F5CAB4 Control Plane Administration Practice Question
An administrator needs to add a new VLAN to a BIG-IP device using TMSH. The administrator wants to ensure the change is immediately active and persisted across reboots. Which command sequence should the administrator use?
⚠ Common exam trap
The trap here is forgetting to save the configuration, or using 'load sys config' which would discard the change.
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
✓
tmsh create net vlan vlan10 tag 10; tmsh save sys config
To add a VLAN and ensure it persists, the administrator must create it and then save the configuration. The 'create net vlan' command makes the VLAN active immediately, and 'save sys config' writes the running configuration to the configuration files, ensuring it survives a reboot. Other commands either do not save or would revert the 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.
- ✗
tmsh create net vlan vlan10 tag 10; tmsh load sys config
Why it's wrong here
The 'load sys config' command reloads the configuration from the configuration files, which would discard the newly created VLAN if it was not saved. This sequence would not persist the change and would actually revert the running configuration. It is the opposite of what is needed.
- ✓
tmsh create net vlan vlan10 tag 10; tmsh save sys config
Why this is correct
This sequence creates the VLAN with the specified tag and then saves the running configuration to the configuration files. The 'create' command makes the change active immediately, and 'save sys config' ensures it persists after a reboot. This is the correct approach for making a persistent configuration change in TMSH.
- ✗
tmsh create net vlan vlan10 tag 10
Why it's wrong here
This command creates the VLAN and makes it active, but it does not save the configuration. Without saving, the change will be lost after a reboot. The administrator must also run 'save sys config' to persist the change. This option is incomplete for the requirement of persistence.
- ✗
tmsh edit net vlan vlan10 tag 10; tmsh save sys config
Why it's wrong here
The 'edit' command is used to modify an existing VLAN, not to create a new one. Since the VLAN does not exist yet, this command would fail. The correct verb for creating a new object is 'create'. Therefore, this option is incorrect.
Visual reference
About these practice questions
Courseiva writes every F5CAB4 question from scratch — 40 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 F5CAB4 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 F5CAB4 exam.