Which Docker networking option allows a container to use the host's network namespace?

Which Docker networking option allows a container to use the host's network namespace?

• A. Bridge
• B. MACVLAN
• C. Overlay
• D. Host Driver

Answer: (D)

The option in use here is the one that makes the container share the host’s network stack. Using the host driver places the container in the host’s network namespace, so it uses the host’s IP address and can access services on localhost directly. There’s no separate network namespace, no NAT between the container and the host, and no port mapping needed. This setup can improve performance and simplify some configurations, but it sacrifices isolation and portability—containers become tightly tied to the host’s network environment. Bridge creates an independent, isolated network for containers behind a virtual bridge. MACVLAN gives each container its own MAC address on the physical network, appearing as a separate device. Overlay builds a network that spans multiple hosts (useful in Swarm) but still uses container-specific namespaces.

The option in use here is the one that makes the container share the host’s network stack. Using the host driver places the container in the host’s network namespace, so it uses the host’s IP address and can access services on localhost directly. There’s no separate network namespace, no NAT between the container and the host, and no port mapping needed. This setup can improve performance and simplify some configurations, but it sacrifices isolation and portability—containers become tightly tied to the host’s network environment.

Bridge creates an independent, isolated network for containers behind a virtual bridge. MACVLAN gives each container its own MAC address on the physical network, appearing as a separate device. Overlay builds a network that spans multiple hosts (useful in Swarm) but still uses container-specific namespaces.