Port Threshold Action is action to take when the number of operational (link up) physical ports is less than tLagPortThreshold. When a physical port ifOperStatus changes and the number of operational physical ports is less than or equal to tLagPortThreshold: - when set to down(1), the ifOperStatus for the Link Aggregation Group (tLagIfIndex) goes to down(2). - when set to dynamicCost(2), the ifOperStatus stays up(2), but dependent protocols such as OSPF are signaled and will adjust their operation (cost) to match the number of physical ports remaining in the Link Aggregation Group. a tLagDynamicCostOn notification is generated. - when set to 'staticCost', the ifOperStatus stays up, but dependent protocols such as ISIS are signaled and will adjust their operation (cost) according to the value of the object tLagPortThresholdStaticCost. When a physical port ifOperStatus changes and the number of operational physical ports is greater than tLagPortThreshold: - when set to down(1), the ifOperStatus for the Link Aggregation Group (tLagIfIndex) goes to up(1). - when set to dynamicCost(2), the ifOperStatus stays up(2), but dependent protocols such as OSPF are signaled and will adjust their operation (cost) to be the value as configured. a tLagDynamicCostOff notification is generated. Regardless of the setting of this object, when the number of operational physical ports goes to zero, the Link Aggregation Group's ifOperStatus goes to down.