What are the main differences between the bridge and host network modes in Docker containers?

Docker network modes bridge and host differ in the way they organize network interaction between the container, the host system, and other containers:

• bridge (bridge mode):

  • Docker creates a virtual bridge that containers connect to.
  • Each container gets its own IP address within this bridge.
  • Containers are isolated from the host network; port forwarding (port mapping) is needed for external access.
  • Allows isolating containers and managing their network rules.

• host (host mode):

  • The container uses the host machine's network stack directly.
  • The container does not get a separate IP but uses the host's IP and ports.
  • No need for port forwarding, as the container and host share the network.
  • Less isolation but higher network performance.

Example of running a container in host mode:

docker run --network host nginx

Thus, bridge provides isolation and ease of management, while host offers maximum performance and simplicity of access to the host network.