NSR: LFM

Nonstop active routing (NSR) support for link fault management (LFM): The Ethernet link fault management daemon (lfmd) runs on the backup Routing Engine as well when GRES is configured. When the lfmd daemon runs on the backup Routing Engine as well, the LFM states are kept in sync and so minimal work is required by the lfmd daemon after switching over. To verify if the LFM states are in sync, use the show oam ethernet link-fault-management command on both primary and backup Routing Engines. The lfmd daemon runs only on the primary Routing Engine when GRES is configured.