CND Practice Question: Network Security Controls Protocols And Devices
A corporate network is segmented into multiple zones. The security policy dictates that the Finance department subnet must be completely isolated from the Guest Wi-Fi subnet, and traffic between them must pass through a security device enforcing access control lists. Where should this security device be placed?
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
✓
On the internal network boundary between the Finance and Guest VLANs
To enforce policies and filter traffic between two distinct internal subnets or zones, the security device must be placed at the internal routing boundary, typically on an internal firewall interface acting as the default gateway for those subnets.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
On the internal network boundary between the Finance and Guest VLANs
Why this is correct
An internal firewall or routing boundary placed between distinct internal zones enforces security controls on east-west traffic.
- ✗
At the perimeter boundary directly connected to the ISP modem
Why it's wrong here
Placing the device at the ISP perimeter only secures traffic entering or leaving the internet, leaving internal east-west traffic between subnets uninspected.
- ✗
On the local loopback interface of each end-user workstation
Why it's wrong here
Configuring network security policies on individual workstation loopback interfaces is unmanageable and does not control VLAN-to-VLAN traffic.
- ✗
Inside the ISP core routing infrastructure
Why it's wrong here
Administrators do not have direct placement control or visibility inside ISP core routing infrastructure for internal enterprise segmentation.
Visual reference
About these practice questions
Courseiva writes every CND question from scratch — 323 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or 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 CND 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 CND exam.