Exam 350-501 topic 1 question 209 discussion

B is correct. When router sends informs, the SNMP server has to acknowledge the Informs. If the server does not send ACK, then router will send inform again.

I think that the correct answer is A https://www.cisco.com/c/m/en_us/techdoc/dc/reference/cli/n5k/commands/snmp-server-enable-traps.html To enable the Simple Network Management Protocol (SNMP) notifications, use the snmp-server enable traps command. To disable SNMP notifications, use the no form of this command.

B is the correct answer

B is correct 'inform' -- notifications

Traps and Informs Unsolicited (asynchronous) notifications can be generated as traps or inform requests (informs). Traps are messages alerting the Simple Network Management Protocol (SNMP) manager to a condition on the network. Informs are traps that include a request for confirmation of receipt from the SNMP manager. Notifications can indicate improper user authentication, restarts, the closing of a connection, loss of connection to a neighbor device, or other significant events. Traps are less reliable than informs because the receiver does not send an acknowledgment when it receives a trap. The sender does not know if the trap was received. An SNMP manager that receives an inform acknowledges the message with an SNMP response protocol data unit (PDU). If the sender never receives a response, the inform can be sent again. Thus, informs are more likely to reach their intended destination. B is the correct answer.

Complicated... A has this problem: "The snmp-server enable traps snmp command is used in conjunction with the snmp-server host command." <https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/snmp/command/nm-snmp-cr-book/nm-snmp-cr-s4.html> B is incomplete, coz lack "version" in the end

Traps are less reliable than informs because an acknowledgment is not sent from the receiving end when a trap is received; however, an SNMP manager that receives an inform acknowledges the message with an SNMP response. https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/snmp/configuration/xe-3se/3850/snmp-xe-3se-3850-book/nm-snmp-inf-req-review.pdf

Commands from B and C are wrong - they cannot be run in cli D is for filtering A seems to be the correct answer

Voting for C. https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/snmp/configuration/xe-3se/3850/snmp-xe-3se-3850-book/nm-snmp-inf-req-review.pdf Traps are less reliable than informs because an acknowledgment is not sent from the receiving end when a trap is received; however, an SNMP manager that receives an inform acknowledges the message with an SNMP response PDU. If the sender does not receive a response for an inform, the inform can be sent again.