This KCNA practice question tests your understanding of kubernetes fundamentals. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A pod named 'db' in the 'default' namespace cannot connect to another pod named 'cache' in the 'prod' namespace via DNS. The service 'cache-svc' exists in the 'prod' namespace. What DNS name should the 'db' pod use to reach the 'cache-svc' service?
cache-svc.default
Why wrong: Incorrect namespace and incomplete domain.
cache-svc.prod
Why wrong: This is incomplete; it may not resolve without the full cluster domain.
cache-svc.prod.svc.cluster.local
The correct DNS format for a service in another namespace is <svc>.<ns>.svc.cluster.local.
cache-svc.default.svc.cluster.local
Why wrong: This uses the wrong namespace (default instead of prod).
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
cache-svc.prod.svc.cluster.local
Option C is correct because Kubernetes DNS resolves services across namespaces using the format <service>.<namespace>.svc.cluster.local. Since the 'cache-svc' service is in the 'prod' namespace, the 'db' pod in the 'default' namespace must use 'cache-svc.prod.svc.cluster.local' to reach it. The default cluster domain is 'cluster.local', and the 'svc' subdomain is part of the standard DNS schema for services.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
cache-svc.default
Why it's wrong here
Incorrect namespace and incomplete domain.
cache-svc.prod
Why it's wrong here
This is incomplete; it may not resolve without the full cluster domain.
cache-svc.prod.svc.cluster.local
Why this is correct
The correct DNS format for a service in another namespace is <svc>.<ns>.svc.cluster.local.
Related concept
Read the scenario before looking for a memorised answer.
cache-svc.default.svc.cluster.local
Why it's wrong here
This uses the wrong namespace (default instead of prod).
Common exam traps
CNCF often tests the misconception that the namespace alone (e.g., 'cache-svc.prod') is sufficient for cross-namespace DNS resolution, but the full 'svc.cluster.local' suffix is mandatory for the cluster DNS to resolve the service correctly.
Detailed technical explanation
Kubernetes DNS is implemented by CoreDNS (or legacy kube-dns), which creates A/AAAA records for services in the format <service>.<namespace>.svc.<cluster-domain>. The default cluster domain is 'cluster.local', but it can be customized via the kubelet's '--cluster-domain' flag. When a pod queries a service in another namespace, the full FQDN is required; short names like 'cache-svc' only work within the same namespace due to DNS search path resolution.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A practitioner preparing for the KCNA exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Kubernetes Fundamentals — study guide chapter
Learn the concepts, then practise the questions
Kubernetes Fundamentals practice questions
Targeted practice on this topic area only
All KCNA questions
997 questions across all exam domains
Kubernetes and Cloud Native Associate KCNA study guide
Full concept coverage aligned to exam objectives
KCNA practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise KCNA questions linked to Kubernetes Fundamentals.
Practise KCNA questions linked to Container Orchestration.
Practise KCNA questions linked to Cloud Native Architecture.
Practise KCNA questions linked to Cloud Native Observability.
Practise KCNA questions linked to Cloud Native Application Delivery.
Practise KCNA questions linked to KCNA fundamentals.
Practise KCNA questions linked to KCNA scenario.
Practise KCNA questions linked to KCNA troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Kubernetes Fundamentals — This question tests Kubernetes Fundamentals — Read the scenario before looking for a memorised answer..
The correct answer is: cache-svc.prod.svc.cluster.local — Option C is correct because Kubernetes DNS resolves services across namespaces using the format <service>.<namespace>.svc.cluster.local. Since the 'cache-svc' service is in the 'prod' namespace, the 'db' pod in the 'default' namespace must use 'cache-svc.prod.svc.cluster.local' to reach it. The default cluster domain is 'cluster.local', and the 'svc' subdomain is part of the standard DNS schema for services.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 30, 2026
This KCNA 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 KCNA exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.