Courseiva
hardMultiple ChoiceObjective-mapped

XK0-006 Practice Question: An administrator is troubleshooting a web server…

Network Topology
0 0 ACCEPT alllo * 0.0.0.0/0456 34567 ACCEPT tcp0 0 ACCEPT tcp0 0 DROP alleth0 * 0.0.0.0/0Refer to the exhibit.

An administrator is troubleshooting a web server that is not accessible from the internet. The server is running on port 80. Based on the iptables output, which of the following is the MOST likely reason?

⚠ Common exam trap

CompTIA often tests the misconception that a default DROP policy is the primary cause of connectivity issues, when in fact a specific rule with an overly restrictive source or destination match is the actual problem.

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

The HTTP rule only allows traffic from the internal network.

The iptables output shows an HTTP rule that explicitly matches traffic from the internal network (e.g., 192.168.1.0/24) and does not include a rule allowing HTTP traffic from external (internet) sources. Since the web server is running on port 80 but the only HTTP rule restricts source IPs to the internal subnet, traffic from the internet is not matched by any ACCEPT rule and will be subject to the default policy. This is the most likely reason the server is inaccessible from the internet.

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 HTTP rule only allows traffic from the internal network.

    Why this is correct

    The rule for port 80 sources from 192.168.1.0/24, so internet traffic is blocked.

  • The SSH rule is blocking HTTP traffic.

    Why it's wrong here

    SSH rule only matches port 22, not port 80.

  • The loopback interface is not accepting traffic.

    Why it's wrong here

    The loopback rule accepts all traffic on lo.

  • The default INPUT policy is DROP.

    Why it's wrong here

    The default INPUT policy is actually ACCEPT, not DROP. Therefore, the default policy is not blocking traffic. The issue is that a specific HTTP rule only allows traffic from internal sources, preventing external access.

Visual reference

192.168.1.0 /24 256 addresses (254 usable) 192.168.1.0 /25 Subnet A 128 addr (126 usable) 192.168.1.128 /25 Subnet B 128 addr (126 usable) Borrowing 1 bit from host portion creates 2 subnets (/25)

About these practice questions

This XK0-006 question is part of Courseiva's 979-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 →

How Courseiva writes practice questions · Editorial policy

JA

Written by Johnson Ajibi, MSc IT Security

Senior Network & Security Engineer · founder of Courseiva

This XK0-006 practice question is part of Courseiva's free CompTIA 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 XK0-006 exam.