LID Address Space
The LID assigned to a port is a 16-bit value assigned by the SM. This means there are 64K LIDs available for assignment to the ports that populate a specific subnet. The 64K overall LID address range is subdivided as follows:
LID address 0000h is reserved and must never be used.
LID addresses 0001h–BFFFh (a 48K minus 1 address range) are set aside for assignment as unicast addresses. A packet with a unicast DLID is always delivered to the single target port that is assigned that address. It is never delivered to more than one port. When a switch receives a packet wherein the DLID field contains a unicast LID address, it consults its unicast Forwarding Table and forwards the packet through the port indicated by the matching entry. ...
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