Enabling the Function of Tracking a Downstream Neighbor

When the Generation ID option in the Hello message received from an upstream neighbor changes, it indicates that the status of the upstream neighbor changes. Therefore, you can configure a PIM interface to deny the Hello messages without Generation ID options to obtain the upstream neighbor status in real time.

Context

Perform the following steps on the PIM-SM FW:

The configuration involves the following cases:

Global configuration: It is valid on all the interfaces.
Configuration on the interface: The configuration on an interface takes precedence over the global configuration. If the configuration on an interface is not done, the global configuration is used.

Procedure

Global configuration
1. Access the system view.
  system-view
2. Access the PIM view.
  pim [ vpn-instance vpn-instance-name ]
3. Enable the function of tracking a downstream neighbor.
  hello-option neighbor-tracking
  
  After this function is enabled, information about the downstream neighbor who has sent a Join message and whose Join state does not time out is recorded.
  
  The function of tracking downstream neighbors cannot be implemented unless all the PIM devices in the shared network segment are enabled with this function.
Configuration on an interface
1. Access the system view.
  system-view
2. Access the interface view.
  interface interface-type interface-number
3. Enable the function of tracking a downstream neighbor.
  pim hello-option neighbor-tracking
  
  After this function is enabled, information about the downstream neighbor who has sent a Join message and whose Join state does not time out is recorded.
  
  The function of tracking downstream neighbors cannot be implemented unless all PIM devices in the shared network segment are enabled with this function.