DevNet Associate (DEVASC) v1.0Infrastructure and AutomationMedium

A network automation script is designed to monitor a specific interface on a Cisco device for state changes (e.g., link up/down). When a change occurs, the script needs to be immediately notified without constantly polling the device. Which NETCONF mechanism should the script subscribe to for these event-driven notifications?

  1. A<get> operation
  2. BNETCONF Notifications
  3. C<edit-config> operation
  4. DNETCONF Alarms
Show answer & explanation

Correct answer: B. NETCONF Notifications

NETCONF Notifications provide an event-driven mechanism where the device proactively sends messages to a subscriber when specific events (like interface state changes) occur. This eliminates the need for constant polling and allows for immediate action.

Why the other options are wrong

  • A. The <get> operation is for retrieving data on demand (polling), not for event-driven notifications.
  • C. The <edit-config> operation is for modifying configuration, not for receiving notifications about operational state changes.
  • D. While 'alarms' are a type of event, 'NETCONF Notifications' is the general and correct term for the mechanism used to send event-driven messages.

NETCONF Notifications

NETCONF Notifications (RFC 5277) provide a publish/subscribe mechanism for network devices to send asynchronous, event-driven messages to subscribed clients. This allows for real-time monitoring and automation based on network events.

  • Event-driven communication
  • Asynchronous messages from device to client
  • Eliminates polling
  • Uses <create-subscription> RPC to subscribe
  • Defined in RFC 5277

Memory trick: Notifications: No need to ask, the device will tell the task.

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