This notification signifies that the SNMP entity, acting as an agent, has detected that one of its NHRP entities, acting as an NHRS perceives that an NHRP entity, acting as an NHRC, is no more registered or failed to register. This notification will be be sent only once for a down event i.e. two consecutive cneNotifNextHopRegClientDown notifications (for the same NHRC) must always be interspersed by a cneNotifNextHopRegclientUp notification(for the same NHRC).