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.
Before adjusting control parameters for maintaining neighbor relationships, complete the following tasks:
Configuring a unicast routing protocol
interface interface-type interface-number
The Hello message without the Generation ID option is rejected.
When the Generation ID option in the Hello message received from an upstream neighbor changes, it indicates that the pim state of upstream neighbor changes, for example restarts. If a FW does not want to receive data from an upstream neighbor, the FW sends a Prune message after receiving a data packet from the upstream neighbor.