JN0-106 User Interfaces Practice Question
Exhibit
user@router> help syslog messages | match error KERNEL_ERROR Kernel error messages USER_ERROR User-level error messages DAEMON_ERROR Daemon error messages
Refer to the exhibit. What does this command accomplish?
⚠ Common exam trap
Candidates often assume that the 'match' operator performs a whole-word search or that there is a dedicated error log file, but in Junos it performs a substring match on the default messages log.
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
✓
Displays syslog messages containing the word 'error'.
The command shown filters the output of the system log file to display only lines containing the substring 'error'. This allows the administrator to quickly see log entries related to errors, rather than viewing all messages or a dedicated error log file.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Displays help for syslog messages that include 'error'.
Why it's wrong here
This option confuses a system log query with the CLI's help facility. The command does not invoke help or return usage hints about syslog messages; it directly reads the existing log output and applies a filter. The filter selects lines containing the literal string "error", displaying actual event entries rather than documentation. Therefore, it is incorrect because the output is operational log data, not help text.
- ✗
Displays all syslog messages.
Why it's wrong here
This option misunderstands the purpose of the pipe filter. Piping the log output to a match filter such as `match error` restricts the display to only those lines whose content satisfies the regular expression `error`. Without that filter, the command would show the entire log file, but the pipe consumes the full output and discards non-matching lines. Thus, the command does not report all messages; it reports a filtered subset of the log.
- ✓
Displays syslog messages containing the word 'error'.
Why this is correct
This is correct because the command combines a log display command with a match filter. For example, `show log messages | match error` displays every line from the messages log that contains the substring "error" (case-sensitive by default in Junos). This is a standard way for an operator to quickly search a system log for error-related entries without reading the whole file. It is not restricted to a specific severity class; it is simply a text-pattern match against the log output.
- ✗
Displays the error log file.
Why it's wrong here
This option incorrectly assumes the command targets a separate file. Junos does not maintain a dedicated "error log" file; all syslog messages, including errors, warnings, notices, and informational messages, are written to the configured log file, commonly `/var/log/messages`. The pipe filter is applied to the output of that standard file, so the command shows matching lines from that file rather than opening a different error-specific log. Hence, the phrase "error log file" is a misnomer.
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JA
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.