A cluster administrator is troubleshooting a DNS issue where some pods can resolve services but others cannot. The CoreDNS pods are running, and the CoreDNS Service exists. What is the first diagnostic step to isolate the problem?

Verify the kubelet's --cluster-dns flag is set to the CoreDNS Service IP.

Check the CoreDNS pod logs for errors.

Run a DNS query from a working pod and a non-working pod using nslookup or dig.

Restart the CoreDNS pods to clear any cached state.

How does CoreDNS integrate with Kubernetes service discovery?

It uses the kubernetes plugin to query the Kubernetes API for Services and Endpoints

It intercepts all network traffic to map Service names to IP addresses

It reads the /etc/hosts file on each node to resolve Service names

It is configured manually by the administrator to add each Service's DNS record

What is the primary role of CoreDNS in a Kubernetes cluster?

To load balance incoming traffic to Services using IPVS rules

To manage network policies and control traffic between Pods

To provide a distributed key-value store for cluster configuration

To serve as the cluster's DNS server, providing name resolution for Services and Pods

An administrator needs to configure CoreDNS to forward queries for the 'example.com' domain to a specific DNS server at 192.168.2.10, while all other external queries should continue to use the default upstream. What is the correct Corefile configuration?

Add a 'hosts' plugin entry for 'example.com' pointing to 192.168.2.10.

Modify the existing 'forward' plugin to use 192.168.2.10 as the primary upstream.

Use the 'rewrite' plugin to change 'example.com' queries to 192.168.2.10.

Add a 'forward' plugin block for 'example.com' pointing to 192.168.2.10.

Certified Kubernetes Administrator (CKA)

Domain 5Objective 6

Understand and Use CoreDNS CKA Practice Questions (Page 4)

Part of the Servicing and Networking domain, which accounts for 20% of the CKA exam. Linux Foundation does not publish an official question count, but from its 120-minute exam (~50–80 total, ~10–16 in this domain), expect 2–3 from this objective — we provide 22 practice questions to prepare you well beyond it. (estimate)

22questions here

5free pages

6concepts

20%of the exam

Questions 16–20

16application · medium
A cluster administrator is troubleshooting a DNS issue where some pods can resolve services but others cannot. The CoreDNS pods are running, and the CoreDNS Service exists. What is the first diagnostic step to isolate the problem?
Select an answer first
17foundation · easy
To add a custom DNS entry for 'internal.example.com' in CoreDNS, which plugin would you use in the Corefile?
Select an answer first
18foundation · easy
How does CoreDNS integrate with Kubernetes service discovery?
Select an answer first
19foundation · easy
What is the primary role of CoreDNS in a Kubernetes cluster?
Select an answer first
20application · medium
An administrator needs to configure CoreDNS to forward queries for the 'example.com' domain to a specific DNS server at 192.168.2.10, while all other external queries should continue to use the default upstream. What is the correct Corefile configuration?
Select an answer first

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