In a Pod, which Linux namespace do containers usually share?

• A. PID namespace
• B. IPC namespace
• C. Network namespace
• D. UTS namespace

Answer: (C)

In a Pod, containers usually share the network namespace. This means they all use the same network stack, share the Pod’s IP address for external communication, and can talk to each other over localhost (127.0.0.1) without special wiring. This shared network namespace is what makes it straightforward for containers in the same Pod to coordinate and expose services to one another as if they were running on the same host network.

Other namespaces exist in Linux, but they aren’t the default shared layer that Pod containers rely on for inter-container communication. For example, process IDs (PID) namespaces aren’t automatically shared across containers in a Pod (there’s a separate option to enable sharing the process space if needed). The key design in Kubernetes is that the network namespace is the one containerized workloads within a Pod commonly share, enabling efficient intra-Pod networking.