hardMultiple Choice
CAS-004 Practice Question: A company deploys a microservices architecture…
A company deploys a microservices architecture using container orchestration. The security team wants to enforce mutual TLS between services. Which technology should be used?
⚠ Common exam trap
Many candidates confuse an API gateway's ability to terminate TLS for external traffic with the need for mTLS between internal services, leading them to incorrectly select API gateway instead of service mesh.
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
✓
Service mesh
A service mesh (e.g., Istio, Linkerd) is the correct technology because it provides a dedicated infrastructure layer for handling service-to-service communication, including automatic mutual TLS (mTLS) enforcement between microservices. It injects sidecar proxies that intercept all traffic and negotiate mTLS using X.509 certificates, ensuring both encryption and authentication without modifying application code.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Service mesh
Why this is correct
A service mesh injects sidecar proxies that terminate and originate mTLS on behalf of each workload, issuing and rotating certificates automatically. This enforces mutual TLS between services without modifying application code, which container orchestration alone does not provide.
- ✗
SSH tunneling
Why it's wrong here
SSH tunneling is not scalable for a microservices environment and requires manual configuration.
- ✗
API gateway
Why it's wrong here
An API gateway terminates TLS at the perimeter and routes north-south client traffic; it does not issue or verify certificates for each east-west service-to-service connection, so mutual TLS between microservices is not enforced. It is tempting because it centralises authentication and TLS termination, and would be correct for exposing APIs to external consumers.
- ✗
VPN
Why it's wrong here
A VPN encrypts traffic between networks or hosts at the IP layer, authenticating endpoints rather than individual service workloads, so it cannot enforce mutual TLS per microservice connection. It is tempting because it secures data in transit across untrusted links, and would be correct for connecting remote offices or users to a corporate network.
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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.