Both SNMP Trap and Inform Request are used by managed devices to send alarms to...

This statement is true. In SNMP, both Trap and Inform messages are used by managed devices to proactively report alarms or events to the Network Management System (NMS). However, their reliability behavior is different. A Trap is sent without requiring an acknowledgment from the NMS. Once it is transmitted, the sender does not confirm whether the manager actually received it.

By contrast, an Inform Request requires the NMS to send a response confirming receipt. If the managed device does not receive the acknowledgment within the expected time, it can retransmit the Inform message. Because of this, Inform is considered more reliable than Trap, although it also introduces slightly more overhead. HCIA-Datacom highlights this difference when explaining SNMP-based monitoring and alarm reporting. In real network O & M scenarios, the choice between Trap and Inform depends on the required balance between reliability and simplicity. This question tests a very standard SNMP knowledge point: Trap is unacknowledged, while Inform is acknowledged. Understanding this distinction helps network engineers choose suitable alarm reporting mechanisms in enterprise monitoring platforms.