Which command is used on a Cisco device to display current CPU usage statistics?
Correct Answer: A
Detailed Explanation: Monitoring the CPU usage of a Cisco device is important for maintaining optimal network performance and for troubleshooting performance issues. High CPU utilization can lead to slow response times, delayed packet processing, and even dropped packets if the device becomes overloaded. Cisco IOS provides a variety of commands to monitor system resources, and the command “show processes cpu” is the standard method for displaying current CPU usage statistics. What “show processes cpu” Displays: When you execute the “show processes cpu” command in privileged EXEC mode, the output includes: Overall CPU Utilization: A summary line that shows the percentage of CPU cycles used over a recent time interval. This often includes details such as the average CPU usage over the last 5 seconds, 1 minute, and 5 minutes. Per-Process CPU Utilization: A list of processes running on the device along with the percentage of CPU time each process is consuming. This breakdown helps identify which processes are using significant CPU resources. CPU Scheduling Information: Additional details about process priority and scheduling, which can be useful for in-depth performance analysis. Importance of Monitoring CPU Usage: Understanding CPU usage is crucial for several reasons: Performance Troubleshooting: If users report slow performance or intermittent connectivity issues, high CPU utilization might be the root cause. By examining the CPU usage, administrators can determine whether the router or switch is overburdened. Resource Management: Network devices have limited processing resources. Monitoring CPU usage helps ensure that these resources are not being exceeded, which could lead to degraded performance or device failure. Capacity Planning: Consistently high CPU usage might indicate that the device is nearing its performance limits, prompting an upgrade or the deployment of additional devices to handle the load. Comparison with Other Options: Option B (“show cpu usage”): Although this name might seem descriptive, it is not a recognized Cisco IOS command. Option C (“show system performance”): This command is not part of the standard Cisco IOS command set; Cisco devices have specific commands for monitoring CPU and memory, with “show processes cpu” being the most common for CPU statistics. Option D (“show process memory”): This command provides information about memory usage rather than CPU usage, so it does not offer the data required to assess CPU performance. Practical Scenario: In a scenario where a network experiences intermittent slowdowns, an administrator can log into the router and execute: Router# show processes cpu The output will reveal if any process is consuming an unusually high percentage of CPU cycles. If, for example, a protocol process or an application is responsible, further investigation can be undertaken to adjust configurations or plan for additional capacity. Conclusion: The command “show processes cpu” (Option A) is the standard method for displaying current CPU usage statistics on a Cisco device. It provides essential information for performance monitoring, troubleshooting, and capacity planning, making it a fundamental command for network administrators.
This CCNA practice question helps students prepare for Cisco networking certification exams by testing knowledge of network fundamentals, routing, switching, and network security concepts.