This help contains the following topics:

·     Introduction

¡     Collaboration mechanism

¡     Collaboration between the Track module and a detection module

¡     Collaboration between the Track module and an application module

·     Configure Track

Introduction

The Track module works between application modules and detection modules. It shields the differences between various detection modules from application modules.

Collaboration mechanism

The Track module collaborates with detection modules and application modules.

As shown in Figure 1, collaboration is enabled when you associate the Track module with a detection module and an application module, and it operates as follows:

1.     The detection module probes specific objects such as interface status, link status, network reachability, and network performance, and informs the Track module of detection results.

2.     The Track module sends the detection results to the application module.

3.     When notified of changes for the tracked object, the application modules can react to avoid communication interruption and network performance degradation.

Figure 1 Collaboration through the Track module

 

Collaboration between the Track module and a detection module

The detection module sends the detection result of the tracked object to the Track module. The Track module changes the status of the track entry as follows:

·     If the tracked object operates correctly, the state of the track entry is Positive. For example, the track entry state is Positive in one of the following conditions:

¡     The target interface is up.

¡     The target network is reachable.

·     If the tracked object does not operate correctly, the state of the track entry is Negative. For example, the track entry state is Negative in one of the following conditions:

¡     The target interface is down.

¡     The target network is unreachable.

If the detection result is invalid, the state of the track entry is NotReady. For example, the track entry state is NotReady if its associated NQA operation does not exist.

Collaboration between the Track module and an application module

The track module reports the track entry status changes to the application module. The application module can then take correct actions to avoid communication interruption and network performance degradation

Configure Track

1.     Select System > High Availability > Track.

2.     Click Add.

3.     Create a track entry.

Table 1 Basic Track configuration items

Item	Description
Track entry	Enter the track entry ID that uniquely identifies a track entry.
Detection module	Select a detection module to be associated with Track.
Positive notification delay	Specifies the delay for notifying the application module that the track entry state has changed to Positive. If the Track module immediately notifies the application module of a track entry state change but the route convergence is not complete, a communication failure might occur. In such cases, you can set a notification delay to avoid immediate notification of track entry state changes. The notification delay settings do not take effect if the track entry is not associated with an application module.
Negative notification delay	Specifies the delay for notifying the application module that the track entry state has changed to Negative. If the Track module immediately notifies the application module of a track entry state change but the route convergence is not complete, a communication failure might occur. In such cases, you can set a notification delay to avoid immediate notification of track entry state changes. The notification delay settings do not take effect if the track entry is not associated with an application module.

 

Table 2 Track-BFD association configuration items

Item	Description
BFD packet output interface	Select an interface to send BFD echo packets. Track can be associated with only echo-mode BFD sessions.
Local IP	Enter the local IP address of the BFD session.
Remote IP	Enter the remote IP address of the BFD session.

 

Table 3 Track-NQA association configuration items

Item	Description
NQA operation administrator	Enter the name of the NQA operation administrator who creates the NQA operation.
Operation tag	Enter the NQA operation tag.
Sequence number	Enter the ID of the reaction entry to be associated with the track entry.

 

Table 4 Track-interface association configuration items

Item	Description
Monitored interface	Select an interface to be associated with Track.
Monitored interface attribute	Select an interface attribute, which can be physical state, data link layer state, IPv4, or IPv6.

 

Table 5 Track-route association configuration items

Item	Description
VPN instance	Select the VPN instance for the route to be associated with Track.
IP	Enter the IP address of the route entry, in dotted decimal notation.
Mask length	Enter the mask length of the IP address.