Kubernetes components work together to ensure seamless communication and network functionality within the cluster. Let’s analyze each option:

A. container runtime

Incorrect:The container runtime (e.g.,containerd,cri-o) is responsible for running containers on worker nodes. It does not maintain network rules.

B. kube-proxy

Correct: kube-proxyis a Kubernetes component that runs on each node and maintains network rules to enable communication between services and pods. It ensures proper load balancing and routing of traffic.

C. kubelet

Incorrect:Thekubeletis responsible for managing the state of pods and containers on a node. It does not handle network rules.

D. kube controller

Incorrect:Thekube controllermanages the desired state of the cluster, such as maintaining the correct number of replicas. It does not directly manage network rules.

Why kube-proxy?

Network Rules:kube-proxy implements iptables or IPVS rules to route traffic between services and pods, ensuring seamless communication.

Load Balancing:It provides basic load balancing for services, distributing traffic across available pods.

JNCIA Cloud References:

The JNCIA-Cloud certification covers Kubernetes networking, including the role of kube-proxy. Understanding how kube-proxy works is essential for managing network communication in Kubernetes clusters.

For example, Juniper Contrail integrates with Kubernetes to enhance networking capabilities, leveraging kube-proxy for service-level traffic management.