A technique prevents multiple multicast forwarders from forwarding
multicast packets for a route over a link in a computer network during
non-stop forwarding (NSF) recovery of one or more failures in a control
plane of a multicast router. The multicast router has a functional
infrastructure that allows data traffic forwarding operations to continue
throughout a data plane of the router in the presence of a failure and/or
software restart to a multicast component, e.g., a protocol independent
multicast (PIM) routing protocol, executing in the control plane. Another
multicast component, e.g., a multicast forwarding information base (MFIB)
executing in the data plane, is configured to prevent multiple multicast
forwarders due to routing changes in the network that arise during NSF
recovery.