This object reports the status of a physical port with respect to PEX binding: unknown(1, the default, not bound to any PEX port), down(2, link down), blocked(3, bound but blocked from forwarding), or forwarding(4, actively forwarding traffic). Admins check this to confirm a physical port that's been bound to a PEX port is actually up and passing traffic. A value of blocked(3) would prompt an admin to investigate why a bound physical port isn't being allowed to forward, for example due to a spanning-tree or loop-prevention state.