In the majority of network scenarios, Docker relies heavily on the docker0 bridge. The docker0 bridge is created automatically when the Docker engine service is started and is the default connection point for any containers spawned by the Docker service. We also saw in earlier recipes that it was possible to modify some of this bridge's attributes at a service level. In this recipe, we'll show you how to tell Docker to use a different bridge entirely.
In this recipe, we'll be demonstrating the configuration on a single Docker host. It is assumed that this host has Docker installed and that Docker is in its default configuration. In order to view and manipulate networking settings, you'll want to ensure that you have the iproute2 toolset installed. If not present on the system, it can be installed using the command:
sudo apt-get install iproute2
In order to make network changes to the host, you'll also need root-level access.