Systems and methods for providing default multicast local identifier values per subnet partition as additional subnet management agent attributes in a high performance computing environment. In accordance with an embodiment, a single multicast local identifier can be associated with multiple multicast group identifiers when the multiple multicast group identifiers are associated with a same subnet partition. That is, a default MLID for each subnet partition (i.e. either all subnet partitions or those subnet partitions that are defined to have multicast communication) can be provided. A subnet node can have a default multicast local identifier table for storing default multicast local identifiers. A relationship between the partition key table of the node and the default multicast local identifier table of the nod can map default assigned multicast local identifiers to relevant partitions.