If the SR OS router is providing a grace period to an adjacent neighbor and the BFD session associated with that neighbor fails, the behavior is determined by the C-bit values sent by each neighbor as follows.
If both BFD endpoints have set their C-bit value, then the graceful restart helper mode is canceled and any routes from that neighbor that are marked as stale are removed from the forwarding table.
If either of the BFD endpoints has not set their C-bit value, then the graceful restart helper mode continues.