Trap Versus Inform Messages

As compared to earlier versions, SNMPv3 provides a higher degree of reliability for notifying management stations when critical events occur. Traditionally, SNMP agents communicated events to SNMP managers via “traps.” However, if a temporary network problem prevented the manager from receiving the trap, then the trap would be lost. SNMPv3 provides “informs”, which are a more reliable form of traps. The SNMP agent initiates the inform process by sending an inform request to the manager. The manager responds to the inform request to acknowledge receipt of the message. If the inform is not received by the manager, the inform request will timeout and a new inform request will be sent. Subsequent inform requests will be sent as previous requests time-out until either an acknowledgement is received from the manager, or until a pre-specified retry-count is reached.