A monitoring team wants interface up and down transitions streamed to their collector as they happen, rather than a full interface table every minute. They will configure one model-driven telemetry subscription on an IOS XE router, and the collector has already opened the gRPC receiver it will use. Which subscription parameter set matches the need for change-only interface state updates?
Select an answer to reveal the explanation.
Short Explanation
You want the router to notify your collector only when interface state changes, not keep resending a table during quiet periods. An on-change stream with an interface-state xpath and the collector as receiver gives you focused updates as they happen. Think of it as a doorbell rather than a camera running all day.
Full Explanation
Model-driven telemetry subscriptions combine three choices: what to collect, when to send it, and where to deliver it. An on-change stream emits a notification when a subscribed value changes, which fits interface up and down transitions; a periodic stream instead repeats the selected data on a timer, even when nothing has changed. Limiting the xpath to interface state keeps the updates focused, and naming the telemetry collector as receiver directs them to the endpoint that has opened its gRPC listener. A periodic stream with the same xpath and receiver still sends repeated samples rather than change-only updates. An on-change stream matching the full operational tree can send unrelated values as well as interface state. An on-change stream with the interface-state xpath but with the collector pulling samples on demand uses polling rather than delivering the requested pushed notifications. Exam caveat: exact keyword names vary across CLI, NETCONF, and gRPC clients, so identify the behavior rather than relying on a particular spelling. As a practical check, shut and then no-shut an interface and verify that the collector receives the corresponding state-change events.