Before configuring IPv6 PIM GR, complete the following tasks:
In a stack system, switches may need to perform active/standby switchover. If multicast services are running in the stack system, a switchover between the active and standby switches will trigger update of the IPv6 PIM routing table and multicast forwarding table. Multicast traffic is interrupted during the update.
If a stack is deployed on an IPv6 PIM-SM network, you can configure IPv6 PIM GR on the stacked switches to ensure uninterrupted multicast forwarding during an active/standby switchover in the stack.
After PIM GR is enabled in the stack system, the standby switch backs up the IPv6 PIM routing entries, multicast forwarding entries, and Join/Prune messages that need to be sent to the upstream switch. When a switchover occurs in the stack system, the new active switch quickly sends Join messages upstream to maintain the Join state of the upstream switch. The IPv6 PIM protocol sends Hello messages carrying Generation IDs to all switches with IPv6 PIM-SM enabled. When a downstream switch finds that the Generation ID of its neighbor changes, it sends a Join/Prune message to the neighbor so that the neighbor can create new routing entries. This mechanism ensures nonstop forwarding of multicast data on the forwarding plane.
On a network using dynamic RP, when a DR receives a Hello message with a Generation ID different from the previous one, the DR sends a unicast Bootstrap message to the stack system. The stack system then restores the RP information from the Bootstrap message. If the stack system cannot learn RP information from the Bootstrap message, it obtains RP information from the Join/Prune messages received from downstream devices and generates new multicast entries.
For details about configurations of the stack system, see Stack Configuration in the S2720, S5700, and S6700 V200R019C10 Configuration Guide - Device Management.
The system view is displayed.
The PIM-IPv6 view is displayed.
PIM GR is enabled.
By default, IPv6 PIM GR is not enabled.
The PIM GR period is configured.
By default, the IPv6 PIM GR period is 120 seconds.
After IPv6 PIM GR is configured, run the following commands to check entries in the IPv6 PIM routing table.
display pim ipv6 routing-table brief [ ipv6-source-address [ mask mask-length ] | ipv6-group-address [ mask mask-length ] | incoming-interface { interface-type interface-number | register } ] *