This LFCS practice question tests your understanding of networking. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Network Topology
Based on the iptables-save output, what is the default policy for the FORWARD chain and what happens to a new SSH connection from an external host on eth0?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Default policy FORWARD is DROP; SSH connections are accepted.
The default policy for the FORWARD chain is DROP, as shown in the iptables-save output (e.g., `:FORWARD DROP [0:0]`). A new SSH connection from an external host on eth0 is accepted because there is a rule in the FORWARD chain that matches incoming SSH traffic (typically TCP port 22) and has a target of ACCEPT, overriding the default DROP policy for that specific traffic.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Default policy FORWARD is ACCEPT; SSH connections are dropped.
Default policy FORWARD is DROP; SSH connections are accepted.
Why this is correct
FORWARD default is DROP; SSH rule allows traffic on port 22.
Related concept
Read the scenario before looking for a memorised answer.
✗
Default policy FORWARD is ACCEPT; SSH connections are accepted.
Why it's wrong here
FORWARD default is DROP.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse the default policy with the actual behavior for specific traffic, assuming that a DROP default policy means all traffic is dropped, ignoring the effect of explicit ACCEPT rules.
Detailed technical explanation
How to think about this question
In iptables, the default policy for a chain determines the fate of packets that do not match any rule in that chain. The FORWARD chain processes packets that are routed through the system (not destined for the local host). A rule matching SSH traffic (e.g., `-p tcp --dport 22`) with a target of ACCEPT will allow the connection, even if the default policy is DROP. This is a common configuration for stateful firewalls where only specific services are permitted to traverse the system.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the LFCS exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Networking — This question tests Networking — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Default policy FORWARD is DROP; SSH connections are accepted. — The default policy for the FORWARD chain is DROP, as shown in the iptables-save output (e.g., `:FORWARD DROP [0:0]`). A new SSH connection from an external host on eth0 is accepted because there is a rule in the FORWARD chain that matches incoming SSH traffic (typically TCP port 22) and has a target of ACCEPT, overriding the default DROP policy for that specific traffic.
What should I do if I get this LFCS question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Question Discussion
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