CPENT Iot And OT Exploitation Practice Question
An ICS penetration tester is auditing a substation utilizing the IEC 61850 standard for electrical substation automation. The tester captures Generic Object Oriented Substation Events (GOOSE) messages on the network. Which Layer 2 Ethernet type hex value identifies GOOSE multicast frames?
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
✓
0x88B8
GOOSE messages in IEC 61850 bypass the IP/TCP stack for speed and operate directly at Layer 2 using EtherType 0x88B8.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
0x0800
Why it's wrong here
0x0800 is the standard EtherType for IPv4 traffic.
- ✗
0x86DD
Why it's wrong here
0x86DD is the EtherType for IPv6 traffic.
- ✓
0x88B8
Why this is correct
IEC 61850 GOOSE protocol frames use EtherType 0x88B8 for high-speed Layer 2 multicast communications.
- ✗
0x88E5
Why it's wrong here
0x88E5 is the EtherType used for IEEE 802.1X port-based network access control.
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.