The administratively assigned value for the contribution
of this port to the path cost of paths toward the spanning
tree root.
Writing a value of '0' assigns the automatically calculated
default Path Cost value to the port. If the default Path
Cost is being used, this object returns '0' when read.
This complements the object dot1dStpPortPathCost or
dot1dStpPortPathCost32, which returns the operational value
of the path cost.
The value of this object MUST be retained across
reinitializations of the management system.