179• For more information about NQA Configuration, see NQA in the Network Managementand Monitoring Configuration Guide.• For more information about BFD, see BFD in the High Availability Configuration Guide.• The interface management module is used to monitor the physical status or Layer 3 protocolstatus of an interface. When the physical status or Layer 3 protocol status of an interface isup, the status of a track entry is Positive; when the physical status or Layer 3 protocol statusof an interface is down, the status of a track entry is Negative.Collaboration between the track module and theapplication modulesYou can establish collaboration between the track module and application modules throughconfiguration. If the status of the track entry changes, the track module notifies the applicationmodules to deal with the change.Application modules that can collaborate with the track module include:• VRRP• Static routingIn some cases, when the status of the track entry changes, if the track module notifies theapplication modules immediately, communication may be interrupted because routes cannot berecovered in time. For example, the master in a VRRP group monitors the uplink interface throughthe track module. When the uplink interface fails, the track module notifies the master to reduceits priority so that a backup with a higher priority can preempt as the master to forward packets.When the uplink interface recovers, if the track module notifies the original master to restore itspriority immediately, the master will forward packets immediately; however, the uplink route hasnot been recovered yet, which may result in packet forwarding failure. To prevent this, you canconfigure a specified delay time before the track module notifies the application modules of thetrack entry status change.Configuring collaboration between the trackmodule and the detection modulesTo implement the collaboration function, you need to establish collaboration between the trackmodule and the detection modules, and between the track module and the application modules.Configuring track-NQA collaborationThrough the following configuration, you can establish collaboration between the track moduleand NQA, which probes the link status and informs the track module of the probe result.To configure track-NQA collaboration:To do… Use the command… Remarks1. Enter system view system-view —
