Courseiva
Essential System Services and NetworkingmediumMultiple ChoiceObjective-mapped

LPIC-1 Essential System Services and Networking Practice Question

Network Topology
ACCEPT tcp0.0.0.0/0 0.0.0.0/0 tcp dpt:22DROP tcp0.0.0.0/0 0.0.0.0/0 tcp dpt:80Refer to the exhibit.# iptables -L -nChain INPUT (policy ACCEPT)target prot opt source destinationChain FORWARD (policy DROP)Chain OUTPUT (policy ACCEPT)

A web server running on this host is not accessible from clients. Based on the exhibit, what is the most likely reason?

⚠ Common exam trap

Many exam-takers confuse the FORWARD chain with the INPUT chain, assuming that blocking traffic to a local service requires a FORWARD rule, when in fact the INPUT chain governs packets destined for the host itself.

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

Incoming HTTP traffic is blocked by a DROP rule on port 80.

The exhibit shows a firewall rule set where the INPUT chain has a DROP rule for destination port 80 (HTTP). Since incoming HTTP traffic from clients must traverse the INPUT chain to reach the local web server process, this DROP rule explicitly blocks all inbound HTTP requests, making the web server inaccessible. The FORWARD chain is irrelevant because traffic destined for the local host uses the INPUT chain, not FORWARD.

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 FORWARD chain policy is DROP.

    Why it's wrong here

    FORWARD does not affect local incoming connections.

  • The OUTPUT chain policy is ACCEPT.

    Why it's wrong here

    OUTPUT allows outgoing traffic.

  • Incoming HTTP traffic is blocked by a DROP rule on port 80.

    Why this is correct

    The rule explicitly drops TCP port 80.

  • SSH traffic is blocked.

    Why it's wrong here

    SSH (port 22) is ACCEPT.

About these practice questions

Courseiva writes every LPIC-1 question from scratch — 527 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 →

How Courseiva writes practice questions · Editorial policy

JA

Written by Johnson Ajibi, MSc IT Security

Senior Network & Security Engineer · founder of Courseiva

This LPIC-1 practice question is part of Courseiva's free LPI 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 LPIC-1 exam.