mediumMultiple Choice
CAS-004 Practice Question: A security architect is designing a network…
A security architect is designing a network segmentation strategy for a multi-tenant cloud environment. Which of the following is the MOST effective technique to isolate tenant workloads while maintaining manageability?
⚠ Common exam trap
A common mix-up: candidates confuse VLAN tagging (a legacy on-premises technique) with cloud-native VPCs, failing to recognize that VLANs cannot provide the scale, automation, or multi-region isolation required in a modern multi-tenant cloud environment.
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
✓
Virtual private clouds (VPCs) with separate subnets
Virtual private clouds (VPCs) with separate subnets provide native, tenant-level isolation in a multi-tenant cloud environment by creating logically isolated network segments with their own IP address space, routing tables, and security policies. This approach is the most effective because it scales easily, integrates with cloud-native security controls (e.g., security groups, network ACLs), and maintains manageability through centralized orchestration without requiring per-tenant hardware or complex overlay configurations.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Host-based iptables
Why it's wrong here
Host-based iptables filters traffic only within a single operating system instance, so it cannot enforce separation between tenant workloads running on separate hosts or across a shared virtual network. It is tempting because iptables genuinely suits hardening one server's ingress and egress rules, which would be the right choice for a single-tenant host rather than multi-tenant isolation.
- ✗
Stateful firewall rules
Why it's wrong here
Stateful firewall rules filter traffic by port and protocol but do not enforce identity-based or workload-level isolation between tenants sharing address space. They suit perimeter and subnet traffic control, not granular tenant workload segmentation in cloud environments.
- ✓
Virtual private clouds (VPCs) with separate subnets
Why this is correct
VPCs provide network-level isolation between tenants, while separate subnets within each VPC segment workloads by tier or function. Security groups and network ACLs then enforce traffic rules, delivering strong tenant separation without the operational overhead of per-tenant accounts or dedicated hardware.
- ✗
VLAN tagging
Why it's wrong here
VLAN tagging operates at layer 2 within a single network boundary and does not provide isolation across cloud provider networks or accounts. It suits segmenting physical or on-premises networks sharing common switching infrastructure, not multi-tenant cloud workload separation.
Visual reference
Go deeper
Related to this question
About these practice questions
This CAS-005 question is part of Courseiva's 973-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 by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CAS-005 practice question is part of Courseiva's free CompTIA 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 CAS-005 exam.