Hi, may be anyone know this ? How mpi process addressing the message to destination (rank 0 send rank 1)? Through LID, GID, QP ID or anything else? Can I strictly define to mpi process outgoing LIDs ? For example, with LMC = 3, a sender of rank 0, lid 1 destination of rank 1 multilid 4 destination of rank 2 multilid 8