This entry's status, by which new entries may be added to
the table and old entries deleted.
cMsdpMeshGroupName and cMsdpMeshGroupPeerAddress must be set
to valid values before the row can be activated. Since
these are the table's INDEX, a row can be activated by
simply setting the cMsdpMeshGroupStatus variable.
It is not possible to modify other columns in the same
conceptual row when the status value is active(1), because
there only other objects in the row are part of the INDEX.
Changing one of these changes the row, so an old row must be
deleted and a new one created.