JN0-106 Junos Configuration Basics Practice Question

Exhibit

Refer to the exhibit.

[edit]
user@router# show | compare
[edit interfaces ge-0/0/0 unit 0 family inet]
+ address 10.0.0.1/24;

[edit security]
+ policies {
+     from-zone trust to-zone untrust {
+         policy permit-all {
+             match {
+                 source-address any;
+                 destination-address any;
+                 application any;
+             }
+             then {
+                 permit;
+             }
+         }
+     }
+ }

Refer to the exhibit. An engineer has made changes to the candidate configuration. What will happen when the engineer issues the 'commit' command?

⚠ Common exam trap

Many exam-takers think security policies require a reboot (a common misconception from other platforms) or that syntax errors are silently ignored, but Junos enforces strict validation and atomic commits.

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

✓

Both the interface address and security policy will be activated.

In Junos, the 'commit' command activates all changes in the candidate configuration atomically. Both the interface address change and the security policy will be applied simultaneously after validation. Junos does not require a reboot for security policy changes, and syntax errors cause the commit to fail, not be ignored.

Answer analysis

Option-by-option breakdown

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

✗
The commit will succeed but the security policy will be ignored due to a syntax error.
Why it's wrong here
A syntax error in the candidate configuration would cause the commit to fail entirely, not simply cause the security policy to be ignored. Junos validates the full configuration syntax during the commit process, and any error aborts the commit, leaving the running configuration unchanged. The exhibit shows no syntax errors, so both the interface address and the security policy changes are committed successfully.
✗
Only the interface address change will be committed because security policies require a reboot.
Why it's wrong here
Security policies in Junos take effect immediately after a successful commit; they do not require a reboot or any separate activation step. The candidate configuration includes both the interface address and the security policy change, and `commit` activates all staged changes together. Only hardware-specific changes (like certain chassis parameters) may require a reboot, but security policy updates are applied to the data plane instantly.
✗
The configuration will be validated; if errors exist, the commit will fail.
Why it's wrong here
While it is true that Junos validates configurations during commit and would fail if errors exist, the exhibit shows a valid candidate configuration, so this option does not describe the actual outcome. The commit will succeed, and both changes will be activated atomically. This option is not incorrect as a general statement about Junos, but it fails to answer the specific question about what happens with the given changes.
✓
Both the interface address and security policy will be activated.
Why this is correct
The commit command in Junos atomically activates all changes in the candidate configuration, including both the interface address and the security policy. There is no separate commit process or reboot needed for security policies, so both changes take effect simultaneously. The validation performed during commit confirms that the configuration is syntactically correct, and since the exhibit shows no errors, both changes will be applied.

Go deeper

JN0-106 Junos Configuration Basics Practice Question

Exhibit

Why each option matters

Option-by-option breakdown

Related to this question