F5CAB1 Install, Initial Configuration, and Upgrade Practice Question
An administrator is preparing to upgrade a BIG-IP from version 14.1.4 to 16.1.2. The administrator runs the command 'tmsh show sys software' and sees that the new version is installed but not active. The administrator then reboots the system. After the reboot, the administrator checks the active software version and finds it is still 14.1.4. What is the most likely reason?
⚠ Common exam trap
The trap here is assuming that installing a new version automatically makes it active after a reboot, when you must explicitly set the active boot location.
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 administrator did not set the new version as the active boot location.
After installing a new software version, it is placed in a separate boot location. To activate it, the administrator must set that boot location as the default boot target, typically using 'tmsh set sys software volume <volume> active' or via the GUI. Rebooting alone will boot the previously active volume. This is a common oversight during upgrades and leads to the old version remaining active.
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 administrator did not run the 'tmsh install sys software' command to finalize the installation.
Why it's wrong here
The 'tmsh install sys software' command is used to install a software image from an ISO or IM file, not to finalize an already installed version. The new version is already installed, as indicated by 'show sys software'. The issue is that it is not set as the active boot location. Running the install command again would not change the active volume.
- ✓
The administrator did not set the new version as the active boot location.
Why this is correct
After installing a new software version, it resides in a separate boot location. To activate it, the administrator must set that boot location as the default boot target using the command 'tmsh set sys software volume <volume> active' or via the GUI. Simply rebooting without setting the active volume will boot the previously active version. This explains why the version remains unchanged after reboot.
- ✗
The administrator did not create a UCS backup before the upgrade.
Why it's wrong here
Creating a UCS backup is a best practice but not a requirement for the new version to become active. The absence of a backup does not affect the boot process. The new version will boot if the boot location is set correctly, regardless of whether a backup exists. Thus, this is not the cause of the observed behavior.
- ✗
The upgrade failed because the administrator did not run the 'tmsh load sys config' command.
Why it's wrong here
The 'tmsh load sys config' command is used to load a configuration from a file, not to activate a software version. Failure to run it would not prevent the new version from booting. The symptom of the old version remaining active after reboot points to the boot location not being changed, not to a configuration loading issue.
About these practice questions
Courseiva writes every F5CAB1 question from scratch — 80 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official F5 exam blueprint
This F5CAB1 practice question is part of Courseiva's free F5 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 F5CAB1 exam.