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350-401 Practice Question: Which two statements about SNMP trap and inform…
Which two statements about SNMP trap and inform operations are true? (Choose two.)
⚠ Common exam trap
350-401 often tests the reliability trade-off between traps and informs — candidates assume traps are 'better' because they're simpler, missing that informs provide acknowledgment at the cost of bandwidth and memory.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
An SNMP inform request is acknowledged by the manager with a response PDU.
Option A is correct because an SNMP inform request is a confirmed notification: the receiving manager must reply with a Response PDU (using the same request-id) so the sender knows the notification was received. Option D is correct because informs require the sender to retain the notification in memory until the acknowledgment arrives and to retransmit if no response is received, adding bandwidth and memory overhead compared with unacknowledged traps. Options B, C, and E are not correct: traps are less reliable than informs since they are unacknowledged, SNMPv1 does not support the inform operation (it was introduced with SNMPv2), and traps are sent from an agent to a manager, not from a manager to an agent to request configuration changes.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
An SNMP inform request is acknowledged by the manager with a response PDU.
Why this is correct
An inform is a confirmed-class notification: the receiving manager must reply with a Response PDU, letting the agent retransmit if none arrives. This satisfies the stem's acknowledgement requirement, unlike an unacknowledged trap, which is fire-and-forget with no confirmation returned to the sender.
- ✗
SNMP traps are more reliable than informs because they use UDP port 162.
Why it's wrong here
Informs are the reliable mechanism because the receiver acknowledges each message, whereas traps are unacknowledged; port 162 is shared by both and implies nothing about reliability. It is tempting because traps do use UDP 162, and traps would be chosen when fire-and-forget delivery without acknowledgement overhead is acceptable.
- ✗
Both SNMPv1 and SNMPv2c support the inform operation.
Why it's wrong here
The inform operation was introduced with SNMPv2c; SNMPv1 has no inform PDU and can only send unacknowledged traps. It is tempting because both versions share community-string authentication and UDP transport, and SNMPv2c would be the correct choice when acknowledged notifications are required.
- ✓
Informs consume more network bandwidth and memory resources than traps.
Why this is correct
Informs require the sender to retain each notification until the receiver acknowledges it, consuming extra device memory, and the acknowledgement round trip adds bandwidth overhead. Traps are fire-and-forget, with no confirmation or retransmission. This satisfies the resource-consumption comparison the stem asks about.
- ✗
Traps are sent from the manager to the agent to request configuration changes.
Why it's wrong here
Traps flow from agent to manager, not manager to agent, and they report events rather than request configuration changes; SET requests perform that function. It is tempting because managers do initiate configuration via SNMP, and a manager-to-agent SET would be correct when pushing configuration changes to a device.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Cisco exam blueprint
This 350-401 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 350-401 exam.