CGRC Control Implementation Practice Question
You are configuring a Linux firewall using 'iptables'. Which chain should you use to filter traffic destined for the local host?
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
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INPUT
The INPUT chain handles traffic that is addressed to the host machine itself.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
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OUTPUT
Why it's wrong here
The OUTPUT chain handles traffic originating from the host.
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INPUT
Why this is correct
The INPUT chain processes traffic intended for the local socket.
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FORWARD
Why it's wrong here
The FORWARD chain handles traffic passing through the host.
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PREROUTING
Why it's wrong here
PREROUTING is for NAT operations before routing decisions.
About these practice questions
One of 199 original CGRC practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. 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 August 2026 · checked against the official (ISC)² exam blueprint
This CGRC practice question is part of Courseiva's free (ISC)² 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 CGRC exam.