This value names a promiscuous port within a given Private VLAN (PVLAN) session, per the source noting the maximum number of such ports is 4, as one row of a table indexed by session ID and port name; promiscuous ports in a PVLAN can communicate with all other port types in that session. A network administrator uses this to confirm which uplink or gateway ports are designated to reach every other port in a given PVLAN session, since isolated and community ports generally cannot reach each other directly. For example, this field might list "gi0/1/24" as the promiscuous uplink port for PVLAN session 2.