JN0-106 User Interfaces 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.

• ✗

  'show' shows the active configuration; 'run show configuration' shows the candidate.

  Why it's wrong here

  This option reverses the actual behavior in Junos. In configuration mode, the bare command 'show' is a configuration-mode command that displays the candidate configuration, which is your working copy containing any uncommitted edits. To view the active, committed configuration that is currently running on the device, you must use 'run show configuration', which executes the operational-mode command from within configuration mode. Therefore, the assignment of which command shows which configuration is exactly backwards, making this option incorrect.

• ✓

  'show' shows the candidate configuration; 'run show configuration' shows the active configuration.

  Why this is correct

  This option correctly describes the behavior of the two commands. Junos maintains two separate configuration databases: the candidate configuration, which holds all uncommitted changes made in configuration mode, and the active configuration, which represents the last committed state that is actually in effect. Typing 'show' in configuration mode displays the candidate configuration, complete with pending modifications. 'run show configuration' invokes the operational command 'show configuration' from inside configuration mode, thereby displaying the active configuration. This distinction is essential for verifying changes before committing.

• ✗

  Both commands produce identical output.

  Why it's wrong here

  This option is false because the outputs of the two commands are not universally identical; they differ whenever uncommitted changes exist. The candidate configuration shown by 'show' in configuration mode is a separate working copy from the active configuration shown by 'run show configuration'. If you have edited the configuration but not yet committed, 'show' reflects those edits while the active configuration remains unchanged. Only in the special case where no modifications have been made since the last commit will the two outputs match, so the absolute claim that they always produce identical output cannot be correct.

• ✗

  'run show configuration' is not allowed from configuration mode.

  Why it's wrong here

  Junos provides the 'run' command precisely to allow operational-mode commands to be executed while remaining in configuration mode. For instance, typing 'run show configuration' is a valid and commonly used way to display the active configuration from within configuration mode, without needing to exit. This feature is fully supported and documented in Junos, making the statement that it is not allowed false. The 'run' command can execute any operational command, such as 'run show interfaces terse', which is a powerful troubleshooting tool while editing.