What Happens When Commit Confirmed Times Out?
During a maintenance window, an engineer issues 'commit confirmed 5' but the change causes a connectivity loss. The engineer is unable to reconnect to the device before the timeout expires. What will happen?
Quick Answer
The answer is that the device automatically reverts to the previous active configuration. This happens because the 'commit confirmed 5' command activates the candidate configuration and starts a five-minute rollback timer; if the timer expires without a confirming 'commit' or 'commit check', Junos treats the timeout as a failure and triggers an automatic rollback to the last committed configuration. On the JNCIA-Junos exam, this scenario tests your understanding of commit confirmed timeout behavior and automatic rollback as a safety mechanism for remote maintenance. A common trap is assuming the device locks up or stays in the failed state—instead, Junos proactively restores connectivity by reverting the change. Remember the mnemonic “Confirm or Revert”: if you don’t confirm within the window, the router reverts to keep you connected.
⚠ Common exam trap
It's easy for candidates to think a 'commit confirmed' requires a manual rollback command (Option A) or that the change persists until a reboot (Option B), but Junos automatically reverts the configuration upon timeout, making it a safety mechanism for remote changes.
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
✓
The device automatically reverts to the previous active configuration.
The 'commit confirmed 5' command activates a candidate configuration and starts a 5-minute rollback timer. If the engineer does not issue a 'commit' or 'commit check' before the timer expires, Junos automatically reverts to the previously active configuration. This ensures the device returns to a known working state without manual intervention, preserving connectivity after the failed change.
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 engineer must manually rollback using the rollback command.
Why it's wrong here
The rollback happens automatically after timeout.
- ✗
The change remains committed until the next reboot.
Why it's wrong here
Commit confirmed automatically rolls back if not confirmed.
- ✗
The device reloads with factory defaults.
Why it's wrong here
The device reverts to the previous configuration, not factory defaults.
- ✓
The device automatically reverts to the previous active configuration.
Why this is correct
Commit confirmed automatically rolls back after the timeout if not confirmed.
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Same concept, more angles
1 more way this is tested on JN0-106
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A network engineer needs to make a change to a Junos device and ensure the change can be reverted if it causes issues. Which feature should be used?
easy- A.configure exclusive
- ✓ B.commit confirmed
- C.commit check
- D.rollback 0
Why B: The `commit confirmed` command allows an engineer to commit a configuration change with a timer (default 10 minutes). If the change causes issues and the engineer does not confirm the commit within the timer, the device automatically reverts to the previous active configuration. This provides a safety net to revert changes without manual intervention.
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.