LPIC-2 System Security Practice Question
Network Topology
Based on the iptables output, what is the expected behavior for incoming SSH connections on eth0?
⚠ Common exam trap
Watch out — candidates often assume the default policy is DROP (a common security practice) and overlook the explicit ACCEPT rule for NEW SSH connections, or they may confuse the NEW state with ESTABLISHED, thinking that only existing connections are allowed.
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
✓
SSH connections from any source to port 22 on eth0 are allowed if they are new.
The iptables output shows a rule on the INPUT chain for eth0 that accepts TCP packets destined for port 22 (SSH) with the state NEW. This means that any incoming SSH connection attempt (SYN packet) that is not part of an existing connection is explicitly allowed. The default policy for the INPUT chain is ACCEPT (not shown as DROP), so even without this rule, SSH would be allowed, but the rule ensures it is explicitly permitted for new connections.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
SSH connections are only allowed if they are part of an established connection.
Why it's wrong here
The rule matches state NEW, not ESTABLISHED.
- ✓
SSH connections from any source to port 22 on eth0 are allowed if they are new.
Why this is correct
The rule matches new SSH connections on eth0.
- ✗
SSH connections are dropped because the default policy is DROP.
Why it's wrong here
The rule overrides the default policy for matching packets.
- ✗
SSH connections are only allowed from the loopback interface.
Why it's wrong here
The rule accepts on eth0, not lo.
Visual reference
Go deeper
Related to this question
About these practice questions
This LPIC-2 question is part of Courseiva's 507-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 by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This LPIC-2 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-2 exam.