This read-write value, when non-zero, designates this lport as belonging to a specific private network segment, identified by that numeric value, rather than being part of the general publicly shared switching fabric, which a value of 0 indicates. An admin uses this to logically partition a shared physical switch into isolated private-network groupings, ensuring traffic and routing on one private network does not inadvertently mix with another or with the general public fabric. For example, setting lportPrivateNet to a specific nonzero value shared only by a particular customer's set of ports would isolate that customer's routing domain from other traffic riding the same physical switch.