A company hosted multiple applications in the Kubernetes environment, using the naming app01, app02, and...

In a Kubernetes environment,Namespacesprovide a logical partition for resources but do not, by default, provide network isolation. To prevent "app01" from communicating with "app02," aNetworkPolicymust be implemented. NetworkPolicies act as the Layer 3/4 distributed firewall for the cluster, allowing administrators to define explicit rules for ingress and egress traffic between pods and namespaces.

To achieve complete isolation, a common design pattern is to implement a "deny-all" default policy for each namespace and then explicitly allow only necessary traffic. This aligns with theCisco SAFEarchitectural principle of micro-segmentation. WhileRoleBinding(Option B) manages permissions for the Kubernetes API (who can create or delete pods), it does not control the actual network traffic between those pods.HTTPRoute(Option A) andGateway(Option D) are components of the Kubernetes Gateway API used for managing external traffic routing and load balancing, rather than internal pod-to-pod isolation. By deploying NetworkPolicies, the administrator ensures that the "blast radius" of a compromised application is contained within its own namespace, fulfilling a core objective of securing cloud-native application infrastructure.

========