CKA Services and Networking Practice Question
A developer asks you to create a Service that resolves to an external database at 'db.example.com'. Which Service type should you use?
⚠ Common exam trap
Test-takers frequently confuse ExternalName with a regular ClusterIP Service that has an external endpoint, but ExternalName is the only type that purely provides DNS-based resolution without any proxy or selector.
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
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ExternalName
An ExternalName Service type maps a Service to a DNS name (e.g., 'db.example.com') by returning a CNAME record, allowing pods to resolve the Service name to an external endpoint without a proxy or selector. This is the only Service type that directly resolves to an external DNS name without requiring endpoints or a backend selector.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
ExternalName
Why this is correct
ExternalName services map a Kubernetes service directly to an external DNS name by returning a CNAME record from the cluster's internal DNS provider (like CoreDNS). This allows pods to reference external resources, such as a managed database, using a consistent internal service name without proxying any traffic through the cluster.
- ✗
LoadBalancer
Why it's wrong here
A LoadBalancer service type provisions an external load balancer in supported cloud environments to route external traffic into your cluster. It does not map to an external DNS name via a CNAME record; instead, it exposes internal pods to the outside world by assigning a public IP address or cloud-managed DNS name to route incoming traffic.
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NodePort
Why it's wrong here
NodePort exposes the service on each Kubernetes node's IP at a static port allocated from a default range (30000-32767). This mechanism is designed to allow external clients to access internal cluster workloads by targeting any node's physical IP address, rather than resolving to an external third-party DNS name.
- ✗
ClusterIP
Why it's wrong here
ClusterIP is the default service type that exposes the service on a cluster-internal IP address. This makes the service only reachable from within the cluster, routing traffic to backend pods via iptables or IPVS rules rather than redirecting clients to an external domain name using CNAME records.
Visual reference
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This CKA practice question is part of Courseiva's free CNCF 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 CKA exam.