KCNA Kubernetes Fundamentals Practice Question
Which component runs on every node and is responsible for maintaining network rules that allow communication to Pods from network endpoints?
⚠ Common exam trap
Candidates often confuse kubelet with kube-proxy because both run on every node, but kubelet manages Pods and containers, while kube-proxy exclusively handles network rules for Service connectivity.
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
✓
kube-proxy
B is correct because kube-proxy is the component that runs on every node in a Kubernetes cluster and is responsible for maintaining network rules (e.g., iptables, IPVS, or userspace proxy) that allow network communication to Pods from network endpoints, both inside and outside the cluster. It implements the Kubernetes Service concept by managing the mapping of Service IPs to backend Pod IPs and performing load balancing.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
kube-controller-manager
Why it's wrong here
The kube-controller-manager runs as a single control-plane process managing controllers such as ReplicaSet and Node; it does not run per node or program network rules. kube-proxy is the per-node agent that maintains iptables/IPVS rules enabling Service traffic to reach Pods, so it is the correct component here.
- ✓
kube-proxy
Why this is correct
kube-proxy runs as a DaemonSet on every node and programs iptables or IPVS rules, translating Service virtual IPs into Pod endpoints. This maintains the network rules enabling communication to Pods from network endpoints, exactly the responsibility the question describes.
- ✗
container runtime
Why it's wrong here
The container runtime starts and stops containers on the node; it does not program iptables or IPVS rules. It tempts because it runs on every node alongside networking, but kube-proxy, not the runtime, maintains the service routing rules.
- ✗
kubelet
Why it's wrong here
The kubelet manages Pod lifecycle and volume mounts on each node, not service network rules. It tempts because it runs on every node, yet kube-proxy programs the iptables or IPVS rules enabling endpoint communication to Pods.
Go deeper
Related to this question
Learn chapter
Pods and Workload Management
Key term
Kubernetes API Primitives
Kubernetes API Primitives are the basic building blocks that the Kubernetes API uses to represent and manage the state of a cluster, such as Pods, Services, Deployments, and Namespaces.
Key term
ReplicaSet and Replication
A ReplicaSet ensures a specified number of identical pod instances are running at all times in Kubernetes, using replication to maintain availability and stability.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.