JNCIA-SEC Junos OS Security Objects Practice Question
An administrator configures a security zone and adds the 'tcp-drop-synfin-set' SCREEN option. What specific packet characteristic does this option target?
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
✓
Packets with both SYN and FIN flags set
The tcp-drop-synfin-set SCREEN option drops TCP packets that have both the SYN and FIN flags set simultaneously, which is an invalid state often used in scanning.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Packets where the SYN flag is set and the sequence number is zero
Why it's wrong here
This is covered by a separate TCP header anomaly check.
- ✗
TCP packets with zero window size and FIN set
Why it's wrong here
This is not the purpose of the synfin-set check.
- ✗
Packets with SYN and ACK flags set without an initial SYN
Why it's wrong here
This refers to unexpected SYN-ACK packets, mitigated by other options.
- ✓
Packets with both SYN and FIN flags set
Why this is correct
This option specifically targets anomalous packets with both SYN and FIN bits enabled.
Visual reference
About these practice questions
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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 Juniper Networks exam blueprint
This JNCIA-SEC practice question is part of Courseiva's free Juniper Networks 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 JNCIA-SEC exam.