On vManage NMS, which severity level indicates events that require immediate action?

The "critical" severity level on vManage NMS indicates events that require immediate action to prevent service degradation or outage. These are serious issues that impact the network's functionality. "Error" indicates a problem that might affect functionality but isn't immediately service-impacting. "Warning" signifies potential issues that don't immediately affect operations but might lead to problems if not addressed. "Alert" is not a standard, distinct severity level in vManage; alerts are typically notifications generated based on configured thresholds, which can be of various severity levels.