In containerized environments using Docker, which networking construct creates a Linux bridge on the host?

In containerized environments using Docker, which networking construct creates a Linux bridge on the host?

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

Answer: (A)

The network setup tested here is about how Docker connects containers on a single host. The Bridge networking option creates a Linux bridge on the host. Docker’s default bridge driver sets up a virtual bridge (often named docker0) on the host and connects each container through a veth pair, with containers getting IPs from the bridge’s subnet. This makes container-to-container and container-to-host communication straightforward within the same host, and containers can reach external networks via NAT. MACVLAN, by contrast, places containers on the physical network as separate MAC addresses, bypassing the host bridge. Overlay networks are designed to span multiple hosts and rely on encapsulation, not a local Linux bridge. The Host driver attaches containers directly to the host’s network namespace, with no bridge involved.

The network setup tested here is about how Docker connects containers on a single host. The Bridge networking option creates a Linux bridge on the host. Docker’s default bridge driver sets up a virtual bridge (often named docker0) on the host and connects each container through a veth pair, with containers getting IPs from the bridge’s subnet. This makes container-to-container and container-to-host communication straightforward within the same host, and containers can reach external networks via NAT.

MACVLAN, by contrast, places containers on the physical network as separate MAC addresses, bypassing the host bridge. Overlay networks are designed to span multiple hosts and rely on encapsulation, not a local Linux bridge. The Host driver attaches containers directly to the host’s network namespace, with no bridge involved.