1Z0-1085-26 Core Oci Services Practice Question
A developer has deployed a Node.js web application on an OCI Compute instance, but external users cannot access the application on port 3000. The instance's VCN has a security list allowing TCP traffic on port 3000. What additional OS-level configuration is likely blocking the traffic?
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 local OS firewall (such as firewalld or iptables) running on the compute instance.
Linux compute instances run local software firewalls (such as firewalld or iptables) by default, which can block incoming traffic even if OCI network security rules allow it.
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 local OS firewall (such as firewalld or iptables) running on the compute instance.
Why this is correct
Local OS firewalls must be configured to allow incoming traffic on application ports like 3000.
- ✗
The OCI Object Storage bucket policy restricting HTTP ports.
Why it's wrong here
Object storage policies have no impact on compute instance networking.
- ✗
The VCN Service Gateway intercepting local port requests.
Why it's wrong here
Service gateways only route traffic destined for Oracle services.
- ✗
The Dynamic Routing Gateway dropping layer 4 packets.
Why it's wrong here
DRGs route packets based on IP headers, not application ports.
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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 Oracle exam blueprint
This 1Z0-1085-26 practice question is part of Courseiva's free Oracle 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 1Z0-1085-26 exam.