JN0-106 Junos OS Fundamentals Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  It compares the candidate configuration with the active configuration

  Why it's wrong here

  This option incorrectly describes the 'show | compare' or 'show compare' command, which displays the difference between the candidate and active configurations. 'commit confirmed' does not perform any comparison; it actively commits the candidate configuration and starts a rollback timer. Comparing configurations is a read-only operation, whereas committing changes the operational state of the device.

• ✓

  It allows the administrator to test a configuration change with automatic rollback if confirmation is not received

  Why this is correct

  This is the correct purpose of 'commit confirmed' in Junos. When you issue 'commit confirmed', the candidate configuration is applied and a timer (default 10 minutes, configurable with 'confirm <minutes>') starts. If you do not explicitly confirm the commit with a subsequent 'commit confirm' before the timer expires, the device automatically reverts to the previous active configuration. This is essential for safely applying remote changes that might disrupt connectivity, because a lost connection means you cannot confirm, so the router rolls back automatically.

• ✗

  It permanently saves the candidate configuration to the startup configuration

  Why it's wrong here

  A standard 'commit' on Junos applies the candidate configuration to the active configuration and writes it to persistent storage, effectively saving it as the configuration loaded at boot. However, 'commit confirmed' is not intended for permanent saves; it is a temporary measure with automatic rollback. The configuration is only made permanent if you follow up with 'commit confirm'; otherwise, it reverts to the previous configuration, so the notion of permanently saving to startup is incorrect.

• ✗

  It confirms that a previous commit was successful

  Why it's wrong here

  There is no Junos command called 'commit confirmed' that verifies the success of a prior commit; that would be 'show log' or 'show system commit' to inspect commit history. Instead, 'commit confirmed' is a proactive mechanism placed *before* a potentially disruptive change: it applies the change and then awaits confirmation. It does not report on past events but sets up a future safety net to automatically roll back a configuration if confirmation is not received.

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