Overnight a warehouse switch's running configuration gained a VLAN that the approved baseline does not contain. Interfaces stayed up and utilization looked normal. Which monitoring type caught that?
Select an answer to reveal the explanation.
Short Explanation
The lights stayed green and the pipes were not full, yet somebody rewrote the recipe you approved. The check that compares tonight's configuration with that approved copy is configuration monitoring. Utilization graphs and up-down pings never open that recipe, and a cable tester does not read a VLAN database.
Full Explanation
Configuration monitoring compares a device's running configuration with an approved baseline and alerts when they differ. A VLAN appeared that the baseline does not contain, while interface state and utilization stayed normal, so the detecting system was looking at configuration rather than at traffic or reachability. Performance monitoring watches measures such as utilization, errors, and latency. Those counters were normal, so a performance alarm is not what fired. Availability monitoring answers whether the device or path is up, often with a ping or a similar probe. A switch that answers and passes traffic looks available. A cable certification report measures the copper or fiber run. It cannot see a VLAN created in software. Exam caveat: discovery finds that a device exists, and configuration monitoring is the later comparison against the standard. Operational check: open the diff, confirm the new VLAN is unauthorized, and restore the approved baseline through the change process rather than editing the baseline to match an unknown change.