JN0-106 Operational Monitoring and Maintenance Practice Question
A technician is troubleshooting a connectivity issue and needs to see the path packets take to a remote host. Which Junos command is appropriate?
⚠ Common exam trap
Many exam-takers confuse `ping` (which tests reachability) with `traceroute` (which shows the path), leading them to select ping when the question explicitly asks for the path packets take.
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
✓
traceroute
The `traceroute` command in Junos is the correct tool for tracing the path packets take to a remote host. It sends UDP probes with increasing TTL values and listens for ICMP Time Exceeded messages from intermediate routers, revealing each hop along the route. This directly matches the technician's need to see the path packets take.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
traceroute
Why this is correct
traceroute is the correct tool because it actively discovers the Layer 3 path by sending packets with incrementally increasing TTL (or hop limit in IPv6) values. Each router that decrements the TTL to zero discards the packet and returns an ICMP Time Exceeded message, revealing its interface address. This builds a sequential list of hops from source to destination, precisely what the technician needs to locate a connectivity break.
- ✗
monitor interface
Why it's wrong here
monitor interface is wrong because it continuously displays real-time statistics, error counts, and traffic rates for a specified interface on the local device. It is useful for observing incoming/outgoing packets, but it cannot reveal the path a packet takes beyond that one interface. The connectivity issue may be several hops away, and this command gives no visibility into remote routers or the sequence of links.
- ✗
ping
Why it's wrong here
ping is wrong because it only verifies that the remote host is reachable by sending ICMP Echo Requests and waiting for Echo Replies. It returns a pass/fail result and round-trip time, but does not show which routers the packets traverse. A successful ping tells you the host is up, yet gives no indication where a performance problem or black hole lies along the path; additionally, reply packets may take a different route than requests.
- ✗
show route
Why it's wrong here
show route is wrong because it displays the routing table locally, listing known prefixes and their next hops as evaluated by the Junos kernel. It reflects the router's forwarding plan for a destination, but not the actual path packets take through the network, since every intermediate router makes its own independent forwarding decision. It is a static snapshot of local state, not a hop-by-hop trace to a remote host.
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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.