CPENT Iot And OT Exploitation Practice Question
An auditor is reviewing an ICS network architecture and notes that a Supervisory Control and Data Acquisition (SCADA) server communicates with remote terminal units (RTUs) via DNP3 over serial-to-ethernet terminal servers. The auditor wants to test if unauthenticated DNP3 control commands can be accepted. Which default port should the auditor probe for DNP3 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
✓
TCP/UDP 20000
DNP3 (Distributed Network Protocol) is heavily used in electric and water utilities and operates by default on TCP/UDP port 20000.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
TCP 443
Why it's wrong here
Port 443 is reserved for HTTPS secure web traffic.
- ✗
TCP 2404
Why it's wrong here
Port 2404 is used for IEC 60870-5-104 protocol communications.
- ✓
TCP/UDP 20000
Why this is correct
Port 20000 is the standard port assigned for DNP3 communications in industrial networks.
- ✗
TCP 44818
Why it's wrong here
Port 44818 is used for EtherNet/IP (CIP).
About these practice questions
This CPENT question is part of Courseiva's 274-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 and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official EC-Council exam blueprint
This CPENT practice question is part of Courseiva's free EC-Council 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 CPENT exam.