cHsrpExtIfTrackedPriority 1.3.6.1.4.1.9.9.107.1.1.1.1.2

Priority of the tracked interface for the corresponding { ifIndex, cHsrpGrpNumber } pair. In the range of 0 to 255, 0 is the lowest priority and 255 is the highest. When a tracked interface is unavailable, the cHsrpGrpPriority of the router is decreased by the value of this object instance (If the cHsrpGrpPriority is less than the cHsrpExtIfTrackedPriority, then the HSRP priority becomes 0). This allows a standby router to be configured with a priority such that if the currently active router's priority is lowered because the tracked interface goes down, the standby router can takeover.