By default, containers in the same Kubernetes Pod share the network namespace, which means they share the same IP address and port space. Therefore, the correct answer is B (Network).
This shared network namespace is a key part of the Pod abstraction. Because all containers in a Pod share networking, they can communicate with each other over localhost and coordinate tightly, which is the basis for patterns like sidecars (service mesh proxies, log shippers, config reloaders). It also means containers must coordinate port usage: if two containers try to bind the same port on 0.0.0.0, they’ll conflict because they share the same port namespace.
Option A (“Host Network”) is different: hostNetwork: true is an optional Pod setting that puts the Pod into the node’s network namespace, not the Pod’s shared namespace. It is not the default and is generally used sparingly due to security and port-collision risks. Option C (“Process ID”) is not shared by default in Kubernetes; PID namespace sharing requires explicitly enabling process namespace sharing (e.g., shareProcessNamespace: true). Option D (“Process Name”) is not a Linux namespace concept.
The Pod model also commonly implies shared storage volumes (if defined) and shared IPC namespace in some configurations, but the universally shared-by-default namespace across containers in the same Pod is the network namespace. This default behavior is why Kubernetes documentation explains a Pod as a “logical host” for one or more containers: the containers are co-located and share certain namespaces as if they ran on the same host.
So, the correct, verified answer is B: containers in the same Pod share the Network namespace by default.
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