hardMultiple Select
350-401 Practice Question: Which three statements about telemetry data…
Which three statements about telemetry data collection intervals and on-change notifications are true? (Choose three.)
⚠ Common exam trap
350-401 often tests the misconception that on-change telemetry captures every single change, but it can miss brief changes due to sampling or dampening.
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
✓
Periodic telemetry sends data at a configured interval regardless of whether the value has changed.
Option A is correct because periodic telemetry is interval-driven: the collector pushes the sensor value at the configured period (e.g., every 30 seconds) whether or not the value differs from the previous sample. Option B is correct because on-change telemetry is event-driven, transmitting a sample only when the monitored value crosses or changes from its prior state, which cuts the volume of updates and thus network and processing overhead. Option C is correct because a single subscription (for example, a gNMI/RFC 8641 or NETCONF telemetry subscription) can carry multiple sensor paths with different modes, so periodic and on-change sensors can coexist under one subscription. Option D is not correct because on-change reporting is not lossless: very brief transitions can be missed between sampling or dampening windows, and some implementations suppress rapid flapping, so no guarantee exists that every transient change is reported. Option E is not correct because neither mode is universally preferable; periodic suits continuous monitoring and trending, while on-change suits state or event monitoring, and the choice depends on the use case.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Periodic telemetry sends data at a configured interval regardless of whether the value has changed.
Why this is correct
Periodic telemetry pushes readings on a fixed schedule, so unchanged values are still transmitted. This satisfies the stem's interval-based collection model, in contrast to on-change notifications, which fire only when a monitored value actually differs from its previous state.
- ✓
On-change telemetry sends data only when the monitored value changes, reducing network overhead.
Why this is correct
On-change telemetry transmits data only when a monitored value differs from its previous state, rather than at fixed intervals. This satisfies the statement's claim by directly reducing network overhead, since no updates are sent while values remain unchanged.
- ✓
A single telemetry subscription can include both periodic and on-change sensors.
Why this is correct
A telemetry subscription defines destination and sensor paths, so it can carry both periodic and on-change sensors simultaneously. This satisfies the statement's claim, as the subscription model does not restrict mixing collection types within one configuration.
- ✗
On-change telemetry guarantees that every change, no matter how brief, will be reported.
Why it's wrong here
On-change telemetry reports state transitions observed at sampling points, so changes occurring and reverting between samples can be missed; no guarantee of completeness exists. It is tempting because it reduces overhead versus polling, and suits monitoring stable interfaces where only sustained state changes matter.
- ✗
Periodic telemetry is always preferred over on-change for all use cases.
Why it's wrong here
Periodic telemetry suits trend analysis and capacity baselines, while on-change suits rapid fault detection; neither dominates every use case. It is tempting because fixed intervals give predictable load, and would be correct where consistent sampling cadence matters more than immediate event notification.
Go deeper
Related to this question
About these practice questions
One of 1,923 original 350-401 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
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.