F5-CTS-LTM BIG-IP Local Traffic Manager Practice Question
An application requires persistence based on a specific custom header named 'X-Session-ID'. The LTM Specialist has confirmed the header is always present in requests. Which persistence method is most appropriate?
⚠ Common exam trap
Candidates often suggest Source Address persistence, incorrectly believing it will work for custom application headers. They fail to realize that Source Address only looks at the client's IP, not request content.
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
✓
Universal persistence
Universal persistence is the only method that allows the BIG-IP to persist traffic based on arbitrary data found within the request. By extracting the value of the 'X-Session-ID' header using an iRule and mapping it to a persistence record, the BIG-IP can ensure that all requests with the same session ID are consistently routed to the same backend server, regardless of the client's IP address.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Cookie Insert persistence
Why it's wrong here
Cookie Insert persistence works by inserting a cookie into the HTTP response. It is limited to cookie-based data and cannot be configured to look at arbitrary custom headers like 'X-Session-ID' for determining persistence mappings, making it unsuitable for this specific application requirement.
- ✓
Universal persistence
Why this is correct
Universal persistence allows for custom persistence logic based on any data within the request, including headers. By using an iRule to extract the 'X-Session-ID' value and calling 'persist uie', the BIG-IP maintains a mapping table entry for that specific ID, ensuring consistent routing.
- ✗
Source Address persistence
Why it's wrong here
Source Address persistence relies solely on the client's IP address. It is entirely unaware of application-layer headers like 'X-Session-ID'. If the client IP changes or if multiple users share an IP, this persistence method will fail to maintain the required application-level session affinity.
- ✗
Hash persistence
Why it's wrong here
Hash persistence uses a mathematical calculation to assign traffic to a pool member. While it can be configured to use specific data, it is a static assignment and does not provide the stateful tracking required to maintain persistence across multiple requests in the way a true persistence method does.
About these practice questions
Courseiva writes every F5-CTS-LTM question from scratch — 119 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 F5-CTS-LTM 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 F5-CTS-LTM exam.