This notification signifies that the SNMP entity, acting as an agent, has detected that that one of its NHRP entities, acting as a NHRC, has detected(by repeated registration retries or learnt from some other source(e.g. from a lower layer protocol)) that the NHRS it was registered to, or was trying to register to, is operationally down(from the NHRC's perspective). This notification doesn't indicate that the concerned NHRP server is down or unreachable or not even that it is unable to provide (other)NHRP services. It just indicates that the NHRC couldn't register successfully with the NHRS. This notification will be be sent only once for a down event i.e. two consecutive cneNotifNextHopRegServerDown notifications (for the same NHRS) must always be interspersed by a cneNotifNextHopRegServerUp notification(for the same NHRS).