pim ipv6 hello-option neighbor-tracking

Usage Scenario

When sending a Hello message, a switch generates a Generation ID and encapsulates it into the message. The Generation ID changes only when the device status changes. In this case, the neighboring device detects the Generation ID change after receiving the Hello message and immediately sends a Join message to the device to update the neighbor relationship. If multiple devices on the shared network segment prepare to send Join messages to the same upstream PIM neighbor, only one device is allowed to send the Join message. After other devices detect the Join message, they do not send Join messages to the upstream neighbor. This means that the upstream neighbor cannot update neighbor relationships with downstream devices after a Generation ID change.

After the neighbor tracking function is enabled, when the device detects Join messages from other devices, the device still sends the Join messages to the same upstream PIM neighbor.

Prerequisites

IPv6 multicast routing has been enabled globally using the multicast ipv6 routing-enable command in the system view.

Precautions

This command is valid for only PIM-SM (IPv6).

The neighbor tracking function can be implemented on a shared network segment only when this function is enabled on all devices on the network segment.

The pim ipv6 hello-option neighbor-tracking command has the same function as the hello-option neighbor-tracking (IPv6) command in the PIM-IPv6 view. By default, if the pim ipv6 hello-option neighbor-tracking command is not used, the configuration in the PIM-IPv6 view takes effect; otherwise, the configuration in the interface view takes effect.