Object tracking is an
independent process that manages creating, monitoring, and removing tracked
objects such as the state of the line protocol of an interface. Clients 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 any change of value. 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 a the state
of an interface line protocol, state of an IP route, or the reachability of a
VRRP provides an
interface to the tracking process. Each VRRP group can track multiple objects
that may affect the priority of the VRRP device. You specify the object number
to be tracked and VRRP is notified of any change to the object. VRRP increments
(or decrements) the priority of the virtual device based on the state of the
object being tracked.