Object tracking is an independent process that manages creation, monitoring, and removal of tracked objects such as the state
of the line protocol of an interface. Client processes such as the Hot Standby Router Protocol (HSRP), Gateway Load Balancing
Protocol (GLBP), and VRRP register their interest with specific tracked objects and act when the state of an object changes.
Each tracked object is identified by a unique number that is specified on the tracking CLI. Client processes such as VRRP
use this number to track a specific object.
The tracking process periodically polls the tracked objects and notes change of value, if any. The changes in the tracked
object are communicated to interested client processes, either immediately or after a specified delay. The object values are
reported as either up or down.
VRRP object tracking gives VRRP access to all the objects available through the tracking process. The tracking process allows
you to track individual objects such as the state of an interface line protocol, state of an IP route, or the reachability
of a route.
VRRP provides an interface to the tracking process. Each VRRP group can track multiple objects that might affect the priority
of the VRRP device. You specify the object number to be tracked and VRRP is notified of changes to the object, if any. VRRP
increments (or decrements) the priority of a virtual device based on the state of the object being tracked.