Explanation/Reference:
Section: Enterprise Network Design Explanation
Explanation:
Duplicate power supplies are a system-level resiliency component of a high-availability solution. High- availability solutions feature redundant components that provide protection in the event that a primary component fails. Cisco defines three components of a high-availability solution: network-level resiliency, system-level resiliency, and management and monitoring. System-level resiliency components provide failover protection for system hardware components. Duplicate power supplies ensure that critical system components can maintain power in the event of a failure of the primary power supply.
Duplicate power supplies are not an example of management and monitoring resiliency components.
Management and monitoring is a resiliency component used to quickly detect changes to various components of a high-availability solution. Examples of the monitoring component include Syslog. Syslog is used to gather information about the state of network components and to compile them in a centralized location. This allows administrators to gain information regarding the state of network or system components without having to log on to each device on the network.
Duplicate power supplies are not an example of network-level resiliency components. Network-level resiliency features redundant network devices, such as backup switches. In addition, network resiliency features duplicate links that can be used to maintain communication between network devices if the primary link fails. When you increase network resiliency by adding redundant links to a network design, you should also configure link management protocols, such as Spanning Tree Protocol (STP), to ensure that the redundant links do not generate loops within the network.
Reference:
Cisco: Deploying High Availability in the Wiring Closet Q&A