KCNA Kubernetes Fundamentals Practice Question

• ✓ A.Namespaces provide a way to divide cluster resources between multiple users or teams.
• B.All Kubernetes resources must be created within a namespace.
• C.Namespaces provide network isolation by default.
• ✓ D.Deleting a namespace will delete all resources in it.
• ✓ E.Resource quotas can be applied to a namespace to limit total resource consumption.

Why A: Option A is correct because Kubernetes Namespaces are designed as a logical partitioning mechanism that lets a single physical cluster be shared among multiple users, teams, or projects, scoping names and resource usage per group. Option D is correct because deleting a Namespace triggers cascading deletion of all namespaced objects contained in it (e.g., Pods, Services, ConfigMaps), so the namespace and its contents are removed together. Option E is correct because ResourceQuota objects are applied at the namespace scope to cap aggregate consumption of resources such as CPU, memory, and object counts within that namespace. Option B is incorrect because many resources are cluster-scoped and cannot live in a namespace, such as Nodes, PersistentVolumes, ClusterRoles, and StorageClasses. Option C is incorrect because namespaces do not enforce network isolation by default; without a NetworkPolicy, pods in different namespaces can communicate freely, so isolation must be explicitly configured.

• ✓ A.Namespaces provide a way to divide cluster resources among multiple users
• B.Namespaces act as a strong security boundary by default
• ✓ C.Namespaces help organize objects in a cluster
• D.Every resource must be created in a namespace
• E.Resources in different namespaces cannot communicate with each other

Why A: Option A is correct because Kubernetes Namespaces are explicitly designed to divide cluster resources among multiple users or teams, commonly via ResourceQuota and LimitRange objects scoped to a namespace, enabling multi-tenancy and resource partitioning. Option C is correct because Namespaces provide a logical grouping mechanism to organize cluster objects (e.g., pods, services, deployments) into distinct virtual clusters, making management and naming easier. Option B is incorrect because Namespaces are not a strong security boundary by default; they provide no network isolation or RBAC isolation unless NetworkPolicies and RBAC are explicitly configured, and cluster-scoped resources remain shared. Option D is incorrect because not every resource is namespaced — cluster-scoped resources such as Nodes, PersistentVolumes, StorageClasses, and ClusterRoles exist outside any namespace. Option E is incorrect because resources in different namespaces can communicate freely over the network by default (e.g., via ClusterIP services using the fully qualified domain name service.namespace.svc.cluster.local) unless NetworkPolicies restrict traffic.

• ✓ A.Resource names must be unique within a namespace
• B.Namespaces provide network isolation by default
• C.All Kubernetes resources are namespaced
• ✓ D.Namespaces provide a way to divide cluster resources between multiple users
• E.You can delete a namespace without affecting the resources inside it

Why A: Option A is correct because within a single namespace, resource names (for a given resource type) must be unique — for example, you cannot have two Pods both named 'web' in the same namespace, though the same name can exist in different namespaces. Option D is correct because namespaces are intended to divide cluster resources among multiple users or teams, commonly combined with ResourceQuota and RBAC to scope access and limit consumption per namespace. Option B is not correct because namespaces do not provide network isolation by default; Pods across namespaces can communicate freely unless NetworkPolicies are applied. Option C is not correct because not all resources are namespaced — cluster-scoped resources such as Nodes, PersistentVolumes, and ClusterRoles exist outside any namespace. Option E is not correct because deleting a namespace deletes all resources contained within it, so it does affect the resources inside.

• A.Services in different namespaces cannot communicate with each other
• B.Every Kubernetes object must be created in a namespace
• ✓ C.Deleting a namespace will delete all objects in it
• ✓ D.Namespaces can be used to implement resource quotas
• E.Namespaces provide a way to divide cluster resources between multiple users

Why C: Option C is correct because deleting a namespace triggers cascading deletion of all resources contained within it, so every object scoped to that namespace is removed along with it. Option D is correct because ResourceQuota objects are applied at the namespace level, allowing administrators to cap aggregate CPU, memory, and object counts per namespace. Option A is false because Services in different namespaces can communicate via fully qualified DNS names such as service.namespace.svc.cluster.local. Option B is false because cluster-scoped objects like Nodes, PersistentVolumes, and ClusterRoles are not created in a namespace. Option E is misleading because namespaces alone do not divide resources; resource division is enforced through quotas and limit ranges, not by the namespace object itself.