JN0-106 Operational Monitoring and Maintenance Practice Question
An administrator observes that the router's CPU utilization is consistently high. Which command helps identify which process is consuming the most CPU?
⚠ Common exam trap
Many exam-takers confuse 'show chassis routing-engine' (which shows aggregate CPU load) with process-level CPU breakdown, leading them to choose option C, but only 'show system processes extensive' provides the per-process detail needed to pinpoint the culprit.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
show system processes extensive
'show system processes extensive', is correct because it displays detailed CPU utilization statistics for each running process on a Junos device, including the percentage of CPU time consumed. This allows the administrator to identify which specific process (e.g., routing protocol daemon, SNMP, or management process) is causing the high CPU load, enabling targeted troubleshooting.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
show log messages
Why it's wrong here
This command displays the system log messages, such as alerts, errors, and operational events, stored in the event log. It does not provide a real-time snapshot of per-process CPU utilization, so it cannot be used to pinpoint which specific process is consuming high router CPU. Even if log entries mention resource thresholds, they lack the detailed, current process-level breakdown needed for this diagnostic.
- ✗
show system resource
Why it's wrong here
This command shows a high-level summary of system-wide resource usage, including percentages for CPU idle time, memory usage, and disk space. While it can indicate that the router is under high CPU load, it does not identify which individual process is responsible, making it too coarse for this task. The output aggregates all processes rather than attributing usage to a specific process.
- ✗
show chassis routing-engine
Why it's wrong here
This command provides status information about the Routing Engine(s), such as model, serial number, and overall CPU and memory utilization. It reports the aggregate load on the RE but does not enumerate per-process CPU usage, so an administrator cannot determine which process is spiking. It is intended for hardware and RE health monitoring, not for process-level CPU diagnostics.
- ✓
show system processes extensive
Why this is correct
This command displays detailed information about every running process, including its process ID, parent, and the amount of CPU and memory it is consuming. The "extensive" variant adds per-thread and per-process statistics, allowing an administrator to identify exactly which process is causing high CPU utilization. It is the equivalent of "top" on Unix and is the appropriate tool for this diagnostic.
Quick reference
Routing Protocol Comparison
| Protocol | Metric | Max Hops | Algorithm | Type |
|---|---|---|---|---|
| RIP v2 | Hop count | 15 | Bellman-Ford | Distance vector |
| OSPF | Cost (bandwidth) | Unlimited | Dijkstra (SPF) | Link state |
| EIGRP | Composite metric | Unlimited | DUAL | Hybrid |
| IS-IS | Cost | Unlimited | Dijkstra | Link state |
| BGP | Policy / attributes | Unlimited | Path vector | Path vector |
RIP's 15-hop limit makes it unsuitable for large networks. OSPF and EIGRP dominate modern enterprise deployments.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This JN0-106 practice question is part of Courseiva's free Juniper Networks certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the JN0-106 exam.