and slotIndex forms the full unique identification of that port. Admins and management systems use this index to walk and address individual management ports on a card when multiple such ports exist, distinct from the network/access data ports covered elsewhere in this MIB. For example, on a card with two redundant management interfaces, an admin would use cmEthernetMgmtPortIndex values 1 and 2 to separately address and configure each management port's settings.