JNCIA-SEC Security Policies Practice Question
An administrator configures a security policy with a custom application definition that matches TCP port 8080. When testing the policy, traffic on port 8080 is matched, but the application identification engine flags the traffic as 'junos-http'. What is the reason for this behavior?
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
✓
Junos AppID uses deep packet inspection and overrides custom port definitions with recognized protocol signatures.
Built-in AppID signatures take precedence over custom port-based application definitions if the protocol signature matches standard traffic patterns.
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 default policy evaluation order places global policies above custom application rules.
Why it's wrong here
Incorrect. Evaluation order does not alter protocol signature recognition.
- ✗
Custom applications are disabled by default when security policies are compiled.
Why it's wrong here
Incorrect. Custom applications are fully functional if properly defined.
- ✓
Junos AppID uses deep packet inspection and overrides custom port definitions with recognized protocol signatures.
Why this is correct
Correct. AppID uses protocol signatures to identify traffic regardless of custom port definitions or standard port mappings.
- ✗
The security policy must be changed from zone-based to global to support custom applications.
Why it's wrong here
Incorrect. Scope (zone vs global) does not alter AppID evaluation priority over port definitions.
About these practice questions
One of 513 original JNCIA-SEC practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
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.