F5-CTS-LTM BIG-IP Local Traffic Manager Practice Question
An administrator wants to use an iRule to log the 'Host' header of every incoming HTTP request. Which iRule event is most appropriate for this task?
⚠ Common exam trap
Candidates often choose incorrect events like 'CLIENT_ACCEPTED', which happens before the HTTP request is parsed, meaning the HTTP headers are not yet available for the iRule to read.
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
✓
HTTP_REQUEST
The 'HTTP_REQUEST' event triggers whenever a client sends an HTTP request, providing immediate access to the headers before the request is processed by the pool selection logic. This is the correct point in the request-response cycle to inspect and log headers. Using this event ensures that the logging logic executes for every single request, providing a full audit trail of host header usage.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
CLIENT_ACCEPTED
Why it's wrong here
The 'CLIENT_ACCEPTED' event triggers when a TCP connection is established, before any HTTP data has been sent. At this stage, the HTTP headers are not yet available to the BIG-IP. Attempting to log the 'Host' header here will result in an error because the request data is missing.
- ✓
HTTP_REQUEST
Why this is correct
The 'HTTP_REQUEST' event is the correct place to handle HTTP header information. It occurs after the BIG-IP has parsed the request headers, allowing the iRule to safely access the 'Host' header and perform the logging operation before the request is forwarded to the backend pool member.
- ✗
HTTP_RESPONSE
Why it's wrong here
The 'HTTP_RESPONSE' event triggers when the server sends a response back to the BIG-IP. This is too late for inspecting the incoming client request headers. The 'Host' header is part of the request, not the response, so logging it in this event would provide incorrect or unavailable data.
- ✗
LB_SELECTED
Why it's wrong here
The 'LB_SELECTED' event triggers after the BIG-IP has already decided which pool member will receive the request. While headers might be available, this event is focused on load balancing decisions. Using it for general header logging is inefficient and less readable than using the dedicated 'HTTP_REQUEST' event.
About these practice questions
This F5-CTS-LTM question is part of Courseiva's 119-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam 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.